U.S. patent application number 16/795031 was filed with the patent office on 2020-08-13 for thermal insulation material from mycelium and forestry byproducts.
The applicant listed for this patent is University of Alaska Anchorage. Invention is credited to Philippe Amstislavski, Maria D. White, Zhaohui Yang.
Application Number | 20200255794 16/795031 |
Document ID | / |
Family ID | 59385405 |
Filed Date | 2020-08-13 |
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United States Patent
Application |
20200255794 |
Kind Code |
A1 |
Amstislavski; Philippe ; et
al. |
August 13, 2020 |
Thermal Insulation Material from Mycelium and Forestry
Byproducts
Abstract
Disclosed are biodegradable insulation materials comprising a
structural scaffold; and at least one temperature resilient fungus.
Also disclosed are methods of making and using biodegradable
insulation materials comprising a structural scaffold; and at least
one temperature resilient fungus. For example, disclosed are
methods of insulating an infrastructure comprising administering
the disclosed biodegradable insulation materials to an
infrastructure.
Inventors: |
Amstislavski; Philippe;
(Anchorage, AK) ; Yang; Zhaohui; (Anchorage,
AK) ; White; Maria D.; (Anchorage, AK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
University of Alaska Anchorage |
Anchorage |
AK |
US |
|
|
Family ID: |
59385405 |
Appl. No.: |
16/795031 |
Filed: |
February 19, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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|
15418018 |
Jan 27, 2017 |
10604734 |
|
|
16795031 |
|
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62288156 |
Jan 28, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E02D 2300/0071 20130101;
Y02A 30/244 20180101; E01C 3/003 20130101; E04B 1/76 20130101; G10K
11/162 20130101; E04B 1/82 20130101; E01C 3/06 20130101; E04B
2001/745 20130101; C12N 1/14 20130101 |
International
Class: |
C12N 1/14 20060101
C12N001/14; E04B 1/82 20060101 E04B001/82; G10K 11/162 20060101
G10K011/162; E04B 1/76 20060101 E04B001/76 |
Claims
1. A biodegradable insulation material comprising a. a structural
scaffold comprising a three-dimensional structure and a mycelium
from a first temperature resilient fungus, wherein the mycelium
form the first temperature resilient fungus has colonized the
three-dimensional structure, wherein the structural scaffold has a
chitinous hydrophobic outer skin; and b. a substrate comprising
nutritive media and a mycelium from a second temperature resilient
fungus, wherein the mycelium from the second temperature resilient
fungus has colonized the substrate; wherein the biodegradable
insulation material is the result of the structural scaffold and
substrate fusing together, wherein the first temperature resilient
fungus and second temperature resilient fungus are the same.
2. (canceled)
3. The biodegradable insulation material of claim 1, wherein the
structural scaffold comprises a biomass.
4. The biodegradable insulation material of claim 3, wherein the
biomass is pasteurized
5. The biodegradable insulation material of claim 1, wherein the
structural scaffold comprises a biomass feedstock.
6. The biodegradable insulation material of claim 1, wherein the
structural scaffold comprises a structural reinforcement.
7. The biodegradable insulation material of claim 1, wherein the
biodegradable insulation material comprises the net shape of an
object to be insulated.
8. The biodegradable insulation material of claim 7, wherein the
biodegradable insulation material comprises the net shape of a
cylinder, tube, circle, oval, rectangle, or square.
9. The biodegradable insulation material of claim 1, wherein the
structural scaffold comprises the net shape of the object to be
insulated.
10. The biodegradable insulation material of claim 1, wherein the
structural scaffold comprises a biopolymer or synthetic polymer
that is non-toxic to the fungus and withstands moisture and
humidity.
11. The biodegradable insulation material of claim 10, wherein the
biopolymer is a cellulose-based biopolymer filament.
12. (canceled)
13. (canceled)
14. The biodegradable insulation material of claim 1, wherein the
first and second temperature resilient fungus is a fungus that
remains biologically viable within a temperature range of
+30.degree. to -50.degree. C.
15. The biodegradable insulation material of claim 1, wherein the
first and second temperature resilient fungus is a saprotrophic
Basidiomycete.
16. The biodegradable insulation material of claim 15, wherein the
saprotrophic Basidiomycete is a polypore.
17. The biodegradable insulation material of claim 16, wherein the
polypore is Irpex lacteus.
18. A method for producing a biodegradable insulation material
comprising a. preparing a structural scaffold comprising a
three-dimensional structure; b. inoculating the structural scaffold
with a first temperature resilient fungus, wherein mycelium of the
temperature resilient fungus colonize the scaffold c. preparing a
substrate comprising nutritive media, d. inoculating the substrate
with a second temperature resilient fungus, wherein mycelium of the
second temperature resilient fungus colonize the substrate; and e.
allowing the mycelium of the first temperature resilient fungus and
the second temperature resilient fungus to fuse forming a
biodegradable insulation material.
19.-44. (canceled)
45. A method of insulating an infrastructure comprising introducing
the biodegradable insulation material of claim 1 to an
infrastructure.
46.-48. (canceled)
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/418,018 filed Jan. 27, 2017, which claims
the benefit of U.S. Application No. 62/288,156, filed Jan. 28,
2016, each of which is incorporated herein by reference in their
entirety.
BACKGROUND
[0002] There is a need for an efficient, cost-competitive
technology to manufacture a renewable and biodegradable thermal
insulation material for cold climate regions.
[0003] Polymeric foams, such as polystyrene and polyurethane, are
commonly used for thermal insulation in infrastructure and housing
construction in cold climates. These hydrocarbon-based materials
are lightweight, hydrophobic, and resistant to photolysis.
Polymeric foams do not decompose after the end of their intended
use, and are problematic with respect to recycling and reuse. These
polymeric foams are non-renewable and their production and use
involve complex manufacturing processes, substantial energy inputs
and associated waste streams. Polymeric foams have been shown to
leach out or off-gas several toxins, which can bio-accumulate in
fish and wildlife, presenting a well-documented environmental
health problem. In most cold regions the construction materials are
shipped in from the manufacturing centers, adding to an already
large negative environmental effect of the polymeric insulation
foams.
[0004] A renewable and biodegradable alternative to these
conventional thermal insulation materials can substantially reduce
environmental and health burdens of construction and promote
sustainable infrastructure development. Biodegradable and renewable
insulation materials are of interest to construction industry in
the cold regions and globally for a range of applications. Such
materials can serve as replacements for the petroleum-based
polymers for a range of applications and offer several advantages
over polymeric foams, including freedom from petroleum products,
low energy inputs and low cost of production, fast renewability,
carbon capture and storage, and bio-degradability at end of use.
Though there have been a number of strategies developed to produce
eco-friendly materials from mycelium by combining various fungi
species with different types of biomass, their disadvantages in the
fragile Arctic ecosystems range from the potential of introducing
an exotic species of fungi that may negatively affect the local
ecosystems, to being too slow and costly to produce, especially in
the cold environments.
[0005] Due to the high cost of the transportation of the polymeric
foam and due to the lack of recycling and landfill services for its
disposal in the many areas of the Circumpolar North, local
production of a cost-competitive, renewable, and biodegradable
insulation material could be the most sustainable approach to
meeting the needs of the infrastructure and population needs.
BRIEF SUMMARY
[0006] Disclosed are biodegradable insulation materials comprising
a structural scaffold comprising a nutritive media for fungal
mycelium and at least one temperature resilient fungus.
[0007] Disclosed are biodegradable insulation materials comprising
a structural scaffold comprising a nutritive media for fungal
mycelium and at least one temperature resilient fungus, wherein the
structural scaffold can be three-dimensional.
[0008] Disclosed are biodegradable insulation materials comprising
a structural scaffold comprising a nutritive media for fungal
mycelium and at least one temperature resilient fungus, wherein the
structural scaffold comprises a biomass. In some instances, the
biomass can be pasteurized. In some instances, the structural
scaffold further comprises a biomass feedstock.
[0009] Disclosed are biodegradable insulation materials comprising
a structural scaffold comprising a nutritive media for fungal
mycelium and at least one temperature resilient fungus, wherein the
structural scaffold comprises a structural reinforcement.
[0010] Disclosed are biodegradable insulation materials comprising
a structural scaffold comprising a nutritive media for fungal
mycelium and at least one temperature resilient fungus, wherein the
biodegradable insulation material comprises the net shape of the
object to be insulated. In some instances, the biodegradable
insulation material comprises the net shape of a cylinder, tube,
circle, oval, rectangle, or square. In some instances, the
structural scaffold comprises the net shape of the object to be
insulated.
[0011] Disclosed are biodegradable insulation materials comprising
a structural scaffold comprising a nutritive media for fungal
mycelium and at least one temperature resilient fungus, wherein the
structural scaffold comprises a biopolymer or synthetic polymer
that is non-toxic to the fungus and withstands moisture and
humidity. In some instances the biopolymer can be a cellulose-based
biopolymer filament.
[0012] Disclosed are biodegradable insulation materials comprising
a structural scaffold comprising a nutritive media for fungal
mycelium and at least one temperature resilient fungus, wherein the
scaffold is colonized by mycelium of the temperature resilient
fungus.
[0013] Disclosed are biodegradable insulation materials comprising
a structural scaffold comprising a nutritive media for fungal
mycelium and at least one temperature resilient fungus, further
comprising mycelium from a second temperature resilient fungus.
[0014] Disclosed are biodegradable insulation materials comprising
a structural scaffold comprising a nutritive media for fungal
mycelium and at least one temperature resilient fungus, wherein the
at least one temperature resilient fungus is a fungus that remains
biologically viable within a temperature range of +40.degree. to
-50.degree. C. In some instances, the temperature resilient fungus
can be a saprotrophic Basidiomycete. In some instances, the
saprotrophic Basidiomycete can belong to one of the polypore
genera, such as Irpex. An example of an Irpex species is Irpex
lacteus.
[0015] Also disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold.
[0016] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the structural scaffold is
three-dimensional.
[0017] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with a culture of at least one
temperature resilient fungus in the presence of a nutritive media
under environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the environmental conditions that allow for
mycelium growth comprise exposure of the mycelium to carbon dioxide
gas in the range of 400-1,000 ppm. In some instances, the
environmental conditions that allow for mycelium growth comprise
exposure of the mycelium to temperatures of 0.degree. to 21.degree.
C. In some instances, the environmental conditions that allow for
mycelium growth comprise exposure of the mycelium to variable
relative humidity. In some instances, the environmental conditions
that allow for mycelium growth comprise exposure of the mycelium to
variable lighting. In some instances, the environmental conditions
that allow for mycelium growth comprise exposure of the culture,
the mycelium and the scaffold to variable pressure.
[0018] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein allowing the mycelium of the temperature
resilient fungus to colonize the scaffold comprises incubating the
scaffolds for a period of 4 to 14 days.
[0019] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, further comprising pressing the scaffold colonized by
mycelium of the temperature resilient fungus to achieve desired
density, thermal conductivity, elastic moduli, Young's modulus,
compressive strength, and thickness.
[0020] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, further comprising machining the scaffold colonized
by mycelium of the temperature resilient fungus to achieve desired
net form and thickness.
[0021] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, further comprising allowing the biodegradable
insulation material to form a chitinous hydrophobic outer skin.
[0022] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, further comprising drying the scaffold colonized with
mycelium of the temperature resilient fungus. In some instances,
the drying comprises temperatures of at least 60.degree. C.
[0023] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the temperature resilient fungus is a fungus
that remains biologically viable after the exposure to temperatures
of less than 0.degree. C.
[0024] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the temperature resilient fungus is a
saprotrophic Basidiomycete. In some instances, the saprotrophic
Basidiomycete can belong to one of the polypore genera, such as
Irpex. An example of an Irpex species is Irpex lacteus.
[0025] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the biodegradable insulation material has a
self-skinning property.
[0026] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the biodegradable insulation material
comprises two or more of the temperature resilient fungus mycelium
colonized scaffolds.
[0027] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, further comprises adding to the biodegradable
insulation material a non-cytotoxic deterrent to vermin and
competing fungi and mold species.
[0028] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, further comprising layering the biodegradable
insulation material to produce flexible or rigid laminated
panels.
[0029] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the biodegradable insulation material has a
thermal conductivity, elastic, shear and Young's moduli, and
compressive strength comparable to synthetic polymeric foams.
[0030] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the biodegradable insulation material is free
of cytotoxic metabolites or compounds.
[0031] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the structural scaffold is formed by:
blending a feedstock comprising biomass to form a blend;
pasteurizing the blend; cooling the blend; forming the blend into
the desired shape; and incubating the blend under conditions
favorable for mycelium growth.
[0032] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the structural scaffold is three-dimensional,
wherein the three-dimensional scaffold can be formed using a 3D
printer. In some instances, the three-dimensional scaffold
comprises biopolymer or synthetic polymers. For example, the
biopolymer or synthetic polymers can be cellulose-based
filaments.
[0033] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the structural scaffold is three-dimensional,
wherein the scaffold is formed by a 3D printing process within a
mold or enclosure that allows for a desired shape. In some
instances, the mold or desired shape can be determined based on the
object or area to be insulated with the biodegradable insulation
material.
[0034] Also disclosed are methods of insulating an infrastructure
comprising introducing the disclosed biodegradable insulation
materials to the infrastructure.
[0035] Disclosed are methods of insulating an infrastructure
comprising introducing the disclosed biodegradable insulation
materials to an infrastructure, wherein the infrastructure is
underlayment for oil and gas pipeline foundations, large civil
infrastructure, road underpayment, housing, piping systems, above
ground and underground environmental controls and sensors, and
backfill in road construction.
[0036] Disclosed are methods of insulating an infrastructure
comprising introducing the disclosed biodegradable insulation
materials to an infrastructure, wherein the temperature resilient
fungus is already found in the environment in which the
infrastructure is present.
[0037] Disclosed are methods of insulating an infrastructure
comprising introducing the disclosed biodegradable insulation
materials to an infrastructure, wherein the introduction occurs by
placing the biodegradable insulation material around the object to
be insulated or spraying the biodegradable insulation material on
the object to be insulated.
[0038] Additional advantages of the disclosed method and
compositions will be set forth in part in the description which
follows, and in part will be understood from the description, or
may be learned by practice of the disclosed method and
compositions. The advantages of the disclosed method and
compositions will be realized and attained by means of the elements
and combinations particularly pointed out in the appended claims.
It is to be understood that both the foregoing general description
and the following detailed description are exemplary and
explanatory only and are not restrictive of the invention as
claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] The accompanying drawings, which are incorporated in and
constitute a part of this specification, illustrate several
embodiments of the disclosed method and compositions and together
with the description, serve to explain the principles of the
disclosed method and compositions.
[0040] FIG. 1 shows a schematic drawing of the bioengineering
process for a biodegradable insulation material: 1 feedstock
hampers, 2--conveyer belt, 3--blended feedstock moving on the
conveyer belt, 4-pasterization chamber, 5--cooling chamber,
6--culture fermenter, 7--cleaning solution tank, 8--printer head
with inoculant broth (method 2), 9--inoculated and pressed-down
material, 10--terminus of the conveyer belt, 11--incubation
chamber.
[0041] FIG. 2 shows a sectional view of the experimental design of
a scaffold created by 3D printing. A light, cellulose-based
scaffold is expected to reduce the weight and thermal conductivity
of the biodegradable insulation material without detrimental impact
on its mechanical properties.
[0042] FIGS. 3A, 3B, and 3C show the process of shaping and
inoculating cuboid shaped scaffolds to produce insulation boards.
A--initial position of chamber; B--chamber is lowering to press
feedstock into final shape and to create inoculation channels;
C--chamber is lifting from the feedstock surface and ejecting
inoculum into the channels.
[0043] FIG. 4 shows a schematic of bioengineering process for
Mixing Protocol II samples.
[0044] FIG. 5 shows a diagram of wave velocity test set-up.
[0045] FIG. 6 shows the determination of P-wave first arrival for
Sample SP15 in vertical direction.
[0046] FIG. 7 shows the determination of S-wave first arrival for
Sample SP15 in vertical direction.
[0047] FIGS. 8A, 8B, and 8C show typical failure modes in the
white-rot fungal mycelium-based biodegradable insulation material
under unconfined compression test: a) Shear failure; and b and c)
bulging.
[0048] FIG. 9 shows Young's and shear moduli of SP samples in
vertical direction
[0049] FIG. 10 shows Young's and shear moduli of SL samples in
vertical direction.
[0050] FIG. 11 shows Young's and shear moduli of SPL samples in
vertical direction.
[0051] FIG. 12 shows elastic moduli anisotropy of SP samples
[0052] FIG. 13 shows elastic moduli anisotropy of SPL samples.
[0053] FIG. 14 shows typical stress-strain relationships in
unconfined compression test.
[0054] FIG. 15 shows compressive strength of SP and SPL
samples.
[0055] FIG. 16 shows thermal conductivity of SP, SL and SPL
samples.
[0056] FIG. 17 shows physical, thermal and mechanical properties of
mycelium-based biodegradable insulation material.
DETAILED DESCRIPTION
[0057] The disclosed method and compositions may be understood more
readily by reference to the following detailed description of
particular embodiments and the Example included therein and to the
Figures and their previous and following description.
[0058] It is to be understood that the disclosed method and
compositions are not limited to specific synthetic methods,
specific analytical techniques, or to particular fungi species or
their strains, and reagents unless otherwise specified, and, as
such, may vary. It is also to be understood that the terminology
used herein is for the purpose of describing particular embodiments
only and is not intended to be limiting.
[0059] Disclosed are materials, compositions, and components that
can be used for, can be used in conjunction with, can be used in
preparation for, or are products of the disclosed method and
compositions. These and other materials are disclosed herein, and
it is understood that when combinations, subsets, interactions,
groups, etc. of these materials are disclosed that while specific
reference of each various individual and collective combinations
and permutation of these compounds may not be explicitly disclosed,
each is specifically contemplated and described herein. For
example, if a scaffold is disclosed and discussed and a number of
modifications that can be made to a number of materials including
the scaffolds are discussed, each and every combination and
permutation and the modifications that are possible are
specifically contemplated unless specifically indicated to the
contrary. Thus, if a class of molecules A, B, and C are disclosed
as well as a class of molecules D, E, and F and an example of a
combination molecule, A-D is disclosed, then even if each is not
individually recited, each is individually and collectively
contemplated. Thus, is this example, each of the combinations A-E,
A-F, B-D, B-E, B-F, C-D, C-E, and C-F are specifically contemplated
and should be considered disclosed from disclosure of A, B, and C;
D, E, and F; and the example combination A-D. Likewise, any subset
or combination of these is also specifically contemplated and
disclosed. Thus, for example, the sub-group of A-E, B-F, and C-E
are specifically contemplated and should be considered disclosed
from disclosure of A, B, and C; D, E, and F; and the example
combination A-D. This concept applies to all aspects of this
application including, but not limited to, steps in methods of
making and using the disclosed compositions. Thus, if there are a
variety of additional steps that can be performed it is understood
that each of these additional steps can be performed with any
specific embodiment or combination of embodiments of the disclosed
methods, and that each such combination is specifically
contemplated and should be considered disclosed.
A. Definitions
[0060] It is understood that the disclosed method and compositions
are not limited to the particular methodology, protocols, fungi
species or strains, and reagents described as these may vary. It is
also to be understood that the terminology used herein is for the
purpose of describing particular embodiments only, and is not
intended to limit the scope of the present invention which will be
limited only by the appended claims.
[0061] It must be noted that as used herein and in the appended
claims, the singular forms "a", "an", and "the" include plural
reference unless the context clearly dictates otherwise. Thus, for
example, reference to "a scaffold" includes a plurality of such
scaffolds, reference to "the scaffold" is a reference to one or
more scaffolds and equivalents thereof known to those skilled in
the art, and so forth.
[0062] The phrase "temperature resilient fungus" refers to a fungus
that remains biologically viable in temperatures +40.degree. to
-50.degree. C. Temperature resilient fungi can continue to grow in
sub-freezing temperatures. For example, mycelium from these fungi
remain biologically viable and can grow at temperatures of less
than 0.degree. C.
[0063] "Optional" or "optionally" means that the subsequently
described event, circumstance, or material may or may not occur or
be present, and that the description includes instances where the
event, circumstance, or material occurs or is present and instances
where it does not occur or is not present.
[0064] Ranges may be expressed herein as from "about" one
particular value, and/or to "about" another particular value. When
such a range is expressed, also specifically contemplated and
considered disclosed is the range from the one particular value
and/or to the other particular value unless the context
specifically indicates otherwise. Similarly, when values are
expressed as approximations, by use of the antecedent "about," it
will be understood that the particular value forms another,
specifically contemplated embodiment that should be considered
disclosed unless the context specifically indicates otherwise. It
will be further understood that the endpoints of each of the ranges
are significant both in relation to the other endpoint, and
independently of the other endpoint unless the context specifically
indicates otherwise. Finally, it should be understood that all of
the individual values and sub-ranges of values contained within an
explicitly disclosed range are also specifically contemplated and
should be considered disclosed unless the context specifically
indicates otherwise. The foregoing applies regardless of whether in
particular cases some or all of these embodiments are explicitly
disclosed.
[0065] Unless defined otherwise, all technical and scientific terms
used herein have the same meanings as commonly understood by one of
skill in the art to which the disclosed method and compositions
belong. Although any methods and materials similar or equivalent to
those described herein can be used in the practice or testing of
the present method and compositions, the particularly useful
methods, devices, and materials are as described. Publications
cited herein and the material for which they are cited are hereby
specifically incorporated by reference. Nothing herein is to be
construed as an admission that the present invention is not
entitled to antedate such disclosure by virtue of prior invention.
No admission is made that any reference constitutes prior art. The
discussion of references states what their authors assert, and
applicants reserve the right to challenge the accuracy and
pertinency of the cited documents. It will be clearly understood
that, although a number of publications are referred to herein,
such reference does not constitute an admission that any of these
documents forms part of the common general knowledge in the
art.
[0066] Throughout the description and claims of this specification,
the word "comprise" and variations of the word, such as
"comprising" and "comprises," means "including but not limited to,"
and is not intended to exclude, for example, other additives,
components, integers or steps. In particular, in methods stated as
comprising one or more steps or operations it is specifically
contemplated that each step comprises what is listed (unless that
step includes a limiting term such as "consisting of"), meaning
that each step is not intended to exclude, for example, other
additives, components, integers or steps that are not listed in the
step
B. Biodegradable Insulation Material
[0067] Disclosed are biodegradable insulation materials comprising
a structural scaffold and at least one temperature resilient
fungus.
[0068] Disclosed are biodegradable insulation materials comprising
a structural scaffold and at least one temperature resilient
fungus, further comprising a non-cytotoxic deterrent to vermin and
competing fungi species. Non-cytotoxic deterrents can be, but are
not limited to monoterpenes, essential oils, and Eutrema japonicum.
The non-cytotoxic deterrent can be incorporated within the
biodegradable insulation material or can be coated on the outside
of the biodegradable insulation material. In some instances, vermin
can include, but are not limited to, rodents, insects, and
competing fungi species.
[0069] Disclosed herein are compositions and methods, that involve
growing a fungal species endemic to the cold regions on a nutrient
and cellulose-rich scaffold, and in some instances subjecting it to
a pressure and thermal treatment. The resultant chitin-based
biodegradable insulation material is renewable, bio-degradable, and
has been shown to be safe for humans and the environment. Standard
cytotoxicity bioassay testing on the samples of resultant material
has shown that the material has no cytotoxic compounds or
metabolites.
[0070] Its physical, environmental health and safety, and
mechanical properties make biodegradable insulation materials an
excellent candidate for eco-friendly thermal insulation and for
other light-weight fill materials in geoengineering. Specifically,
bench testing showed that the protocol can be used to rapidly
produce a thermally insulating biodegradable insulation material
that can perform in some of the most challenging environments on
the planet, with temperatures ranging from -50 to +30 degrees
C.
[0071] Utilizing novel 3D printing methods and microbiology
techniques, described herein are methods of developing a
structurally sound, "self-healing" material with thermal
conductivity properties comparable to the conventional polymeric
foams. Several innovative elements of the disclosed biodegradable
insulation materials set them apart from other developments in the
field and allow for a greater degree of thermal insulation and
superior strength, while simultaneously drastically reducing the
density of the material: 1) introduction of an internal structural
scaffold that is also a source of nutrients for the growing
mycelium; 2) direct application of the biologically-active slurry
for insulation in locations where direct contact with the soil is
expected; 3) protocol to produce a self-healing, hydrophobic skin
to prevent water-logging; 4) incubation process to produce
specified thermal and mechanical properties; and 5) producing thin
layers of the material and allowing them to fuse together by
placing them in close proximity to produce a campsite material with
desired properties.
[0072] Currently used composite materials that utilize mycelia of
various of fungi grown through wood sawdust and other agricultural
and forestry byproducts are rapidly renewable and biodegradable.
The combination of these characteristics with the carbon footprint
and the low amount of energy needed in the manufacturing process
makes fungal mycelium composites attractive to the packaging
industry.
[0073] The mechanical properties of a mycelium-based composite
using Ganoderma lucidum fungus grown through an enriched sawdust
substrate was investigated. The study found that their
mycelium-based composite was performing similarly to the polymeric
foams. It exhibited the compressive strength almost 3 times the
tensile strength, which attests to the potential of their methods
to produce various mycelium-based composites for biodegradable
packaging. However, this study as well as several others also
reported that the exposure to moisture rapidly decreases the
performance of these mycelium-based composites.
[0074] The effect of different feedstock blends on the physical
properties of resulting mycelium-based composites was studied. An
optimization of the biomass feedstock the particle size to improve
colonization of the substrate by the mycelium was reported to be
effective for production of material used for packaging
applications. Their findings included data on the evaluation on the
physical properties of the resultant material. Based on these
findings a process was developed which uses agricultural biomass
and fungi culture to produce an eco-friendly packaging and
insulating board. Cost analysis showed that that such materials
could be cost-competitive with the conventional packaging, when
considering production, shipping and operation, installation, and
remediation costs associated with the polymeric alternatives.
[0075] However, these composites have distinct disadvantages that
make them unusable for infrastructure thermo-insulation across
different temperatures for several reasons. Fungal species reported
to be used for manufacture of mycelium-based materials originate
from the warm regions and thus their mycelium grows well at
temperatures close to +22 degrees Centigrade. This is far above the
mean annual temperature in many cold climate regions including
Alaska, where the spatial mean annual air temperature in 2014 was
-4.4 degrees Centigrade, consistent with other areas in the
Circumpolar North. When exposed to colder temperatures, these
species and strains of fungi found in the warmer climates typically
become dormant or become biologically inert and their rate of
substrate colonization either slows to a glacial pace or stops.
While it is technically possible to maintain in-mold temperatures
close to 22 degrees Centigrade during the manufacturing process,
with the average temperatures at -4.4 degrees Centigrade, the steep
thermal gradient between the ambient and the in-mold temperature
needed for incubation will require very large energy inputs, most
likely from the hydrocarbon sources. This would deny the
mycelium-based materials its key environmental advantage over the
polymeric foams--that of being carbon-neutral or negative.
Therefore a new process is required to produce composites produced
using one of these species for in situ applications for off-site
manufacturing in the colder temperatures.
[0076] There is a risk of introducing exotic and potentially
invasive species of fungi into the local ecosystem associated with
these fungi composites. Use of a species of fungi already found in
the region directly addresses this concern.
[0077] Thermal conductivity values of the existing mycelium-based
material are between 0.18 and 0.10 W/(mK). These conductivity
values were within the ranges of gypsum (0.17), high-density
hardboard (0.15), plywood (0.12), hardwoods (0.16), and softwoods
(0.12). They are inferior to the extruded polymeric foams such as
polystyrene and polyurethane, and are inadequate for most cold
climates applications, where lower thermal conductivity is
needed.
[0078] 1. Scaffolds
[0079] Disclosed herein are biodegradable insulation material
comprising a structural scaffold. Structural scaffolds can include,
or can have added to it, a nutritive media for fungal mycelium.
Disclosed herein are biodegradable insulation materials comprising
a structural scaffold wherein the structural scaffold comprises a
nutritive media for fungal mycelium and at least one temperature
resilient fungus. In some instances where the structural scaffold
comprises a nutritive media for fungal mycelium, the structural
scaffold can be considered the source of nutrients for a
temperature resilient fungus. Nutritive medias for fungal mycelium
are well known in the art, for example, they can be, but are not
limited to, potato dextrose agar or sabouraud agar. In some
instances, a second nutrient or nutritive media can be added to the
structural scaffold.
[0080] Disclosed are biodegradable insulation materials comprising
a structural scaffold, wherein the structural scaffold is
three-dimensional. Also disclosed are biodegradable insulation
materials comprising a structural scaffold comprising a nutritive
media for fungal mycelium; and at least one temperature resilient
fungus, wherein the structural scaffold is three-dimensional.
[0081] Disclosed are biodegradable insulation materials comprising
a structural scaffold comprising a nutritive media for fungal
mycelium; and at least one temperature resilient fungus, wherein
the structural scaffold comprises a biomass. In some instances, the
biomass is pasteurized. In some instances, the structural scaffold
comprises a biomass feedstock. The biomass or biomass feedstock can
comprise a nutritive media for fungal mycelium. In some instances,
the structural scaffold can be coated with a nutritive media for
fungal mycelium.
[0082] Disclosed are biodegradable insulation materials comprising
a structural scaffold comprising a nutritive media for fungal
mycelium; and at least one temperature resilient fungus wherein the
structural scaffold comprises a structural reinforcement. In some
instances, the structural reinforcement can consist of ceramic,
polymeric, metal, or cellulose filaments that are interwoven to
form a three-dimensional structure or/and a mesh.
[0083] Disclosed are biodegradable insulation materials comprising
a structural scaffold comprising a nutritive media for fungal
mycelium; and at least one temperature resilient fungus, wherein
the biodegradable insulation material comprises the net shape of
the object to be insulated. In some instances, it is the structural
scaffold that comprises the net shape of the object to be
insulated. The object to be insulated can be, but is not limited
to, a flat surface, a round surface, or a rectangular surface.
Thus, in some instances, the biodegradable insulation material or
the structural scaffold can comprise the net shape of a sphere,
cylinder, cube, cuboid, cone, slab, pyramid, and of non-rigid 3D
shapes. In other words, the biodegradable insulation material or
the structural scaffold can be molded, pressed, grown, or formed in
any manner to any shape or size.
[0084] Disclosed are biodegradable insulation materials comprising
a structural scaffold comprising a nutritive media for fungal
mycelium; and at least one temperature resilient fungus, wherein
the structural scaffold comprises a biopolymer or synthetic polymer
that is non-toxic to the fungus and withstands moisture and
humidity and a nutritive media layer. For example, a biopolymer can
be, but is not limited to, a cellulose-based biopolymer filament,
polynucleotide, polypeptide, or polysaccharide. A synthetic polymer
can be, but is not limited to, nylons, polythenes, polyethylenes,
polyvinyl chlorides, polystyrenes, polyamides, polyesters,
polyurethanes, polysulfides, polycarbonates, or silicone.
[0085] 2. Fungus
[0086] Disclosed are biodegradable insulation materials comprising
a structural scaffold comprising a nutritive media for fungal
mycelium; and at least one temperature resilient fungus, wherein
the scaffold is colonized by mycelium of the temperature resilient
fungus. In some instances, the mycelium can be present on or
throughout the scaffold.
[0087] In some instances, the disclosed biodegradable insulation
materials further comprise mycelium from a second temperature
resilient fungus. The second temperature resilient fungus can be
any temperature resilient fungus that is different of the
temperature resilient fungus originally present in the
biodegradable insulation material. For example, it can be a
temperature resilient fungus of a different genus or different
species.
[0088] Disclosed are biodegradable insulation materials comprising
a structural scaffold comprising a nutritive media for fungal
mycelium; and at least one temperature resilient fungus, wherein
the at least one temperature resilient fungus is a fungus that
remains biologically viable within a temperature range of
+30.degree. to -50.degree. C.
[0089] Disclosed are biodegradable insulation materials comprising
a structural scaffold comprising a nutritive media for fungal
mycelium; and at least one temperature resilient fungus, wherein
the temperature resilient fungus is a saprotrophic Basidiomycete.
In some instances, the saprotrophic Basidiomycete can be a
polypore. For example, the polypore can be, but is not limited to,
Irpex lacteus. In some instances, a temperature resistant Polypore
already present in environments such as Alaska and the Circumpolar
North can be the Irpex lacteus strain US Forest Service, Center for
Forest Mycology Research FP-102064-Sp, strain FP-102220-Sp.
C. Methods of Making
[0090] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold. In some instances, inoculating the structural
scaffold with at least one temperature resilient fungus in the
presence of a nutritive media under environmental conditions that
allow for mycelium growth can include a structural scaffold
comprising the nutritive media or the addition of nutritive media
to the structural scaffold at the time of inoculating the
structural scaffold with the at least one temperature resilient
fungus.
[0091] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the inoculum comprises mycelium from at least
two temperature resilient fungi. The second temperature resilient
fungus can be added at the same time or at a different time as a
first temperature resilient fungus. For example, the second
temperature resilient fungus can be added hours or days after the
first temperature resilient fungus is added or provided. When at
least two temperature resilient fungi are present the at least two
temperature resilient fungi can be different species from the same
genus or from a different genus.
[0092] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the structural scaffold is
three-dimensional.
[0093] In some instances, environmental conditions that allow for
mycelium growth comprise exposure of the mycelium to carbon dioxide
gas in the range of 400-2,000 ppm. Carbon dioxide conditions that
are too high can prevent mycelium growth and ultimately kill the
temperature resilient fungus. In some instances, environmental
conditions that allow for mycelium growth comprise exposure of the
mycelium to temperatures of +4.degree. to 21.degree. C. In some
instances, mycelia can remain biologically viable at lower
temperatures but they will not continue to grow. In some instances,
environmental conditions that allow for mycelium growth comprise
exposure of the mycelium to variable relative humidity. For
example, the relative humidity can be 50%, 55%, 60%, 65%, 70%, 75%,
80%, 85%, 90%, 95%, or 100%.
[0094] In some instances, allowing the mycelium of the temperature
resilient fungus to colonize the scaffold comprises incubating the
scaffolds from 1 day to 30 days. In some instances, allowing the
mycelium of the temperature resilient fungus to colonize the
scaffold comprises incubating the scaffolds for a period of 4 to 14
days. In some instances, the period of time for incubating the
scaffolds can depend on the desired thermal conductivity and
mechanical properties needed for the specific location application
of the biodegradable insulation material.
[0095] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, further comprising pressing the scaffold colonized by
mycelium of the temperature resilient fungus to achieve desired
density, thermal conductivity, elastic moduli, Young's modulus,
compressive strength, and thickness. The thickness can depend on
location and temperature. For example, the thickness can vary based
on how much room is present in the infrastructure to be insulated.
In some instances, the thickness can be 2.5 cm to 10 cm. The
density can be in a range of 20-250 kg/m.sup.3 depending on the
applications.
[0096] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, further comprising machining the scaffold colonized
by mycelium by cutting, pressing, and sanding of the temperature
resilient fungus to achieve desired net form and thickness.
[0097] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, further comprising allowing the biodegradable
insulation material to form a chitinous hydrophobic outer skin.
Controlling environmental conditions including, but not limited to,
lighting temperature, and relative humidity can allow for formation
of a chitinous hydrophobic outer skin. In some instances, allowing
the biodegradable insulation material to form a chitinous
hydrophobic outer skin comprises machining or cutting the scaffold
or placing the incubating scaffold next to a glass or synthetic
polymer surface so that the mycelium self-skins when it comes into
physical contact with the said surface during the incubation under
similar environmental conditions to those that allow for mycelium
growth. Two or more structural scaffolds can be joined to form a
single larger structural scaffold by placing the two or more
structural scaffolds in close proximity so that the chitinous
hydrophobic outer skin can grow from one structural scaffold to
another.
[0098] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, further comprising drying the scaffold colonized with
mycelium of the temperature resilient fungus. Drying the scaffold
can result in rendering the fungus or mycelium biologically inert,
or at least preventing further growth of the mycelium. In some
instances, drying comprises temperatures above 50.degree. C. For
example, drying can comprise temperatures of at least 60.degree. C.
In some instances, the amount of time needed for drying can vary
based on the net thickness or density of the biodegradable
insulation material. In some instances, drying the scaffold does
not occur and instead the method of making the biodegradable
insulation materials comprises maintaining a low environmental
humidity so that the mycelium remains biologically viable and
capable of vegetative growth and self-healing if damaged during or
after installing or applying the biodegradable insulation material
to the location or object of interest.
[0099] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the temperature resilient fungus is a fungus
that remains biologically viable within a temperature range of
+30.degree. to -50.degree. C. In some instances, the temperature
resilient fungus is a fungus that remains biologically viable at
temperatures of less than 0.degree. C. Therefore, temperature
resilient fungi can remain viable under freezing conditions.
[0100] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the temperature resilient fungus is a
saprotrophic Basidiomycete. In some instances, the saprotrophic
Basidiomycete can be a polypore. For example, the polypore can be,
but is not limited to, Irpex lacteus. In some instances, a
temperature resistant Polypore already present in environments such
as Alaska and the Circumpolar North can be the Irpex lacteus
strain, US Forest Service, Center for Forest Mycology Research
FP-102064-Sp, or strain FP-102220-Sp.
[0101] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the biodegradable insulation material has a
self-skinning property. While the inside of the colonized scaffold
resembles an open-cell foam, the hyphae on its exposed outer
surfaces form a solid face with hydrophobic properties, comprising
a self-skinning process.
[0102] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the biodegradable insulation material
comprises two or more of the temperature resilient fungus mycelium
colonized scaffolds. Two or more structural scaffolds can be joined
to form a single larger structural scaffold by placing the two or
more structural scaffolds in close proximity so that the chitinous
hydrophobic outer skin can grow from one structural scaffold to
another.
[0103] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, further comprises adding to the biodegradable
insulation material a non-cytotoxic deterrent to vermin and
competing fungi species. Non-cytotoxic deterrents can be, but are
not limited to, monoterpenes, essential oils, and Eutrema
japonicum. Adding a non-cytotoxic deterrent includes, but is not
limited to, incorporating the deterrent within the biodegradable
insulation material or structural scaffold or coating the deterrent
on the outside of the biodegradable insulation material. In some
instances, vermin can include, but are not limited to, rodents,
insects, and competing fungi species.
[0104] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, further comprising layering the biodegradable
insulation material to produce flexible or rigid laminated panels.
Layering the biodegradable insulation material can comprise two or
more of the disclosed biodegradable insulation materials layered
one on top of the other or beside each other. In some instances,
the two or more biodegradable insulation material can be identical
or different. In some instances, each of the two or more
biodegradable insulation materials can be different in terms of
each comprising mycelium from a different temperature resilient
fungus, each comprising a different structural scaffold, or a
combination therefore. In some instances, layering comprises a
scaffold core with fiber-reinforced panel outer surfaces.
[0105] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the biodegradable insulation material has a
thermal conductivity, density, elastic, shear and Young's moduli,
and compressive strength comparable to synthetic polymeric
foams.
[0106] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the biodegradable insulation material is free
of cytotoxic metabolites or compounds. The presence of cytotoxic
metabolites or compounds can be determined by an effect based
colorimetric bioassay or by other methods which enable the
detection of such compounds.
[0107] 1. Stamping
[0108] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the structural scaffold is formed by blending
a feedstock comprising biomass to form a blend; pasteurizing the
blend; cooling the blend; forming the blend into the desired shape;
incubating the blend under conditions favorable for mycelium
growth.
[0109] In some instances, cooling the blend occurs rapidly. For
example, the cooling occurs in seconds, minutes, or hours. In some
instances, cooling can occur in 1, 2, 3, 4, 5, 10, 15, 20, 25, 30,
35, 40, 45, 50, 55, or 60 minutes. In some instances cooling can
occur in 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20 or 24 hours.
[0110] In some instances, forming the blend into the desired shape
comprises stamping/pressing or putting into a mold. The desired
shape can be determined based on the location or object to be
insulated.
[0111] In some instances, conditions favorable for mycelium growth
comprise exposure of the mycelium to carbon dioxide gas in the
range of 400-2,000 ppm. Carbon dioxide conditions that are too high
can prevent mycelium growth and ultimately kill the temperature
resilient fungus. In some instances, environmental conditions that
allow for mycelium growth comprise exposure of the mycelium to
temperatures of +4.degree. to 21.degree. C. In some instances,
mycelia can remain biologically viable at lower temperatures but
they will not continue to grow. In some instances, environmental
conditions that allow for mycelium growth comprise exposure of the
mycelium to variable relative humidity. For example, the relative
humidity can be 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%,
or 100%.
[0112] 2. 3D Printing
[0113] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the structural scaffold is three-dimensional,
wherein the three-dimensional scaffold is formed using a 3D
printer. In some instances, the three-dimensional scaffold can
comprise biopolymers or synthetic polymers. For example, a
biopolymer can be, but is not limited to, a cellulose-based
biopolymer filament, polynucleotide, polypeptide, or
polysaccharide. A synthetic polymer can be, but is not limited to,
nylons, polythenes, polyethylenes, polyvinyl chlorides,
polystyrenes, polyamides, polyesters, polyurethanes, polysulfides,
polycarbonates, or silicone.
[0114] Disclosed are methods for producing a biodegradable
insulation material comprising forming a structural scaffold;
inoculating the structural scaffold with at least one temperature
resilient fungus in the presence of a nutritive media under
environmental conditions that allow for mycelium growth; and
allowing mycelium of the temperature resilient fungus to colonize
the scaffold, wherein the structural scaffold is three-dimensional,
wherein the scaffold is formed by a 3D printing process within a
mold or enclosure that allows for a desired shape. In some
instances, the mold or desired shape can be determined based on the
object or area to be insulated with the biodegradable insulation
material. The object to be insulated can be, but is not limited to,
a flat surface, a round surface, or a rectangular surface. Thus, in
some instances, the biodegradable insulation material or the
structural scaffold can comprise the net shape of a sphere,
cylinder, cube, cuboid, cone, slab, pyramid, and of non-rigid 3D
shapes. In other words, the biodegradable insulation material or
the structural scaffold can be printed, molded, pressed, grown, or
formed in any manner to any shape or size.
D. Methods of Using
[0115] Disclosed are methods of insulating an infrastructure
comprising introducing the biodegradable insulation material of any
one of the disclosed biodegradable insulation materials to an
infrastructure. For example, disclosed are methods of insulating an
infrastructure comprising introducing to an infrastructure a
biodegradable insulation materials comprising a structural scaffold
comprising a nutritive media for fungal mycelium; and at least one
temperature resilient fungus. In some instances, an infrastructure
can be, but is not limited to, underlayment for oil and gas
pipeline foundations, large civil infrastructure, road
underpayment, wall insulation in buildings, piping systems, above
ground and underground environmental controls and sensors, and
backfill in road construction. The biodegradable insulation
material can also be used in manufacture of mobile coolers and
freezer units, disposable fish and food shipping containers,
acoustic insulation boards, floating buoys in nets and other
commercial fishing gear, buoys, textiles, and enclosures for
floating sensors and logging units for environmental monitoring and
automated reporting for applications in the remote and marine
environments. In some instances, the infrastructures being
insulated with the disclosed biodegradable insulation material are
infrastructures that are present or are used in temperatures below
freezing.
[0116] Disclosed are methods of insulating an infrastructure
comprising introducing to an infrastructure a biodegradable
insulation materials comprising a structural scaffold comprising a
nutritive media for fungal mycelium; and at least one temperature
resilient fungus, wherein the temperature resilient fungus is
endemic to or already occurs in the environment in which the
infrastructure is present. The use of endemic fungus prevents a
potentially negative effect on an ecosystem by a species that was
not previously present. An introduced species of fungus could alter
the ecosystem and have negative impacts. Thus, it is beneficial to
use a fungal strain native or endemic to the environment being
treated or insulated. In some instances, a temperature resistant
Polypore already present in environments can be the Irpex lacteus
USFS strain FP-102064-Sp, or strain FP-102220-Sp.
[0117] Disclosed are methods of insulating an infrastructure
comprising introducing to an infrastructure a biodegradable
insulation materials comprising a structural scaffold comprising a
nutritive media for fungal mycelium; and at least one temperature
resilient fungus, wherein the administering occurs by placing the
biodegradable insulation material around the object to be insulated
or spraying the biodegradable insulation material on the object to
be insulated. Units of the biodegradable insulation material can be
placed under or around the object that is being insulated. Units of
the biodegradable insulation material can be interlocking to form a
closely fitted mold around the object. Two or more units of the
biodegradable insulation material can form a "clamshell"
interlocking around the object that is being insulated.
Additionally, units of the biodegradable insulation material that
remains biologically viable can be placed under or around the
object that is being insulated so that the outer skin of the units
is absorbed within the cellular structure of the biodegradable
insulation material forming a larger self-healing unit.
E. Kits
[0118] The materials described above as well as other materials can
be packaged together in any suitable combination as a kit useful
for performing, or aiding in the performance of, the disclosed
method. It is useful if the kit components in a given kit are
designed and adapted for use together in the disclosed method. For
example disclosed are kits for producing the disclosed
biodegradable insulation materials, the kit comprising a structural
scaffold and a nutritive media for fungal mycelium. The kits also
can contain a temperature resilient fungus.
EXAMPLES
F. Example 1
[0119] 1. Biodegradable Insulation Material
[0120] Under proper environmental conditions, the use of the
disclosed biodegradable insulation material as thermal insulation
between the thermally conductive infrastructure element (e.g.,
embankment under an elevated pipeline, roadway, or a building
foundation) and the cold or frozen ground is more beneficial than
inclusion of the polymeric foams used today for several reasons. It
is rapidly renewable and biodegradable, which makes it uniquely
desirable in hard-to-reach, remote areas, and ecologically
sensitive habitats of the Arctic, the Antarctic, and in the marine
environments, with no landfill services available. In some
instances, the biodegradable insulation material includes 3D
scaffolds, self-healing properties, and hydrophobic skin that
prevents water-logging, and an incubation process to produce the
said thermal and mechanical properties. A schematic sketch of a
proposed bioengineering process is provided in FIG. 1. Unlike
materials derived from trees, which require several years of
growth, the proposed material can be produced in 1 to 2 weeks from
inoculation of the blend with fungal culture to the final
product.
[0121] The overall goal of this Example is to develop a
biodegradable insulation material that uses fungal mycelium to
provide thermal insulation to infrastructure in cold regions. There
are three innovative processes in this invention: Process 1: the
development of the manufacturing process from inoculation and
incubation to final product processing. This process includes an
advanced system for controlled process to optimize energy use.
Process 2: Adaptation of an existing 3D printing technology to
produce scaffolds that can be interfaced with the growing mycelium
for maximum strength and insulation, and Process 3: Innovation in
material properties of the resultant biodegradable insulation
material.
[0122] i. Process 1: Development of the Manufacturing Process
[0123] This manufacturing process of a biodegradable insulation
material involves several stages: biomass feedstock production;
pasteurization of the feedstock; inoculation of the feedstock with
culture of suitable white-rot fungi (for example, Irpex sp.);
shaping of the inoculated feedstock slurry into desired 3D shapes
through application of pressure and 3D-printing technology;
incubation of the resultant product; and post-processing of the
final product.
[0124] A process was developed of producing virtually any shape
form of the biodegradable insulation material because the nutrient
slurry can be shaped into any 3D shape, as long as the geometry
permits the propagation of the vegetative mycelium through the
nutritive matrix (FIG. 1). The method involves a standardized
process to produce a material with known thermal insulation,
mechanical and biophysical properties by employing a saprotrophic
fungus, typically a Basidiomycete. The process begins with blending
of the feedstock consisting of biomass, such as macerated wood with
calcium sulfate, cereal grain bran, and water. The hampers
containing the ingredients required for producing this blend
discharge them onto a conveyer belt. The blend is then pasteurized
and rapidly cooled to reduce the number of potentially competing
organisms. The blend continues to move on the conveyer belt and is
subjected to shaping into the final net shape and to inoculation
with the liquid culture.
[0125] Two distinctive methods can be used to shape and inoculate
the material (please refer to Scaffold methods 1 and 2) to produce
internal scaffolds. The pressed bend is then cut into blocks and
placed into an incubation chambers for a period of 7 to 14 days. In
the incubation chambers, humidity, CO.sub.2 concentration, and
temperature are closely controlled to facilitate most favorable
conditions for vegetative mycelium propagation through the pressed
blend. After the incubation process is completed, the blocks become
hydrophobic due to the self-skinning properties of the fungus.
Self-skinning occurs when a solid face, film-like barrier produced
by the mycelium when it encounters a non-nutritive barrier. This
self-skinning property produces a self-healing, hydrophobic skin
that prevents water-logging.
[0126] The fungus can be kept biologically active, and the blocks
of the resultant open-cell foam are transported to the construction
site and applied without additional treatments, thus minimizing the
energy demand. A process of joining single units of the
biodegradable insulation material into more complex shapes by
placing them in physical contact and allowing the hyphae to bridge
the gap between the units was developed. The skin is absorbed into
the mycelium's overall cellular structure, creating a single larger
unit.
[0127] For other applications where biomass expansion is not
desirable, the fungal mycelium is rendered biologically inert by
heating the blocks to 60 degrees centigrade or higher in a dryer
during the manufacturing process.
[0128] ii. Process 2: Innovative 3D Internal Scaffolds
[0129] One of the aspects of the compositions and methods described
herein is introduction of a structural scaffold that also provides
a source of nutrients for the growing mycelium. There are several
benefits of this new approach. Firstly, it affords greater degree
of thermal insulation, superior strength, while simultaneously
drastically reducing the density of the material.
[0130] Secondly, higher precision in controlling the thermal,
mechanical, and fire retardant properties of the resultant
biodegradable insulation material during the manufacturing process
is critical because it affords the manufacturer to program the
shape and material properties needed for a specific application
(i.e., thermally insulated concrete pavement, pipe insulation,
foundation insulation) by specifying the scaffold's thickness,
porosity, nutrient content, shape and other variables that effect
the biodegradable insulation material's performance for a given
application.
[0131] The technique currently used in production of mycelium-based
materials relies on packing of various biomass blends and of the
inoculant into disposable plastic molds for incubation of the mix
to allow the fungus to convert part of the biomass into mycelium
and to shape into the final product. However, this method produces
a material that is fairly dense and fragile. This method also does
not permit to control the matrix to achieve the desired degree of
thermal conductivity. In addition, once this material is made
biologically inert it can be easily water-logged once cut.
[0132] Because 3D printing technology can produce internal
scaffolds of virtually any shape and thickness, it liberates the
manufacturing process from molds and permits manufacturing of
virtually any shape. Depending on the application, two related
scaffold methods for biodegradable insulation material production
can be used.
[0133] Scaffold Method 1: The filament that is used to print the
scaffold would combine structural and nutritive properties (FIG.
2). The addition of the internal scaffold will result in a lighter
material of superior strength and of low thermal conductivity. As
the rapidly growing fungus quickly colonizes the scaffold, it
becomes an embedded and structural part of the biodegradable
insulation material.
[0134] Scaffold Method 2: The second method of producing the
scaffolds is by employing a mechanism that stamps the blend into
the desired net shape as it moves on the conveyer belt (Item 8 in
FIG. 1 and FIG. 3). An aerobic liquid culture fermenter tank is
fitted with a pump, which delivers inoculum aseptically into the
stamping chamber, equipped with an array of hollow-core needles.
The hydraulic piston pushes the chamber toward the blended
feedstock on the belt. As the chamber is lowered, the needles
create channels for the inoculum. As the chamber is lifted, the
hollow-core needle array begins to gradually eject the liquid
culture into the blend. This process is repeated to create a
pattern of equally spaced injections that facilitate rapid
colonization of the feedstock by the fugal mycelium.
[0135] The 3D scaffolds can be printed in a variety of sizes and
geometries. They can be designed to bend and move with the
deformation of the ground or/and the structure. Thanks to the
higher tensile strength, the embedment of the scaffold into
mycelium can improve other mechanical properties of the resulting
material. While others have proposed insulating materials from
fungi and from other organisms, this approach differs in its
incorporation of 3D scaffolds, removal of the raw feedstock of
inconsistent quality, and the tailoring the material for use in
cold environments. Once produced, 3D printed scaffolds can be
mass-stamped in the production and open exciting possibilities for
producing biodegradable insulation materials in any desired size
and shape. With predictable material properties, 3D-printed
scaffolds make the implementation and control easy and
repeatable.
[0136] Furthermore, the proposed approach features a robust, yet
flexible manufacturing system designed for the ease of quality
control and monitoring of the production of uniform material. The
implementation requires no complicated components and can be
installed in a hangar.
[0137] iii. Process 3: Innovation in Material Properties of the
Resultant Foam
[0138] Microcombustion calorimetry tests showed that cotton fabrics
coated with chitin, the structural component of a biodegradable
insulation material, had a significantly lower peak heat-release
rate and total heat-release values compared with that of uncoated
cotton fabric. Thus, the biodegradable insulation material can have
similar fire-retardant properties.
[0139] Six blending protocols were investigated and characterized
the production, thermal and mechanical properties of the resulting
biofoam. Results show that thermal conductivity of biofoam samples
(n=60) averaged 0.0533.+-.0.004 W/(mK), density 220.+-.38.98
kg/m.sup.3, shear modulus 7.4.+-.4.95 (MPa), Young's modulus
21.18.+-.16.21 (MPa), and compressive strength 150.83.+-.113.8
(kPa). One blending protocol produced the highest shear and Young's
moduli, and compressive strength, while its thermal conductivity is
comparable to other groups.
[0140] Samples of biodegradable insulation material produced with
Irpex sp. Fungus, grown on birch sawdust feedstock, were sent to an
independent laboratory for toxicology analysis.
[0141] Methods: The MTT-cell culture assay with swine kidney target
cells is an effect based colorimetric bioassay which enables the
detection of cytotoxic metabolites produced by toxigenic fungi and
other cytotoxic compounds. Extracts with organic solvents were
prepared of 3 samples (with duplicates) and log 2-dilutions tested
in the MTT-cell culture assay.
[0142] Based on the results of bioassay analysis there was no
evidence for the presence of cytotoxic compounds in the
biodegradable insulation material samples. The target cells
responses towards duplicates of crude extracts and control without
fungus were identical. The IC50-values were 62.5 and 125.0 mg/ml,
indicating that no cytotoxic metabolites originated from culturing
the fungus on this particular medium. In summary, the data obtained
provides no indication for occurrence of cytotoxic
compounds/metabolites in the samples tested.
[0143] Comparison of properties of biodegradable insulation
materials with these of expanded polystyrene, a material widely
used for building and infrastructure insulation in cold climates,
is appropriate. Compressive strength of bioengineered biodegradable
insulation materials is comparable to that of expanded polystyrene,
thermal is slightly higher, and the density is higher. The findings
indicate that mycelia-based biodegradable insulation material is a
viable alternative to polymeric thermal insulation materials under
extreme Northern environmental conditions.
G. Example 2
1. Introduction
[0144] Polymeric foams, such as polystyrene and polyurethane, are
commonly used for thermal insulation in infrastructure and housing
construction, particularly in cold climates. These
hydrocarbon-based materials are lightweight, hydrophobic, and
resistant to photolysis. They are not subject to decomposition or
decay, and create problems with respect to recycling, reuse, and
landfill operation. More importantly, these polymeric foams are
non-renewable and their production and use involve complex
manufacturing processes, substantial energy inputs and associated
waste streams. Polymeric foams have been shown to leach out or
off-gas several toxins that bio-accumulate in fish and wildlife,
presenting a well-documented environmental and public health
problem. A renewable alternative to today's conventional thermal
insulation materials would substantially reduce environmental and
public health burden of construction and promote sustainable
infrastructure development.
[0145] Mycelium, the vegetative part of fungus, is a hollow
structure consisting of a mass of branching, hollow tubular,
chitinous hyphae which provide a fast growing, safe and inert
material as the matrix for a new generation of natural foams, or
biofoams. As the mycelium grow, a network of branching hyphae,
primarily composed of chitin, binds together the nutritive
substrate consisting of biomass and creates a vast
three-dimensional matrix. The biodegradable insulation materials
can serve as replacements for the petroleum based-polymeric
materials for applications in insulation, packaging, noise control,
and sandwich panels. Biodegradable insulation materials offer
several advantages over polymeric foams, including freedom from
petroleum products, low cost production, fast renewability, carbon
capture and storage and bio-degradability at its end of life use.
Several studies in this front have revealed the unique mechanical
properties and the promising potentials of biofoam biodegradable
insulation materials in engineering applications. The impact of
mixing ratio of rice husks and wheat grain on the physical
properties, microstructure and porosity of a mycelium biodegradable
insulation material was investigated. The manufacturing of
biodegradable molded packaging materials based on fungal mycelium
and cotton plant materials was investigated and they found that
these materials met or exceeded like characteristics of extruded
polystyrene foam. The acoustic performance of a mycelium
biodegradable insulation material based on agricultural by-product
substrates was evaluated and results suggested an optimal
performance in automotive road noise control. The elastic and
strength properties of mycelium biodegradable insulation material
in both tension and compression were investigated and found the
strength of the biodegradable insulation material decreases with
increasing moisture content, and the compressive strength is almost
three times the tensile strength. The flexural properties of
mycology matrix core sandwich composites by four-point bend testing
were also investigated.
[0146] Presented herein are bioengineering processes for the
development of a fungal mycelium-based biodegradable insulation
material and characterization of its physical, thermal and
mechanical properties. Test results including dry density, thermal
conductivity, Young's and shear moduli, stress-strain relationship,
failure mode, and compressive strength are presented. The
effectiveness of the processes, and impact of packing condition and
addition of natural fiber are discussed here.
2. Description of Bioengineering Process
[0147] Several mixing, packing and incubating protocols have been
explored. Table 1 specifies the groups according to the mixing,
packing and incubating protocols. Three batches of samples,
designated as SP, SL and SPL respectively, were tested to evaluate
the effectiveness of the incubation protocol and test status on the
properties. The samples are right cylinders with a diameter of
about 5 cm and a height of about 6 cm formed by polycarbonate
tubular molds. Samples in SP and SL were incubated for two weeks,
while samples in SPL were the same as SL except that they were
incubated for additional four weeks before testing. All samples
except those in SL were dried in an oven set at 60.degree. C. for
24 hours before testing. It is worthy of noting that only
difference between SP and SL is that samples in SP are dried, while
samples in SL are live, and the difference between SP and SPL is
the additional four week incubation applied to samples in SPL. Each
batch had 30 samples, which were divided into six groups (G1-G6) to
evaluate various blends of the biomass materials as a substrate and
packing conditions for colonization of selected white-rot
saprotrophic fungi cultures harvested from Alaska in molds. The
blends comprised macerated sawdust pulp of Alaska birch (Betula
neoalaskana) of 5 mm or smaller in size, millet grain, wheat bran,
a natural fiber and calcium sulfate.
TABLE-US-00001 TABLE 1 Group specification according to mixing,
packing and incubating protocols Group No. Sample No. Mixing
Protocol Packing Incubation Time/Wks Test Status SP1 G1: SP01~SP05
I Dense Two Dried SP2 G2: SP06~SP10 I Loose Two Dried SP3 G3:
SP11~SP15 II Dense Two Dried SP4 G4: SP16~SP20 II Loose Two Dried
SP5 G5: SP21~SP25 III Dense Two Dried SP6 G6: SP26~SP30 III Loose
Two Dried SL1 G1: SL01~SL05 I Dense Two Live SL2 G2: SL06~SL10 I
Loose Two Live SL3 G3: SL11~SL15 II Dense Two Live SL4 G4:
SL16~SL20 II Loose Two Live SL5 G5: SL21~SL25 III Dense Two Live
SL6 G6: SL26~SL30 III Loose Two Live SPL1 G1: SPL01~SPL05 I Dense
Six Dried SPL2 G2: SPL06~SPL10 I Loose Six Dried SPL3 G3:
SPL11~SPL15 II Dense Six Dried SPL4 G4: SPL16~SPL20 II Loose Six
Dried SPL5 G5: SPL21~SPL25 III Dense Six Dried SPL6 G6: SPL26~SPL30
III Loose Six Dried
[0148] In Mixing Protocol I, the feedstock ingredients (substrate)
and live fungi culture are mixed and packed in molds, and then
placed in temperature and moisture controlled incubator. In Mixing
Protocol II, the substrate and the fungi culture was incubated in
filtered polypropylene bags for a defined period before the blend
is macerated and packed into the cylindrical molds, permitting it
re-knit into a more structurally uniform and denser foam. Mixing
Protocol III is the same as Protocol I but with natural fiber (50%
of substrate's dry weight) added during mixing. Two packing
conditions have been applied: loose and dense, the former being
naturally deposited without compaction and the latter with
approximately twice the original volume of materials packed. FIG. 4
illustrates the complete bioengineering process for Group 3
samples. Birch sawdust from the local forestry industry and added
nutrients were mixed with certain amount of water and pasteurized.
Then the slurry was inoculated with a culture of a Basidiomycete
saprotrophic fungus, present in Alaska and incubated for a certain
period of time to achieve full colonization of the nutritive
substrate by vegetative mycelium. The inoculated slurry was either
mixed and loaded into cylindrical molds for further incubation
(Protocols 1 and 3) or in Protocol II, the inoculated substrate was
incubated in filtered polypropylene bags for a defined period,
after which it was macerated and re-packed into the cylindrical
molds. The incubation took place within a defined humidity and
temperature range. The samples were dried in a dryer before
de-molding for testing.
3. Testing Procedures
[0149] Tests were conducted to obtain the dry density, thermal
conductivity, Young's and shear moduli, and unconfined compressive
strength. The Transient Line Heat Source method built in KD2 Pro
Thermal Analyzer (Decagon Devices, Inc. 2015) was used to measure
thermal conductivity. The KD2 Pro complies fully with ASTM D5334-14
(ASTM, 2014). The KS-1 needle with a diameter of 1.3 mm and a
length of 6 cm has a valid range of thermal conductivity from 0.02
to 2.00 W/(mK) and was used in this study. During the tests, the
needle was inserted into the sample from the top or bottom
surface.
[0150] The compressive strength was obtained by unconfined
compression tests according to ASTM Standard D2166-13 (ASTM, 2013).
Displacement control with a vertical strain rate of 2%/min was
applied. Note one exception from the ASTM standard: the sample
diameter to height ratio was larger than 1:2 due to equipment
limitation. However, sufficient lubricant was applied to the sample
ends to minimize the end effect on strength. The Young's and shear
moduli were measured by shear wave (S-wave) or compressional wave
(P-wave) velocity method as described below.
[0151] i. Experiment Set-Up for Elastic Modulus Measurement
[0152] The application of S-wave or P-wave velocity methods for
measuring the elastic moduli of civil engineering materials have
become increasingly popular for the convenience and the
non-intrusiveness of the testing method. In these methods,
piezoelectric bender elements (BE) or piezoelectric disk elements
(PDE) are employed to generate and detect the first arrival of
S-wave or P-wave traveling through the subject material, therefore
enabling the measurement of S-wave or P-wave velocity if the travel
distance is known. Based on the elastic wave propagation theory,
the modulus at small-strain can be calculated by the following
equations:
G=.rho.V.sub.S.sup.2 (1)
E=.rho.V.sub.P.sup.2 (2)
where G is the shear modulus, E is the Young's modulus, .rho. is
the mass density, V.sub.S is the S-wave velocity, and V.sub.P is
the P-wave velocity.
[0153] FIG. 5 illustrates the experiment set-up for elastic moduli
measurement. This set-up consists of a Function Generator (Agilent
model 33521A), a power amplifier with filter (Krohn-Hite model
3364), and a Mixed Signal Oscilloscope (Agilent model 70104B). The
Function Generator was used to apply a sine or a step excitation
signal with a peak-to-peak amplitude of 1 V for S-wave velocity
test and 4 V for P-wave velocity test. The received signal was
filtered by a bandpass filter with the bandwidth frequency in 500
Hz to 50 kHz and amplified accordingly. Finally, the Oscilloscope
is used to acquire the wave signal data, which was compared with
the excitation signal for travel time measurement.
[0154] As illustrated in FIG. 5, two pairs of BEs were laid in
top-to-bottom direction and in diameter direction at the middle
sample height to measure S-wave velocity in vertical (VVS) and
horizontal direction (VHS), respectively. Similarly two pair of
PDEs were used to measure the P-wave velocity in vertical (VVP) and
horizontal direction (VHP), respectively.
[0155] ii. Wave Velocity Determination
[0156] Travel length and travel time need to be determined for
evaluating wave velocity. The travel length is determined by
measuring the tip-to-tip distance between the transmitter and
receiver sensors. The time domain analysis method is used to
determine the travel time. The P-wave first arrival is determined
by the initial arrival of transmitted P-wave as it is much faster
than any S-waves in the system, as shown in FIG. 6. The
determination of S-wave first arrival is more difficult due to
near-field effects, interference from faster P-waves in the system
and other factors. There are a number of ways to minimize the error
involved in S-wave first arrival determination and the zero after
first bump method was used, as illustrated in FIG. 7. However, the
total travel time determined as illustrated is the net travel time
in the sample as there are system delays in the peripheral
electronics, which can be measured by contacting the tips of the
transmitter and the receiver sensors. The system delay to should be
subtracted from the total travel time. The wave velocity is
calculated using the following equation:
V=L/.DELTA.t=L/(t-t.sub.o) (3)
where V is the wave velocity, L is the travel distance, .DELTA.t is
the net travel time, t is the total travel time, t.sub.o is the
system delay.
4. Results and Analyses
[0157] This section presents and analyzes the results from various
tests conducted for the three batches of samples. It is noted that
only elastic moduli and thermal properties were measured for SL
samples as this batch was later incubated for an additional four
weeks (as identified as SPL) for further testing.
[0158] i. Sample Description and Failure Modes
[0159] FIGS. 8a, b and c present images of three representative
samples (e.g. SPL 12, SPL 17 and SPL 21) after unconfined
compression test to show the appearance of the biofoam and
illustrate the failure modes of the biofoam under compression. SPL
12 was densely packed without natural fiber, SPL 21 was densely
packed with natural fiber visible on the sample, and SPL 17 was
loosely packed without natural fiber. One can observe from FIG. 8
that the biodegradable insulation material samples have a chitinous
skin formed around all the samples due to the polycarbonate molds
which constrained the mycelium growth in the radial direction and
stimulated the generation of the outer skin when expanding biomass
of mycelium came in contact with molds and formed a fairly strong
protection layer on the circumferential surface of the sample. The
skin was white when the sample was live and became off-white to
beige when the sample was dried in the oven. Such skin did not
exist on the top and bottom surfaces of the samples as it was in
contact with air during the incubating process. The substrate
materials such as sawdust and natural fiber are still visible on
the top and bottom of sample surfaces or when the material is cut
or cracked.
[0160] In general, shear failure was observed for densely packed
samples without natural fiber, as shown in FIG. 8a for SPL12, and
bulging for loosely packed samples, as evidenced in FIG. 8b for SPL
17. When natural fibers are present, the samples all failed in
bulging, regardless of the packing condition, as evidenced in FIG.
8c for SPL 21. One can note that the natural fiber prevented or
minimized the surface cracking on the samples during unconfined
compressive test. This is important as it would be more difficult
for water to seep into the samples under loading. It is also
visible from FIG. 8 that loosely packed samples (e.g. SPL 17)
experienced substantially more plastic strain than densely packed
samples after compression test, as the residual height for SPL 17
was noticeably shorter than the other two samples when their
original height was about the same.
[0161] ii. Elastic Moduli
[0162] The elastic moduli including Young's and shear modulus are
basic mechanical properties for evaluating elastic deformation for
engineering materials. FIGS. 9, 10 and 11 present Young's and shear
moduli in vertical direction for SP, SL and SPL batches of samples.
In general Young's modulus for all groups of samples are much
higher than shear modulus. The packing condition has obvious impact
on the stiffness, with the dense sample exhibiting higher stiffness
than loose samples given the same mixing protocol and this impact
can also be observed for other physical and mechanical properties
presented throughout this study.
[0163] One can observe from FIGS. 9-11 that Young's moduli for SP
samples are the largest with a peak value of 74 MPa occurring for
G3, and those for SL batch samples are the smallest with a peak
value of 15 MPa occurring for G3. The largest shear modulus occurs
in G3 of SP batch with a peak value of 20 MPa and the smallest
shear modulus occurs in SL batch as well. It is easy to observe
that shear modulus for G3 samples in SPL batch are substantially
smaller than those in SP batch. Comparing FIGS. 9 and 10, one can
easily see that the elastic moduli of live samples are
substantially smaller than dried samples with the same blend and
packing condition. Comparing FIGS. 9 and 11, additional four weeks'
incubation time has mixed impact on Young's modulus and mostly
negative impact on shear modulus.
[0164] iii. Anisotropy of Elastic Moduli
[0165] The elastic moduli was also measured in the horizontal
direction with BE and PDE methods. FIGS. 12 and 13 present the
elastic moduli in horizontal direction in relation to those in
vertical direction for SP and SPL samples, respectively. It is
surprising to find that Young's and shear moduli in horizontal
direction for all samples in SP and SPL batches is much higher than
those in vertical direction. The linear regression equations for SP
and SPL samples are presented in FIGS. 12 and 13. Specifically,
Young's modulus in horizontal direction EH is about 1.8 to 2.1
times of that in vertical direction, and shear modulus in
horizontal direction is about 1.2-1.6 times of that in vertical
direction. This strong elastic modulus anisotropy is likely caused
by the strong protection skin formed on the circumferential surface
of the sample.
[0166] iv. Stress-Strain Relationship and Compressive Strength
[0167] Samples in the same groups of SP and SPL batches exhibit
similar stress-strain relationships in the unconfined compression
test. For example, FIG. 14 shows stress-strain relationships for
G1-G6 samples of SPL batch. In general, like for soil materials,
the stress-strain curve exhibits strain-softening behavior for
densely packed samples such as SPL02 and SPL12, and
strain-hardening behavior for loosely packed samples such as SPL08
and SPL17. For the samples with natural fiber included in the
substrate such as SPL 21 and SPL26, the stress-strain relationships
exhibit strain-hardening behavior regardless of the packing
condition, as the natural fiber serve to reinforce the
biodegradable insulation material and prevent shear failure from
occurring.
[0168] The compressive strength can be obtained from the
stress-strain relationships for each sample. It is defined as the
peak stress when a peak occurs in the stress-strain relationship
(strain-softening behavior), or the stress at 15% failure strain
when no peak occurs in the stress-strain relationship
(strain-hardening behavior). FIG. 15 presents the compressive
strength of SP and SPL samples. The compressive strengths for G3
samples are substantially larger than other groups in both SP and
SPL batches. One can also observe a substantial increase in the
compressive strength when the incubation time increases from two
weeks to six weeks.
[0169] v. Thermal Conductivity
[0170] FIG. 16 presents the thermal conductivity of SP, SL and SPL
samples. The thermal conductivity values of live samples (SL
samples) are in a range of 0.13 to 0.40 W/(mK), and those of dried
samples (SP and SPL samples) fall in a much smaller range, i.e.
0.05 to 0.07 W/(mK). The large value and variation in thermal
conductivity of live samples are due to high moisture content and
varying packing condition of the different blends. The variation of
thermal conductivity is still visible but much smaller for dried
samples. This substantial drop in thermal conductivity for dried
samples is expected and is due to the fact that the varying amount
of moisture existing in the substrates and mycelium of live samples
is replaced with low-thermal-conductivity air during the drying
process.
5. Discussion
[0171] To allow further examination of the characteristics of
different groups of blends, the physical, thermal and mechanical
properties such as dry density, shear and Young's moduli,
compressive strength, and thermal conductivity of samples in each
group were averaged and presented in FIG. 17. Higher values for
shear and Young's moduli indicate less elastic deformation and
better handling performance during installation, while higher
compressive strength suggests less chance of damage when large load
is applied. Lower thermal conductivity is desirable for thermal
insulation materials. FIG. 17 shows that the average dry density of
densely packed samples is in a range of 240.about.265 kg/m3 for SP
samples, and 230.about.280 kg/m.sup.3 for SPL samples. The average
dry density of loosely packed samples is in a range of
165.about.195 kg/m.sup.3 for SP samples, and 160.about.280
kg/m.sup.3 for the SPL samples. The dry density of loosely packed
samples with natural fiber is considerably lower than those without
natural fiber. The impact of additional incubation time on density
is mixed with slight increase observed for G1, G3 and G4 samples
and slight decrease observed for G2, G5 and G6 samples.
TABLE-US-00002 TABLE 2 Physical, thermal and mechanical properties
of mycelium-based biofoam Shear Young's Compressive Thermal Density
modulus modulus strength conductivity Group (kg/m.sup.3) (MPa)
(MPa) (kPa) (W/(m K)) SP 1 252.71 5.10 16.55 97.20 0.054 2 194.13
3.20 5.39 29.50 0.050 3 265.63 19.20 58.63 346.70 0.057 4 195.72
9.93 34.62 172.10 0.051 5 244.43 6.93 15.15 190.80 0.059 6 165.69
4.50 7.25 68.70 0.049 SPL 1 257.98 6.30 31.31 206.41 0.057 2 185.79
2.84 8.82 75.09 0.052 3 283.25 10.70 51.72 567.56 0.066 4 213.04
4.55 22.48 269.86 0.056 5 231.97 6.84 32.45 249.00 0.059 6 159.24
3.22 12.57 100.35 0.052
[0172] One can observe from FIG. 17 that the thermal conductivity
of SPL samples is only slightly larger than SP samples, even if the
SPL samples were incubated for an additional four weeks. It is
quite clear from FIG. 17 that the impact of incubation time on
shear modulus is mostly negative except for G1, which sees only
slight increase, and mixed on Young's modulus with G3 and G4
samples experiencing decrease and the rest experiencing increase.
The shear modulus of G3 samples decreases from 19 MPa to 11 MPa, or
40%. This decrease is very likely due to further fungal digestion
of granular substrates such as millet grain and gypsum, which
otherwise contributed to the shear stiffness in the earlier stage
of mycelium growth. However, the compressive strength for all
groups see appreciative gains with increasing incubation time, with
the largest absolute value increase occurring for G3 samples, from
350 kPa to 570 kPa, or over 60%. This is very likely due to the
growth of mycelium that serves as a random matrix binding together
the substrate. In summary, densely packed samples following Mixing
Protocol II have the highest dry density, shear and Young's moduli,
compressive strength, and comparable thermal conductivity.
[0173] As mentioned before, Mixing Protocol III (i.e. samples in G5
and G6) is the same as Mixing Protocol I (i.e. samples in G1 and
G2) but with natural fiber added. Comparing the properties of G1
with G5, or G2 with G6 of the same packing condition in either SP
or SPL batch, it is interesting to observe that the addition of
natural fiber clearly increased the shear modulus and compressive
strength, while having mixed impact on the Young's modulus, even
when addition of natural fiber decreased the density of samples.
The natural fiber plays a positive role in the mycelium-based
biodegradable insulation material as it helped increase the shear
stiffness, changed the failure mode from potential shear failure to
bulging for dense samples, and prevented or reduced occurring of
surface cracks.
[0174] The properties of these biodegradable insulation materials
can be compared to the properties of Insulfoam (ARCAT, Inc., 2012),
an expanded polystyrene foam, widely used as insulation material in
the building and infrastructure construction industry, particularly
in cold regions. The density of Insulfoam is in a range of 16 to 48
kg/m3, its thermal conductivity in a range of 0.03 to 0.04 W/(mK),
and its compressive strength in a range of 69 to 400 kPa. The
compressive strength of mycelium-based biodegradable insulation
material meets or exceeds that of Insulfoam products and the
thermal conductivity is slightly higher. The density is
considerably higher than Insulfoam and can be improved by
techniques including the scaffold technique for practical
applications.
6. Conclusions
[0175] This Example shows a fungal mycelium-based biodegradable
insulation material, attributes of the same as well as methods of
making the same. Three different mixing protocols with various
substrate materials including wood pulp, millet grain, wheat bran,
natural fiber and calcium sulfate, and two packing conditions were
experimented to produce three batches of samples for physical,
thermal, and mechanical property characterization. Dry density,
thermal conductivity, elastic moduli including shear and Young's
moduli, and compressive strength were obtained. Based on the
findings from this study the following conclusions can be drawn: 1)
The biodegradable insulation materials are relatively light-weight;
2) Results show that densely packed samples following Mixing
Protocol II, i.e. G3 samples, have the highest dry density, shear
and Young's moduli, and compressive strength; 3) The dried
biodegradable insulation materials demonstrate good thermal
conductivity, which falls in a range of 0.05 to 0.07 W/(mK). Live
samples possess higher conductivity due to existence of relatively
high moisture content; 4) These biodegradable insulation materials
exhibit fairly good shear and Young's moduli when it is dried.
However, the live sample exhibits much lower elastic moduli; 5)
These biodegradable insulation materials exhibit strong elastic
anisotropy, with a Young's modulus in horizontal direction 1.8 to
2.1 times that in vertical direction, and a shear modulus in
horizontal direction 1.2-1.6 times that in vertical direction. This
strong elastic anisotropy can be attributed to a strong protection
skin formed on the circumferential surface of samples; 6) These
biodegradable insulation materials demonstrates excellent
compressive strength with an average value of 350 kPa to 570 kPa
for G3 samples; 7) The incubation time has small impact on the dry
density and thermal conductivity, mixed impact on Young's modulus,
negative impact on the shear modulus, but clear positive impact on
the compressive strength; 8) The addition of natural fiber helps
improve the shear modulus and compressive strength, and change the
failure mode of densely packed samples from shear failure to
bulging, and prevent or minimize the occurrence of surface cracks
during compression test; and 9) These biodegradable insulation
materials have met or exceeded like characteristics of the
conventional polymeric thermal foams except dry density.
[0176] Those skilled in the art will recognize, or be able to
ascertain using no more than routine experimentation, many
equivalents to the specific embodiments of the method and
compositions described herein. Such equivalents are intended to be
encompassed by the following claims.
REFERENCES
[0177] Alaska Climate Research Center, U. o. A. F. (2014), Alaska
2014 Statewide Climate Summary, edited, University of Alaska
Fairbanks, University of Alaska Fairbanks. [0178] Holt, G. A., G.
McIntyre, D. Flagg, E. Bayer, J. D. Wanjura, and M. G. Pelletier
(2012), Fungal Mycelium and Cotton Plant Materials in the
Manufacture of Biodegradable Molded Packaging Material: Evaluation
Study of Select Blends of Cotton Byproducts, Journal of Biobased
Materials and Bioenergy, 6(4), 431-439. [0179] Huang Y C, Tsuang W.
Health effects associated with faulty application of spray
polyurethane foam in residential homes. Environ Res. 2014 October;
134:295-300. [0180] Pan, H., W. Wang, Y. Pan, L. Song, Y. Hu, and
K. M. Liew (2015), Formation of self-extinguishing flame retardant
biobased coating on cotton fabrics via Layer-by-Layer assembly of
chitin derivatives, Carbohydrate polymers, 115, 516-524. [0181]
Travaglini, S. N., J. Ross, P. G (2013), Mycology matrix
composites, 8th Annual Technical Conference of the American Society
for Composites. [0182] Gareis, M. 2006. Diagnostic cell culture
assay (MTT-test) for the detection of cytotoxic contaminants and
residues (in German). Journal Consumer Protection and Food Safety
(J. fur Verbraucherschutz and Lebensmittelsicherheit) 1: 354-363.
[0183] Johanning, E., M. Gareis, C. S. Yang, E. L. Hintikka, M.
Nikulin, B. Jarvis, and R. Dietrich. 1998. Toxicity screening of
materials from buildings with fungal indoor air quality problems
(Stachybotrys chartarum). Mycotoxin Research 14: 60-73. [0184]
Hanelt, M., Gareis, M., and Kollarczik, B. (1995) Cytotoxicity
evaluation of mycotoxins evaluated by the MTT cell culture assay.
Mycopathologia, 128, 167-174. [0185] Zhang H, Kuo Y Y, Gerecke A C,
Wang J. Co-release of hexabromocyclododecane (HBCD) and Nano- and
microparticles from thermal cutting of polystyrene foams. Environ
Sci Technol. 2012 Oct. 16; 46(20):10990-6. [0186] ARCAT, Inc.
Insulfoam Specifications, Section 07210, EPS Building Insulation.
www.insulfoam.com/specifications. Last accessed Sep. 16, 2015.
[0187] G. M. Eben Bayer, Method for producing rapidly renewable
chitinous material using fungal fruiting bodies and product made
thereby, in The United States Patent and Trademark Office, edited
by T. U.S.P.a.T. Office, US, 2011. [0188] A. Bandyopadhyay, G. C.
Basak, Studies on photocatalytic degradation of polystyrene,
Materials Science and Technology, 23(3) (2007) 307-314. [0189] T.
Hofer, Marine pollution: new research, in Marine pollution: new
research, edited, p. 59, Nova Science Publishers, New York, 2008.
[0190] S. Travaglini, J. Noble, P. G. Ross, C. K. H. Dharan,
Mycology matrix composites. Proc. 28th Annual Technical Conference
of the American Society for Composites. 1 (2013) 517-535. [0191] Y.
H. Arifin, Y. Yusuf, Mycelium fibers as new resource for
environmental sustainability." procedia engineering: Malaysian
Technical Universities Conference on Engineering & Technology.
53 (2013) 504-508. [0192] G. A. Holt, G. McIntyre, D. Glagg, J. D.
Wanjura, M. G. Pelletier, fungal mycelium and cotton plant
materials in the manufacture of biodegradable molded packaging
material: evaluation study of select blends of cotton byproducts,
Journal of Biobased Materials and Bioenergy, 6 (2012) 431-439.
[0193] M. G. Pelletier, G. A. Hol, J. D. Wanjura, E. Bayer, G.
McIntyre, An evaluation study of mycelium based acoustic absorbers
grown on agricultural by-product substrates." Industrial Crops and
Products, 51 (2013) 480-485. [0194] S. Travaglini, C. Dharan, P. G.
Ross, Mycology matrix composites. Proc. 29th Technical Conference
of the American Society for Composites, 2014. [0195] Decagon
Devices, Inc., Operator's Manual for KD2 Pro Thermal Properties
Analyzer, Pullman Wash., 2015. [0196] ASTM D5334-14, Standard Test
Method for Determination of Thermal Conductivity of Soil and Soft
Rock by Thermal Needle Probe Procedure, ASTM International, West
Conshohocken, Pa., www.astm.org, 2014. [0197] ASTM D2166-13,
Standard Test Method for Unconfined Compressive Strength of
Cohesive Soil, ASTM International, West Conshohocken, Pa.
www.astm.org, 2013. [0198] D. J. Shirley, A. L. Anderson, Acoustic
and engineering properties of sediments. Report ARL-T R-75-58.
Applied Research Laboratory, University of Texas, Austin, 1975.
[0199] P. De Alba, K. Baldwin, V. Janoo, G. Roe, B. Celikkol,
Elastic-Wave Velocities and Liquefaction Potential. Geotechnical
Testing Journal, ASTM, 7(2) (1984) 77-88. [0200] R. Dyvik, C.
Madshus, Lab measurements of G. using bender element, Proc., ASCE
Convention on Advances in the Art of Testing Soils under Cyclic
Conditions, (1985) 186-196. [0201] J. S. Lee, J. Carlos
Santamarina, Bender elements: performance and signal
interpretation, Journal of Geotechnical and Geoenvironmental
Engineering, 131 (9) (2005) 1063-1070. [0202] E. C. Leong, S. H.
Yeo, H. Rahardjo, Measuring shear wave velocity using bender
elements. Geotechnical Testing Journal, 28(5) (2005) 1-11. [0203]
E. Eseller-Bayat, S. Gokyer, M. K. Yegian, R. O. Deniz, A.
Alshawabkeh, Bender elements and bending disks for measurement of
shear and compression wave velocities in large fully and partially
saturated sand specimens. Geotechnical Testing Journal, 36(2)
(2013) 1-8. [0204] Veronica M. Padula, Sydney Stewart, and Douglas
Causey. The impacts of plastic on western Aleutian Islands
seabirds: detection of phthalates in muscle and embryonic tissues.
Proceedings of the 16th Alaska Bird Conference, Juneau, A K, USA;
2014. [0205] K. V. Harish Prashanth and R. N. Tharanathan.
Chitin/chitosan: modifications and their unlimited application
potential--an overview. Trends in Food Science & Technology. 18
(2007) 117-131. [0206] Shirley and Anderson 1975; De Alba et al.
1984; Dyvik and Madshus 1985; Lee and Santamarina 2005; Leong et
al. 2005; Eseller-Bayat et al. 2013
* * * * *
References