CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority of U.S. Provisional Patent Applications 63/350,395, filed 8 June 2022; 63/399,577, filed 19 August 2022; and 63/427,698, filed 23 November 2022. Each of the above-referenced applications is incorporated herein by reference in its entirety.

FIELD

This disclosure relates generally to methods for making textile materials, and particularly to methods of forming a textile material by gel casting.

BACKGROUND

Methods for making leather analog materials or other composite textile materials from non-animal-derived biomaterials (e.g., size-reduced particles of filamentous fungal biomats) have recently received significant interest and investment. Conventionally, such materials have been formed by one of two methods: (1) wet-laying of biomaterial-containing films, whereby a dilute (2 to 4 wt%) mixture of biomass and other components in a liquid medium (usually all or mostly water) are cast onto a filter that allows the liquid medium to drain away, or (2) slurry casting/doctor blading methods, whereby a slurry having a somewhat higher solids content (18 to 24 wt%) is cast onto a sheet and a blade is used to spread the viscous mixture into a cohesive film. However, both conventional methods suffer from major disadvantages: in the practice of wet-laying methods, it can be difficult both to control the content of plasticizers and other water-soluble components (because these drain through the filter together with the liquid medium) and to add large quantities of high- molecular weight components such as polymers (because these can clog the filter and impede draining of the liquid medium), whereas slurry casting/doctor blading methods also have limited capacity for high-molecular weight additives (because these tend to render the slurries too viscous to effectively spread) and are often ineffective for forming materials with a flat or smooth surface and/or a uniform thickness due to the rheology of the slurry.

There is thus a need in the art for methods of making biocomposite materials from particulate non-animal-derived biomaterials that allow for increased use of water-soluble and/or high-molecular weight components, as well as improved uniformity of surface texture and thickness. SUMMARY

In an aspect of the present disclosure, a method for producing a biocomposite material comprises (a) depositing a fluid mixture comprising a carrier fluid, biomass, and a gelling agent, wherein the biomass comprises a fraction that is at most slightly soluble in the carrier fluid, into a desired spatial configuration; (c) triggering gelation of the fluid mixture to form a biomass gel; and (d) removing at least a portion of the carrier fluid from the biomass gel to form the biocomposite material, wherein the carrier fluid makes up no more than about 95 wt%, no more than about 80 wt%, no more than about 65 wt%, or no more than about 50 wt% of the biocomposite material.

In embodiments, the method may further comprise depositing a second fluid mixture comprising a second carrier fluid, second biomass, and a second gelling agent, wherein the second biomass comprises a fraction that is at most slightly soluble in the second carrier fluid, into a second desired spatial configuration; triggering gelation of the second fluid mixture to form a second biomass gel; before step (c), layering the biomass gel and the second biomass gel in physical contact with each other; and removing at least a portion of the second carrier fluid from the second biomass gel, wherein the biocomposite material comprises first and second layers that are adhered to each other.

In embodiments, the biomass may comprise a fermented biomass.

In embodiments, the biomass may comprise fungal mycelium.

In embodiments, the biomass may comprise a microbial biomass. The biomass may, but need not, comprise a bacterial biomass.

In embodiments, the biomass may comprise a plant biomass.

In embodiments, the biomass may comprise an algal biomass.

In embodiments, a mass ratio of the biomass to the gelling agent in the fluid mixture may be about 1 :18 to about 18:1. The mass ratio of the biomass to the gelling agent in the fluid mixture may, but need not, be no more than about 10:3.

In embodiments, the fluid mixture may further comprise a filler. The filler may, but need not, be selected from the group consisting of microfibrillated cellulose, nanofibrillated cellulose, recycled fibers, recycled particles, polymeric fibers, polymeric particles, and combinations thereof.

In embodiments, step (a) may comprise casting the fluid mixture.

In embodiments, step (a) may comprise extruding or spraying the fluid mixture into a first desired spatial configuration. The method may, but need not, further comprise depositing a second mixture having a different composition than the fluid mixture into a second desired spatial configuration having a preselected spatial relationship with the first desired spatial configuration. Step (a) may, but need not, comprise extruding the fluid mixture onto a surface.

In embodiments, step (a) may comprise casting or patterning the fluid mixture by printing.

In embodiments, step (a) may comprise forming fibers of the fluid mixture by solution spinning. At least a portion of the carrier fluid may, but need not, gel during step (a). At least a portion of the carrier fluid may, but need not, evaporate from the fluid mixture during step (a).

In embodiments, the carrier fluid may be selected from the group consisting of water, one or more alcohols, and combinations thereof.

In embodiments, the fluid mixture may further comprise dispersed or emulsified compounds that are insoluble in the carrier fluid and become trapped in the biomass gel during step (b).

In embodiments, in step (a), the fluid mixture may be cast onto a substantially planar surface, z.e., to form a layer or sheet that is substantially “two-dimensional” in that its length and width are substantially greater than its thickness.

In embodiments, in step (a), the fluid mixture may be cast into or onto a cavity or mold. The cavity or mold may have any suitable three-dimensional shape (e.g., the shape of an article of manufacture intended to be made from the biocomposite material).

In embodiments, step (b) may be carried out by at least one of reducing a temperature of the fluid mixture, increasing a temperature of the fluid mixture, changing a pH of the fluid mixture, adding a metal ion to the fluid mixture, initiating polymerization of a monomer in the fluid mixture, and exposing the fluid mixture to a selected wavelength of electromagnetic radiation.

In embodiments, step (b) may be carried out by removing at least a portion of the carrier fluid.

In embodiments, the fluid mixture may remain fluid for about five seconds to about twelve hours after step (a).

In embodiments, between steps (a) and (b), the fluid mixture may self-level.

In embodiments, the method may further comprise, between steps (a) and (b), mechanically agitating the fluid mixture.

In embodiments, the gelling agent may comprise a polymer having a molecular weight of at least about 80,000 daltons. The polymer may, but need not, be a polysaccharide, a polypeptide, a protein, a starch, a block copolymer, a polyelectrolyte, or a vegetable gum. The polymer may, but need not, be a hydrocolloid selected from the group consisting of r- carrageenan, K-carrageenan, k-carrageenan, agar, starch, modified starch, xanthan, guar gum, locust bean gum, gum arabic, acacia gum, gum karaya, gum tragacanth, alginate, pectin, methyl cellulose, hydroxypropylmethyl cellulose, carboxymethyl cellulose, and combinations thereof.

In embodiments, the gelling agent may comprise one or more monomers. The gelling agent may, but need not, further comprise an initiator.

In embodiments, the gelling agent may comprise at least one of a colloid and a thixotropic agent.

In embodiments, the gelling agent may comprise an amphiphilic molecule.

In embodiments, the fluid mixture may further comprise at least one cation. The at least one cation may, but need not, comprise an organic cation, a metal cation, or both.

In embodiments, the fluid mixture may further comprise at least one plasticizer. The at least one plasticizer may, but need not, be insoluble, practically insoluble, very slightly soluble, or slightly soluble in the carrier fluid. The at least one plasticizer may, but need not, be sparingly soluble, soluble, freely soluble, or very soluble in the carrier fluid. The at least one plasticizer may, but need not, make up about 10 wt% to about 85 wt% of a total solids content of the biocomposite material.

In embodiments, the fluid mixture may further comprise one or more functionalizing compounds or crosslinking agents. The one or more functionalizing compounds or crosslinking agents may, but need not, comprise at least one of a carboxylic acid, an ester, an acid anhydride, an epoxide, amidoamine epichlorohydrin, a carbodiimide, a peptide, an oligopeptide, a polypeptide, a protein, and an enzyme, which may, but need not, comprise trans-glutaminase. The method may, but need not, further comprise covalently functionalizing or crosslinking at least one of the biomass and the gelling agent during or after step (c).

In embodiments, the fluid mixture may further comprise at least one non-gelling polymer. The at least one non-gelling polymer may, but need not, be soluble in the carrier fluid. The at least one non-gelling polymer may, but need not, comprise a polysaccharide. The at least one non-gelling polymer may, but need not, be partially soluble or insoluble in the carrier fluid; the at least one non-gelling polymer may, but need not, be selected from the group consisting of lignin, rubber (which may, but need not, be a natural latex rubber), and combinations thereof. In embodiments, step (c) may be carried out by freeze drying or critical point drying.

In embodiments, the biomass gel may be pinned during step (c). The biomass gel may, but need not, be pinned by compression. The biomass gel may, but need not, be pinned by uniaxial or biaxial tension.

In embodiments, during step (c), the biomass gel may be in contact with a release layer and an adhesive force between the biomass gel and the release layer may be strong enough to prevent delamination of the biomass gel, and, after step (c), an adhesive force between the biocomposite material and the release layer may be weak enough to allow the biocomposite material to be peeled away from the release layer. The release layer may, but need not, comprise a wax, polytetrafluoroethylene, polyethylene, polypropylene, silicone, or a combination thereof.

In embodiments, the biocomposite material may be uniaxially or biaxially stretched after step (c). The biocomposite material may, but need not, be heated while being uniaxially or biaxially stretched.

In embodiments, the method may further comprise embossing the biomass gel. The embossing step may, but need not, be carried out simultaneously with step (c). Step (c) may, but need not, begin before the embossing step.

In embodiments, the method may further comprise introducing at least one gas into the fluid mixture before step (a). After the introducing step, the fluid mixture may, but need not, be a foam. The at least one gas may, but need not ,be selected from the group consisting of air, carbon dioxide, nitrogen, and combinations thereof.

In embodiments, the method may further comprise introducing a foaming agent into the fluid mixture. The foaming agent may, but need not, be a surfactant and the method may further comprise introducing at least one gas into the fluid mixture; the at least one gas may, but need not, be selected from the group consisting of air, carbon dioxide, nitrogen, and combinations thereof, and the surfactant may, but need not, be introduced in an amount from about 0.1 wt% to about 4 wt% of the fluid mixture. The foaming agent may, but need not, be a blowing agent, which may, but need not, be selected from the group consisting of bicarbonate salts, compressed gases, hydride salts, and combinations thereof.

In embodiments, step (c) may be carried out by heating the biomass gel, applying a negative pressure to the biomass gel, radiofrequency irradiation of the biomass gel, microwave irradiation of the biomass gel, or a combination thereof. In embodiments, a rate at which the carrier fluid is removed from the biomass gel during step (c) may be controlled, optimized, selected, or tuned to provide a preselected porosity to the biocomposite material.

In embodiments, step (a) may comprise casting the fluid mixture onto a temperature- controlled surface. The method may, but need not, further comprise controlling a spatial temperature gradient of the temperature-controlled surface. During step (a), at least a portion of the temperature-controlled surface may, but need not, be cooled to a temperature below the freezing point of the carrier fluid. The fluid mixture may, but need not, further comprise a liquid additive and, during step (a), at least a portion of the temperature-controlled surface may, but need not, be cooled to a temperature below the freezing point of the liquid additive to cause the liquid additive to freeze and form a frozen additive; the liquid additive may, but need not, be immiscible with, insoluble in, practically insoluble in, very slightly soluble in, or slightly soluble in the carrier fluid and the method may, but need not, further comprise, after step (a), removing at least a portion of the frozen additive.

In embodiments, step (a) may comprise depositing the fluid mixture in physical contact with a backing material. The backing material may, but need not, be a woven material (e.g. , a planar woven mesh), which may, but need not, comprise cotton (which may, but need not, be selected from the group consisting of cotton cheesecloth, muslin, and combinations thereof) and may, but need not, comprise nylon. The backing material may, but need not, be selected from the group consisting of a foam material, a non-woven fabric, a knitted fabric, and combinations thereof. The backing material may, but need not, comprise a cellulosic fabric.

In another aspect of the present disclosure, a biocomposite material comprises about 0.01 wt% to about 95 wt%, about 0.01 wt% to about 80 wt%, about 0.01 wt% to about 65 wt%, or about 0.01 wt% to about 50 wt% of a carrier fluid; biomass, wherein the biomass is at most slightly soluble in the carrier fluid; and at least one gelling agent, wherein the biocomposite material has a tensile strength of at least about 3 MPa.

In embodiments, the biocomposite material may further comprise at least one additive selected from the group consisting of fillers, functionalizing compounds, crosslinkers, polymers, sizing agents, hydrophobing agents, plasticizers, pigments, dyes, antifoaming agents, defoaming agents, flocculants, deflocculants, antimicrobial agents, antistatic agents, UV stabilizers, surface modifiers, foaming agents, blowing agents, and flame retardants. The at least one additive may, but need not, comprise a functionalizing compound or crosslinker, wherein the functionalizing agent or crosslinker is a carboxylic acid, an ester, an acid anhydride, or an epoxide. The at least one additive may, but need not, comprise a deep eutectic solvent. The at least one additive may, but need not, comprise a surface modifier selected from the group consisting of a texture modifier, a slip agent, a non-slip agent, a matting agent, and a gloss agent.

In embodiments, the at least one gelling agent may comprise a polymer, and the polymer may make up between about 1 wt% and about 90 wt% of the biocomposite material. The polymer may, but need not, be a polysaccharide, a polypeptide, a protein, a starch, a block copolymer, a polyelectrolyte, or a vegetable gum. The polymer may, but need not, be a hydrocolloid selected from the group consisting of i-carrageenan, K-carrageenan, - carrageenan, agar, starch, modified starch, xanthan, guar gum, locust bean gum, gum arabic, acacia gum, gum karaya, gum tragacanth, alginate, pectin, methyl cellulose, hydroxypropylmethyl cellulose, carboxymethyl cellulose, and combinations thereof. The at least one gelling agent may, but need not, further comprise at least one hydrophobic modifier covalently bonded to the polymer. The at least one hydrophobic modifier may, but need not, be non-covalently bonded to the polymer, and may, but need not, be bonded to the polymer by electrostatic interactions. The at least one gelling agent may, but need not, further comprise at least one cation with which the polymer is complexed; the at least one cation may, but need not, comprise an organic cation, a metal cation, or both, and may, but need not, crosslink a first portion of the polymer to at least one of a second portion of the polymer and a polymeric constituent of the biomass. The polymer may, but need not, have a molecular weight of at least about 80,000 daltons.

In embodiments, the at least one gelling agent may comprise one or more monomers. The at least one gelling agent may, but need not, further comprise an initiator.

In embodiments, the gelling agent may comprise a colloid or a thixotropic agent.

In embodiments, the gelling agent may comprise an amphiphilic molecule.

In embodiments, the gelling agent may be a peptide or an oligopeptide.

In embodiments, the biocomposite material may further comprise at least one of a plasticizer, a filler, and a crosslinking agent.

In embodiments, the biocomposite material may comprise a plasticizer, wherein the plasticizer makes up about 10 wt% to about 85 wt% of a total solids content of the biocomposite material.

In embodiments, a mass ratio of the gelling agent to the biomass may be at least about 0.3. In embodiments, the biocomposite material may further comprise a backing material. The backing material may, but need not, comprise a woven material (e.g., a planar woven mesh), which may, but need not, comprise cotton (which may, but need not, be selected from the group consisting of cotton cheesecloth, muslin, and combinations thereof) and may, but need not, comprise nylon. The backing material may, but need not, comprise a non-woven fabric, a knitted fabric, or both. The backing material may, but need not, comprise a cellulosic fabric.

In another aspect of the present disclosure, a biocomposite gel comprises a carrier fluid; biomass, wherein the biomass is at most slightly soluble in the carrier fluid; and at least one gelling agent.

In embodiments, the biocomposite gel may comprise first and second polymer networks, wherein the first polymer network comprises a gelling polymer. The first and second polymer networks may, but need not, interpenetrate each other. The second polymer network may, but need not, comprise a gelling polymer. The second polymer network may, but need not, comprise a non-gelling polymer.

In embodiments, a mass ratio of the gelling agent to the biomass may be at least about 0.3.

In embodiments, the biocomposite gel may further comprise a backing material. The backing material may, but need not, comprise a woven material (e.g. , a planar woven mesh), which may, but need not, comprise cotton (which may, but need not, be selected from the group consisting of cotton cheesecloth, muslin, and combinations thereof), and may, but need not, comprise nylon.

While specific embodiments and applications have been illustrated and described, the present disclosure is not limited to the precise configuration and components described herein. Various modifications, changes, and variations which will be apparent to those skilled in the art may be made in the arrangement, operation, and details of the methods and systems disclosed herein without departing from the spirit and scope of the overall disclosure.

As used herein, unless otherwise specified, the terms “about,” “approximately,” etc., when used in relation to numerical limitations or ranges, mean that the recited limitation or range may vary by up to 10%. By way of non-limiting example, “about 750” can mean as little as 675 or as much as 825, or any value therebetween. When used in relation to ratios or relationships between two or more numerical limitations or ranges, the terms “about,” “approximately,” etc. mean that each of the limitations or ranges may vary by up to 10%; by way of non-limiting example, a statement that two quantities are “approximately equal” can mean that a ratio between the two quantities is as little as 0.9: 1.1 or as much as 1.1 :0.9 (or any value therebetween), and a statement that a four-way ratio is “about 5:3: 1 : 1” can mean that the first number in the ratio can be any value of at least 4.5 and no more than 5.5, the second number in the ratio can be any value of at least 2.7 and no more than 3.3, and so on.

The embodiments and configurations described herein are neither complete nor exhaustive. As will be appreciated, other embodiments are possible utilizing, alone or in combination, one or more of the features set forth above or described in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 illustrates a biocomposite material comprising filamentous fungal biomass made by a gel casting method five minutes after casting, according to embodiments of the present disclosure.

Figure 2 illustrates biocomposite materials comprising filamentous fungal biomass during a drying step of a gel casting method, according to embodiments of the present disclosure.

Figures 3A and 3B are graphs of the tensile strength and elongation at break, respectively, of cellulose fiber-loaded gel casting sheets, according to embodiments of the present disclosure.

Figures 4A and 4B are graphs of the tensile strength and elongation at break, respectively, of gel casting sheets containing epoxidized soybean oil, according to embodiments of the present disclosure.

Figure 5 is an illustration of brittle, poorly cohesive gel casting sheets containing i- carrageenan, according to embodiments of the present disclosure.

Figures 6A and 6B are optical microscopy images of a cotton cheesecloth backing, according to embodiments of the present disclosure.

Figures 6C and 6D are optical microscopy images of a muslin backing, according to embodiments of the present disclosure.

Figure 6E is an optical microscopy image of a nylon backing, according to embodiments of the present disclosure.

Figures 7A and 7B are graphs of the relationship between tensile strength (Figure 7 A) or tensile modulus (Figure 7B) and a fungal biomass/gelling agent mass ratio, according to embodiments of the present disclosure. Figures 8 A and 8B are illustrations of foamed and unfoamed gel casting sheets, respectively, according to embodiments of the present disclosure.

DETAILED DESCRIPTION

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of ordinary skill in the art. All patents, applications, published applications, and other publications to which reference is made herein are incorporated by reference in their entirety. If there is a plurality of definitions for a term herein, the definition provided in the Summary prevails unless otherwise stated.

As used herein, unless otherwise specified, the term “aqueous” refers to any mixture or solution that includes water. It is to be expressly understood, therefore, that in an “aqueous” solution as that term is used herein, water may be the only solute, one of two or more solutes, the only solvent, or one of two or more solvents.

As used herein, unless otherwise specified, the term “backing material” or “backing layer” refers to a material, or a layer of material, that is added to a composite article to impart one or more desired mechanical and/or structural characteristics (e.g., improved tensile modulus, improved strain at break, increased rigidity/stiffness, etc.). It is to be expressly understood that a backing material or backing layer, as those terms are used herein, need not be disposed on a “back” (i.e., rear, anterior) aspect of a composite article but may be disposed on any exterior aspect (front, back, top, bottom, sides, etc.) or within an interior of the article (e.g., distributed throughout the article, “sandwiched” between layers of other material(s), etc.).

As used herein, unless otherwise specified, the term “biodegradable” refers to a material that, under a given set of conditions (e.g., the conditions specified in ISO 20136:2017, “Leather — determination of degradability by micro-organisms”), biodegrades at least 10% more quickly than “true” (i.e. animal) leather.

As used herein, unless otherwise specified, the term “biomass” refers to a mass of a living or formerly living organism, including microbial and plant biomass. Microbial biomass sources can include bacterial, fungal (including higher fungi) and microalgal biomass sources. Plant biomass sources can include any source of plant-based biopolymers such as celhdose, lignin and pectin. By way of non-limiting example, the phrase “filamentous fungal biomass” as used herein refers to a mass of a living or formerly living filamentous fungus. Filamentous fungal biomasses may include biomats (as that term is used herein), as well as filamentous fungus produced by submerged fermentation, such as (but not limited to) a mycoprotein paste as described in U.S. Patent 7,635,492 to Finnigan et al. and/or a filamentous fungal biomass described (or produced by the methods described) in U.S. Patent 11,058,137 to Pattillo, or filamentous fungus produced by solid substrate fermentation.

As used herein, unless otherwise specified, the term “biomat” refers to a cohesive mass of filamentous fungal tissue comprising a network of interwoven hyphae filaments. Biomats as that term is used herein may, but need not, be characterized by one or more of a density of between about 50 and about 200 grams per liter, a solids content of between about 5 wt% and about 20 wt%, and sufficient tensile strength to be lifted substantially intact from the surface of a growth substrate (e.g., a liquid growth medium, a solid fungal composite, or a solid membrane or mesh). Biomats, as that term is used herein, may be produced by any one or more fungal fermentation methods known in the art, such as, by way of nonlimiting example, methods described in PCT Application Publications 2020/176758, 2019/099474, and 2018/014004.

As used herein, unless otherwise specified, the term “biomaterial” refers to any tissue or other physical material derived from one or more living or formerly living organisms other than animals (e.g., filamentous fungi, plants, bacteria, algae, yeasts, etc.). “Biomaterials,” as that term is used herein, may be biomasses or portions thereof, but may also be materials that are directly or indirectly derived from the organism(s) (e.g., extracts, metabolites, etc.).

As used herein, unless otherwise specified, the term “cohesive” refers to any material that has sufficient structural integrity and tensile strength to be picked up and/or physically manipulated by hand as a solid object, without tearing or collapsing.

As used herein, unless otherwise specified, the term “colloid” refers to a mixture in which particles of one substance (the “dispersed phase”) are dispersed throughout a volume of a different substance (the “dispersion medium”); for example, the dispersed phase can comprise or consist of microscopic or macroscopic bubbles, particles, etc. Where the dispersed phase and the dispersion medium of a colloid are specifically identified herein, they are separated by a hyphen, with the dispersed phase identified first, e.g, a reference herein to an “oil-water colloid” refers to a colloid in which an oil is the dispersed phase and water is the dispersion medium.

As used herein, unless otherwise specified, the term “degree of swelling” refers to the relative amount of change in the mass of a solid item when the solid is saturated with a liquid. By way of non-limiting example, a solid item that has a mass of 200 g when dry and a mass of 300 g when saturated with water has a degree of swelling in water of 50%, or 0.5. Where the term “degree of swelling” is used herein without explicitly identifying a liquid, the liquid may be assumed to be water.

As used herein, unless otherwise specified, the term “deposit” means to cast, lay down, place, or put a deformable mass of material into a desired spatial configuration, such as by extrusion or other suitable techniques.

As used herein, unless otherwise specified, the term “durable” refers to a material that has at least one of a tear strength of at least about 5 N/mm, a tear force of at least about 5 N, and a tensile strength of at least about 1.5 MPa.

As used herein, unless otherwise specified, the term “emulsion” refers to a colloid in which both the dispersed phase and the dispersion medium are liquids. Examples of emulsions as that term is used herein include but are not limited to lotions, latex, and many biological membranes.

As used herein, unless otherwise specified, the term “filamentous fungus” refers to any multicellular fungus that is capable of forming an interconnected network of hyphae (vegetative hyphae or aerial hyphae, and most commonly both) known as “mycelium.” Examples of filamentous fungi as that term is used herein include, but are by no means limited to, fungi of the genera Acremonium, Ahernaria. Aspergillus, Cladosporium, Fusarium, Mucor, Penicillium, Rhizopus, Stachybotrys, Trichoderma, and Trichophyton, among many others, with specific examples including Fusarium strain flavolapis (ATCC Accession Deposit No. PTA-10698) and Fusarium venenatum. It is to be expressly understood that filamentous fungi, as that term is used herein, may be capable of forming other fungal structures, such as fruiting bodies, in addition to hyphae/mycelium.

As used herein, unless otherwise specified, the term “foam” refers to a colloid in which the dispersed phase is a gas, and the dispersion medium is a liquid. Examples of foams as that term is used herein include but are not limited to shaving cream, soap bubbles, and the “head” of a carbonated or nitrogenated beverage.

As used herein, unless otherwise specified, the terms “fungal mycelial matter” and “fungal mycelial biomass” are interchangeable and each refer to any material that includes at least about 50 wt% fungal mycelium on a dry basis (i.e., disregarding the mass of any water). More specifically, as used herein, unless otherwise specified, the term “consisting essentially of fungal mycelium” refers to any material that includes at least about 95 wt% fungal mycelium on a dry basis.

As used herein, unless otherwise specified, the term “gel” refers to a colloid in which the dispersed phase is a liquid, and the dispersion medium is a solid. Examples of gels as that term is used herein include but are not limited to agar, hair gel, and opal. Gels, as that term is used herein, may behave as solids or semi-solids and typically have a storage modulus greater than their loss modulus in the linear strain regime under dynamic deformation at frequencies of 0.1 Hz to 100 Hz, and thus do not readily flow.

As used herein, unless otherwise specified, the terms “hide leather” and “true leather” are interchangeable and each refer to a durable, flexible material created by tanning the hide or skin of an animal.

As used herein, unless otherwise specified, the term “inactivated” refers to a filamentous fungal biomass in which the fungal cells have been rendered nonviable (hereinafter referred to as “inactivation of viability”), or enzymes capable of degrading or causing biochemical transformations within the biomass have been deactivated (hereinafter referred to as “deactivation of enzymes”), or both. By extension, the term “inactivation” refers to any method or process by which a filamentous fungal biomass may be inactivated, such as, by way of non-limiting example, boiling, immersion in an organic liquid (e.g., an alcohol, peracetic acid, etc.), irradiation, pressure treatment, rinsing, size reduction, steaming, and temperature cycling.

As used herein, unless otherwise specified, the term “infiltration” refers to the permeation and/or saturation of a solution into a mass of solid, but permeable and/or porous, material, such that the solution or a portion thereof is distributed in the mass of solid material, such as, for example and without limitation, a polymer solution permeating the interstitial spaces in a fungal biomat comprised of mycelia. Without being bound by theory, the infiltration of a fungal mycelial biomass with a solution comprising components such as polymers and plasticizers, results in a textile material having such components distributed in the biomass after the solvent is removed by curing. Such a distribution can be substantially uniformly distributed or not uniformly distributed.

As used herein, unless otherwise specified, the term “liquid aerosol” refers to a colloid in which the dispersed phase is a liquid, and the dispersion medium is a gas.

As used herein, unless otherwise specified, the term “loading ratio” refers to a weight ratio of fungal biomass to polymer in a fungal textile composition.

As used herein, unless otherwise specified, the term “mass loss upon soaking” refers to the relative amount of mass lost by a solid item after soaking in a liquid, disregarding the mass of liquid absorbed by the solid item. By way of non-limiting example, a solid item that has a mass of 100 grams when dry and a mass (disregarding the mass of absorbed liquid) of 95 grams after soaking in water has a mass loss upon soaking in water of 5%. Where the term “mass loss upon soaking” is used herein without explicitly identifying a liquid, the liquid may be assumed to be water.

As used herein, unless otherwise specified, the term “particle” refers to a small, discrete, localized object to which can be ascribed chemical or physical properties such as volume, density, and/or mass. “Particles,” as that term is used herein, may be microscopic or macroscopic; may be in the gas (e.g., air bubbles), liquid (e.g., droplets of the dispersed phase in an emulsion), or solid (e.g., granules of a powder) phase; and may take any of a variety of shapes (e.g., spheres, oblate spheroids, fibers, tubes, rods, etc.). Particles in the solid phase may be referred to herein as “particulates” or “particulate matter.”

As used herein, unless otherwise specified, the term “sheet” refers to a layer of solid material having a generally flat or planar shape and a high ratio of surface area to thickness.

As used herein, unless otherwise specified, the term “sol” refers to a colloid in which the dispersed phase is a solid and the dispersion medium is a liquid. Examples of sols as that term is used herein include but are not limited to blood, mud, paint, and pigmented ink.

As used herein, unless otherwise specified, the term “solid aerosol” refers to a colloid in which the dispersed phase is a solid and the dispersion medium is a gas. Examples of solid aerosols as that term is used herein include smoke, ice clouds, and atmospheric particulates.

As used herein, unless otherwise specified, the term “solid foam” refers to a colloid in which the dispersed phase is a gas, and the dispersion medium is a solid. Examples of solid foams as that term is used herein include but are not limited to aerogel, pumice, and styrofoam.

As used herein, unless otherwise specified, the term “solid sol” refers to a colloid in which both the dispersed phase and the dispersion medium are solids. Examples of solid sols as that term is used herein include cranberry glass.

As used herein, unless otherwise specified, the term “tannin” refers generally to any molecule that forms strong bonds with protein structures, and more particularly to a molecule that, when applied to hide leather, bonds strongly to protein moieties within the collagen structures of the skin to improve the strength and degradation resistance of the leather. The most commonly used types of tannins are vegetable tannins, z.e., tannins extracted from trees and plants, and chromium tannins such as chromium(III) sulfate. Other examples of tannins as that term is used herein include modified naturally derived polymers, biopolymers, and salts of metals other than chromium, e.g., aluminum silicate (sodium aluminum silicate, potassium aluminum silicate, etc.). As used herein, unless otherwise specified, the term “water uptake” refers to the degree of swelling of a solid material when the solid material is saturated with water.

The present disclosure provides biocomposite materials having advantageous and beneficial properties, and methods for manufacturing biocomposite materials by gel casting. In general, the methods of the present disclosure comprise (a) casting (e.g., into a cavity/mold or onto a surface by extrusion) or otherwise depositing (e.g., by solution spinning) a fluid mixture comprising a carrier fluid, biomass, and a gelling agent, wherein the biomass comprises a fraction that is at most slightly soluble in the carrier fluid, into a desired spatial configuration, (b) triggering gelling of the fluid mixture to form a biomass gel, and (c) removing at least a portion of the carrier fluid of the fluid mixture from the biomass gel to form a biocomposite material. The fluid mixture may be produced, by way of non-limiting example, by size-reducing a cohesive biomass (e.g., a cohesive fungal mycelial biomass) by any suitable method, thoroughly blending, combining, and/or mixing the size-reduced biomass with the carrier fluid, and vacuum-degassing the mixture to remove entrapped gases.

When depositing or casting of the fluid mixture is done by extrusion, the mixture is fed into the feed section of an extruder. The temperature and screw speed of the extruder is set to ensure appropriate mixing of materials in the extruder barrel. Multiple feeders can used to tune the relative loading of each component during the extrusion process. A vacuum port may also be used after a mixing section of the screw to remove air bubbles before the material exits the extruder through the extruder die which can be in an appropriate shape to achieve the desired cross section of a material and which can be temperature-controlled. After mixing and degassing, the material exits the die at the end of the extruder in the form of a sheet or other desired shape and gels. The resulting monolithic gel is collected, and can be dehydrated and dried.

In embodiments of the methods disclosed herein, fluid mixtures having a total solids content that allows such mixtures to flow easily but to achieve thicknesses of the resulting biocomposite material that are comparable to existing conventional textiles and thus allow the biocomposite materials to be used as analogs for such conventional textiles (e.g., about 0.5 to about 1.5 mm in the case of leather analogs). Typically, such a solids content is intermediate between that of the mixtures used for wet-laid film methods (2 to 4 wt%) and that of the mixtures used for slurry casting/doctor blading (18 to 24 wt%) are provided; most typically, the solids content of the fluid mixtures used in embodiments disclosed herein is about 10 to about 14 wt%. The solids of the fluid mixtures used for the gel casting methods disclosed herein include at least non-animal biomass (e.g., by way of non-limiting example, particles of size-reduced cohesive fungal mycelial biomasses) and a gelling agent, but may include one or more additives, such as, by way of non-limiting example, plasticizers, polymers, crosslinkers (e.g., metal ions), and the like. These solid components are provided as a mixture with a carrier fluid to form the fluid mixture.

In many embodiments, biomasses used in methods according to the present disclosure are filamentous fungal biomasses — that is, biomasses of one or more fungi that produce an interconnected network of hyphae known as mycelium. Particularly, in many embodiments, the filamentous fungal biomass may be a fungal mycelial biomass as that term is defined herein (although other filamentous fungal biomasses, such as biomasses that contain a significant quantity of material derived from fruiting bodies of a filamentous fungus, are also contemplated and are within the scope of this disclosure). Most typically, the fungal mycelial biomasses used according to the present disclosure are particles derived (e.g., by size reduction) from cohesive fungal mycelial biomasses, i.e., mycelial biomasses that have sufficient structural integrity and tensile strength to be picked up and physically manipulated by hand without tearing or collapsing; non-limiting examples of cohesive fungal mycelial biomasses that may suitably be used to form fluid mixtures in embodiments of the present disclosure include fungal mycelial biomasses produced by a liquid surface fermentation process or membrane fermentation process as described in PCT Application Publication 2019/046480 (the entirety of which is incorporated herein by reference) and/or fungal mycelial biomasses produced by a solid-substrate fermentation process as described in, e.g., PCT Application Publication 2016/149002 (the entirety of which is incorporated herein by reference).

In embodiments of the methods disclosed herein, the biomass may include at least one fraction (e.g., carbohydrates and/or proteins) that is very soluble, freely soluble, soluble, or sparingly soluble in the carrier fluid (i.e., at least sparingly soluble in the carrier fluid) and at least a second fraction (e.g., lipids and/or other hydrophobic compounds) that is insoluble, practically insoluble, very slightly soluble, or slightly soluble in the carrier fluid (i.e., at most slightly soluble in the carrier fluid). In some such embodiments, the fluid mixture may be an emulsion in which at least a portion of the second fraction is emulsified and substantially uniformly distributed prior to gelling. Incorporation of hydrophobic insoluble components into the fluid mixture, and thus into the biomass gel and eventually the biocomposite material, may be desirable to make the finished biocomposite material resistant to fluid uptake (e.g., water-resistant where the biocomposite material is intended for use as a leather analog). In embodiments in which the biomass includes an insoluble, practically insoluble, very slightly soluble, or slightly soluble fraction, this fraction is generally present in amounts of about 20 to about 80 wt% of the biomass or any subrange between about 20 to about 80 wt% of the biomass.

Many different gelling agents, including, by way of non-limiting example, polysaccharides, polypeptides, proteins, starches, block copolymers, polyelectrolytes, and vegetable gums, may suitably be employed in the fluid mixtures of the methods disclosed herein. In some embodiments, the gelling agent may preferably comprise one or more polysaccharides, may more preferably comprise one or more carrageenans, may even more preferably comprise at least one of r-carrageenan, K-carrageenan, and k-carrageenan, and may most preferably comprise K-carrageenan. In many embodiments, the amount of the gelling agent is selected to be low enough to allow the mixture to flow upon heating but high enough to form a gel upon cooling (e.g., to room temperature); by way of non-limiting example, in embodiments in which the gelling agent is K-carrageenan, the amount of K- carrageenan may be about 10 to about 30 wt% of the total solids content of the fluid mixture or any subrange thereof, or alternatively about 2 to about 4 wt% of the overall fluid mixture or any subrange thereof. In some embodiments, the concentration of a single gelling agent and/or the relative amounts of two or more gelling agents (e.g., a polysaccharide and a metal cation) may be varied to achieve a desired characteristic of the gelling behavior of the fluid mixture; by way of non-limiting example, gelling may be slowed down or sped up depending on the gelling agents provided (e.g., the gelling agent(s) and concentration(s) thereof may be selected to provide for a gelling time under standard conditions of temperature and pressure of about five seconds to about twelve hours. The ratio of the biomass to the gelling agent can, in some embodiments, also be an important determinant of the combination of mechanical performance and aesthetic “look and feel” of the finished biocomposite material; most typically, a mass ratio of biomass to gelling agent, on a dry basis, in the fluid mixture is about 1 : 18 to about 18: 1 or any subrange of ratios between about 1 : 18 to about 18: 1. In other embodiments, the mass ratio of biomass to gelling agent is at least about 1 :18, at least about 1 : 17, at least about 1 : 16, at least about 1 : 15, at least about 1 : 14, at least about 1 : 13, at least about 1 : 12, at least about 1 : 11, at least about 1 : 10, at least about 1 :9, at least about 1 :8, at least about 1 :7, at least about 1 :6, at least about 1 :5, at least about 1 :4, at least about 1 :3, at least about 1 :2, at least about 1 : 1, at least about 2: 1, at least about 3: 1, at least about 4: 1, at least about 5: 1, at least about 6: 1, at least about 7: 1, at least about 8: 1, at least about 9: 1, at least about 10: 1, at least about 11 :1, at least about 12: 1, at least about 13:1, at least about 14: 1, at least about 15: 1, at least about 16: 1, or at least about 17: 1; and/or no more than about 18: 1, no more than about 17: 1, no more than about 16: 1, no more than about 15: 1, no more than about 14: 1, no more than about 13: 1, no more than about 12: 1, no more than about 11 : 1, no more than about 10: 1, no more than about 9: 1, no more than about 8: 1, no more than about 7: 1, no more than about 6: 1, no more than about 5: 1, no more than about 4: 1, no more than about 3:1, no more than about 2: 1, no more than about 1 : 1, no more than about 1 :2, no more than about 1 :3, no more than about 1 :4, no more than about 1 :5, no more than about 1 :6, no more than about 1 :7, no more than about 1 :8, no more than about 1 :9, no more than about 1 : 10, no more than about 1 : 11, no more than about 1 : 12, no more than about 1 : 13, no more than about 1 : 14, no more than about 1 : 15, no more than about 1 : 16, or no more than about 1 : 17; and/or in any range having a lower bound of A:B and an upper bound of C:D, where each of A, B, C, and D is any integer greater than or equal to 1 and less than or equal to 18.

In many embodiments, the fluid mixture may necessarily or preferably be heated above room temperature to improve its flowability before being cast or deposited. The flowability of the heated fluid mixture may have the additional benefit of enabling the fluid mixture to “self-level,” z.e., to naturally form a flat or smooth layer having a substantially uniform thickness when cast, thereby eliminating the need for labor-, energy-, and/or costintensive steps of spreading or otherwise leveling the fluid mixture before gelling.

In some embodiments, the casting or depositing step may comprise two or more separate casting or depositing substeps to provide a layered structure to the resulting biocomposite material. Even more particularly, some embodiments of the method may include a first casting substep in which a first layer of the fluid mixture is cast into a desired spatial orientation; a reinforcing substep in which a layer of a reinforcing material (e.g., natural and/or synthetic fibers, a membrane, a mesh scaffold, etc.) is placed atop the first layer of the fluid mixture; and a second casting substep in which a second layer of the fluid mixture is cast into a desired spatial orientation atop the layer of reinforcing material. Of course, this sequence of steps may be repeated any number of times to create a “sandwiched” material (z.e., with a first layer of reinforcing material between first and second layers of fluid mixture, a second layer of reinforcing material between second and third layers of fluid mixture, etc.). In some, but by no means all, embodiments, a previously cast or deposited layer of the fluid mixture may be gelled before a subsequent layer of the fluid mixture is cast or deposited, while in other embodiments. Advantageously, this process of placing layers of reinforcing material between layers of the fluid mixture may allow the reinforcing material to be “embedded” or “hidden” within the finished biocomposite material, such that they provide structural integrity to the biocomposite material and/or augment or improve physical properties or attributes of the biocomposite material (e.g., ability to withstand stitching, flexibility, tensile strength, etc.) without being visible to an observer (e.g., a consumer purchasing an item of clothing or other article made from the biocomposite material) and/or may eliminate the need for adhesives or glues for bonding the fungal biomass layers to the reinforcing material layers. In further embodiments, more particularly, some embodiments of the method may include a first reinforcing substep in which a layer of a reinforcing material (e.g., natural and/or synthetic fibers, a membrane, a mesh scaffold, etc.) is placed in a position and a second casting substep in which a layer of the fluid mixture is cast into a desired spatial orientation atop the layer of reinforcing material. In all such embodiments, the reinforcing material can be placed in position and held under tension for a desired time period. For example, the reinforcing material can be held under tension until the fluid mixture is cast but before it has gelled or until the fluid mixture is fully gelled. For example, maintaining the reinforcing material under tension until the cast material is gelled can improve the texture or smoothness of the resulting product, such as, reducing or eliminating wrinkles in the final material.

Once the fluid mixture has been cast or otherwise deposited into a desired spatial configuration (most commonly, but not always, a flat or planar sheet), gelling of the fluid mixture to form a biomass gel is triggered by any suitable method. Most commonly, gelling may be triggered by cooling (either actively or passively) the fluid mixture, e.g., to room or ambient temperature, but other gelling mechanisms may also be possible depending on the composition of the fluid mixture; non-limiting examples of additional or alternative gelation triggering mechanisms include changing the pH of the fluid mixture, adding a metal ion to the fluid mixture, initiating a polymerization reaction in the fluid mixture, and exposing the fluid mixture to a selected wavelength of electromagnetic radiation. The self-leveling nature of the fluid mixture and the many mechanisms available for gelling not only offer the possibility of reducing the energy requirements of the manufacture process (e.g., the fluid mixture can be made to gel without any active energy demands whatsoever, merely by exposing the fluid mixture to ambient conditions) but also simplifies and reduces equipment needs for the manufacturing process by rendering filter membranes, doctor blades, etc. optional or superfluous.

In some embodiments, a surface onto which the fluid mixture is deposited may be temperature-controlled, and particularly may have at least one region that has a temperature that is below the freezing point of the carrier fluid and/or an additive in the fluid mixture. By way of non-limiting example, in embodiments in which the fluid mixture is an emulsion comprising water, a biomass, a water-soluble gelling agent, and a hydrophobic wax, the solution may be cast onto a surface whose temperature is lower than the freezing point of the wax, thereby inducing solidification of the wax and phase separation of the water- soluble/water-dispersed components; after water is removed in the drying step, a lamellar biocomposite material having alternating layers of hydrophobic and hydrophilic materials may be produced.

One particular advantage and benefit of the biocomposite materials made by the methods disclosed herein is that they may be picked up, handled, and/or moved, without breaking or disintegrating, after gelling but before removal of the carrier fluid (z.e., before the materials are dry), which is generally untrue of wet-laid or slurry-cast films. This feature makes subsequent processing of the biocomposite materials much easier, as the materials can be easily hung to air-dry, transferred to an oven for drying, embossed with a pattern, etc. In some embodiments, the biomass gel can be embossed or texturized before any carrier fluid is removed and/or during the drying step (z.e., when removal of the carrier fluid is incomplete and continuing).

The use of gel casting methods to produce biocomposite materials as disclosed herein results in the production of strong, tough biocomposite materials that have mechanical, and in many cases aesthetic (z.e., “look and feel”) characteristics comparable to conventional textile materials, e.g., leather. Particularly, the combination of fungal biomass, gelling agent(s), and (in some embodiments) plasticizers can give the desired look and feel of conventional textiles.

In some embodiments, the biocomposite materials disclosed herein can have tensile strengths that are suitable for a variety of applications of conventional materials. For example, the materials can have tensile strengths that are greater than about 3 MPa, greater than about 4 MPa, greater than about 5 MPa, greater than about 6 MPa, greater than about 7 MPa, greater than about 8 MPa, greater than about 9 MPa, greater than about 10 MPa, greater than about 11 MPa, greater than about 12 MPa, greater than about 13 MPa, greater than about 14 MPa, greater than about 15 MPa, greater than about 16 MPa, greater than about 17 MPa, greater than about 18 MPa, greater than about 19 MPa, or greater than about 20 MPa.

In some embodiments, the biocomposite materials disclosed herein can have a tensile modulus that is suitable for a variety of applications of conventional materials. For example, the materials can have tensile moduli that are greater than about 20 MPa, greater than about 25 MPa, greater than about 30 MPa, greater than about 35 MPa, greater than about 40 MPa, greater than about 45 MPa, greater than about 50 MPa, greater than about 60 MPa, greater than about 70 MPa, greater than about 80 MPa, greater than about 90 MPa, greater than about 100 MPa, greater than about 125 MPa, greater than about 150 MPa, greater than about 175 MPa, or greater than about 200 MPa.

Materials of the invention can achieve combinations of beneficial properties, such as having both high tensile strength values and high tensile modulus values. For example, such materials can have a tensile strength of greater than about 3 MPa (or any other tensile strength value referenced above) while also having a tensile modulus of greater than about 20 MPa (or any other tensile modulus value reference above).

Other components (e.g., polymers, crosslinkers such as metal ions, etc.) in the fluid mixture can enhance the biocomposite material’s mechanical performance after gelling and removal of the carrier fluid, for example by crosslinking the gelling agent and/or functional moi eties (e.g., carboxylic acids of surface proteins) of the biomass. In some embodiments, the biocomposite material may include as an additive at least one functionalizing agent or crosslinker selected from the group consisting of carboxylic acids, esters (e.g., fatty acids, fatty acid esters, waxes, esterified waxes, triglycerides, and derivatives thereof), acid anhydrides, and epoxides. In some embodiments, the biocomposite material may be partially dried and then exposed to another aliquot of a fluid to introduce additional components, e.g., crosslinkers, metal ions, etc., into the biocomposite material via infusion/uptake of the fluid into the biocomposite material.

Parameters of the drying/carrier fluid removal step may be selected to provide for desired features of the finished biocomposite material. By way of first non-limiting example, freeze-drying or critical point drying may be employed to retain high porosity in the finished biocomposite material. By way of second non-limiting example, the biomass gel may be “pinned” by a compressive force, a uniaxial tensile force, or a biaxial tensile force during and/or after the drying step to prevent curling of the biomass gel during drying and/or to improve toughness and crazing of the finished biocomposite material. By way of third nonlimiting example, the rate at which the carrier fluid is removed can be selected to provide a desired degree of porosity and/or thermal conductivity to the biocomposite material, as faster removal of the carrier fluid generally results in a more porous material.

In some embodiments, the fluid mixture may be a foam, z.e., one or more gases (e.g., air, carbon dioxide, nitrogen, etc.) may be incorporated into the fluid mixture, to provide for desired thermal characteristics (e.g, insulation characteristics) and/or textural characteristics and/or ratio of strength to porosity in the biocomposite material. In some embodiments, the fluid mixture may be a sol-gel precursor that, upon gelling, forms a solgel; embodiments of this type may be particularly suitable for forming biocomposite materials that include metal and/or ceramic components.

In some embodiments, one or more reinforcing materials, such as natural or synthetic fibers or a combination thereof, may be added to the fluid mixture prior to the drying/carrier fluid removal step to reinforce and provide additional structural integrity to the resulting biocomposite material. Non-limiting examples of suitable reinforcing materials include cellulose fibers, cardboard, and paper. Most typically, the reinforcing materials, e.g, fibers, may be added to the fluid mixture in an amount of about 2 wt% to about 10 wt%, more preferably about 2.5 wt% to about 9 wt%, and most preferably about 3 wt% to about 8 wt%, or any subrange of any of these ranges, of the fluid mixture on a dry basis (i.e., excluding water).

In some embodiments, one or more plant oils may be added to the fluid mixture prior to the drying/carrier fluid removal step. The plant oil may act in the biocomposite material as any one or more of a fragrance, a pest repellent or pesticide, a preservative, a lubricant, a dirt-proofing or dirt resistance agent, a stain-proofing or stain resistance agent, and a waterproofing or water resistance agent. Non-limiting examples of suitable plant oils include cedar oil. Most typically, the plant oil, e.g, cedar oil, may be added to the fluid mixture in an amount of about 0.1 wt% to about 0.5 wt%, more preferably about 0.15 wt% to about 0.35 wt%, and most preferably about 0.2 wt%, or any subrange of any of these ranges, of the fluid mixture on a dry basis (i.e., excluding water).

In some embodiments, one or more salts may be added to the fluid mixture prior to the drying/carrier fluid removal step. The salt may be useful as part of a brine rinse to separate organic contaminants, to promote “salting out” of dyestuff precipitates, to blend with concentrated dyes, to provide a cationic charge to promote absorption of anionic dyes (or vice versa), as an antimicrobial and/or preservative, as a humectant, as a desiccant, etc. Non-limiting examples of suitable salts include sodium chloride, sodium benzoate, and sodium hydroxide. Most typically, the salt, e.g., sodium chloride, may be added to the fluid mixture in an amount of about 0.1 wt% to about 2 wt%, or any subrange thereof, of the fluid mixture on a dry basis i.e., excluding water).

In some embodiments, the fluid mixture prior to the drying/carrier fluid step may include, on a dry basis (i.e., excluding water), about 25 wt% to about 60 wt% fungal biomass, about 15 wt% to about 30 wt% plasticizer(s), about 15 wt% to about 30 wt% polymer(s), about 2 wt% to about 10 wt% reinforcing materials (e.g., natural or synthetic fibers such as cellulose fibers), about 0.1 wt% to about 0.5 wt% plant oil(s) (e.g., cedar oil), and about 0.1 wt% to about 2 wt% salt(s) e.g., sodium chloride, sodium benzoate, and/or sodium hydroxide) or any subranges within those ranges.

In some embodiments, one or more water uptake-resistant or anti-swelling crosslinkers may be added to the fluid mixture prior to the drying/carrier fluid removal step. The water uptake-resistant or anti-swelling crosslinker may be useful to decrease the water uptake of the finished biocomposite material, i.e., decrease the tendency of the finished biocomposite material to absorb water. Non-limiting examples of suitable crosslinkers include polyamideamine-epichlorohydrin (PAE) resins, epoxides, and acrylates. Most typically, the water uptake-resistant or anti-swelling crosslinker, e.g., PAE resin, may be added to the fluid mixture in an amount of about 0.1 wt% to about 10 wt%, or any subrange thereof, of the fluid mixture on a dry basis (i.e., excluding water). Additionally or alternatively, the biocomposite material may be treated with or otherwise include a waterproofing or water resistance agent, such as lecithin and/or beeswax, in an amount of between about 0.1 wt% and about 50 wt%, or alternatively in any range having a lower bound of any number of tenths of a percent between 0.1 wt% and 40 wt% and an upper bound of any other number of tenths of a percent between 0.1 wt% and 40 wt%. In some embodiments, the water uptake of the finished biocomposite material may be no more than about 80%, no more than about 75%, no more than about 70%, no more than about 65%, no more than about 60%, no more than about 55%, no more than about 50%, no more than about 45%, no more than about 40%, no more than about 35%, no more than about 30%, no more than about 25%, no more than about 20%, no more than about 15%, no more than about 10%, no more than about 5%, no more than about 4%, no more than about 3%, no more than about 2%, or no more than about 1%.

Embodiments of the present disclosure enable the creation of biocomposite materials that are resilient to repeated flexing. By way of non-limiting example, the materials of the present disclosure may be able to withstand at least about 5,000, at least about 10,000, at least about 15,000, at least about 20,000, at least about 25,000, at least about 30,000, at least about 35,000, or at least about 40,000 flex cycles in flex cycle testing according to BS EN ISO 5402:2009.

Biocomposite materials according to the present disclosure may be manufactured such that they are characterized by a desired strain at break. In some embodiments, by way of non-limiting example, the biocomposite materials may be manufactured to have a strain at break of at least about 5 percent, at least about 10 percent, at least about 15 percent, at least about 20 percent, at least about 25 percent, at least about 30 percent, at least about 35 percent, at least about 40 percent, at least about 45 percent, at least about 50 percent, at least about 55 percent, at least about 60 percent, or at least about percent, or of no more than about 70 percent, no more than about 65 percent, no more than about 60 percent, no more than about 55 percent, no more than about 50 percent, no more than about 45 percent, no more than about 40 percent, no more than about 35 percent, no more than about 30 percent, no more than about 25 percent, no more than about 20 percent, no more than about 15 percent, no more than about 10 percent, or alternatively in any range having a lower bound of any whole-number percentage between 1 percent and 70 percent and an upper bound of any other whole-number percentage between 1 percent and 70 percent.

In some embodiments, biocomposite materials according to the present disclosure may be made into multilayer textiles by being adhered, laminated, or otherwise affixed to one or more backing layers of a non-fungal material (e.g., a cotton backing, a nylon backing, a cardboard backing, a paper backing, etc.) and/or a different fungal or biocomposite material. Non-limiting examples of non-fungal textiles that may be adhered, laminated, or otherwise affixed to biocomposite materials according to the present disclosure to form a multilayer textile include an acrylic textile, an alpaca textile, an angora textile, a cashmere textile, a coir textile, a cotton textile, an eisengarn textile, a hemp textile, a jute textile, a Kevlar textile, a linen textile, a microfiber textile, a mohair textile, a nylon textile, an olefin textile, a pashmina textile, a polyester textile, a pina textile, a ramie textile, a rayon textile, a sea silk textile, a silk textile, a sisal textile, a spandex textile, a spider silk textile, a wool textile, and combinations thereof. In some embodiments, the backing layer may be a porous or mesh material, which may have a pore size of between about 5 pm and about 25.4 mm, between about 25 pm and about 5.60 mm, between about 0.165 mm and about 2.00 mm, between about 15 pm and about 400 pm, or alternatively in any range having a lower bound of any whole number of microns between 1 pm and 25.4 mm and an upper bound of any other whole number of microns between 1 pm and 25.4 mm. An adhesion force between the layer(s) of biocomposite material and the layer(s) of non-fungal or other fungal or biocomposite material may be at least about 1 N, at least about 2 N, at least about 3 N, at least about 4 N, at least about 5 N, at least about 6 N, at least about 7 N, at least about 8 N, at least about 9 N, at least about 10 N, at least about 11 N, at least about 12 N, at least about 13 N, at least about 14 N, or at least about 15 N, and the multilayer textile may, but need not, be engineered such that a failure mode of adhesion between the layers is either adhesive or cohesive.

Biocomposite materials according to the present disclosure may be manufactured such that they are characterized by a desired tear strength. In some embodiments, by way of non-limiting example, the biocomposite materials may be manufactured to have a tear strength of at least about 5 N/mm, at least about 10 N/mm, at least about 15 N/mm, at least about 20 N/mm, at least about 25 N/mm, at least about 30 N/mm, at least about 35 N/mm, at least about 40 N/mm, at least about 45 N/mm, at least about 50 N/mm, at least about 55 N/mm, at least about 60 N/mm, at least about 65 N/mm, at least about 70 N/mm, at least about 75 N/mm, at least about 80 N/mm, at least about 85 N/mm, at least about 90 N/mm, at least about 95 N/mm, or at least about 100 N/mm.

In some embodiments, one or more gases (e.g., air, carbon dioxide, nitrogen, etc.) may be incorporated into biocomposite materials according to the present disclosure to produce a “foamed” biocomposite material that has a significantly lower mass density than a corresponding “unfoamed” biocomposite material. Conversely, in other embodiments, it may be desirable to degas the pre-gelation slurry to remove any air bubbles and thereby increase the mass density of the biocomposite material. In some embodiments, the biocomposite material may be “unfoamed” and have a mass density of at least about 1 g/cm ³ , at least about 1.05 g/cm ³ , at least about 1.1 g/cm ³ , at least about 1.15 g/cm ³ , at least about 1.2 g/cm ³ , at least about 1.25 g/cm ³ , at least about 1.3 g/cm ³ , at least about 1.35 g/cm ³ , at least about 1.4 g/cm ³ , at least about 1.45 g/cm ³ , or at least about 1.5 g/cm ³ . In other embodiments, the biocomposite material may be “foamed” such that the density of the biocomposite material is decreased relative to a corresponding “unfoamed” biocomposite material by at least about 5%, at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, or at least about 95%, e.g., such that the “foamed” biocomposite material has a mass density of no more than about 1 g/cm ³ , no more than about 0.95 g/cm ³ , no more than about 0.9 g/cm ³ , no more than about 0.85 g/cm ³ , no more than about 0.8 g/cm ³ , no more than about 0.75 g/cm ³ , no more than about 0.7 g/cm ³ , no more than about 0.65 g/cm ³ , no more than about 0.6 g/cm ³ , no more than about 0.55 g/cm ³ , no more than about 0.5 g/cm ³ , no more than about 0.45 g/cm ³ , no more than about 0.4 g/cm ³ , no more than about 0.35 g/cm ³ , no more than about 0.3 g/cm ³ , no more than about 0.25 g/cm ³ , no more than about 0.2 g/cm ³ , no more than about 0.15 g/cm ³ , no more than about 0.1 g/cm ³ , or no more than about 0.05 g/cm ³ .

Biocomposite materials according to the present disclosure may be manufactured such that they are characterized by a desired thickness. In some embodiments, by way of non-limiting example, the biocomposite materials may be manufactured to have a thickness of between about 0.1 mm and about 10 cm, or alternatively a thickness in any range having a lower bound of any number of tenths of millimeters between 0.1 mm and 10 cm and an upper bound of any other number of tenths of millimeters between 0.1 mm 10 cm.

In some embodiments, an emulsifier and/or surfactant may be provided in the fungal slurry to improve the incorporation of hydrophobic materials into the fungal slurry. Nonlimiting examples of such emulsifiers and/or surfactants include epoxidized soybean oil, cationic fat liquors, polysorbates, and alkyl polyglycosides. The emulsifier and/or surfactant may be provided in any amount between about 2 wt% and about 20 wt%, or alternatively in any range having a lower bound of any whole number of percent between 2 wt% and 20 wt% and an upper bound of any other whole number of percent between 2 wt% and 20 wt%.

It is to be expressly understood that the methods and systems disclosed herein are suitable for making biocomposite materials from fibrous or particulate non-animal biomasses other than fungal biomasses. Non-limiting examples of such fibrous or particulate, non-animal, non-fungal biomasses include corn stover, sugarcane bagasse, coconut coir, fruit waste, vegetable waste, and spent coffee grounds. The use of certain biomasses, particularly those that may be waste materials from other agricultural or industrial processes, can advantageously produce biocomposite materials with desired bulk mechanical, aesthetic, and/or textural properties while mitigating the environmental impact (e.g., carbon emissions) of production of such materials.

Biocomposite materials made according to the methods described above may have advantageous mechanical properties compared to conventional or currently known materials. By way of first non-limiting example, biocomposite materials made according to the present disclosure may have a water uptake after 24 hours of no more than about 140%, no more than about 130%, no more than about 120%, no more than about 110%, no more than about 100%, no more than about 90%, no more than about 80%, no more than about 70%, no more than about 60%, no more than about 50%, or no more than about 40%. By way of second non-limiting example, biocomposite materials made according to the present disclosure may survive at least about 10,000 flex cycles, at least about 20,000 flex cycles, at least about 30,000 flex cycles, at least about 40,000 flex cycles, at least about 50,000 flex cycles, at least about 60,000 flex cycles, at least about 70,000 flex cycles, at least about 80,000 flex cycles, at least about 90,000 flex cycles, at least about 100,000 flex cycles, at least about 110,000 flex cycles, at least about 120,000 flex cycles, at least about 130,000 flex cycles, at least about 140,000 flex cycles, at least about 150,000 flex cycles, at least about 160,000 flex cycles, at least about 170,000 flex cycles, at least about 180,000 flex cycles, at least about 190,000 flex cycles, or at least about 200,000 flex cycles in bally flex testing. By way of third non-limiting example, biocomposite materials made according to the present disclosure may have a strain at break of from about 10 to about 70 percent, or alternatively between a lower bound of any whole number of percent from 10 percent to 70 percent and an upper bound of any other whole number of percent from 10 percent to 70 percent. By way of fourth non-limiting example, biocomposite materials made according to the present disclosure may have a tensile strength of at least about 1 MPa, at least about 2 MPa, at least about 3 MPa, at least about 4 MPa, at least about 5 MPa, at least about 6 MPa, or at least about 7 MPa.

Biocomposite materials made according to the methods described above may particularly have combinations of beneficial properties, such as having both high tensile strength values and the ability to survive a high number of flex cycles in bally flex testing. For example, such materials can have a tensile strength of greater than about 3 MPa (or any other tensile strength value referenced above) while also surviving at least about 40,000 flex cycles (or any other number of flex cycles referenced above) in bally flex testing.

Embodiments of the present disclosure are further described by way of the following illustrative and non-limiting Examples.

Example 1

A fluid mixture comprising 90 wt% water, 5 wt% size-reduced particles of a biomat of the filamentous fungus Fusarium six.flavolapis, 2.4 wt% glycerol, 2 wt% K-carrageenan, and 0.6 wt% urea was prepared. This mixture was heated until it flowed readily, cast onto a PTFE sheet, allowed to gel (by cooling to room temperature), passively dried at room temperature overnight while being pressed between two wire racks, and then baked in an oven at 100 °C for 6 hours. Figure 1 illustrates a segment of the biomass gel after casting and gelling, and Figure 2 illustrates several segments of the biomass gel during the ambient air drying step. The biomass gel had a thickness of about 6.6 mm prior to any water removal; the finished biocomposite material had a thickness of about 0.95 mm.

The mechanical performance of the resulting biocomposite material was then tested. The biocomposite material passed the double bend test and survived 21,350 flex cycles in flex cycle testing, and had a tensile modulus of 39.5 MPa, a tensile strain at break of 42.13%, and a tensile strength of 6.11 MPa.

Example 2

Biomats of the filamentous fungus Fusarium six.flavolapis grown on a liquid growth medium were boiled to deactivate the fungus and rinsed with water to remove any residual growth medium. These biomats were then placed in a standard kitchen blender and size- reduced and blended with water until a homogeneous aqueous slurry was obtained. 0.1 wt% sodium benzoate was added to the slurry as a preservative.

To each of these slurries were added (a) potassium chloride, (b) glycerol and urea as plasticizers, (c) Fiberlean cellulose fiber as a reinforcing material, (d) iron(III) oxide (Fe2O3) as a pigment, and (e) K-carrageenan as a gelling agent. In some cases, additional water was added to achieve a desired total solids content of 5 to 8 wt%. Each slurry contained, on a dry basis (z.e., excluding water), 36.9 wt% fungal biomass, 18.0 wt% K-carrageenan, 1.1 wt% potassium chloride, and 2.0 wt% iron(III) oxide; the amounts of plasticizer and cellulose were varied relative to each other, but in all cases totaled 42 wt% of the dry components.

Each slurry was heated in a pot with continuous stirring until a smooth, free-flowing mixture was obtained. This free-flowing mixture was then placed in a vacuum chamber for a brief period to degas (ie., to remove air). After degassing, each mixture was cast into a preheated mold, and the mold was then agitated to ensure an even cast and remove any surface bubbles. The molds were subsequently allowed to cool to room temperature under ambient conditions.

Upon cooling, monolithic gels were obtained from each mold. These gels were transferred to a dehydrator and dried at 40 °C for 24 hours. The resulting materials were then stretched, clamped to a solid substrate, and placed in an oven at 60 °C for an additional 24 hours, after which each material was in the form of a smooth, bubble-free sheet. The composition of each slurry is given in Table 1, and the tensile strength and elongation at break of the obtained smooth, bubble-free sheets are illustrated in Figures 3A and 3B, respectively; note that in Table 1, the fractions of plasticizer and Fiberlean are reported on a dry mass basis (z.e., excluding water), whereas the “solids fraction” is the mass of all nonwater components of the initial slurry relative to the initial slurry as a whole (z.e., including water). Table 1

Example 3

Biomats of the filamentous fungus Fusarium six.flavolapis grown on a liquid growth medium were boiled to deactivate the fungus and rinsed with water to remove any residual growth medium. These biomats were then placed in a standard kitchen blender and size- reduced and blended with water until a homogeneous aqueous slurry was obtained. 0.1 wt% sodium benzoate was added to the slurry as a preservative.

To each of these slurries were added (a) sulfuric acid, (b) glycerol and urea as plasticizers, (c) Fiberlean cellulose fiber as a reinforcing material, (d) iron(III) oxide (Fe2O3) as a pigment, and (e) K-carrageenan as a gelling agent. In some cases, additional water was added to achieve a desired total solids content of 5 to 6 wt%. Epoxidized soybean oil was also added to some slurries and mixed until a uniform emulsion was formed; this demonstrates the ability of slurries according to the present disclosure to evenly and uniformly incorporate and distribute hydrophobic materials. Each slurry contained, on a dry basis (z.e., excluding water), 18.0 wt% K-carrageenan, 0.5 wt% sulfuric acid, and 1.0 wt% iron(III) oxide.

Each slurry was heated in a pot with continuous stirring until a smooth, free-flowing mixture was obtained. This free-flowing mixture was then placed in a vacuum chamber for a brief period to degas (ie., to remove air). After degassing, each mixture was cast into a preheated mold, and the mold was then agitated to ensure an even cast and remove any surface bubbles. The molds were subsequently allowed to cool to room temperature under ambient conditions.

Upon cooling, monolithic gels were obtained from each mold. These gels were transferred to a dehydrator and dried at 40 °C for 24 hours. The resulting materials were then stretched, clamped to a solid substrate, and placed in an oven at 60 °C for an additional 24 hours, after which each material was in the form of a smooth, bubble-free sheet. The composition of each slurry is given in Table 2, and the tensile strength and elongation at break of the obtained smooth, bubble-free sheets are illustrated in Figures 4A and 4B, respectively; note that in Table 2, the fractions of biomass, plasticizer, epoxidized soybean oil, and Fiberlean are reported on a dry mass basis (ie., excluding water), whereas the “solids fraction” is the mass of all non-water components of the initial slurry relative to the initial slurry as a whole (ie., including water).

5 Table 2

Example 4

Biomats of the filamentous fungus Fusarium six.flavolapis grown on a liquid growth medium were boiled to deactivate the fungus and rinsed with water to remove any residual 0 growth medium. These biomats were then placed in a standard kitchen blender and size- reduced and blended with water until a homogeneous aqueous slurry was obtained. 0.1 wt% sodium benzoate was added to the slurry as a preservative.

To this slurry, K-carrageenan, Thermolec 57 lecithin, beeswax, sodium hydroxide, and potassium chloride were added. The slurry contained, on a dry basis (z.e., excluding 5 water), 43.4 wt% fungal biomass, 15.0 wt% K-carrageenan, 0.5 wt% Thermolec 57, 38.3 wt% beeswax, 1.9 wt% sodium hydroxide, and 0.9 wt% potassium chloride, and had a total solids content of 13.0 wt% of the slurry.

The slurry was heated in a pot with continuous stirring until a smooth, free-flowing mixture was obtained. This free-flowing mixture was then cast into a preheated mold, and 0 the mold was then agitated to ensure an even cast and remove any surface bubbles. The mold was subsequently allowed to cool to room temperature under ambient conditions.

Upon cooling, a monolithic gel was obtained from the mold. This gel was transferred to a dehydrator and dried at 38 °C for 24 hours. The resulting material was clamped to a solid substrate and dried at 60 °C for an additional 6 hours, then cut into two sections; one 5 sample was heated to 130 °C for 3 hours, and the other sample was heated to 150 °C for 3 hours. Both samples of the finished material were then weighed, soaked in water for 1 hour, and weighed again to determine their water uptake. Both samples showed strong resistance to water uptake; the sample heated to 130 °C had a water uptake of 1.60%, and the sample heated to 150 °C had a water uptake of 1.58%. Example 5

Biomats of the filamentous fungus Fusarium six.flavolapis grown on a liquid growth medium were boiled to deactivate the fungus and rinsed with water to remove any residual growth medium. These biomats were then placed in a standard kitchen blender and size- reduced and blended with water until a homogeneous aqueous slurry was obtained. 0.1 wt% sodium benzoate was added to the slurry as a preservative.

To this slurry, glycerol, urea, r-carrageenan, potassium chloride, Fiberlean cellulose fiber, and cedar oil were added. The slurry contained, on a dry basis (z.e., excluding water), 38.7 wt% fungal biomass, 27.2 wt% glycerol, 6.8 wt% urea, 18.0 wt% i-carrageenan, 1.1 wt% potassium chloride, 8.0 wt% Fiberlean, and 0.2 wt% cedar oil, and had a total solids content of 2.0 wt% of the slurry.

The slurry was mixed and heated until a free-flowing, relatively inviscid fluid was obtained, and this fluid was cast into glass trays; after cooling to room temperature under ambient conditions, the fluid was qualitatively observed to slightly more viscous but still free-flowing. The glass trays were then heated to 90 °C for 24 hours to dry. As illustrated in Figure 5, the thick solution did not dry into a continuous film, presumably because the r- carrageenan did not gel.

Example 6

Biomats of the filamentous fungus Fusarium six.flavolapis grown on a liquid growth medium are boiled to deactivate the fungus and rinsed with water to remove any residual growth medium. These biomats are then placed in a standard kitchen blender and size- reduced and blended with water until a homogeneous aqueous slurry is obtained. 0.1 wt% sodium benzoate is added to the slurry as a preservative.

To each of these slurries are added (a) potassium chloride, (b) glycerol and urea as plasticizers, (c) Fiberlean cellulose fiber as a reinforcing material, (d) iron(III) oxide (Fe2O3) as a pigment, and (e) K-carrageenan as a gelling agent. In some cases, additional water is added to achieve a desired total solids content of 5 to 8 wt%. Each slurry contains, on a dry basis (z.e., excluding water), 36.9 wt% fungal biomass, 18.0 wt% K-carrageenan, 1.1 wt% potassium chloride, and 2.0 wt% iron(III) oxide; the amounts of plasticizer and cellulose are varied relative to each other, but in all cases totaled 42 wt% of the dry components.

Each slurry is fed into the feed section of an extruder. The temperature and screw speed of the extruder is set to ensure appropriate mixing of materials in the extruder barrel. In some cases, multiple feeders are used to tune the relative loading of each component during the extrusion process. A vacuum port may also be used after a mixing section of the screw to remove air bubbles before the material exits the extruder.

After mixing and degassing, the material exits a temperature-controlled die at the end of the extruder in the form of a sheet and gels. The resulting monolithic gel is collected, transferred to a dehydrator, and dried at 40 °C for 24 hours. The resulting materials are then stretched, clamped to a solid substrate, and placed in an oven at 60 °C for an additional 24 hours, after which each material is in the form of a smooth, bubble-free sheet. The composition of each slurry is given in Table 3; note that in Table 3, the fractions of plasticizer and Fiberlean are reported on a dry mass basis (z.e., excluding water), whereas the “solids fraction” is the mass of all non-water components of the initial slurry relative to the initial slurry as a whole (z.e., including water).

Table 3

Example 7

Biomats of the filamentous fungus Fusarium six.flavolapis grown on a liquid growth medium were boiled to deactivate the fungus. Subsequently, these biomats were blended in deionized water in a standard kitchen blender until a flowable and substantially homogeneous mixture was produced.

To this mixture, glycerol, additional deionized water, microfibrillated cellulose, and acyl gellan gum were added; the total solids content of this mixture was 5 wt%, and on a dry solids basis the mixture consisted of about 36 wt% fungal biomass, about 36 wt% glycerol, about 20 wt% acyl gellan gum, and about 8 wt% microfibrillated cellulose. This mixture was blended in the standard kitchen blender until it appeared to form a viscous and substantially homogeneous slurry. This slurry was then poured into a stainless steel container and stirred while heated by an induction hot plate until a free-flowing mixture was formed; this free-flowing mixture was then poured into a heated tray and allowed to cool at room temperature for about 30 minutes, during which time gelation of the mixture took place to form a hydrogel. After cooling to room temperature, the hydrogel was removed from the tray and allowed to dry on a non-stick PTFE sheet within a drying oven at an elevated temperature of approximately 70 °C. After 8 hours at this elevated temperature, the dried gel was removed and its tensile properties were evaluated according to ISO 3376. The dried gel was found to have a tensile modulus of 84.77 ± 10.72 MPa, a tensile strength of 9.80 ± 1.51 MPa, and an elongation at break of 27.90% ± 3.97%.

Example 8

A substantially homogeneous aqueous slurry having a total solids content of 8 wt% (z.e., 92 wt% water) and consisting, on a dry basis, of 34.4 wt% fungal (Fusarium str. flavolapis') biomass, 30.0 wt% glycerol, 7.6 wt% urea, 18.0 wt% K-carrageenan, 1.0 wt% potassium chloride, 8.0 wt% microfibrillated cellulose, and 1.0 wt% magnetite pigment was prepared by mixing all components in a standard kitchen blender and transferring the contents to an induction pot. The mixture was then heated on an induction burner until its temperature exceeded 60 °C, at which point it became free-flowing. The mixture was then de-gassed in a vacuum chamber for 2.5 minutes.

Separately, three different types of woven backings — unbleached 90 mesh cotton cheesecloth, unbleached muslin, and food-grade nylon mesh with a pore size of 400 pm — were dipped in deionized water, placed into 18” x 24” (45.7 cm x 61.0 cm) aluminum baking trays, pulled taut, and clipped to the edges of the trays using blinder clips; the trays were preheated on heating pads to maintain a surface temperature above 40 °C. Optical microscopy images of the cheesecloth backing are shown in Figures 6A and 6B, optical microscopy images of the muslin backing are shown in Figures 6C and 6D, and an optical microscopy images of the nylon backing is shown in Figure 6E.

The fungal slurry was cast into the aluminum trays over the woven backings, and the trays were shaken on a shaker table to evenly distribute the slurry within the tray. The trays were then allowed to cool to room temperature such that the slurries formed stiff hydrogels that could be removed from the tray by hand. The hydrogel/backing composite materials were transferred to drying racks and the composites were dried in an oven for 8 hours at 45 °C followed by another 8 hours at 70 °C. A control sample, containing only a cast fungal slurry with no woven backing, was made by a similar procedure. All samples were then baked at 100 °C for 1 hour and placed in an environmental chamber under controlled environmental conditions of 25 °C and 50% relative humidity for 24 hours.

The tear strength of the four materials, evaluated as the peak force averaged over five tests and normalized to the thickness of the test sample, was tested using a single-edge tear test in an Instron machine by cutting 4.5 cm x 7 cm samples of each material and cutting a slit down the middle of each sample to leave exactly 2cm remaining intact. The adhesion of the fungal gels to the backing materials was also evaluated using a T-peel test with sample strips 6 inches (15.2 cm) in length and 1 inch (2.5 cm) in width. The data are summarized in Table 4 below; as Table 4 illustrates, the tear strength of the finished material is improved by over an order of magnitude by casting the fungal slurry directly onto a backing material.

Table 4 Example 9

Several substantially homogeneous aqueous slurries having a total solids content of 5-10 wt% and whose dry ingredients consisted of 32.0 wt% glycerol, 3.6 wt% urea, 2.0 wt% pigment, and varying amounts of fungal (Fusarium str . flavolapis') biomass, K-carrageenan, and potassium chloride were prepared by mixing all components in a standard kitchen blender and transferring the contents to an induction pot; in all cases, K-carrageenan and potassium chloride were provided in a 20: 1 weight ratio. The slurries were then heated on an induction burner until the temperature exceeded 60 °C, at which point the slurries became free-flowing. These slurries were then cast into Pyrex trays preheated to 90 °C, which were shaken on a shaker table to evenly distribute the slurry within the tray. The trays were then allowed to cool to room temperature such that the slurries formed stiff hydrogels that could be removed from the tray by hand. The hydrogel materials were transferred to drying racks and the composites were dried in an oven for 12 hours at 50 °C, followed by 5 hours at 70 °C, followed by 1 hour at 100 °C. Each material was cut into five samples for tensile testing, the average results of which are summarized in Table 5 below and graphed in Figures 7A (tensile strength) and 7B (tensile modulus). As Table 5 illustrates, as the content of gelling agent (in this Example, K-carrageenan) increases, so too do the tensile modulus and tensile strength — a six-fold increase in strength is achieved by increasing the gelling agent/fungal biomass ratio from 1 : 17.35 (3.4 wt% gelling agent) to 1 : 1.03 (30.0 wt% gelling agent).

Table 5

Example 10

Two substantially homogeneous aqueous slurries having a total solids content of 8 wt% — a first slurry whose dry ingredients consisted of 31.0 wt% fungal (Fusarium str. flavolapis biomass, 30.0 wt% glycerol, 10.0 wt% urea, 18.0 wt% K-carrageenan, 6.0 wt% microfibrillated cellulose, 2.0 wt% cationic fat liquor (Catalix LX), and 3.0 wt% Epoxol 9- 5, and a second slurry whose dry ingredients consisted of 34.4 wt% fungal (Fusarium str. flavolapis biomass, 30.0 wt% glycerol, 7.6 wt% urea, 18.0 wt% K-carrageenan, 1.0 wt% potassium chloride, 8.0 wt% microfibrillated cellulose, and 1.0 wt% magnetite pigment — were prepared by mixing all components in a standard kitchen blender and transferring the contents to an induction pot. The slurries were then heated on an induction burner until the temperature exceeded 60 °C, at which point the slurries became free-flowing; during heating, the first slurry was intermittently mixed with a handheld homogenizer to incorporate air, which was stabilized by the fat liquor to form a stable air-in-water foam. The two slurries (the “foamed” and “unfoamed” slurries) were cast into aluminum trays preheated to 90 °C, which were allowed to cool to room temperature over a period of 15 minutes such that the slurries formed stiff hydrogels that could be removed from the tray by hand. These hydrogels were transferred to a drying oven and dried at 70 °C for 24 hours. The dried material produced by the foamed slurry was a flexible, closed-cell solid foam with an average density of 0.243 ± 0.010 g/cm ³ , whereas the dried material produced by the unfoamed slurry had a mass density of about 1.289 g/cm ³ . Cross-sectional micrographs of the dried materials produced by the foamed and unfoamed slurries are shown in Figures 8A and 8B, respectively.

Example 11

Two substantially homogeneous aqueous slurries having a total solids content of 8 wt%, “Slurry A” and “Slurry B” were prepared and formed into dried gels by mixing all components in a Vitamix blender, transferring to a pot and heating the solution to 65 °C, transferring the pot to a vacuum chamber and subjecting the mixture to vacuum for 150 seconds, and pouring the contents into a Pyrex tray. The mixture gels as it cools to room temperature. After gelation the material was dried in a dehydrator oven at 70 °C for 24 hours. Both slurries contained, on a dry basis, 18.0 wt% K-carrageenan, 1.0 wt% potassium chloride, and 8.0 wt% microfibrillated cellulose, but differed in the plasticizers used; Slurry A contained 35.4 wt% fungal (Fusarium str . flavolapis) biomass, 30.0 wt% glycerol, and 7.6 wt% urea on a dry basis, whereas Slurry B contained 33.0 wt% fungal (Fusarium str. flavolapis) biomass and 40.0 wt% of a deep eutectic solvent (DES), where the DES was a 3:2 molar mixture of urea and trimethylglycine. The dried sheet made from Slurry A was determined to have a tensile modulus of 68.10 ± 1.42 MPa, a tensile strain at break of 34.71% ± 1.49%, and a tensile strength of 11.44 ± 0.20 MPa, whereas the dried sheet made from Slurry B was determined to have a tensile modulus of 102.76 ± 12.12 MPa, a tensile strain at break of 48.10% ± 1.76%, and a tensile strength of 11.97 ± 1.73 MPa.

Example 12

Biomats of the filamentous fungus Fusarium six. flavolapis grown on a liquid growth medium were boiled to deactivate the fungus. Subsequently, these biomats were blended in deionized water in a standard kitchen blender until a flowable and substantially homogeneous mixture was produced.

Three mixtures were produced by adding glycerol, urea, additional deionized water, microfibrillated cellulose, potassium chloride, and K-carrageenan to the fungal biomass and deionized water; the total solids content of each mixture was 7 wt%. Each mixture was blended in the standard kitchen blender until it appeared to form a viscous and substantially homogeneous slurry. This slurry was then poured into a stainless steel container and stirred while heated by an induction hot plate until a free-flowing mixture was formed; during heating and stirring, an aqueous solution of polyamide-epichlorohydrin (PAE) resin was added to two of the three slurries and allowed to mix for 1 minute. Each of the three slurries contained, on a dry basis, 30.0 wt% glycerol, 7.6 wt% urea, 18.0 wt% K-carrageenan, 1.0 wt% potassium chloride, and 8.0 wt% microfibrillated cellulose; the balance (35.4 wt%) of the dry ingredients in each slurry consisted of the fungal biomass and the PAE resin. Each slurry was then briefly degassed using a vacuum pump before being poured into a preheated tray and allowed to cool at room temperature for 15 minutes, during which time gelation of the slurries took place to form hydrogels.

After cooling to room temperature, the hydrogels were removed from the trays and allowed to dry on a non-stick PTFE sheet within a drying oven at approximately 40 °C for 16 hours, then at 71 °C for approximately 5 hours, then at 100 °C for 1 hour. Samples were cut from each sheet and soaked in water for 1 hour to evaluate the degree of swelling. Results are given in Table 6.

Table 6

Example 13

Fusarium str. flavolapis biomass was prepared by submerged (stirred-tank) fermentation. After fungal fermentation, steam was injected into the stirred-tank fermenter until a temperature of about 80 °C was achieved in the fermenter to inactivate the fungus. The deactivated biomass was then washed with deionized water and collected as a wet mixture having a solids content of about 25 wt%. This wet mixture was then spray-dried to a solids content of about 98 wt%. The particle size distribution of this spray-dried biomass was determined by sequential sieving and is shown in Table 7 below.

Table 7 Separately, a Fusarium str. flavolapis biomass in the form of an intact biomat was produced by liquid surface fermentation, inactivated by boiling, and blended with water in a conventional kitchen blender to produce a slurry having a fungal solids content of 7.7 wt%.

Each of the two fungal biomasses (the submerged-fermentation, spray-dried biomass and the surface-fermentation slurry) was mixed with water and other components in a conventional kitchen blender to obtain a substantially homogeneous aqueous slurry having a total solids content of 7 wt% and consisting, on a dry basis, of 35.4 wt% fungal biomass, 30.0 wt% glycerol, 7.6 wt% urea, 18.0 wt% K-carrageenan, 1.0 wt% potassium chloride, and 8.0 wt% microfibrillated cellulose. These mixtures were heated in pots on an induction burner until their temperatures exceeded 60 °C, at which point they became substantially free-flowing. Each mixture was then degassed in a vacuum chamber for 3 minutes and cast into a preheated tray; the trays were agitated to ensure evenness and uniformity of the cast mixtures and remove any surface bubbles. The trays were allowed to cool to room temperature under ambient conditions, whereupon each mixture formed an elastic hydrogel. These hydrogels were removed from the trays and allowed to dry on a non-stick PTFE sheet in a drying oven at about 40 °C for 18 hours, followed by drying at 100 °C for 1 hour, followed by 1 hour of cooling under ambient conditions.

Each dried biocomposite material’s tensile properties were then evaluated according to ISO 3376. The biocomposite material containing the surface fermentation-derived biomass was found to have a tensile modulus of 681 .6 ± 1 .4 MPa, a tensile strength of 1 1.4 ± 0.2 MPa, and an elongation at break of 34.7% ± 1.5%, whereas the biocomposite material containing the submerged fermentation-derived biomass was found to have a tensile modulus of 44.5 ± 5.4 MPa, a tensile strength of 8.1 ± 0.6 MPa, and an elongation at break of 51.8% ± 2,3%. This Example thus demonstrates that submerged fermentation and/or spray-drying/sieving procedures may allow for the tuning of bulk mechanical properties and surface texture of fungal biocomposite materials by controlling the composition and size of fungal mycelial particles.

Example 14

A portion of a brick of coconut coir was cut and washed by hand with deionized water; the resulting coir slurry was pressed by hand in a 400 pm nylon mesh to remove water until a solids content of 12 wt% (as measured by thermogravimetric analysis) was achieved. This washed coir material was mixed with water and other components in a conventional kitchen blender to form a substantially homogeneous aqueous slurry having a total solids content of 7 wt% and consisting, on a dry basis, of 43.4 wt% coconut coir, 30.0 wt% glycerol, 7.6 wt% urea, and 18.0 wt% K-carrageenan. This mixture was transferred to a pot and heated on an induction burner until its temperature exceeded 60 °C, at which point it became substantially free-flowing. The mixture was then degassed in a vacuum chamber for 2.5 minutes and cast into a preheated Pyrex tray; the tray was agitated to ensure evenness and uniformity of the cast mixtures and remove any surface bubbles. The tray was allowed to cool to room temperature under ambient conditions, whereupon each mixture formed an elastic hydrogel. This hydrogel was removed from the tray and allowed to dry on a nonstick PTFE sheet in a drying oven at 70 °C for 24 hours, followed by baking at 100 °C for 1 hour, followed by 24 hours of equilibration in an environmental chamber with a temperature of 30 °C and a relative humidity of 50%.

The dried biocomposite material’s tensile properties were then evaluated according to ISO 3376. The coconut coir-containing biocomposite material was found to have a tensile modulus of 629.9 MPa, a tensile strength of 14.1 MPa, and an elongation at break of 12.7%.

Example 15

A substantially homogeneous aqueous biomass slurry was prepared by blending inactivated surface fermentation-derived Fusarium strain flavolapis. nanofibrillated cellulose, and chopped coconut coir with water and other components in a conventional kitchen blender. The resulting mixture had a total solids content of 8 wt% and consisted, on a dry basis, of 26.6 wt% fungal biomass, 30.0 wt% glycerol, 7.6 wt% urea, 15.0 wt% K- carrageenan, 0.8 wt% potassium chloride, 12.0 wt% coconut coir, and 8.0 wt% nanofibrillated cellulose. This mixture was transferred to a pot and heated on an induction burner until its temperature exceeded 60 °C, at which point it became substantially free- flowing. The mixture was then degassed in a vacuum chamber for 2.5 minutes and cast into a preheated Pyrex tray; the tray was agitated to ensure evenness and uniformity of the cast mixtures and remove any surface bubbles. The tray was allowed to cool to room temperature under ambient conditions, whereupon each mixture formed an elastic hydrogel. This hydrogel was removed from the tray and allowed to dry on a non-stick PTFE sheet in a drying oven at 70 °C for 24 hours, followed by baking at 100 °C for 1 hour, followed by 24 hours of equilibration in an environmental chamber with a temperature of 30 °C and a relative humidity of 50%.

The dried biocomposite material’s tensile properties were then evaluated according to ISO 3376. The fungal biomass/cellulose/coconut coir-containing biocomposite material was found to have a tensile modulus of 68.2 MPa, a tensile strength of 6.1 MPa, and an elongation at break of 34.3%.

Example 16

A substantially homogeneous aqueous slurry was prepared by blending recycled copy paper with water and other components in a conventional kitchen blender. The resulting mixture had a total solids content of 7 wt% and consisted, on a dry basis, of 44.4 wt% recycled copy paper, 30.0 wt% glycerol, 7.6 wt% urea, and 18.0 wt% K-carrageenan. This mixture was transferred to a pot and heated on an induction burner until its temperature exceeded 60 °C, at which point it became substantially free-flowing. The mixture was then degassed in a vacuum chamber for 3 minutes and cast into a preheated Pyrex tray; the tray was agitated to ensure evenness and uniformity of the cast mixtures and remove any surface bubbles. The tray was allowed to cool to room temperature under ambient conditions, whereupon each mixture formed an elastic hydrogel. This hydrogel was removed from the tray and allowed to dry on a non-stick PTFE sheet in a drying oven at about 40 °C for 18 hours, followed by baking at 100 °C for 1 hour, followed by 1 hour of cooling to room temperature under ambient conditions.

The dried biocomposite material’s tensile properties were then evaluated according to ISO 3376. The recycled paper-containing biocomposite material was found to have a tensile modulus of 57.6 ± 16.9 MPa, a tensile strength of 9.13 ± 0.8 MPa, and an elongation at break of 30.7% ± 2.1. The tear strength of the dried recycled paper-containing biocomposite material was also evaluated using a single-edge tear test in an Instron instrument with a tear length of 2 cm; the tear strength, defined as the average peak force over five tests, was found to be 5.99 ± 0.18 N/mm.

The concepts illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein. It is apparent to those skilled in the art, however, that many changes, variations, modifications, other uses, and applications of the disclosure are possible, and changes, variations, modifications, other uses, and applications which do not depart from the spirit and scope of the disclosure are deemed to be covered by the disclosure.

The foregoing discussion has been presented for purposes of illustration and description. The foregoing is not intended to limit the disclosure to the form or forms disclosed herein. In the foregoing Detailed Description, for example, various features are grouped together in one or more embodiments for the purpose of streamlining the disclosure. The features of the embodiments may be combined in alternate embodiments other than those discussed above. This method of disclosure is not to be interpreted as reflecting an intention that the claims require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment.

Moreover, though the present disclosure has included description of one or more embodiments and certain variations and modifications, other variations, combinations, and modifications are within the scope of the disclosure, e.g. as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights which include alternative embodiments to the extent permitted, including alternate, interchangeable, and/or equivalent structures, functions, ranges, or steps to those claimed, regardless of whether such alternate, interchangeable, and/or equivalent structures, functions, ranges, or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter.