Improvements include reinforcing the ply of aerogel composite

Abstract

The present disclosure relates to improved panels comprising reinforced aerogel composites. In particular, the present disclosure can provide an aerogel composite. The aerogel composite comprises at least one base layer having an upper surface and a lower surface, the base layer comprising a reinforced aerogel composition and the aerogel composition comprising a reinforcing material and a monolithic aerogel framework; a first facing layer comprising a first facing material adhered to the upper surface of the base layer; and a second facing layer comprising a second facing material adhered to the lower surface of the base layer. At least a portion of the monolithic aerogel framework of the base layer is a portion that extends into both the first facing layer and the second facing layer. The first facing material and the second facing material can each comprise or consist essentially of an elastic fiber such as spandex, nylon, lycra, elastane, or combinations thereof.

Description

[0001] This application is a continuation-in-part of PCT Patent Application No. PCT / US2017 / 021339, filed January 27, 2017, which claims priority to U.S. Provisional Patent Application No. 62 / 287,762, filed January 27, 2016, and U.S. Patent Application No. 15 / 417,170, filed January 26, 2017, which are incorporated by reference as if fully set forth herein in their entireties and for all applicable purposes. TECHNICAL FIELD

[0002] [CROSS-REFERENCE TO RELATED APPLICATIONS]

[0003] This application claims the benefit of U.S. Patent Application No. 62 / 287,762, filed January 27, 2016, and U.S. Patent Application No. 15 / 417,170, filed January 26, 2017, which are incorporated by reference as if fully set forth herein in their entireties and for all applicable purposes to the extent that the subject matter incorporated by reference does not contradict the subject matter of the present application. BACKGROUND

[0004] Low density aerogel materials are widely recognized as the best solid insulators available. Aerogels derive their insulating efficacy primarily by minimizing conduction (low structural density leads to tortuous paths for energy transfer through the solid framework), convection (large pore volume and very small pore diameters lead to minimal convection), and radiation (IR absorbing or scattering dopants are easily dispersed throughout the aerogel matrix). Aerogels can be used in a large number of applications including: thermal and cold insulation, sound dampening, electronic dielectric, aerospace, energy storage and production, and filtration. In addition, aerogel materials exhibit a number of other interesting acoustic, optical, mechanical, and chemical properties that make them useful in a large number of insulating and non-insulating applications. SUMMARY

[0005] In a general aspect, the present disclosure can provide a durable and easy-to-handle aerogel material or composition. In an embodiment, the aerogel composition is a flexible, resilient, and self-supporting reinforced aerogel composition. In an embodiment, the aerogel composition is a flexible, resilient, and self-supporting foam-reinforced aerogel composition. In an embodiment, the aerogel composition is a foam-reinforced aerogel composition laminated with at least one facing sheet, wherein the resulting laminated composite is flexible, resilient, and self-supporting.

[0006] In a general aspect, the disclosure can provide an aerogel composite, comprising: at least one base layer comprising a reinforced aerogel composition, wherein the reinforced aerogel composition comprises a reinforcing material and an aerogel framework, and wherein the base layer has an upper surface and a lower surface; and at least one overlay layer adhered to at least one surface of the base layer. In an embodiment, at least a portion of the aerogel framework of the base layer extends into at least a portion of the aerogel framework of the overlay layer. In an embodiment, the overlay layer comprises an aerogel framework integrated into the overlay material, and at least a portion of the aerogel framework of the base layer is continuous with at least a portion of the aerogel framework of the overlay layer.

[0007] In a general aspect, the disclosure can provide an aerogel composite, comprising: at least one base layer comprising a reinforced aerogel composition, wherein the reinforced aerogel composition comprises a reinforcing material and an aerogel framework, and wherein the base layer has an upper surface and a lower surface; and at least one overlay layer adhered to the upper surface of the base layer and at least one overlay layer adhered to the lower surface of the base layer. In an embodiment, at least a portion of the aerogel framework of the base layer extends into at least a portion of the aerogel framework of the upper and lower overlay layers. In an embodiment, both the upper and lower overlay layers comprise an aerogel framework integrated into the overlay material, and at least a portion of the aerogel framework of the base layer is continuous with at least a portion of the aerogel framework of both the upper and lower overlay layers.

[0008] In a general aspect, the disclosure can provide a method of making an aerogel composite, comprising: providing a base layer comprising a reinforcing material and an aerogel framework, wherein the base layer has an upper surface and a lower surface; providing an overlay layer comprising a sheet of overlay material; and adhering the overlay layer to the base layer. In an embodiment, the method comprises providing at least two overlay layers comprising a sheet of overlay material; adhering an overlay layer to the upper surface of the base layer; and adhering an overlay layer to the lower surface of the base layer.

[0009] In one general aspect, the present disclosure can provide a method for making an aerogel composite, comprising: providing a substrate layer comprising a reinforcement material, wherein the substrate layer has an upper surface and a lower surface; providing a facing layer comprising a sheet of facing material; adhering the facing layer to a surface of the substrate layer; providing a gel precursor solution comprising a gel precursor material and a solvent; contacting the precursor solution with the facing layer and allowing at least a portion of the gel precursor solution to travel through the facing layer into the reinforcement material of the substrate layer; allowing the gel precursor material in the precursor solution to transform into a gel composition to form a sheet of reinforced gel; and extracting at least a portion of the solvent from the sheet of reinforced gel to obtain a reinforced aerogel composite. In one embodiment, the method comprises providing at least two facing layers comprising a sheet of facing material; adhering the facing layers to the upper surface of the substrate layer and adhering the facing layers to the lower surface of the substrate layer; providing a gel precursor solution comprising a gel precursor material and a solvent; contacting the precursor solution with the upper facing layer; allowing at least a portion of the gel precursor solution to travel through the upper facing layer into the reinforcement material of the substrate layer; and allowing at least a portion of the gel precursor solution to travel through the upper facing layer and through the substrate layer into the lower facing layer.

[0010] In one embodiment, the step of adhering the facing layer to a surface of the substrate layer produces a stack of reinforcement material; and the stack of reinforcement material is dispensed onto a moving assembly before the precursor solution is dispensed onto the facing layer of the stack. In one embodiment, the step of adhering the facing layer to a surface of the substrate layer produces a stack of reinforcement material; and the stack of reinforcement material is rolled into a preformed roll and placed in a container before the precursor solution is dispensed onto the facing layer of the stack using the container.

[0011] In an embodiment, the reinforcing material is a foam reinforcing material. In an embodiment, the reinforcing material is an open-cell foam reinforcing material, including reticulated open-cell foam reinforcing material. In an embodiment, the foam reinforcing material is a polyurethane foam or melamine foam. In an embodiment, the reinforced aerogel composite has a density of 0.250 grams (g) per cubic centimeter (cc) or less, 0.230 g / cc or less, 0.200 g / cc or less, 0.160 g / cc or less, 0.180 g / cc or less, between 0.140 g / cc and 0.250 g / cc, or between 0.160 g / cc and 0.250 g / cc. In an embodiment, the reinforced aerogel composite has a thermal conductivity of 26.0 mW / m-K or less, 24.0 mW / m-K or less, 22.0 mW / m-K or less, 20.0 mW / m-K or less, 19.0 mW / m-K or less, between 12.0 mW / m-K and 26.0 mW / m-K, between 14.0 mW / m-K and 26.0 mW / m-K, between 16.0 mW / m-K and 26.0 mW / m-K, or between 18.0 mW / m-K and 26.0 mW / m-K.

[0012] In an embodiment, the facing layer is a polymeric sheet; more particularly, a polymeric sheet comprising a polyester, polyethylene, polyurethane, polypropylene, polyacrylonitrile, polyamide, aramid; and, more particularly, a polymer such as poly(ethylene terephthalate), low density polyethylene, ethylene-propylene copolymer, poly(4-methyl-pentane), poly(tetrafluoroethylene), poly(l-butene), polystyrene, polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride, polyvinyl acrylonitrile, polymethyl methacrylate, polyoxymethylene, polyphenylsulfone, cellulose triacetate, polycarbonate, polyethylene naphthalate, polycaprolactam, polyhexamethylene adipamide, polyundecanoamide, polyacyl, or combinations thereof. In an embodiment, the polymeric sheet comprises or consists essentially of an expanded polymer material; more particularly, an expanded polymer material comprising PTFE (ePTFE), expanded polypropylene (ePP), expanded polyethylene (ePE), expanded polystyrene (ePS), or combinations thereof. In an embodiment, the polymeric sheet comprises or consists essentially of a microporous polymer material characterized by a pore size ranging from 0.1 micrometers (pm) to 210 pm, 0.1 pm to 115 pm, 0.1 pm to 15 pm, or 0.1 pm to 0.6 pm.

[0013] In one embodiment, the facing layer material comprises or consists essentially of a fluoropolymer material; more particularly, a fluoropolymer material comprising polytetrafluoroethylene (PTFE), microporous PTFE disclosed in U.S. Patent No. 5,814,405, expanded PTFE (ePTFE) such as Gore-Tex® (available from W.L. Gore), polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), perfluoroalkoxy (PFA), fluorinated ethylene-propylene (FEP), polychlorotrifluoroethylene (PCTFE), ethylene-tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), ethylene-chlorotrifluoroethylene (ECTFE), or combinations thereof.

[0014] In one embodiment, the facing layer material comprises or consists essentially of a non-fluoropolymer material; more particularly, a non-fluoropolymer material comprising aluminized Mylar; low density polyethylene, such as Tedlar® (available from DuPont); rubber or rubber composites; elastomeric fibers, such as spandex, nylon, Lycra, or elastane; or combinations thereof. In one embodiment, the facing material is a flexible facing material. In one embodiment, the facing material is made of elastomeric fibers comprising spandex, nylon, Lycra, elastane, or combinations thereof. In one embodiment, the facing material is a fluid permeable facing material.

[0015] In one embodiment, the facing layer is adhered to the base layer by an adhesive or non-adhesive mechanism. In one embodiment, the adhesive comprises an aerosol adhesive, a urethane adhesive, an acrylate adhesive, a hot melt adhesive, an epoxy, a rubber resin adhesive, or a polyurethane composite adhesive. In one embodiment, the non-adhesive mechanism comprises stitching, a sealed pocket, rivets, buttons, clips, wrapping, or bracing.

[0016] In one general aspect, the present disclosure can provide a method of making an aerogel composition, the method comprising: providing a reinforced aerogel block comprising a foam reinforcement material; exposing the reinforced aerogel block to a shaving or skiving device; causing the shaving or skiving device to remove a continuous piece of reinforced aerogel material from the reinforced aerogel block, thereby producing a piece of reinforced aerogel.

[0017] In a general aspect, the disclosure can provide a method of making an aerogel composition, the method comprising: placing a plurality of reinforced aerogel pieces comprising a foam reinforcing material in a container; providing a precursor solution comprising a gel precursor material and a solvent; dispensing the gel precursor solution into the container and allowing the gel precursor to infiltrate each foam reinforcing material in the container; allowing the gel precursor material in the precursor solution to transform into a gel composition, forming a piece of reinforced gel material; exposing the piece of reinforced gel material to a shaving or peeling device; allowing the shaving or peeling device to remove a continuous piece of reinforced gel material from the piece of reinforced gel, thereby producing a piece of reinforced gel; and removing at least a portion of the solvent from the piece of reinforced gel material to obtain a piece of reinforced aerogel material.

[0018] In a general aspect, the disclosure can provide a method of making an aerogel composition, the method comprising: placing a plurality of reinforced aerogel pieces comprising a foam reinforcing material in a container; providing a precursor solution comprising a gel precursor material and a solvent; dispensing the gel precursor solution into the container and allowing the gel precursor to infiltrate each foam reinforcing material in the container; allowing the gel precursor material in the precursor solution to transform into a gel composition, forming a piece of reinforced gel material; removing at least a portion of the solvent from the piece of reinforced gel material to obtain a piece of reinforced aerogel material; exposing the piece of reinforced aerogel material to a shaving or peeling device; and allowing the shaving or peeling device to remove a continuous piece of reinforced aerogel material from the piece of reinforced aerogel, thereby producing a piece of reinforced aerogel.

[0019] In a general aspect, the disclosure can provide a method of making an aerogel composition, the method comprising: providing a piece of reinforced aerogel material comprising a foam reinforcing material; heating the piece of reinforced aerogel material to a target temperature; molding or shaping the piece of reinforced aerogel material before, during, or after the heating step; and allowing the molded or shaped piece of reinforced aerogel to cool, such that the piece of reinforced aerogel material retains its molded shape after cooling. In an embodiment, the target temperature is between 50°C and 200°C, between 75°C and 200°C, between 100°C and 175°C, between 120°C and 160°C, or about 150°C. In an embodiment, the target temperature is a temperature that is above the softening point of the foam reinforcing material and below the maximum use temperature of the foam reinforcing material. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 To illustrate a method of making a piece of reinforced gel from an aerogel precursor and a reinforcing piece using a conveyor system.

[0021] Figure 2To illustrate a method of making reinforced gel sheets from aerogel precursors and reinforcing sheets using a roll-to-roll gel system.

[0022] Figure 3 To illustrate a flat laminated sheet that comprises a base layer having a foam-reinforced aerogel composite and a flexible facing layer on each surface of the base layer.

[0023] Figure 4 To illustrate a rolled laminated sheet that comprises a base layer having a foam-reinforced aerogel composite and a flexible facing layer on each surface of the base layer.

[0024] Figure 5 To illustrate a laminated sheet that comprises a base layer having a foam-reinforced aerogel composite and an impermeable facing layer on each surface of the base layer.

[0025] Figure 6 To illustrate a rolled laminated sheet that comprises multiple layers bonded using ultrasonic stitching.

[0026] Figure 7 To illustrate a flat laminated sheet that comprises multiple layers bonded using ultrasonic stitching.

[0027] Figure 8 To illustrate a flat foam-reinforced aerogel sheet that is folded into a preformed shape and secured using a strap.

[0028] Figure 9 To illustrate a foam-reinforced aerogel sheet that is formed into a curved preformed shape from a flat sheet using heat treatment.

[0029] Figure 10 To illustrate a multi-layered laminate that comprises multiple foam-reinforced aerogel sheets that are formed into curved preformed shapes from flat sheets using heat treatment and subsequently laminated together using an adhesive.

[0030] Figure 11 To illustrate a pipe insulation section that comprises multiple foam-reinforced aerogel sheets that are formed into curved preformed shapes from flat sheets using heat treatment, subsequently laminated together using an adhesive, and finally secured around a pipe section. DETAILED DESCRIPTION

[0031] Aerogels are a class of porous materials with open pores that comprise a framework of interconnected structures and a corresponding network of pores integrated within the framework, and an interstitial phase between the network of pores that is primarily composed of a gas such as air. Aerogels are typically characterized by low density, high porosity, large surface area, and small pore size. Aerogels can be distinguished from other porous materials by their physical and structural properties.

[0032] Aerogels can also be extremely brittle and difficult to handle. The brittleness of low-density aerogels can present significant complications during manufacturing and processing, which can significantly limit the large-scale manufacturing of such materials. The brittleness of aerogels can also make aerogel materials difficult to infuse and apply due to concerns of pulverization, breakage, or structural degradation. Thus, there is a need to develop aerogel compositions that are flexible, durable, and easy to handle.

[0033] One solution to the brittleness of low-density aerogels is to manufacture aerogel materials that are reinforced with more rigid or resilient materials. Such reinforcing materials can include polymeric binders, adhesives, fibrous or fibrous mats, sealed envelopes, cements, and foams. However, most reinforced composite aerogels are subject to significantly degraded thermal insulation performance when compared to monolithic aerogels composed solely of aerogel. Reinforced composite aerogels can also have poor stability under wet or high-temperature conditions, and insufficient flexibility for most applications. Most reinforcing materials do not completely solve the problems associated with pulverization, breakage, or structural degradation of aerogel materials. Furthermore, reinforcing materials can generally be expensive and difficult to obtain, presenting significant complications and drawbacks in large-scale manufacturing and market operations of commodities.

[0034] Thus, there is a need to develop reinforced aerogel compositions that are flexible, durable, easy to handle, and resistant to pulverization, breakage, and general structural degradation. There is also a need to develop reinforced aerogel compositions that are inexpensive, easily produced through large-scale manufacturing, and effectively applicable in insulating applications across the spectrum.

[0035] In the context of the present disclosure, the term "aerogel" or "aerogel material" refers to a gel that comprises a framework of interconnected structures, and a corresponding network of interconnected pores integrated within the framework, and containing a gas such as air as a dispersed interstitial medium; characterized by the following physical and structural properties that can be attributed to aerogels (according to the nitrogen porosimetry method): (a) an average pore diameter ranging from about 2 nanometers (nm) to about 100 nm, (b) a porosity of at least 80% or higher, and (c) a surface area of about 20 square meters (m 2 ) / gram (g) or higher.

[0036] The aerogel materials of the present disclosure thus include any aerogel or other open- cell compound that satisfies the defining elements detailed in the preceding paragraphs; including compounds that can otherwise be classified as xerogels, cryogels, ambigels, microporous materials, and the like.

[0037] Aerogel materials can also be further characterized by additional physical properties, including: (d) a pore volume of about 2.0 milliliters (mL) / g or greater, preferably about 3.0 mL / g or greater; (e) a density of about 0.50 g / cc or less, preferably about 0.25 g / cc or less; and (f) at least 50% of the total pore volume comprises pores having a pore diameter between 2 and 50 nm; although a compound need not satisfy these additional properties to be characterized as an aerogel material.

[0038] In the context of the present disclosure, the term "innovative processing and extraction techniques" refers to methods of replacing the liquid interstitial phase in a wet gel material with a gas, such as air, in a manner that results in low pore collapse and low shrinkage of the gel framework structure. Drying techniques, such as atmospheric evaporation, often induce strong capillary pressure and other mass transfer limitations at the liquid-vapor interface where the interstitial phase is being evaporated or removed. The strong capillary forces generated by liquid evaporation or removal can cause significant pore shrinkage and framework collapse within the gel material. The use of innovative processing and extraction techniques during the extraction of the liquid interstitial phase serves to mitigate the negative effects of capillary forces on the pores and framework of the gel during the liquid phase extraction process.

[0039] In certain embodiments, the innovative processing and extraction techniques involve the use of near-critical or supercritical fluids, or near-critical or supercritical conditions, to extract the liquid interstitial phase from a wet gel material. This can be accomplished by removing the liquid interstitial phase near or above the critical point of the liquid or liquid mixture. Co-solvents and solvent exchange can be used to optimize the near-critical or supercritical fluid extraction process.

[0040] In the context of the present disclosure, the term "framework" or "framework structure" refers to the network of interconnected oligomers, polymers, or colloidal particles that form the solid structure of a gel or aerogel. The polymers or particles that make up the framework structure are typically of about 100 Angstroms in diameter. However, the framework structures of the present disclosure can also include networks of interconnected oligomers, polymers, or colloidal particles that form the solid structure of a gel or aerogel. Furthermore, the term "silica is an aerogel" or "silica is a framework" refers to an aerogel framework in which silica comprises at least 50% (by weight) of the oligomers, polymers, or colloidal particles that form the solid framework structure within the gel or aerogel.

[0041] In the context of the present disclosure, the term "aerogel composition" refers to any composite material that includes an aerogel material as a component of the composite. Examples of aerogel compositions include, but are not limited to: fiber-reinforced aerogel composites; aerogel composites that include additional elements such as sunscreens; aerogel-foam composites; aerogel-polymer composites; and composites that incorporate aerogel particles, granules, pellets, beads, or powder into a solid or semi-solid material such as an adhesive, resin, cement, foam, polymer, or similar solid material.

[0042] In the context of the present disclosure, the term "foam" refers to a material that comprises a framework of interconnected polymeric structures, and a corresponding network of interconnected pores or a collection of independent pores integrated into the framework, the pores of the foam containing a gas such as air as a dispersion medium; and the foam has an average pore diameter greater than 300 nm.

[0043] Alternatively, the term "foam" can refer to a material that comprises a porous solid formed by dispersing a large volume fraction of gas in the form of bubbles in a liquid, solid, or gel, where the bubbles are generally stabilized by solid particles or by soluble substances. Generally, a wide variety of processes can be used to make foams, see, for example, U.S. Patent Nos. 6,147,134; 5,889,071; 6,187,831; and 5,229,429.

[0044] The pores within the foam framework can also be referred to as "cells." Cells can be separated by cell walls or membranes, creating a collection of independent, closed pores within the foam. The term "closed cell foam" refers to a foam material in which at least 50% of the pore volume is narrow cells that are closed by membranes or walls. The cells in the foam can also be interconnected by open pores, creating a network of interconnected open pores within the foam. The term "open cell foam" refers to a foam material in which at least 50% of the pore volume is open. The open cell foam can comprise reticulated open cell foam, non-reticulated open cell foam, or a combination thereof. Reticulated foam is an open cell foam that is made by a reticulation process that eliminates or punctures the cell membranes in the foam material. Reticulated foam typically has a higher open cell concentration than non-reticulated foam, but tends to be more expensive and more difficult to make. Generally, no foam material is completely one type of cell structure (open or closed). A wide variety of processes can be used to make foams, including the foam-making processes in U.S. Patent Nos. 6,147,134; 5,889,071; 6,187,831; 5,229,429; and 4,454,248; and U.S. Patent Application No. 20070213417.

[0045] In the context of the present invention, the term "rebound foam" refers to foam from a process that involves bonding together particles or pieces of a batch of foam material, typically processing scrap. A variety of adhesives and bonding processes can be used, and the foam used can be ground or shredded prior to rebounding. The foam can be rebounded as a way to reduce costs by using foam that would otherwise be discarded. A typical application of rebounded foam is as a carpet underlayment.

[0046] In the context of the present invention, the term "monolithic" refers to aerogel materials in which a majority (by weight) of the aerogels included in the aerogel material or composition are in the form of a single interconnected aerogel nanostructure. Monolithic aerogel materials include aerogel materials that are initially formed without a single interconnected gel aerogel nanostructure, but are subsequently broken, fractured, or divided into non-single aerogel nanostructures. Monolithic aerogel materials are distinct from particulate aerogel materials. The term "particulate aerogel material" refers to aerogel materials in which a majority (by weight) of the aerogels included in the aerogel material are in the form of microparticles, particles, granules, beads, or powder that can be aggregated or compressed together but lack interconnected aerogel nanostructures between the individual particles.

[0047] In the context of the present invention, the term "reinforced aerogel composition" refers to an aerogel composition that includes a reinforcing phase that is located within the aerogel material and is not part of the aerogel framework. The reinforcing phase can be any material that provides increased flexibility, resiliency, consistency, or structural stability to the aerogel material. Examples of known reinforcing materials include, but are not limited to, open cell foam reinforcing materials, polymeric reinforcing materials, and fibrous reinforcing materials, such as discrete fibers, woven materials, non-woven materials, batting, webs, mats, and blankets. In addition, the fibers as reinforcement can be used in combination with one or more other reinforcing materials, and can be aligned continuously within the entire composition or within a limited preferred portion of the composition.

[0048] In the context of the present invention, the term "fiber reinforced aerogel composition" refers to a reinforced aerogel composition that includes a fiber reinforcement material as the reinforcing phase. Examples of fiber reinforcement materials include, but are not limited to, discrete fibers, woven materials, non-woven materials, batts, webs, felts, and blankets. The fiber reinforcement material can include a range of materials including, but not limited to: polyesters, polyolefin polyphthalate, polyethylene naphthalate, polycarbonates (examples are rayon, nylon), cotton (e.g., Lycra manufactured by DuPont), carbon (e.g., graphite), polyacrylonitrile (PAN), oxidized PAN, uncabonized heat treated PAN (e.g., those manufactured by SGL carbon), fiberglass as a material (e.g., S-glass, 901 glass, 902 glass, 475 glass, E-glass), silica as a fiber such as quartz (e.g., Quartzel manufactured by Saint-Gobain), Q-blanket (manufactured by Johns Manville), Saffil (manufactured by Saffil), Durablanket (manufactured by Unifrax), and other silica fibers, Duraback (manufactured by Carborundum), polyaramid fibers such as Kevlar, Nomex, Sontera (all manufactured by DuPont), Conex (manufactured by Taijin), polyolefins such as Tyvek (manufactured by DuPont), Dyneema (manufactured by DSM), Spectra (manufactured by Honeywell), other polypropylene fibers such as Typar, Xavan (both manufactured by DuPont), fluoropolymers such as PTFE under the trade name Teflon (manufactured by DuPont), Goretex (manufactured by W.L. GORE), silicon carbide fibers such as Nicalon (manufactured by COI Ceramics), ceramic fibers such as Nextel (manufactured by 3M), acrylic polymers, wood fibers, silk fibers, hemp fibers, leather fibers, sheepskin fibers, PBO-Zylon fibers (manufactured by Tyobo), liquid crystal materials such as Vectan (manufactured by Hoechst), Cambrelle fibers (manufactured by DuPont), polyurethanes, polyaramids, wood fibers, boron fibers, aluminum fibers, iron fibers, stainless steel fibers, and other thermoplastic materials such as PEEK, PES, PEI, PEK, PPS.

[0049] In the context of the present invention, the term "foam-reinforced aerogel composition" or "aerogel-foam composite" refers to a reinforced aerogel composition comprising a foam reinforcement material as the reinforcing phase. The foam reinforcement material can comprise an open-cell foam, a closed-cell foam, or a combination thereof. Foams suitable for use in the present invention include, but are not limited to, foams made from polymeric materials. Examples include foams made from polyolefins, polyurethanes, phenol formaldehyde resins, melamine, cellulose acetate, and polystyrene. Polyolefin foams are preferred; more preferred are polyurethane foams. Polyether polyurethane foams are preferred for non- reticulated foams; polyester polyurethane foams are preferred for reticulated foams. Examples of polyurethane foams and polyepoxide foams for use in the present invention are found in U.S. Patents Nos. 2,117,605; 3,094,433; 2,739,134; 3,112,524; 2,789,095; 3,129,191; 2,811,499; 3,171,820; 2,831,820; 2,920,983; 3,342,922; 2,926,390; 3,386,877; 2,936,294; 3,459,274; 2,993,869; 3,504,064; 3,025,200; 3,506,600; 3,055,360; 3,650,993; 3,057,750; 3,860,537; 3,060,137; 4,252,517; 3,075,926; 3,082,611; and 3,090,094. Melamine foams are also preferred in certain embodiments. Examples of melamine foams for use in the present invention are found in U.S. Patents Nos. 8,546,457 and 4,666,948 and WO 2001 / 094436. The foam reinforcement material can be a recombined foam.

[0050] In the context of the present disclosure, the term "aerogel blanket" or "aerogel blanket composition" refers to an aerogel composition reinforced with a continuous sheet of reinforcement material. The aerogel blanket composition can be distinguished from other reinforced aerogel compositions reinforced with non-continuous fibers or foam webs such as discrete agglomerates or fiber material clumps. The aerogel blanket composition is particularly useful in applications requiring flexibility because it is highly conformable and can be used as a blanket to cover the surface or complex geometry of a sample while also retaining the excellent thermal insulation properties of aerogels. Aerogel blanket compositions and similar fiber-reinforced aerogel compositions are disclosed in U.S. Patent Application No. 2002 / 0094426 (paragraphs 12-16, 25-27, 38-58, 60-88) which is incorporated herein by reference for the independently recited paragraphs and sections.

[0051] In the context of the present disclosure, the term "wet gel" refers to a gel in which the mobile interstitial phase within the network of interconnected pores is primarily composed of a liquid phase such as a traditional solvent, a liquefied gas such as liquid carbon dioxide, or a combination thereof. Aerogels are typically derived from a starting wet gel that is subjected to novel processing and extraction to replace the mobile interstitial liquid phase with air, thereby forming a dry gel. Examples of wet gels include, but are not limited to, alcohol gels, water gels, ketone gels, carbon gels, and other wet gels known to those skilled in the art.

[0052] In the context of the present disclosure, the term "additive" or "additive element" refers to a material that can be added to an aerogel composition before, during, or after the manufacture of the aerogel. Additives can be added to alter or enhance desired properties of the aerogel, or to offset undesirable properties of the aerogel. Additives are typically added to the aerogel material before or during gelation. Examples of additives include, but are not limited to, microfibers, fillers, reinforcing agents, stabilizers, thickening agents, elastomeric compounds, sunscreens, colorants or pigments, radiation absorbing compounds, radiation reflecting compounds, corrosion inhibitors, thermal conductive components, phase change materials, pH adjusters, redox adjusters, HCN mitigants, exhaust gas mitigants, electrically conductive compounds, dielectric compounds, magnetic compounds, radar blocking components, hardening agents, anti-shrinkage agents, and other aerogel additives known to those skilled in the art. Other examples of additives include smoke suppressants and fire retardants. U.S. Patent Application Publication No. 20070272902 Al (paragraphs

[0008] and

[0010] to

[0039] ) discloses teachings of smoke suppressants and fire retardants, and is incorporated herein by reference for the independently recited paragraphs.

[0053] In the context of the present disclosure, the terms "flexible" and "flexibility" refer to the ability of an aerogel material or composition to bend or flex without causing macroscopic failure. Preferably, the aerogel compositions of the present disclosure can bend at least 5°, at least 25°, at least 45°, at least 65°, or at least 85° without macroscopic failure; and / or have a bend radius of less than 4 feet, less than 2 feet, less than 1 foot, less than 6 inches, less than 3 inches, less than 2 inches, less than 1 inch, or less than 0.5 inches without macroscopic failure. Likewise, the terms "highly flexible" and "high flexibility" refer to the ability of an aerogel material or composition to bend at least 90° and / or have a bend radius of less than 0.5 inches without macroscopic failure. Further, the terms "classified as flexible" and "classified as flexibility" refer to the ability of an aerogel material or composition to be classified as flexible according to ASTM Classification Standard C1101 (ASTM International, West Conshohocken, PA).

[0054] The aerogel materials or compositions of the present disclosure can be flexible, highly flexible, and / or classified as flexible. The aerogel materials or compositions of the present disclosure can also be hangable. In the context of the present disclosure, the terms "hangable" and "hangability" refer to the ability of an aerogel material or composition to bend or flex to an angle of 90° or greater with a radius of curvature of about 4 inches or less without macroscopic failure. The aerogel materials or compositions of the present disclosure are preferably flexible, such that the compositions are non-rigid and can be applied and conform to three-dimensional surfaces or objects, or pre-formed into a variety of shapes and configurations to simplify installation or application.

[0055] In the context of the present disclosure, the terms "resilient" and "resiliency" refer to the ability of an aerogel material or composition to at least partially return to its original form or size after deformation by compression, flexing, or bending. Resiliency can be full or partial, and it can be expressed as a percentage of recovery. The aerogel materials or compositions of the present disclosure preferably have a resiliency of more than 25%, more than 50%, more than 60%, more than 70%, more than 75%, more than 80%, more than 85%, more than 90%, or more than 95% in returning to its original form or size after deformation. Likewise, the terms "classified as resilient" and "classified as resiliency" refer to the ability of the aerogel materials or compositions of the present disclosure to be classified as resilient according to ASTM Classification Standard C1101 (ASTM International, West Conshohocken, PA).

[0056] In the context of the present disclosure, the term "self-supporting" refers to the ability of an aerogel material or composition to be flexible and / or resilient based primarily on the physical properties of the aerogel and any reinforcing phases in the aerogel composition. The self-supporting aerogel materials or compositions of the present disclosure can be distinguished from other aerogel materials, such as coatings, which rely on an underlying substrate to provide flexibility and / or resiliency to the material.

[0057] In the context of the present disclosure, the term "shrinkage" refers to the ratio of 1) the difference between the final density of a measured dried aerogel material or composition and the target density calculated from the solids content of the sol-gel precursor solution, to 2) the target density calculated from the solids content of the sol-gel precursor solution. Shrinkage can be calculated by the following equation: Shrinkage = [Final Density (g / cm 3 ) - Target Density (g / cm 3 )] / [Target Density (g / cm 3 )]. Preferably, the shrinkage of the aerogel materials of the present disclosure is preferably 50% or less, 25% or less, 10% or less, 8% or less, 6% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, 0.1% or less, about 0.01% or less, or within a range between any two of these values.

[0058] In the context of the present disclosure, the terms "thermal conductivity" and "TC" refer to a measure of the ability of a material or composition to transfer heat between two surfaces of the material or composition, where the two surfaces are at a temperature difference. Thermal conductivity is specifically measured as the amount of heat energy transferred per unit of time and per unit of surface area divided by the temperature difference. It is typically reported in the SI unit of mW / m*K (milliwatts per meter Kelvin). The thermal conductivity of a material can be determined by methods known in the art, including, but not limited to: Test Method for Steady-State Thermal Transmission Properties by Means of Heat Flow Meter Apparatus (ASTM C518, ASTM International, West Conshohocken, PA); Test Method for Measuring Thermal Flux and Thermal Transmission Under Steady-State Conditions with Guarded Hot Plate Apparatus (ASTM C177, ASTM International, West Conshohocken, PA); Test Method for Steady-State Heat Transfer Properties of Pipe Insulations (ASTM C335, ASTM International, West Conshohocken, PA); Thin Heater Thermal Conductivity Test (ASTM C1114, ASTM International, West Conshohocken, PA); Determination of Thermal Resistances by Means of Guarded Hot Plate and Heat Flow Meter Methods (EN 12667, British Standards Institution, United Kingdom); Determination of Thermal Resistances by Means of Guarded Hot Plate Apparatus or Steady-State Heat Flow and Related Properties (ISO 8203, International Organization for Standardization, Switzerland). In the context of the present disclosure, unless explicitly stated, thermal conductivity measurements are taken according to the ASTM C177 standard at a temperature of about 37.5 °C, atmospheric pressure, and a pressure of about 2 psi. Preferably, the aerogel material or composition of the present disclosure has a thermal conductivity of about 50 mW / m*K or less, about 40 mW / m*K or less, about 30 mW / m*K or less, about 25 mW / m*K or less, about 20 mW / m*K or less, about 18 mW / m*K or less, about 16 mW / m*K or less, about 14 mW / m*K or less, about 12 mW / m*K or less, about 10 mW / m*K or less, about 5 mW / m*K or less, or within a range between any two of these values.

[0059] In the context of this disclosure, the term "density" refers to a measurement of the mass of an aerogel material or composition per unit volume. The term "density" generally refers to the true density of the aerogel material and the bulk density of the aerogel composition. Density is typically expressed in kg / m³. 3 Density may be recorded in g / cc. The density of aerogel materials or compositions can be determined by methods known in the art, including, but not limited to: standard test methods for the dimensions and density of preformed blocks and plate-type thermal insulators (ASTM C303, ASTM International, West Conshohocken, PA); standard test methods for the thickness and density of coated or flocculent thermal insulators (ASTM C167, ASTM International, West Conshohocken, PA); or determination of the apparent density of preformed tubular insulators (ISO 18098, International Organization for Standardization, Switzerland). In the context of this disclosure, unless explicitly stated otherwise, density measurements are obtained according to ASTM C167. Preferably, the density of the aerogel material or composition disclosed herein is about 0.60 g / cc or less, about 0.50 g / cc or less, about 0.40 g / cc or less, about 0.30 g / cc or less, about 0.25 g / cc or less, about 0.20 g / cc or less, about 0.18 g / cc or less, about 0.16 g / cc or less, about 0.14 g / cc or less, about 0.12 g / cc or less, about 0.10 g / cc or less, about 0.05 g / cc or less, about 0.01 g / cc or less, or within any two of these values.

[0060] In the context of this disclosure, the term "hydrophobicity" refers to a measure of the ability of an aerogel material or composition to repel water.

[0061] The hydrophobicity of an aerogel material or composition can be expressed in terms of liquid water uptake. In the context of the present disclosure, the term "liquid water uptake" refers to a measure of the potential of an aerogel material or composition to absorb or retain liquid water. Liquid water uptake can be expressed as the percentage (by weight or volume) of water absorbed or retained by an aerogel material or composition when exposed to liquid water under certain measured conditions. Liquid water uptake of an aerogel material or composition can be determined by methods known in the art, including, but not limited to: Standard Test Method for Determining Water Retention (Repellency) of Glass Fiber Insulation (ASTM C1511, ASTM International, West Conshohocken, PA); Standard Test Method for Testing Water Absorption by Immersion of Thermal Insulation Materials (ASTM C1763, ASTM International, West Conshohocken, PA); Determination Method for Short-term Water Absorption by Partial Immersion for Thermal Insulation Products of Application (EN 1609, British Standards Institution, United Kingdom). In the context of the present disclosure, unless explicitly indicated, liquid water uptake measurements are taken according to the ASTM C1511 standard at about ambient temperature and pressure. Preferably, according to ASTM C1511, the aerogel materials or compositions of the present disclosure have a liquid water uptake of about 100 wt% or less, about 80 wt% or less, about 60 wt% or less, about 50 wt% or less, about 40 wt% or less, about 30 wt% or less, about 20 wt% or less, about 15 wt% or less, about 10 wt% or less, about 8 wt% or less, about 3 wt% or less, about 2 wt% or less, about 1 wt% or less, about 0.1 wt% or less, or in a range between any two of these values. According to ASTM C1763, the aerogel materials or compositions of the present disclosure can have a liquid water uptake of about 100 wt% or less, about 80 wt% or less, about 60 wt% or less, about 50 wt% or less, about 40 wt% or less, about 30 wt% or less, about 20 wt% or less, about 15 wt% or less, about 10 wt% or less, about 8 wt% or less, about 3 wt% or less, about 2 wt% or less, about 1 wt% or less, about 0.1 wt% or less, or in a range between any two of these values. An aerogel material or composition having improved liquid water uptake relative to another aerogel material or composition will have a percentage of liquid water uptake / retention that is reduced relative to the reference aerogel material or composition.

[0062] The hydrophobicity of an aerogel material or composition can be manifested by the water vapor uptake. In the context of the present disclosure, the term "water vapor uptake" refers to a measure of the potential of an aerogel material or composition to absorb water vapor. The water vapor uptake can be manifested as the percentage (by weight) of water absorbed or retained by an aerogel material or composition when exposed to water vapor under certain measured conditions. The water vapor uptake of an aerogel material or composition can be determined by methods known in the art, including, but not limited to, Standard Test Method for Determining Water Vapor Sorption of Non-Fibrous Insulation (ASTM C1104, ASTM International, West Conshohocken, PA). In the context of the present disclosure, unless explicitly stated otherwise, water vapor uptake measurements are taken according to the ASTM C1104 standard at about room temperature and pressure. Preferably, the aerogel materials or compositions of the present disclosure have a water vapor uptake of about 50 wt% or less, about 40 wt% or less, about 30 wt% or less, about 20 wt% or less, about 15 wt% or less, about 10 wt% or less, about 8 wt% or less, about 3 wt% or less, about 2 wt% or less, about 1 wt% or less, about 0.1 wt% or less, or in a range between any two of these values. An aerogel material or composition having an improved water vapor uptake relative to another aerogel material or composition will have a reduced percentage of water vapor uptake / residence relative to the reference aerogel material or composition.

[0063] The hydrophobicity of an aerogel material or composition can be manifested by measuring the equilibrium contact angle of a water droplet at the interface with the surface of the material. The aerogel materials or compositions of the present disclosure can have a water contact angle of about 90° or greater, about 120° or greater, about 130° or greater, about 140° or greater, about 150° or greater, about 160° or greater, about 170° or greater, about 175° or greater, or in a range between any two of these values.

[0064] An aerogel is a framework of interconnected structures, most commonly composed of interconnected oligomers, polymers, or colloidal particles. Aerogel frameworks can be made from precursor materials including the range of: inorganic precursor materials (such as used to produce silica as an aerogel precursor); organic precursor materials (such as used to produce carbon as an aerogel precursor); hybrid inorganic / organic precursor materials; and combinations thereof. In the context of the present disclosure, the term "composite aerogel" refers to an aerogel produced from two or more different gel precursors.

[0065] Inorganic aerogels are generally made from metal oxide or metal alkoxide materials. The metal oxide or metal alkoxide materials can be oxides or alkoxides based on any metal that can form an oxide. Such metals include, but are not limited to: silicon, aluminum, titanium, zirconium, hafnium, yttrium, vanadium, cerium, and the like. Inorganic silica aerogels are traditionally made by hydrolysis and condensation of silica as an alkoxide, such as tetraethoxysilane, or by gelation of silicic acid or water glass. Other related inorganic precursor materials for silica as aerogel synthesis include, but are not limited to: metal silicates such as sodium silicate or potassium silicate, alkoxysilanes, partially hydrolyzed alkoxysilanes, tetraethoxysilane (TEOS), partially hydrolyzed TEOS, condensates of TEOS, tetramethoxysilane (TMOS), partially hydrolyzed TMOS, condensates of TMOS, tetra-n-propoxysilane, partially hydrolyzed tetra-n-propoxysilane, and / or condensates of tetra-n-propoxysilane, ethyl silicate, partially hydrolyzed ethyl silicate, monomeric alkyl alkoxysilanes, bis-trialkoxylalkyl or aryl silanes, polyhedral silsesquioxanes, or combinations thereof.

[0066] In one embodiment of the present application, pre-hydrolyzed TEOS such as Silbond H-5 (SBH5, Silbond Corp) is hydrolyzed with a water / silica ratio of about 1.9 to 2, and can be purchased directly for use or can be further hydrolyzed prior to incorporation into the gelation process. Partially hydrolyzed TEOS or TMOS, such as ethyl silicate (Silbond 40) or methyl silicate can also be purchased directly for use or can be further hydrolyzed prior to incorporation into the gelation process.

[0067] Inorganic aerogels can also include gel precursors that include at least one hydrophobic group, such as alkyl metal alkoxides, cycloalkyl metal alkoxides, and aryl metal alkoxides, which can impart certain properties or improve certain properties such as stability and hydrophobicity to the gel. Inorganic silica aerogels can specifically include hydrophobic precursors such as alkylsilanes or arylsilanes. Hydrophobic gel precursors can be used as the primary precursor material to form the framework of the gel material. However, hydrophobic gel precursors are more commonly used as co-precursors in combination with simple metal alkoxides in the formation of composite aerogels. Hydrophobic inorganic precursor materials for silica as aerogel synthesis include, but are not limited to: trimethylmethoxysilane [TMS], dimethyldimethoxysilane [DMS], methyltrimethoxysilane [MTMS], trimethylethoxysilane, dimethyldiethoxysilane [DMDS], methyltriethoxysilane [MTES], ethyltriethoxysilane [ETES], diethyldiethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane [PhTES], hexamethyldisilazane, and hexaethyldisilazane, among others.

[0068] Aerogels can also be treated to impart or improve hydrophobicity. Hydrophobic treatments can be applied to sol-gel solutions, to wet gels prior to liquid extraction, or to aerogels after liquid extraction. Hydrophobic treatments are particularly common in the production of metal oxide aerogels such as silica aerogels. One example of a hydrophobic treatment of a gel is explored in more detail below, specifically in the context of treating a silica wet gel. However, the specific examples and illustrative descriptions herein are not intended to limit the scope of the invention to any particular type of hydrophobic treatment process or aerogel substrate. The invention can include any gel or aerogel known to those skilled in the art, as well as methods of treating the gel or aerogel in a hydrophobic wet gel form or a dry aerogel form.

[0069] A hydrophobic treatment is accomplished by reacting the hydroxyl groups on the gel, such as the silanol groups (Si-OH) present on the framework of a silica gel, with the functional groups of a hydrophobic agent. The resulting reaction is a transformation of the silanol groups and the hydrophobic agent into a hydrophobic group on the framework of the silica gel. The hydrophobic agent compound can react with the hydroxyl groups on the gel according to the following reaction: 4-N (hydrophobic agent) + MOH (silanol) → MOMRN (hydrophobic group) + HX. The hydrophobic treatment can occur on the external large surface of the silica gel and on the internal pore surface within the porous network of the gel.

[0070] The gel can be immersed in a mixture of a hydrophobic agent and, optionally, a hydrophobic treatment solvent, where the hydrophobic agent is soluble in the solvent and the solvent is also miscible with the gel solvent in the wet gel. A large number of hydrophobic treatment solvents can be used, including solvents such as methanol, ethanol, isopropanol, xylene, toluene, benzene, dimethylformamide, and hexane. The hydrophobic agent can also be contacted directly with the gel in liquid or gaseous form to impart hydrophobicity to the latter.

[0071] The hydrophobic treatment process can include mixing or agitation to help the hydrophobic agent penetrate the wet gel. The hydrophobic treatment process can also include varying other conditions such as temperature and pH to further enhance and optimize the reaction conditions. After the reaction is complete, the wet gel is washed to remove unreacted compounds and reaction byproducts.

[0072] The hydrophobic agent used for the hydrophobic treatment of the aerogel is generally a compound of the formula: N MX 4-N; wherein M is a metal; R is a hydrophobic group such as CH3, CH2CH3, C6H6, or similar hydrophobic alkyl, cycloalkyl, or aryl moiety; and X is a halogen, typically CI. Specific examples of hydrophobation agents include, but are not limited to: trimethylchlorosilane [TMCS], triethylchlorosilane [TECS], triphenylchlorosilane [TPCS], dimethylchlorosilane [DMCS], dimethyldichlorosilane [DMDCS], and the like. The hydrophobation agent can also be of the form: Y(R3M)2; wherein M is a metal; Y is a bridging group such as NH or O; and R is a hydrophobic group such as CH3, CH2CH3, C6H6, or similar hydrophobic alkyl, cycloalkyl, or aryl moiety. Specific examples of such hydrophobation agents include, but are not limited to: hexamethyldisilazane [HMDZ] and hexamethyldisiloxane [HMDSO]. The hydrophobation agent can further include compounds of the form: R N MV 4-N wherein V is a reactive or leaving group other than halogen. Specific examples of such hydrophobation agents include, but are not limited to: vinyltriethoxysilane and vinyltrimethoxysilane.

[0073] Organic aerogels are typically formed from carbon-based polymeric precursors. Such polymeric materials include, but are not limited to: resorcinol formaldehyde (RF), polyimide, polyacrylate, polymethyl methacrylate, acrylate oligomer, polyoxene, polyurethane, polyphenol, polybutadiene, polydimethylsiloxane terminated with trialkoxysilane groups, polystyrene, polyacrylonitrile, polyfurfural, melamine-formaldehyde, cresol-formaldehyde, phenol-furfural, polyether, polyalcohol, polyisocyanate, polyhydroxybenzene, polyvinyl alcohol dialdehyde, polycyanurate, polyacrylamide, various epoxides, agar, agarose, chitosan, and combinations thereof. As an example, organic RF aerogels are typically made from the sol-gel polymerization of resorcinol or melamine with formaldehyde under basic conditions.

[0074] Organic / inorganic hybrid aerogels are composed primarily of ormosil (organically modified silica) aerogels. Such ormosil materials include organic components covalently bonded to a silica network. Ormosils are typically formed by hydrolysis and condensation of organically modified silanes R— Si(OX)3 using conventional alkoxylated precursors Y(OX)4. In these formulas: X can represent, for example, CH3, C2H5, C3H7, C4H9; Y can represent, for example, Si, Ti, Zr, or Al; and R can be any organic fragment such as methyl, ethyl, propyl, butyl, isopropyl, methacrylate, acrylate, vinyl, epoxide, etc. The organic components in ormosil aerogels can also be dispersed throughout or chemically bonded to the silica network.

[0075] In the context of the present invention, the term "ormosil" is intended to encompass the aforementioned materials as well as other organically modified ceramics, sometimes referred to as "ormocers." Ormosils are generally used as coatings, wherein the ormosil film is cast onto a substrate material through a process such as sol-gel. Other examples of organic-inorganic hybrid aerogels of the present invention include, but are not limited to, silica-polyether, silica-PMMA, silica-chitosan, carbides, nitrides, and other combinations of the aforementioned organic and inorganic aerogel-forming compounds. U.S. Patent Publication No. 20050192367 (paragraphs

[0022] to

[0038] and

[0044] to

[0058] ) is incorporated herein by reference for its teachings of such hybrid organic-inorganic materials.

[0076] The aerogels of the present invention are preferably inorganic silica aerogels, which are formed primarily from an alcohol solution of hydrolyzed silicate, which is formed from a silicon alkoxide. However, any other aerogel composition known to those skilled in the art can be used to practice the present invention as a whole, and the present invention is not limited to any one precursor material or combination of precursor materials.

[0077] The production of aerogels generally includes the following steps: i) formation of a sol-gel solution; ii) formation of a gel from the sol-gel solution; and, iii) extraction of the solvent from the gel material through innovative processing and extraction to obtain a dry aerogel material. This process is discussed in greater detail below, particularly in the context of forming inorganic aerogels such as silica aerogels. However, the specific examples and illustrative descriptions provided herein are not intended to limit the present invention to any particular type of aerogel and / or method of preparation. The present invention can include any aerogel formed by any related method of preparation known to those skilled in the art.

[0078] The first step in forming inorganic aerogels is generally the hydrolysis and condensation of metal alkoxide precursors in an alcohol solvent to form a sol-gel solution. The primary variables in the formation of inorganic aerogels include: the type of alkoxide precursor included in the sol-gel solution, the inherent properties of the solvent, the processing temperature and pH of the sol-gel solution (which can be altered by the addition of acid or base), and the precursor / solvent / water ratio in the sol-gel solution. Controlling these variables in the formation of the sol-gel solution can allow for control of the growth and coalescence of the gel framework during the subsequent transition of the gel material from a "sol" state to a "gel" state. Although the properties of the resulting aerogel are affected by the pH and molar ratio of the reactants of the precursor solution, any pH and any molar ratio that allows for the formation of a gel can be used in the present disclosure.

[0079] The sol-gel solution is formed by combining at least one gelation precursor with a solvent. Suitable solvents for forming the sol-gel solution include lower alcohols having from 1 to 6 carbon atoms, preferably 2 to 4 carbon atoms, but other solvents known to those skilled in the art can be used. Examples of useful solvents include, but are not limited to, methanol, ethanol, isopropanol, ethyl acetate, ethyl acetoacetate, acetone, dichloromethane, tetrahydrofuran, and the like. Multiple solvents can also be combined to achieve the desired level of dispersion or to optimize the properties of the gel material. Thus, the selection of the optimal solvent for the sol-gel step and the gel formation step depends on the specific precursors, fillers, and additives incorporated into the sol-gel solution; as well as the target processing conditions for gelation and liquid phase extraction, and the desired properties of the final aerogel material.

[0080] Water can be present in the precursor-solvent solution. The water acts to hydrolyze the metal alkoxide precursor to a metal hydroxide precursor. The hydrolysis reaction can be (using TEOS in an ethanol solvent as an example): Si(OC2H5)4 + 4H2O → Si(OH)4 + 4(C2H5OH). The resulting hydrolyzed metal hydroxide precursor is held in a "sol" state suspended in the solvent solution, either as an individual molecule or as a polymeric (or oligomeric) small colloidal cluster of molecules. For example, polymerization / condensation of Si(OH)4precursor can occur as follows: 2 Si(OH)4= (OH)3Si-O-Si(OH)3 + H2O. This polymerization reaction can continue until a polymeric (or oligomeric) colloidal cluster of SiO2(silica) is formed.

[0081] Acids and bases can be incorporated into the sol-gel solution to control the pH of the solution and to catalyze the hydrolysis and condensation reactions of the precursor materials. Although any acid can be used to catalyze the precursor reactions to obtain a lower pH solution, preferred acids include: HC1, H2SO4, H3PO4, oxalic acid, and acetic acid. Likewise, any base can be used to catalyze the precursor reactions and obtain a higher pH solution, but preferred bases include NH4OH.

[0082] The sol-gel solution can include additional co-gelation precursors, as well as filler materials and other additives. Filler materials and other additives can be distributed into the sol-gel solution at any point prior to or during gel formation. Filler materials and other additives can also be incorporated into the gel material after gelation through various techniques known to those skilled in the art. Preferably, the sol-gel solution including the gelation precursor, solvent, catalyst, water, filler materials, and other additives is a homogeneous solution that is effective to form a gel under the appropriate conditions.

[0083] Once the sol-gel solution is formed and optimized, the gel-forming components in the sol-gel can be converted to a gel material. The process of converting the gel-forming components to a gel material includes an initial gel formation step in which the gel is allowed to solidify to a gelation point of the gel material. The gelation point of the gel material can be considered the point at which the gelled solution exhibits resistance to flow and / or forms a substantially continuous polymer framework throughout its volume. Numerous gel formation techniques are known to those skilled in the art. Examples include, but are not limited to, maintaining the mixture in a quiescent state for a period of time, adjusting the pH of the solution, adjusting the temperature of the solution, directing energy forms onto the mixture (ultraviolet light, visible light, infrared light, microwaves, ultrasound, particle radiation, electromagnetic radiation), or combinations thereof.

[0084] The process of converting the gel-forming components to a gel material can also include an aging step (also referred to as solidification) prior to the liquid phase extraction. Allowing the gel material to age after it reaches its gelation point can further strengthen the gel framework by increasing the number of crosslinks within the network. The duration of the gel aging can be adjusted to control various properties of the resulting aerogel material. The aging process can be used to prevent volume loss and shrinkage during the liquid phase extraction process. Aging can involve maintaining the gel (prior to extraction) in a quiescent state for an extended period of time, maintaining the gel at an elevated temperature, adding a crosslinking promoting compound, or any combination thereof. Preferred aging temperatures are generally between about 10 °C and about 100 °C. Aging of the gel material is typically continued until the wet gel material is subjected to the liquid phase extraction.

[0085] The time period for converting the gel-forming material to a gel material includes both the duration of the initial gel formation (from the start of gelation to the gelation point) and any subsequent solidification and aging of the gel material prior to the liquid phase extraction (from the gelation point to the start of the liquid phase extraction). The total time period for converting the gel-forming material to a gel material is typically between about 1 minute and several days, preferably about 30 hours or less, about 24 hours or less, about 15 hours or less, about 10 hours or less, about 6 hours or less, about 4 hours or less, about 2 hours or less, about 1 hour or less, about 30 minutes or less, or about 15 minutes or less.

[0086] The resulting gel material can be washed in a suitable second solvent to replace the first reaction solvent present in the wet gel. Such a second solvent can be a linear monohydric alcohol having 1 or more aliphatic carbon atoms, a dihydric alcohol having 2 or more carbon atoms, a branched alcohol, a cyclic alcohol, an alicyclic alcohol, an aromatic alcohol, a polyhydric alcohol, an ether, a ketone, a cyclic ether, or a derivative thereof.

[0087] Once the gel material has been formed and processed, the liquid phase of the gel can then be at least partially extracted from the wet gel using an extraction process, including innovative processing and extraction techniques, to form an aerogel material. Among other factors, extraction of the liquid phase plays an important role in the management of the properties of the aerogel, such as porosity and density, and related properties such as thermal conductivity. Generally, when the liquid phase is extracted from the gel in a manner that causes low shrinkage of the porous network and structure of the wet gel, an aerogel is obtained.

[0088] Aerogels are often formed by removing the liquid mobile phase from the gel material at temperatures and pressures near or above the critical point of the liquid mobile phase. Once the critical point is reached (near-critical) or exceeded (supercritical), a new supercritical phase appears in a fluid form that is distinct from the liquid or gas phase. The solvent can be removed without introducing liquid-gas interfaces, capillary pressures, or any associated mass transfer limitations typically associated with liquid-gas boundaries. In addition, the supercritical phase is generally more miscible with organic solvents, thus having greater extraction capabilities. Co-solvents and solvent exchange are often also used to optimize the supercritical fluid drying process.

[0089] If evaporation or extraction occurs below the supercritical point, the strong capillary forces generated by liquid evaporation can cause shrinkage and pore collapse within the gel material. Maintaining the mobile phase near or above the critical pressure and temperature during solvent extraction reduces the negative effects of these capillary forces. In some embodiments of the present invention, near-critical conditions just below the critical point of the solvent system are used to produce aerogel materials or compositions with sufficiently low shrinkage, thus producing commercially viable end products.

[0090] Several additional aerogel extraction techniques are known in the art, including a variety of different approaches for using supercritical fluids to dry aerogels. For example, Kistler (J. Phys. Chem. (1932) 36:52-64) disclosed a simple supercritical extraction process in which the gel solvent is maintained above its critical pressure and temperature, thereby reducing evaporation capillary forces and maintaining the structural integrity of the gel network. U.S. Patent No. 4,610,863 disclosed an extraction process in which the gel solvent is exchanged with liquid carbon dioxide, followed by extraction under conditions in which the carbon dioxide is in a supercritical state. U.S. Patent No. 6,670,402 teaches production of aerogels by injecting supercritical (rather than liquid) carbon dioxide into an extractor preheated and pre-pressurized to conditions substantially supercritical or above, thereby extracting the liquid phase from the gel via rapid solvent exchange. U.S. Patent No. 5,962,539 discloses a process for obtaining an aerogel from a polymeric material in sol-gel form in an organic solvent by exchanging the organic solvent with a fluid having a supercritical temperature below the decomposition temperature of the polymer and supercritically extracting the fluid / sol-gel. U.S. Patent No. 6,315,971 discloses a process for producing a gel composition comprising drying a wet gel comprising a gel solid and a drying agent to remove the drying agent under drying conditions that minimize shrinkage of the gel during the drying process. U.S. Patent No. 5,420,168 discloses a process by which resorcinol / formaldehyde aerogels can be made using a simple air drying process. U.S. Patent No. 5,565,142 discloses a drying technique in which the gel surface is modified to be stronger and more hydrophobic, so that the gel framework and pores can resist collapse during room temperature drying or subcritical extraction processes. Other examples of extracting a liquid phase from an aerogel material can be found in U.S. Patent Nos. 5,275,796 and 5,395,805.

[0091] One preferred embodiment for extracting a liquid phase from a wet gel is the use of carbon dioxide under supercritical conditions, including, for example, first substantially exchanging a first solvent present in the pore network of the gel with liquid carbon dioxide; and subsequently heating (typically in an autoclave) the wet gel to above the critical temperature of carbon dioxide (about 31.06°C) and increasing the pressure of the system to a pressure above the critical pressure of carbon dioxide (about 1070 psig). The pressure surrounding the gel material can be slightly fluctuated to facilitate removal of the supercritical carbon dioxide fluid from the gel. The carbon dioxide can be recycled through the extraction system to facilitate continuous removal of the first solvent from the wet gel. Finally, the temperature and pressure are slowly returned to ambient conditions to produce a dry aerogel material. Carbon dioxide can also be pre-processed to the supercritical state prior to injection into the extraction chamber.

[0092] One example of an alternative method of forming aerogels includes acidifying an alkaline metal oxide precursor (such as sodium silicate) in water to create a hydrogel. Salt byproducts can be removed from the silica precursor by ion exchange and / or by washing the subsequently formed gel with water. Removal of water from the pores of the gel can be performed via exposure to a polar organic solvent such as ethanol, methanol, or acetone. Subsequently, the liquid phase in the gel is at least partially extracted using innovative processing and extraction techniques.

[0093] Another example of an alternative method of forming aerogels includes reducing the damaging capillary pressure at the solvent / pore interface by chemical modification of the matrix material in the wet gel state, thereby allowing extraction of the liquid phase from the gel material at temperatures and pressures below the critical point of the solvent, wherein the chemical modification is conversion of surface hydroxyl groups to hydrophobic trimethylsilyl ether groups.

[0094] Large scale production of aerogel materials or compositions can be accompanied by difficulties associated with forming gel materials in large scale continuously; and difficulties associated with extracting liquid phase from large volume gel materials using innovative processing and extraction techniques. Aerogel materials or compositions of the present disclosure are preferably adapted to accommodate large scale production. In certain embodiments, the gel materials of the present disclosure can be produced in large scale by continuous casting and gelation processes. In certain embodiments, the aerogel materials or compositions of the present disclosure are produced in large scale, which requires the use of large scale extraction vessels. Large scale extraction vessels of the present disclosure can include extraction vessels having a volume of about 0.1 m3or greater, about 0.25 m3or greater, about 0.5 m3or greater, about 0.75 m3or greater, or about 1 m3or greater. 3 3 3 3

[0095] Large scale production of aerogel compositions can include a conveyor-based system that combines gel precursors with continuous reinforcement fiber reinforcement or open cell foam reinforcement at one end of a conveyor to produce continuous reinforcement gel sheets. This reinforcement gel sheet can be wound in multiple layers (preferably around a mandrel with uniform tension) and subsequently subjected to chemical treatment, aging, and drying steps. Additional spacer layers can be co-wound with the sheet layers between the gel sheet layers to facilitate aging or drying of the gel material, such as by providing a flow path for an aging agent or drying material. The spacer layers can be impermeable (preferably, impermeable to fluids at pressures below 1 psi, 5 psi, or 10 psi) or permeable. Permeable layers can be in the form of perforated plastic sheets, mesh-like materials, perforated foils, and the like.

[0096] Figure 1 ​​​​A conveyor-based system 100 for large-scale production of aerogel compositions is illustrated. A gel precursor solution 110 is mixed with a catalyst solution 120 at a mixing section 114. The flow of the gel precursor solution 110 and the catalyst solution 120 is controlled by a flow controller 130. Reinforcing material 150 is provided on a conveyor system 140. The reinforcing material 150 can be a continuous sheet from a roll of reinforcing material. The reinforcing material 150 can also include segments of reinforcing material. In a preferred embodiment, the reinforcing material 150 is a fibrous reinforcing material or an open cell foam reinforcing material. The precursor solution (including the gel precursor and catalyst) is dispersed on the conveyor belt 140 and combined with the reinforcing material 150. As the reinforcing material is advanced by the conveyor system 140, the gel-forming precursor in the gel precursor solution is converted to a gel material. The resulting reinforcing gel sheet is wound for subsequent chemical treatment, aging, and drying steps. Additional separator layers 164 can be co-wound between the gel sheet layers 160.

[0097] Large-scale production of aerogel compositions can include a semi-continuous, batch-wise process, which is generally referred to as a gel-in-a-roll process. Figure 2 A specific embodiment of a semi-continuous, batch-wise system 200 for large-scale production of aerogel compositions is illustrated. A sheet of reinforcing material is wound in multiple layers as a preformed roll 220 and placed in a container 210. Additional separator layers 250 can be co-wound with the reinforcing material in the preformed roll 220. The separator layers can be impermeable (preferably, impermeable to fluids at pressures below 1 psi, 5 psi, or 10 psi) or permeable. Permeable layers can be in the form of perforated plastic sheets, mesh-like materials, perforated foils, and the like. A gel precursor solution 240 is infused into or combined with the reinforcing material in the preformed roll 220. The gel-forming precursor in the gel precursor solution is converted to a gel material. The resulting reinforcing gel sheet can be immediately advanced for subsequent chemical treatment, aging, and drying steps. The resulting reinforcing gel sheet can also be unwound, subsequently rewound with a different separator layer, and then subjected to subsequent chemical treatment, aging, and drying steps.

[0098] Aerogel composites can be reinforced with other materials such as facing materials in a layered or faced construction. In one embodiment, the present invention is a multi-layered construction comprising at least one base layer comprising a reinforced aerogel composition, and at least one facing layer. In one embodiment, the facing layer comprises a reinforcing material. In one embodiment, the reinforced aerogel composition is reinforced with a fibrous reinforcement layer or an open cell foam reinforcement layer. In one embodiment, the present invention is a multi-layered construction comprising at least one base layer comprising a reinforced aerogel composition, and at least two facing layers comprising a reinforcing material, wherein the two facing layers are on opposite surfaces of the base layer. The multi-layered aerogel construction can be produced according to the methods and materials disclosed in paragraphs

[0004] ,

[0010] ,

[0011] ,

[0017] to

[0021] , and

[0023] to

[0027] of U.S. Patent Application No. 20070173157; which are incorporated herein by reference to the above- referenced paragraphs.

[0099] The facing layer can comprise a material that will help provide a particular characteristic to the final composite structure, such as improved flexibility and reduced chipping. The facing material can be brittle or flexible. The facing material can comprise a reflective foil. In one embodiment, the facing layer comprises a polymeric sheet; more particularly, a polymeric sheet comprising a polyester, polyethylene, polyurethane, polypropylene, polyacrylonitrile, aramid, aromatic polyamide; and more particularly, a polymer such as poly(ethylene terephthalate), low density polyethylene, ethylene-propylene copolymer, poly(4-methylpentene), poly(tetrafluoroethylene), poly(l-butene), polystyrene, polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride, polyvinyl acrylonitrile, polymethyl methacrylate, polyoxymethylene, polyphenylsulfone, cellulose triacetate, polycarbonate, polyethylene naphthalate, polycaprolactam, poly(hexamethylene adipamide), polyundecanoamide, polyimide, or combinations thereof. In one embodiment, the polymeric sheet comprises or consists essentially of an expanded polymeric material; more particularly, an expanded polymeric material comprising PTFE (ePTFE), expanded polypropylene (ePP), expanded polyethylene (ePE), expanded polystyrene (ePS), or combinations thereof. In one embodiment, the polymeric sheet comprises or consists essentially of a macroporous polymeric material characterized by a pore size ranging from 0.1 μm to 210 μm, 0.1 μm to 115 μm, 0.1 μm to 15 μm, or 0.1 μm to 0.6 μm.

[0100] In one embodiment, the facing layer material is comprised of or consists essentially of a fluoropolymer material. In the context of the present disclosure, the term "fluoropolymeric" or "fluoropolymer material" refers to a material comprised essentially of a polymeric fluorocarbon. Suitable fluoropolymeric facing layer materials include, but are not limited to: polytetrafluoroethylene (PTFE), including the large pore PTFE disclosed in U.S. Patent No. 5,814,405; and expanded PTFE (ePTFE) such as (available from W.L. Gore); polyvinyl fluoride (PVF); polyvinylidene fluoride (PVDF); perfluoroalkoxy (PFA); fluorinated ethylene-propylene (FEP); polychlorotrifluoroethylene (PCTFE); ethylene-tetrafluoroethylene (ETFE); polyvinylidene fluoride (PVDF); ethylene-chlorotrifluoroethylene (ECTFE); and combinations thereof.

[0101] In one embodiment, the facing layer material is comprised of or consists essentially of a non-fluoropolymeric material. In the context of the present disclosure, the term "non-fluoropolymeric" or "non-fluoropolymer material" refers to a material that does not include a fluoropolymeric material. Suitable non-fluoropolymer facing layer materials include, but are not limited to: aluminized Mylar; low density polyethylene, such as (available from DuPont); rubber or rubber compounds; elastic fibers such as spandex, nylon, lycra, or elastane; and combinations thereof. In a preferred embodiment, the facing material is a flexible facing material. In a preferred embodiment, the facing material is comprised of elastic fibers such as spandex, nylon, lycra, elastane, or combinations thereof. In a preferred embodiment, the facing material consists essentially of a non-fluoropolymer material.

[0102] The facing layer can be adhered to the base layer by the use of an adhesive, wherein the adhesive is a reinforcing material suitable for securing inorganic or organic facing materials to the base layer. Examples of adhesives that can be used in the present application include, but are not limited to: bone cement as an adhesive, sodium silicate, latex, cyanoacrylate adhesives, silicone, polystyrene, aerosol adhesives, urethanes, acrylate adhesives, hot melt bonding systems, bonding systems commercially available from 3M, epoxies, rubber resin adhesives, polyurethane adhesive mixtures such as those disclosed in U.S. Patent No. 4,532,316.

[0103] The facing layer can also be adhered to the base layer by using non-adhesive materials or techniques, wherein the non-adhesive materials or techniques are reinforcing materials suitable for securing inorganic or organic facing materials to the base layer. Non-adhesive materials or techniques that can be used in the present invention include, but are not limited to: heat sealing, ultrasonic stitching, RF sealing, thread stitching, sealed pockets, rivets or buttons, clamps, wrapping, or other non-adhesive lamination materials. In a preferred embodiment, the facing layer is adhered to the base layer by stitching or riveting. In another preferred embodiment, the facing layer is adhered to the base layer by ultrasonic stitching or bonding.

[0104] The facing layer can be adhered to the base layer at any stage of aerogel composite production. In one embodiment, the facing layer is adhered to the base layer after the sol-gel solution is infused into the base layer reinforcing material but before gelation. In another embodiment, the facing layer is adhered to the base layer after the sol-gel solution is infused into the base layer reinforcing material and after subsequent gelation but before aging or drying the gel material. In yet another embodiment, the facing layer is adhered to the base layer after aging and drying the gel material. In a preferred embodiment, the facing layer is adhered to the reinforcing material of the base layer before the sol-gel solution is infused into the base layer reinforcing material.

[0105] The facing layer can be solid and impermeable to fluids. The facing layer can be porous and permeable to fluids. In a preferred embodiment, the facing layer is porous and permeable to fluids and contains pores or voids of sufficient diameter to allow fluid diffusion through the facing material. In another preferred embodiment, the facing layer is adhered to the reinforcing material of the base layer before the sol-gel solution is infused into the base layer reinforcing material, wherein the facing layer is porous and permeable to fluids and contains pores or voids of sufficient diameter to allow fluid diffusion through the facing material. In yet another preferred embodiment, the facing layer is adhered to the open-cell foam reinforcing material before the sol-gel solution is infused into the foam reinforcing material, wherein the facing layer is porous and permeable to fluids and contains pores or voids of sufficient diameter to allow fluid diffusion through the facing material.

[0106] Production of a multi-layered gel or aerogel composition can include the steps of: a) adhering a fluid-permeable facing layer to a sheet of reinforcing material to produce a laminated reinforcing sheet, wherein the facing layer has pores or voids large enough to allow fluid to diffuse through the facing material; b) infusing a gel precursor solution through the facing layer into the reinforcing sheet; and c) converting the gel precursor material into a gel material comprising a gel framework. A portion of the gel precursor solution can reside within the pores or voids of the facing layer, so the gel framework in the reinforcing material of the base layer will extend into at least a portion of the facing layer. The resulting product is a multi-layered gel composition comprising: a) at least one base layer comprising a reinforcing material and a gel framework integrated into the reinforcing material; and b) at least one facing layer comprising a fluid-permeable facing material and a gel framework integrated into the fluid-permeable facing material; wherein at least a portion of the gel framework of the base layer extends into and is continuous with at least a portion of the gel framework of the facing layer.

[0107] Large-scale production of a multi-layered aerogel composition can include a conveyor-based system, wherein the production comprises the steps of: a) adhering at least one fluid-permeable facing layer to a sheet of reinforcing material to produce a laminated reinforcing sheet, wherein the facing layer has pores or voids large enough to allow fluid to diffuse through the facing material; and b) combining a gel precursor solution with the laminated reinforcing sheet at one end of a conveyor to produce a continuous laminated sheet of reinforced gel; wherein at least a portion of the gel precursor solution is infused through the facing layer into the reinforcing sheet; and wherein the gel precursor solution is combined with the laminated reinforcing sheet at a rate that allows the gel precursor solution to travel through the facing layer and into the reinforcing sheet. In a preferred embodiment, the reinforcing material comprises an open-cell foam reinforcing material.

[0108] The reinforced and laminated gel sheet can be wound into multiple layers (preferably around a mandrel with uniform tension) and processed in subsequent chemical treatment, aging, and drying steps. Additional separator layers can be co-wound between the gel sheet layers to facilitate aging and drying of the gel material, such as to provide a flow path for aging agents and drying materials. In a preferred embodiment, the facing layer provides a flow path for aging agents or drying materials, so additional separator layers for aging and drying of the gel material are not needed.

[0109] Large scale production of the multi-layered aerogel composition can include a semi-continuous, batch process, generally referred to as an in-roll gel process, wherein the production includes the steps of: a) adhering a fluid permeable facing layer to a sheet of reinforcing material, wherein the facing layer includes pores or voids large enough to allow fluid to diffuse through the facing material; b) winding the laminated reinforcing material into a preform roll in multiple layers; and c) combining a gel precursor solution with the preform roll. Additional separator layers can be co-wound with the reinforcing material into the preform roll to provide flow paths for the gel precursor solution, aging agent, and drying material. In a preferred embodiment, the facing layer provides flow paths for the gel precursor solution, aging agent, and drying material, so that additional separator layers are not required. In a preferred embodiment, the reinforcing material includes an open cell foam reinforcing material.

[0110] The shape of the reinforced aerogel composite of the present invention can be a variety of three-dimensional forms, including panels, preformed tubes, half-shell preforms, elbows, joints, and other regular shapes required for insulation applications in industrial and commercial applications. In one embodiment, the reinforcing material is shaped into the desired shape prior to infusion with the gel precursor material. The gel material is processed in a manner that allows the preform to maintain its shape, thus obtaining a reinforced aerogel preform of the desired shape. This technique of forming aerogels of a certain shape is challenging and inefficient due to the difficulty of processing gel materials in a variety of shapes and configurations.

[0111] In one embodiment, the reinforced gel composite is initially in the form of a sheet and is processed into the desired three-dimensional shape after the gelation of the gel material or after the gelation and subsequent drying of the gel material. In a preferred embodiment, a sheet of reinforced aerogel material is heated to a desired temperature, shaped into the desired shape, and then cooled. This technique of shaping reinforced aerogel material is particularly effective when using a foam reinforcing material. In a preferred embodiment, a sheet of reinforced aerogel material including a foam reinforcing material is heated to a desired temperature, shaped into the desired shape, and then cooled. The desired temperature for heating the aerogel material should be above the softening point of the foam reinforcing material and below the maximum use temperature of the reinforcing material and below the self-heating temperature of the aerogel material. The desired temperature should be high enough to make the reinforcing material soft and pliable enough to be shaped into the desired shape, but still stable enough to support the aerogel material during the shaping process. The desired temperature for heating the aerogel material will therefore vary depending on the reinforcing material and aerogel material used. In one embodiment, the desired temperature is between 50°C and 200°C, between 75°C and 200°C, between 100°C and 175°C, between 120°C and 160°C, or about 150°C.

[0112] In one embodiment, the reinforced gel composite is initially in a block or molded form and is processed into a desired three-dimensional shape after the gelation of the gel material or after the gelation of the gel material and subsequent drying. In one embodiment, a block of reinforced aerogel material is formed by combining a reinforcing material with a gel precursor in a mold of a particular shape. The material is gelled within the mold and then dried to produce a shaped aerogel composite. In a preferred embodiment, a block of reinforced aerogel material is produced and then cut or milled into a desired shape. In another preferred embodiment, a block of reinforced aerogel material is produced and then cut into individual pieces using a cutting machine or apparatus.

[0113] The aerogel composition can also include a sunscreen to reduce the radiative component of heat transfer. The sunscreen compound or its precursor can be dispersed in the mixture containing the gel precursor at any point prior to gel formation. Examples of sunscreen compounds include, but are not limited to: boron carbide [B4C], diatomaceous earth, manganese ferrite, MnO, NiO, SnO, Ag2O, Bi2O3, carbon black, titanium oxide, iron titanium oxide, zirconium silicate, zirconium oxide, iron (II) oxide, iron (III) oxide, manganese dioxide, titanium iron oxide (ilmenite), chromium oxide, carbides (such as SiC, TiC, or WC), or mixtures thereof. Examples of sunscreen compound precursors include, but are not limited to: TiOSO4or TiOCl2.

[0114] Embodiments of the present application can be practiced using any of the processing, extraction, and handling techniques disclosed herein, as well as other processing, extraction, and handling techniques known to those skilled in the art for producing the aerogels, aerogel-like materials, and aerogel compositions defined herein.

[0115] The aerogel materials and compositions of the present application have been shown to be highly effective as insulating materials. However, the use of the methods and materials of the present application are not intended to be limited to applications related to insulation. The methods and materials of the present application can be applied to applications that would benefit from the unique combination of properties or processes provided by the materials and methods of the present application. Such applications include, but are not limited to: thermal barriers and panels (including fire resistant panels and panels), insulation (including in clothing or apparel, in buildings, in pipes, or in industrial facilities), soundproofing, electronics, shock and impact isolation, and chemical catalysis. Applications using the compositions of the present application can use a single layer or multiple layers of the composites, and the composites of the present application can be mechanically altered, such as by cutting them to size.

[0116] The following examples are provided to illustrate various non-limiting embodiments and features of the present application.

[0117] [Examples]

[0118] Example 1

[0119] A polyurethane (PU) open cell foam sheet having a density of 0.022 g / cc is provided. A silica precursor solution is formed by combining methyltriethoxysilane (MTES), tetraethyl orthosilicate (TEOS), water, an acid catalyst, and ethanol. A gelation catalyst solution is formed by combining ethanol and dilute aqueous ammonia. The catalyst solution and the silica precursor solution are combined to form a catalyzed silica precursor solution. The catalyzed silica solution is poured into the polyurethane foam sheet. The composite is allowed to gel and then aged in a hexamethyldisilazane (HMDS) ethanol solution. The solvent is extracted from the aged material under supercritical conditions to produce a foam-reinforced aerogel composite. The resulting aerogel-open cell polyurethane foam composite is flexible.

[0120] Example 2

[0121] A polyurethane (PU) open cell foam sheet is rolled into a preformed roll and placed in a cylindrical walled container. A melamine-formaldehyde open cell foam sheet is rolled into a separate preformed roll and placed in a separate cylindrical walled container. A silica precursor solution is formed by combining methyltriethoxysilane (MTES), tetraethoxysilane (TEOS), water, an acid catalyst, and ethanol. A gelation catalyst solution is formed by combining ethanol and dilute aqueous ammonia. The catalyst solution and the silica precursor solution are combined to form a catalyzed silica precursor solution. The resulting solution is then poured onto the open cell foam roll pre-placed in the separate container. The material is allowed to gel. After gelation, the resulting gel-foam composite is aged in a sealed ethanol bath at 50 °C overnight. The solvent is removed from the gel by supercritical CO2 extraction to produce a foam-reinforced aerogel composite sheet. The resulting aerogel-open cell polyurethane foam composite is flexible. The resulting aerogel-open cell melamine foam composite is flexible.

[0122] Example 3

[0123] A melamine formaldehyde foam sheet is provided. A silica precursor solution is formed by combining methyltriethoxysilane (MTES), tetraethoxysilane (TEOS), water, an acid catalyst, and ethanol. A gelation catalyst solution is formed by combining ethanol and dilute aqueous ammonia. The catalyst solution and the silica precursor solution are combined to form a catalyzed silica precursor solution. The composite is allowed to gel and then aged in a hexamethyldisilazane (HMDS) ethanol solution. The solvent is extracted from the aged material under supercritical conditions to produce a melamine-foam reinforced aerogel composite. The resulting aerogel-melamine foam composite is flexible.

[0124] Example 4

[0125] A plurality of flexible facing material sheets are provided, each comprising about 18% spandex and 82% nylon and having a density of 0.3 g / cc. A first surface of each of the foam reinforced aerogel composite sheets is coated with an acrylic as a water-based adhesive (3M Quick-Bond Adhesive, 4224-NF Clear or Blue). The adhesive is allowed to partially dry until tacky. A flexible facing material sheet is applied to each of the adhesive-coated surfaces of the foam reinforced aerogel composite. As the adhesive fully dries, pressure is applied to the laminate, thus forming a solid bond between the foam reinforced aerogel composite and the flexible facing layer. Subsequently, the lamination process is repeated for a second surface of each of the foam reinforced aerogel composite, thus forming a sandwiched laminate sheet comprising a base layer having a foam reinforced aerogel composite and a flexible facing layer on each surface of the base layer. FIGS. 3 and 4 illustrate the sandwiched laminate material produced in Example 4.

[0126] Example 5

[0127] A plurality of flexible facing material sheets are provided, each comprising a fluid- impermeable polyurethane. A first surface of each of the foam reinforced aerogel composite sheets is coated with a hot-bonding polyethylene as an adhesive. A flexible facing material sheet is applied to each of the adhesive-coated surfaces of the foam reinforced aerogel composite. As the adhesive fully bonds, pressure and heat are applied to the laminate, thus forming a solid bond between the foam reinforced aerogel composite and the flexible facing layer. Subsequently, the lamination process is repeated for a second surface of each of the foam reinforced aerogel composite, thus forming a sandwiched laminate sheet comprising a base layer having a foam reinforced aerogel composite and a flexible facing layer on each surface of the base layer. Figure 5 FIGS. 5 and 6 illustrate the sandwiched laminate material produced in Example 5.

[0128] Example 6

[0129] A plurality of flexible facing material sheets are provided, each comprising about 18% spandex and 82% nylon and having a density of 0.3 g / cc. A first surface of each of the foam reinforced aerogel composite sheets is coated with an acrylic as a water-based adhesive (3M Quick-Bond Adhesive, 4224-NF Clear or Blue). The adhesive is allowed to partially dry until tacky. A flexible facing material sheet is applied to each of the adhesive-coated surfaces of the foam reinforced aerogel composite. As the adhesive fully dries, pressure is applied to the laminate, thus forming a solid bond between the foam reinforced aerogel composite and the flexible facing layer. Subsequently, the lamination process is repeated for a second surface of each of the foam reinforced aerogel composite, thus forming a sandwiched laminate sheet comprising a base layer having a foam reinforced aerogel composite and a flexible facing layer on each surface of the base layer. FIGS. 3 and 4 illustrate the sandwiched laminate material produced in Example 4. Figure 6 and 7To illustrate the sandwiched laminated material produced in Example 6.

[0130] Example 7

[0131] Samples from Examples 4, 5, and 6 were provided. The density and thermal conductivity (TC) of each sample was tested before and after the lamination process. The TC was measured at 37.5 °C under atmospheric pressure and 2 psi load. Table 1 below provides the results of the measurements:

[0132] Table 1

[0133]

[0134] Example 8

[0135] The steps of Example 1 were repeated using a sheet of reticulated polyurethane foam having a thickness of 12 mm as the reinforcing material. The foam-reinforced aerogel sheet was folded into a pre-shaped form and secured using straps as shown in Figure 8 The folded sheet was placed in an oven and heat treated at a temperature of 150 °C for 3 hours. The material was removed from the oven and allowed to cool. The securing straps were removed and the heat treated sheet was allowed to partially unfold. The resulting heat treated sheet permanently retained a semi-circular shape as shown in Figure 9

[0136] Example 9

[0137] The steps of Example 1 were repeated using a sheet of reticulated polyurethane foam having a thickness of 12 mm as the reinforcing material. The foam-reinforced aerogel sheet was folded into a pre-shaped form and secured using straps as shown in Figure 8 The folded sheet was placed in an oven and heat treated at a temperature of 150 °C for 3 hours. The material was removed from the oven and allowed to cool. The securing straps were removed and the heat treated sheet was allowed to partially unfold. The resulting heat treated sheet permanently retained a semi-circular shape as shown in Figure 9

[0138] Example 10

[0139] Multiple pieces of the heat-shaped aerogel composite sheet from Example 9 were provided. Multiple layers of the heat-shaped sheet were bonded together using an adhesive to form a multi-layered semi-shell insulation laminate as shown in Figure 10 Two of these semi-shell, pre-shaped insulation laminates were brought together around a pipe section and secured using straps to form an insulation jacket that completely encircles the outer circumference of the pipe section as shown in Figure 11

[0140] Example 11

[0141] ​​​A polyurethane (PU) open cell foam sheet is provided. Two sheets of flexible facing material are provided, each comprising about 18% spandex and 82% nylon, and having a density of 0.3 g / cc. A polyurethane composite adhesive is applied to a portion of a first surface of the foam sheet. One sheet of flexible facing material is applied to the adhesive-modified surface of the foam sheet. As the adhesive fully dries, pressure is applied to the laminate, thus forming a solid bond between the foam sheet and the flexible facing layer. The lamination process is then repeated on a second surface of the foam sheet, thus forming a sandwiched laminate sheet comprising a base layer having a foam sheet, and a flexible facing layer adhered to each surface of the base layer.

[0142] Example 12

[0143] A sandwiched laminate sheet from Example 11 is provided. The sandwiched laminate sheet is rolled into a preformed roll; a separator material is co-rolled with the sandwiched laminate sheet to provide separation between the layers of the roll. The roll is placed in a cylindrical walled container. A silica precursor solution is formed by combining methyltriethoxysilane (MTES), tetraethoxysilane (TEOS), water, an acid catalyst, and ethanol. A gelation catalyst solution is formed by combining ethanol and dilute aqueous ammonia. The catalyst solution and the silica precursor solution are combined to form a catalyzed silica precursor solution. The resulting solution is then poured into the container. The catalyzed silica precursor solution is allowed to reside for a period of time to allow it to penetrate through the facing layers and into the foam base layer of the sandwiched laminate sheet, and to allow the material to gel. After gelation, the resulting gel-foam composite is aged at 50°C overnight in a sealed ethanol bath. Solvent is removed from the gel by supercritical CO2 extraction to produce a laminated foam-reinforced aerogel composite sheet.

[0144] Example 13

[0145] A sandwich laminate sheet from Example 11 was provided. A silica precursor solution was formed by combining methyltriethoxysilane (MTES), tetraethoxysilane (TEOS), water, an acid catalyst, and ethanol. A gelling catalyst solution was formed by combining ethanol and dilute aqueous ammonia. The catalyst solution and the silica precursor solution were combined to form a catalyzed silica precursor solution. The sandwich laminate sheet was fed onto a moving conveyor and the resulting catalyzed silica precursor solution was poured onto the overlying face layer of the sandwich laminate sheet as the sheet traveled with the moving conveyor. The catalyzed silica precursor solution was allowed to reside for a period of time to allow it to penetrate through the overlying face layer into the foam base layer of the sandwich laminate sheet and to allow the material to gel. After gelling, the resulting sandwich laminate gel-foam composite was placed in a cylindrical walled container; a separator material was co-wound with the composite sheet to provide separation between the layers of the roll. The coiled composite sheet was aged in a sealed ethanol bath at 50°C overnight. Solvent was removed from the gel by supercritical CO2 extraction to produce a laminated foam reinforced aerogel composite sheet.

[0146] Unless specifically stated otherwise, and unless expressly contrasted, in this document, the conjunction "and" is intended to be inclusive and the conjunction "or" is not intended to be exclusive. For example, the phrase "or, or" is intended to be exclusive.

[0147] In the context of the present disclosure, particularly in the context of the claims, the terms "a," "an," "the" or similar referents are to be construed to cover both the singular and plural unless otherwise indicated by context or by expressly stated to the contrary.

[0148] Unless otherwise noted, the terms "comprising," "having," "including," and "containing" are to be construed as open-ended terms (i.e., meaning "including, but not limited to").

[0149] As used herein, the term "about" is used in the context of a particular characteristic, component, quantity, value, or parameter to mean approximately that specific value, as understood by persons of ordinary skill in the art, such as experimental error, measurement error, approximation error, calculation error, standard deviation of the mean, routine rounding off error, etc.

[0150] Unless expressly excluded, the recitation of numerical ranges by endpoints herein is merely intended to serve as a shorthand method of referring individually to each separate numerical value falling within the range, and each separate value is incorporated into the specification as if it were individually recited herein.

[0151] The recitation of different specific examples as disjunctive is not intended to exclude combining the disjunctive examples into a single example.

[0152] Unless otherwise indicated herein, the entirety of this disclosure can be performed in any suitable order. The use of any and all examples, or exemplary language (e.g., "such as", "for instance") provided herein, is intended merely to better illustrate the application and does not pose a limitation on the scope of the application unless otherwise claimed.

Claims

1. An aerogel composite comprising: at least one base layer having an upper surface and a lower surface, the base layer comprising a reinforced aerogel composition, the reinforced aerogel composition comprising a foam reinforcement material and a monolithic aerogel framework; a first facing layer comprising a first facing material adhered to the upper surface of the base layer; and a second facing layer comprising a second facing material adhered to the lower surface of the base layer; wherein, The first facing material and the second facing material are each comprised of a non-fluoropolymer material; wherein the first facing layer or the second facing layer comprises a porous reflective foil; wherein at least a portion of the monolithic aerogel framework of the substrate layer extends into at least a portion of at least one of the first facing layer or the second facing layer; and wherein the first facing layer or the second facing layer is adhered to the substrate layer by a non-adhesive mechanism selected from the group consisting of stitching, sealed pockets, rivets, buttons, clips, wraps, supports, and combinations thereof.

2. An aerogel composite comprising: at least one base layer having an upper surface and a lower surface, the base layer comprising a reinforced aerogel composition, the reinforced aerogel composition comprising a fibrous reinforcement material and a monolithic aerogel framework; a first facing layer comprising a first facing material adhered to the upper surface of the base layer; and a second facing layer comprising a second facing material adhered to the lower surface of the base layer; wherein, The first facing material and the second facing material are each comprised of a non-fluoropolymer material; wherein the first facing layer or the second facing layer comprises a porous reflective foil; wherein at least a portion of the monolithic aerogel framework of the substrate layer extends into at least a portion of at least one of the first facing layer or the second facing layer; and wherein the first facing layer or the second facing layer is adhered to the substrate layer by a non-adhesive mechanism selected from the group consisting of stitching, sealed pockets, rivets, buttons, clips, wraps, supports, and combinations thereof.

3. The aerogel composite of claim 1, wherein, The foam reinforcement material comprises a material selected from polyolefin, polyurethane, phenol formaldehyde resin, melamine, cellulose acetate, and polystyrene.

4. The aerogel composite of claim 1, wherein, The foam reinforcement material comprises a polyurethane foam.

5. The aerogel composite of claim 1, wherein, The foam reinforcement material comprises a melamine foam.

6. The aerogel composite of claim 2, wherein, The fiber reinforcement material comprises a material selected from discrete fibers, woven materials, non-woven materials, or combinations thereof.

7. The aerogel composite of claim 2, wherein, The fiber reinforcement material comprises batts.

8. The aerogel composite of claim 2, wherein, The fiber reinforcement material comprises mesh, felt, blanket, or combinations thereof.

9. The aerogel composite of claim 1 or 2, wherein, The monolithic aerogel framework comprises inorganic aerogel material, organic aerogel material, hybrid inorganic / organic aerogel material, or combinations thereof.

10. The aerogel composite of claim 1 or 2, wherein, The first facing layer or the second facing layer comprises elastic fibers comprising spandex, nylon, lycra, or combinations thereof.

11. The aerogel composite of claim 1 or 2, wherein, The first facing layer or the second facing layer comprises aluminized Mylar, low density polyethylene, rubber, rubber compounds, elastic fibers, or combinations thereof.

12. The aerogel composite of claim 1 or 2, wherein, The first facing layer or the second facing layer comprises polyester, polyethylene, polyurethane, polypropylene, polyacrylonitrile, polyamide, polyvinyl chloride, polyimide, or combinations thereof.

13. The aerogel composite of claim 1 or 2, wherein, The first facing layer or the second facing layer comprises polyethylene terephthalate.

14. The aerogel composite of claim 1 or 2, wherein, The first facing layer or the second facing layer comprises a polymeric sheet.

15. The aerogel composite of claim 1 or 2, wherein, At least one of the first facing layer and the second facing layer comprises a fluid permeable facing material.

16. The aerogel composite of claim 1 or 2, wherein, The aerogel composite has a thermal conductivity between 18.0 mW / m·K and 40.0 mW / m·K.

17. The aerogel composite of claim 1 or 2, wherein, The aerogel composite has a resiliency of more than 25%.

18. The aerogel composite of claim 1 or 2, wherein, The aerogel composite has a resiliency of more than 50%.

19. The aerogel composite of claim 1 or 2, wherein, The aerogel composite has a resiliency of more than 60%.

20. The aerogel composite of claim 1 or 2, wherein, The aerogel composite has a resiliency of more than 95%.

21. A thermal barrier or panel comprising the aerogel composite of any one of claims 1 to 20.

22. A method of making an aerogel composite, comprising: A substrate layer having an upper surface and a lower surface is provided, the substrate layer comprising a reinforced aerogel composition, the reinforced aerogel composition comprising a reinforcing material and a monolithic aerogel framework; A first surfacing layer comprising a first surfacing material and a second surfacing layer comprising a second surfacing material are provided, wherein The first facing material and the second facing material are each comprised of a non-fluoropolymer material; The first facing layer is adhered to the upper surface of the substrate layer, and the second facing layer is adhered to the lower surface of the substrate layer, thereby forming the aerogel composite; A gel precursor solution is provided, the gel precursor solution comprising a gel precursor material and a solvent; The gel precursor material in the gel precursor solution is converted to a gel composition, forming a reinforced gel composite; At least a portion of the solvent is extracted from the reinforced gel composite to obtain the aerogel composite; wherein the gel precursor solution is in contact with at least one facing layer, and at least a portion of the gel precursor solution in contact with the facing layer travels through the facing layer into the reinforcing material in the substrate layer; wherein the first facing layer or the second facing layer comprises a porous reflective foil; and wherein, At least one of the first facing layer or the second facing layer is adhered to the substrate layer by a non-adhesive mechanism selected from the group consisting of stitching, sealed pockets, rivets, buttons, clips, wrapping, bracing, and combinations thereof.

23. The method of claim 22, wherein, The method further comprises dispensing at least a portion of the substrate layer on a moving assembly prior to dispensing the gel precursor solution on the substrate layer.

24. The method of claim 22, wherein, The method further comprises rolling the substrate layer into a preformed roll comprising multiple overlapping layers of the substrate layer, and placing the preformed roll of the substrate layer into a container prior to contacting the gel precursor solution with the substrate layer.

25. The method of claim 22, wherein, The method further comprises exposing the substrate layer to a skiving or shaving device; causing the skiving or shaving device to remove a continuous piece of material from the substrate layer, thereby producing a sheet of material.

26. The method of claim 22, wherein the method further comprises heating the aerogel composite to a target temperature; molding or shaping the aerogel composite before, during, or after the heating step; and allowing the molded or shaped aerogel composite to cool, whereby the aerogel composite retains its molded shape upon cooling.

27. The method of claim 22, wherein, The reinforcing material comprises a foam reinforcing material.

28. The method of claim 27, wherein, The foam reinforcing material comprises a material selected from the group consisting of polyolefins, polyurethanes, phenol formaldehyde resins, melamine, cellulose acetate, and polystyrene.

29. The method of claim 22, wherein, The reinforcing material comprises a fiber reinforcing material.

30. The method of claim 22, wherein, The first facing layer or the second facing layer comprises an elastic fiber, the elastic fiber comprising spandex, nylon, lycra, or combinations thereof.

31. The method of claim 22, wherein, The first facing layer or the second facing layer comprises an aluminized Mylar, low density polyethylene, rubber, rubber composite, elastic fiber, or combinations thereof.

32. The method of claim 22, wherein, The first facing layer or the second facing layer comprises a polyester, polyethylene, polyurethane, polypropylene, polyacrylonitrile, polyamide, polyvinyl chloride, polyimide, and combinations thereof.

33. The method of claim 22, wherein, The first facing layer or the second facing layer comprises a polyethylene terephthalate.

34. The method of claim 22, wherein, The first facing layer or the second facing layer is a polymeric sheet.

35. The method of claim 22, wherein, At least one of the first facing layer or the second facing layer is a fluid permeable facing material.

36. An aerogel composite manufactured by the method of any one of claims 22 to 35, wherein, The aerogel composite has a thermal conductivity coefficient of between 18.0 mW / m-K and 40.0 mW / m-K.

37. A thermal barrier or panel comprising an aerogel composite manufactured by the method of any one of claims 22 to 35.

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