Fire class enhanced aerogel compositions

Abstract

The present disclosure provides a fire-enhanced aerogel composition, specifically a robust and easily handled enhanced aerogel composition that has good performance in aqueous environments, has good insulating properties, and has good properties for fire reaction, combustion, and fire retardant performance. The present disclosure also provides a method of making or manufacturing the enhanced aerogel composition. In certain embodiments, the composition has a silica-based aerogel skeleton, and the aerogel skeleton is enhanced with an open-cell macroporous skeleton and includes one or more fire additives, wherein the silica-based aerogel skeleton includes at least one hydrophobically bound silicon, and the composition or each component thereof has the desired properties.

Description

[0001] This application is a divisional application of the PCT patent application filed in China with Chinese patent application number 201980050544.X, entitled "Fire-enhanced Aerogel Composition", filed on May 29, 2019.

[0002] This application claims U.S. Provisional Application No. 62 / 678,850, filed May 31, 2018, the entire contents of which are incorporated herein by reference, and the terminology used herein shall be defined. Technical Field

[0003] This disclosure generally relates to aerogel technology. More specifically, this disclosure relates to aerogel compositions containing fire-related additives. Background Technology

[0004] Low-density aerogel materials are widely considered the best available solid insulators. Aerogels primarily function as insulators by minimizing conduction (low structural density leads to tortuous paths for energy transfer through a solid framework), convection (large pore volume and small pore size result in minimal convection), and radiation (facilitating the dispersion of IR-absorbing or scattering dopants throughout the aerogel matrix). Aerogels have a wide range of applications, including heating and cooling insulation, sound insulation, dielectrics, aerospace, energy storage and production, and filtration. Furthermore, aerogel materials exhibit many intriguing acoustic, optical, mechanical, and chemical properties, making them highly useful in a variety of insulating and non-insulating applications.

[0005] However, there is a need for fire-reinforced aerogel compositions, either individually or in one or more combinations, that possess improved properties in various aspects, including heat resistance, hydrophobicity, ignition reactivity, and others. However, considering the technology as a whole considered at the time of this disclosure, how to overcome the shortcomings of the prior art is not apparent to those skilled in the art.

[0006] To facilitate the disclosure of this invention, although certain aspects of the conventional art have been discussed, the applicant does not abandon these techniques, and it should be expected that the claimed invention may cover one or more of the conventional art aspects discussed herein.

[0007] In this specification, when a document, action, or knowledge item is referenced or discussed, such reference or discussion does not imply that the document, action, or knowledge item, or any combination thereof, was publicly available, was known to the public, was part of common general knowledge, or otherwise constituted prior art under applicable law as of the priority date; or that any problem relating to this specification is known. Summary of the Invention

[0008] Now, new, useful, and non-obvious inventions are being used to meet the long-standing unmet need for improved aerogel compositions.

[0009] In one embodiment, the present invention is an enhanced aerogel composition comprising a silica-based aerogel framework reinforced with an open-cell macroporous framework (OCMF) material and fire-based additives, wherein the silica-based aerogel framework comprises at least one hydrophobically bonded silicon.

[0010] In a general sense, this disclosure provides a durable and easy-to-handle reinforced aerogel composition that exhibits good performance in aqueous environments, good insulating properties, and also good flammability and flame retardancy. In some embodiments, this disclosure provides a reinforced aerogel composition reinforced with OCMF that exhibits good performance in aqueous environments, good insulating properties, and also good flammability and flame retardancy.

[0011] In another general aspect, this disclosure provides an enhanced aerogel composition comprising a silica-based aerogel framework and OCMF, and having the following properties: a) thermal conductivity of ≤30 mW / m*K; b) liquid water absorption of ≤30 wt%; c) heat of combustion of ≤717 cal / g. In some embodiments, the enhanced aerogel composition of the present invention has the following properties: a) thermal conductivity of ≤25 mW / m*K; b) liquid water absorption of ≤20 wt%; c) heat of combustion of ≤717 cal / g. In some embodiments, the enhanced aerogel composition of the present disclosure has a thermal conductivity of 0.40 g / cm³. 3 Below, 0.30g / cm 3 Below, 0.25g / cm 3 Below or 0.20g / cm 3The following densities are specified. In some embodiments, the enhanced aerogel composition of the present invention has a thermal conductivity of less than 25 mW / m*K, less than 20 mW / m*K, less than 18 mW / m*K, a thermal conductivity between 15 mW / m*K and 30 mW / m*K, or a thermal conductivity between 15 mW / m*K and 20 mW / m*K. In some embodiments, the enhanced aerogel composition disclosed herein has an absorption of less than 30 wt%, less than 25 wt%, less than 20 wt%, less than 15 wt%, less than 10 wt%, or less than 5 wt% of liquid water. In some embodiments, the enhanced aerogel composition disclosed herein has a heat of combustion of less than 717 cal / g, less than 700 cal / g, less than 675 cal / g, less than 650 cal / g, less than 625 cal / g, less than 600 cal / g, or a heat of combustion between 580 cal / g and 717 cal / g. In certain specific aspects, the combination of the above-mentioned thermal conductivity, water absorption and heat of combustion can be achieved by changing the composition of the gel precursor, the composition of the additives, the catalyst or other reagent that activates the precursor, the pH of the precursor solution, the partition rate, each precursor, catalyst or additive, the time of gelation, the entanglement of the gel (in some aspects), the aging time and pH, any post-gelation treatment, the extraction time and conditions (temperature, pressure) and any subsequent drying steps.

[0012] In another general aspect, this disclosure provides an enhanced aerogel composition comprising a silica-based aerogel framework, a melamine-based OCMF, and a fire-related additive, and having the following properties: a) thermal conductivity between 15 mW / M*K and 30 mW / M*K; b) liquid water absorption of less than 30% by weight; c) heat of combustion between 580 cal / g and 717 cal / g. In some preferred embodiments, the OCMF material is an organic OCMF material. In another particular preferred embodiment, the OCMF material is a melamine-based OCMF material. In some embodiments, the enhanced aerogel composition of this disclosure has a hydrophobic organic content between about 1% to about 30% by weight, about 1% to about 25% by weight, about 1% to about 20% by weight, between about 1% and about 15% by weight, between about 1% and about 10% by weight, or between about 1% and about 5% by weight.

[0013] In another general aspect, this disclosure provides a method for preparing a reinforced aerogel composition, comprising: a) providing a precursor solution comprising a silica gel precursor material, a solvent, and optionally a catalyst; b) combining the precursor solution with a reinforcing material comprising OCMF; c) converting the silica gel precursor material in the precursor solution into a gel material or composition; and d) extracting at least a portion of the solvent from the gel material or composition to obtain the aerogel material or composition. In some embodiments, the method of this disclosure includes incorporating a pyrophoretic additive material into the reinforced aerogel composition by combining it with the precursor solution before or during the conversion of the silica gel precursor material in the precursor solution. In a preferred embodiment, the reinforcing material comprises a melamine-based OCMF material. In some embodiments, the method of this disclosure includes incorporating at least one hydrophobically bonded silicon into the aerogel material or composition by one or both of the following: i) including at least one hydrophobic group having at least one silica gel precursor material in the precursor solution, or ii) exposing the precursor solution, gel composition, or aerogel composition to a hydrophobic agent. In some embodiments, the method disclosed herein includes the step of incorporating at least one hydrophobically bonded silicon into an aerogel composition to provide a hydrophobic organic content in the aerogel composition between about 1 wt% and about 25 wt%, about 1 wt% and about 20 wt%, about 1 wt% and about 15 wt%, about 1 wt% and about 10 wt%, or about 1 wt% and about 5 wt%. In a preferred embodiment, the method disclosed herein produces an enhanced aerogel composition. In some embodiments, the method disclosed herein produces an enhanced aerogel composition comprising a silica-based aerogel framework, a melamine-based OCMF, and fire-resistant additives, having the following properties: a) thermal conductivity between 15 mW / m*K and 30 mW / m*K; b) liquid water absorption of less than 30 wt%; c) heat of combustion between 580 cal / g and 717 cal / g.

[0014] Furthermore, specific non-limiting embodiments / exemplifications are disclosed in the following description. The examples presented are intended to illustrate a range of embodiments of the inventive concept, including combinations of such embodiments or examples. The scope of the invention as described in the claims disclosed herein extends beyond these non-limiting embodiments.

[0015] Implementation Scheme 1 is an enhanced aerogel composition comprising a silica-based aerogel framework reinforced with OCMF material and a fire-related additive; wherein the silica-based aerogel framework comprises at least one hydrophobically bonded silicon; wherein the enhanced aerogel composition has the following properties: i) liquid water absorption of less than 20% by weight; ii) thermal conductivity of less than 30 mW / M*K; iii) heat of combustion of less than 717 cal / g.

[0016] Implementation scheme 2 is an enhanced aerogel composition comprising a density of 2 kg / m³ 3 and 25kg / m 3 The OCMF material is used to reinforce a silica-based aerogel framework, and fire-resistant additives are used; wherein the silica-based aerogel framework contains at least one hydrophobically bonded silicon; wherein the reinforced aerogel composition has the following properties: i) the amount of liquid water absorbed is less than 20% by weight; ii) the thermal conductivity is less than 30 mW / M*K; iii) the heat of combustion is less than 717 cal / g.

[0017] Implementation scheme 3 is an enhanced aerogel composition comprising a density of 2 kg / m³ 3 and 25kg / m 3 The OCMF material reinforces a silica-based aerogel framework and fire-related additives; wherein the silica-based aerogel framework comprises at least one hydrophobically bonded silicon; wherein the reinforced aerogel composition has the following properties: i) liquid water absorption is between 1% and 10% by weight; ii) thermal conductivity is greater than 8 and less than 25 mW / M*K; iii) heat of combustion is less than 717 cal / g and greater than 400 cal / g.

[0018] Implementation scheme 4 is a reinforced OCMF composition reinforced with a silica-based aerogel composition and fire-resistant additives; wherein the skeleton of the silica-based aerogel contains at least one hydrophobically bonded silicon; wherein the reinforced aerogel composition has the following properties: i) liquid water absorption of less than 20% by weight; ii) thermal conductivity of less than 30 mW / M*K; iii) heat of combustion of less than 717 cal / g.

[0019] Implementation scheme 5 is a reinforced OCMF composition reinforced with a silica-based aerogel composition and fire-resistant additives; wherein the silica-based aerogel framework contains at least one hydrophobically bonded silicon; wherein the reinforced aerogel composition has the following properties: i) liquid water absorption of less than 20% by weight; ii) thermal conductivity of less than 30 mW / M*K; iii) heat of combustion of less than 717 cal / g.

[0020] Implementation Scheme 6 is a reinforced OCMF composition reinforced with a silica-based aerogel composition and fire-resistant additives; wherein the skeleton of the silica-based aerogel contains at least one hydrophobically bonded silicon; wherein the reinforced aerogel composition has the following properties: i) the absorption of liquid water is between 1% by weight and 10% by weight; ii) the thermal conductivity is greater than 8 and less than 25 mW / M*K; iii) the heat of combustion is less than 717 cal / g and greater than 400 cal / g.

[0021] Embodiment 7 is a set of embodiments having an enhanced aerogel composition as described in any one of embodiments 1 to 3 or an enhanced OCMF composition as described in any one of embodiments 4 to 6, wherein the OCMF material comprises or is an organic OCMF material.

[0022] Embodiment 8 is a set of embodiments having an enhanced aerogel composition as described in any one of embodiments 1 to 3 or an enhanced OCMF composition as described in any one of embodiments 4 to 6, wherein the OCMF material comprises or is a melamine-based OCMF material.

[0023] Embodiment 9 is a set of embodiments having an enhanced aerogel composition as described in any one of embodiments 1 to 3 or an enhanced OCMF composition as described in any one of embodiments 4 to 6, wherein the OCMF material comprises or is a sheet of OCMF material.

[0024] Embodiment 10 is a set of embodiments having an enhanced aerogel composition as described in any one of embodiments 1 to 3 or an enhanced OCMF composition as described in any one of embodiments 4 to 6, wherein the OCMF material is an organic foam.

[0025] Embodiment 11 is a set of embodiments having an enhanced aerogel composition as described in any one of embodiments 1 to 3 or an enhanced OCMF composition as described in any one of embodiments 4 to 6, wherein the OCMF material is a melamine-based foam.

[0026] Embodiment 12 is a set of embodiments having an enhanced aerogel composition or an enhanced OCMF composition as described in any one of embodiments 1 to 11, wherein the OCMF material is neither a low-flammability material nor a non-flammable material.

[0027] Embodiment 13 is a set of embodiments having an enhanced aerogel composition or an enhanced OCMF composition as described in any one of embodiments 1 to 11, wherein the OCMF material is neither a flammable material nor a non-flammable material.

[0028] Embodiment 14 is a set of embodiments having an enhanced aerogel composition or an enhanced OCMF composition as described in any one of embodiments 1 to 11, wherein the OCMF material accounts for 2% to 10% by weight of the composition.

[0029] Embodiment 15 is a set of embodiments having any one of embodiments 1 to 14 of an enhanced aerogel composition or an enhanced OCMF composition, wherein the content of hydrophobically bonded silicon in the composition is between 2% by weight and 10% by weight.

[0030] Embodiment 16 is a set of embodiments having any one of embodiments 1 to 14 of an enhanced aerogel composition or an enhanced OCMF composition, wherein the content of hydrophobically bonded silicon in the composition is 2% to 8% by weight.

[0031] Embodiment 17 is a set of embodiments having any one of embodiments 1 to 14 of an enhanced aerogel composition or an enhanced OCMF composition, wherein the content of hydrophobically bonded silicon in the composition is 2% to 6% by weight.

[0032] Embodiment 18 is a set of embodiments having an enhanced aerogel composition or an enhanced OCMF composition as described in any one of embodiments 1 to 17, wherein the composition has a heat of combustion of less than 700 cal / g.

[0033] Embodiment 19 is a set of embodiments having an enhanced aerogel composition or an enhanced OCMF composition as described in any one of embodiments 1 to 17, wherein the composition has a heat of combustion of less than 675 cal / g.

[0034] Embodiment 20 is a set of embodiments having an enhanced aerogel composition or an enhanced OCMF composition as described in any one of embodiments 1 to 17, wherein the composition has a heat of combustion of less than 650 cal / g.

[0035] Embodiment 21 is a set of embodiments having an enhanced aerogel composition or an enhanced OCMF composition as described in any one of embodiments 1 to 17, wherein the composition has a heat of combustion of less than 625 cal / g.

[0036] Embodiment 22 is a set of embodiments having an enhanced aerogel composition or an enhanced OCMF composition as described in any one of embodiments 1 to 21, wherein the composition has a thermal conductivity of less than 22 mW / M*K.

[0037] Embodiment 23 is a set of embodiments having an enhanced aerogel composition or an enhanced OCMF composition as described in any one of embodiments 1 to 21, wherein the enhanced aerogel composition has a thermal conductivity of less than 20 mW / M*K.

[0038] Embodiment 24 is a set of embodiments having an enhanced aerogel composition or an enhanced OCMF composition as described in any one of embodiments 1 to 21, wherein the enhanced aerogel composition has a thermal conductivity of less than 18 mW / M*K.

[0039] Embodiment 25 is a group of embodiments having an enhanced aerogel composition or an enhanced OCMF composition as described in any one of embodiments 1 to 21, wherein the enhanced aerogel composition has a concentration of 0.15 to 0.40 g / cm³. 3 The density.

[0040] Embodiment 26 is a set of embodiments having an enhanced aerogel composition or an enhanced OCMF composition as described in any one of embodiments 1 to 21, wherein the enhanced aerogel composition has an initial thermal decomposition of 350°C or higher.

[0041] Embodiment 27 is a set of embodiments having an enhanced aerogel composition or an enhanced OCMF composition as described in any one of embodiments 1 to 21, wherein the enhanced aerogel composition has an initial thermal decomposition of 360°C or higher.

[0042] Embodiment 28 is a set of embodiments having an enhanced aerogel composition or an enhanced OCMF composition as described in any one of embodiments 1 to 21, wherein the enhanced aerogel composition has an initial thermal decomposition of 370°C or higher.

[0043] Embodiment 29 is a set of embodiments having an enhanced aerogel composition or an enhanced OCMF composition as described in any one of embodiments 1 to 21, wherein the enhanced aerogel composition has an initial thermal decomposition of 380°C or higher.

[0044] Embodiment 30 is a set of embodiments having an enhanced aerogel composition or an enhanced OCMF composition as described in any one of embodiments 1 to 21, wherein the enhanced aerogel composition has an initial thermal decomposition of 390°C or higher.

[0045] Implementation scheme 31 is an organic OCMF-enhanced aerogel composition comprising a pyrophoretic additive and a hydrophobic organic component, wherein the initial endothermic decomposition of the pyrophoretic additive in the composition is within 50°C of the initial thermal decomposition of the remaining components of the composition that do not contain the pyrophoretic additive.

[0046] Implementation scheme 32 is an organic OCMF-reinforced aerogel composition comprising a pyrophoric additive and at least 5% hydrophobic content, wherein the total heat of endothermic decomposition of the pyrophoric additive in the composition is at least 30% of the heat of decomposition of the remaining components in the composition that do not contain the pyrophoric additive.

[0047] Implementation scheme 33 is an organic OCMF-enhanced aerogel composition containing at least two fire-type additives, each of which has an initial endothermic decomposition difference of at least 10°C.

[0048] Implementation scheme 34 is an organic OCMF-enhanced aerogel composition comprising a pyrophoric additive and a hydrophobic component, wherein the total heat of endothermic decomposition of the pyrophoric additive in the composition does not exceed 80% of the heat of decomposition of the remaining components in the composition that do not contain the pyrophoric additive.

[0049] Embodiment 35 is a set of embodiments having any one of embodiments 1 to 11 of an enhanced aerogel composition or an enhanced OCMF composition, wherein the hydrophobic content is at least 5%, and the total heat of endothermic decomposition of the pyrophoric additive in the composition is at least 30% of the heat of decomposition of the remaining components in the composition that do not contain the pyrophoric additive.

[0050] Embodiment 36 is a set of embodiments having an enhanced aerogel composition or an enhanced OCMF composition as described in any one of embodiments 1 to 11, wherein the initial endothermic decomposition of the pyrophoric additive in the composition is within 50°C of the initial thermal decomposition of the remaining components in the composition that do not contain the pyrophoric additive.

[0051] Embodiment 37 is a set of embodiments having an enhanced aerogel composition or an enhanced OCMF composition as described in any one of embodiments 1 to 11, having at least two pyrophoric additives, wherein the initial endothermic decomposition of each of the two pyrophoric additives differs by at least 10°C.

[0052] Embodiment 38 is a set of embodiments having an enhanced aerogel composition or an enhanced OCMF composition as described in any one of embodiments 1 to 11, wherein the total heat of endothermic decomposition of the pyrophoric additive in the composition does not exceed 80% of the heat of decomposition of the remaining components in the composition that do not contain the pyrophoric additive.

[0053] Implementation scheme 39 is a set of implementation schemes having any one of the components of implementation schemes 1 to 38, wherein the furnace temperature rise of the components conforms to ISO 1182 and is below about 100°C, below about 90°C, below about 80°C, below about 70°C, below about 60°C, below about 50°C, below about 45°C, below about 40°C, below about 38°C, below about 36°C, below about 34°C, below about 32°C, below about 30°C, below about 28°C, below about 26°C, below about 24°C, or within a range of any two of these values.

[0054] Implementation scheme 40 is a set of implementation schemes having any one of the components of implementation schemes 1 to 39, wherein the burning time of the components conforms to ISO 1182 and is less than about 30 seconds, less than about 25 seconds, less than about 20 seconds, less than about 15 seconds, less than about 10 seconds, less than about 5 seconds, less than about 2 seconds, or within a range of any two of these values.

[0055] Implementation 41 is a set of implementations having the composition of any one of Implementation 1 to 40, wherein, according to ISO 1182, the mass loss of the composition is less than about 50%, less than about 40%, less than about 30%, less than about 28%, less than about 26%, less than about 24%, less than about 22%, less than about 20%, less than about 18%, less than about 16%, or within a range of any two of these values.

[0056] Implementation scheme 42 is a set of implementation schemes having the components described in any one of the above implementation schemes, wherein the components are low flammability.

[0057] Implementation scheme 43 is a set of implementation schemes having the components described in any one of the above implementation schemes, wherein the components are non-flammable.

[0058] Implementation scheme 44 is a set of implementation schemes having the components described in any one of the above implementation schemes, wherein the components are low-flammability.

[0059] Implementation scheme 45 is a set of implementation schemes having the components described in any one of the above implementation schemes, wherein the components are non-flammable.

[0060] Implementation scheme 46 is a set of implementation schemes having the composition of any one of the above implementation schemes, wherein the initial endothermic decomposition of the flammable additive is greater than 280°C, 300°C, 350°C, 400°C, 450°C or 500°C.

[0061] Implementation scheme 47 is a set of implementation schemes having any one of the above implementation schemes, wherein the initial exothermic decomposition of the composition without fire additives is greater than 280°C, 300°C, 350°C, 400°C, 450°C or 500°C.

[0062] Implementation scheme 48 is a set of implementation schemes having the composition of any one of the above implementation schemes, wherein the OCMF material is a melamine-based foam.

[0063] Implementation scheme 49 is a set of implementation schemes having the composition of any one of the above implementation schemes, wherein the OCMF material is a urethane-based polymer foam.

[0064] Implementation scheme 50 is a set of embodiments having the composition of any one of the preceding claims, wherein the OCMF material is a mesh foam.

[0065] Furthermore, the aerogel materials or frameworks of various embodiments of the present invention can also be implemented using a slurry or suspension based on aerogel particles infiltrated into the OCMF materials described in the various embodiments. In yet another embodiment, the various embodiments of the present invention can be implemented using non-particulate aerogel materials produced in-situ by infiltrating the OCMF material in a suitable solvent with various gel precursors and then removing the solvent using various methods (including the use of supercritical fluids) or at elevated temperatures and ambient pressures or under subcritical pressures.

[0066] In individual embodiments, the present invention includes reinforced aerogel compositions or OCMF-reinforced compositions that contain one or more or all of the foregoing features and properties, including various combinations thereof and methods of manufacture.

[0067] As this disclosure proceeds, these and other important objects, advantages and features of the invention will become clear.

[0068] Therefore, the present invention will be illustrated in the following disclosure with features including construction, combination of elements and arrangement of components, and the scope of the invention will be set forth in the claims. Attached Figure Description

[0069] Figure 1 Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) measurements of the hydrophobic aerogel composition of the present invention, which contains no additives and is reinforced with melamine foam, are described. The hydrophobic aerogel composition has about 120% magnesium hydroxide, with the weight of silica and hydrophobic components in the aerogel composition being 100% as a reference (Example 3).

[0070] Figure 2 Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) measurements of the hydrophobic aerogel composition of the present invention, which contains no additives and is reinforced with melamine foam, are described. The hydrophobic aerogel composition has about 120% halloysite clay, with the weight of silica and hydrophobic components of the aerogel composition being 100% as a reference (Example 21). Detailed Implementation

[0071] In the following detailed description of preferred embodiments, reference is made to the accompanying drawings, which form part of the reference, and specific embodiments in which the invention can be practiced are illustrated by way of illustration in the drawings. It should be understood that other embodiments and structural changes may be utilized without departing from the scope of the invention.

[0072] As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural references unless the context clearly indicates otherwise. As used in this specification and the appended claims, the term “or” is generally used in a sense that includes “and / or” unless the context clearly indicates otherwise.

[0073] As used herein, “about” means approximately or close to, and in the context of the numerical value or range described, it means ±15% of the numerical value. In one embodiment, the term “about” may include conventional rounding based on the significant figures of the numerical value. Additionally, the phrase “about 'x' to 'y'” includes “about 'x' to 'about y'”.

[0074] As used herein, the terms “composition” and “complex” are used interchangeably.

[0075] Aerogels are a class of porous materials with open pores, comprising an interconnected framework, a corresponding network of pores integrated within the framework, and an interstitial phase within the network of pores, 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 are distinguished from other porous materials by their physical and structural properties.

[0076] In the context of this disclosure, the term "aerogel" or "aerogel material" refers to a gel comprising a framework of interconnected structures, a corresponding network of interconnected pores integrated within the framework, and a gas, such as air, as a dispersing interstitial medium; and characterized in that the aerogel has the following physical and structural properties (based on nitrogen porosity testing): (a) an average pore size ranging from about 2 nm to about 100 nm, (b) a porosity of at least 80% and (c) about 20 nm. 2 Surface area above / g.

[0077] Therefore, the aerogel materials disclosed herein include any aerogel or other open-cell compound that satisfies the elements defined in the foregoing paragraphs; including compounds that can be further classified as dry gels, freeze gels, ambient drying gels (ambigels), microporous materials, etc.

[0078] Aerogel materials may further be characterized by additional physical properties, including: (d) a pore volume of more than about 2.0 mL / g, particularly more than about 3.0 mL / g; (e) a density of less than about 0.50 g / cc, particularly less than about 0.25 g / cc; and (f) at least 50% of the total pore volume comprising pores having a pore size between 2 and 50 nm; although satisfying these other properties is not a required characteristic of a compound as an aerogel material.

[0079] In the context of this disclosure, the term "innovative processing and extraction techniques" refers to methods that replace the liquid interstitial phase in a wet gel material with a gas, such as air, in a manner that induces low-pore collapse. The gel skeleton structure exhibits low shrinkage. Drying techniques, such as atmospheric evaporation, often introduce strong capillary pressures and other mass transfer constraints at the liquid-gas interface of the evaporated or removed interstitial phase. The strong capillary forces generated by liquid evaporation or removal lead to significant pore shrinkage and skeleton collapse within the gel material. Using innovative processing and extraction techniques during the extraction of the liquid interstitial phase can reduce the adverse effects of capillary forces on the pores and skeleton of the gel during liquid extraction processes (also known as solvent removal or drying).

[0080] In some embodiments, innovative processing and extraction techniques utilize near-critical or supercritical fluids, or near-critical or supercritical conditions, to extract the interstitial liquid phase from wet gel materials. This can be achieved by removing the interstitial liquid phase from the gel at 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.

[0081] In some embodiments, innovative processing and extraction techniques include modification of the gel matrix to reduce the irreversible effects of capillary pressure and other mass transfer limitations at the liquid-vapor interface. This embodiment may include treating the gel matrix with a hydrophobic agent or other functionalizing agent that allows the gel matrix to withstand or recover from any collapse forces during liquid extraction occurring before the critical point of the interstitial phase. This embodiment may also include the combination of functional groups or matrix elements that provide a sufficiently high matrix modulus to withstand or recover from collapse forces during liquid extraction occurring below the critical point of the interstitial phase.

[0082] In the context of this disclosure, the term "skeleton" or "skeleton structure" refers to a network of interconnected oligomers, polymers, or colloidal particles that form a solid structure within a material. In the context of this disclosure, the term "aerogel skeleton" or "aerogel skeleton structure" refers to a network of interconnected oligomers, polymers, or colloidal particles that form a solid structure within a gel or aerogel. The polymers or particles constituting an aerogel skeleton structure typically have a diameter of about 100 angstroms. However, the skeleton structure of this disclosure may also include networks of interconnected oligomers, polymers, or colloidal particles of all diameter sizes forming a solid structure within a material such as a gel or aerogel. Furthermore, the term "silica-based aerogel" or "silica-based aerogel skeleton" refers to an aerogel skeleton in which silica comprises at least 50% (by weight) of oligomers, polymers, or colloidal particles that form a solid skeleton structure within a gel or aerogel.

[0083] In the context of this disclosure, the term "aerogel composition" refers to any composite in which an aerogel material is included as a component. Examples of aerogel compositions include, but are not limited to, fiber-reinforced aerogel composites; aerogel composites containing additive elements such as opacifiers; aerogel composites reinforced by an open-pore macroporous framework; aerogel-polymer composites; and composites of solid or semi-solid materials incorporating aerogel microparticles, particles, fine particles, beads, or powders into, for example, adhesives, resins, cements, foams, polymers, or similar solid materials. Aerogel compositions are typically obtained by removing solvents from the various gel materials disclosed in this invention. The resulting aerogel compositions may be further subjected to additional processing or treatment. The various gel materials may also undergo other processing or treatments known or useful in the art prior to solvent removal (or liquid extraction or drying).

[0084] In the context of this disclosure, the term "monolithic" refers to an aerogel material in which the majority (by weight) of the aerogel contained in the aerogel material or composition is a monolithically interconnected aerogel nanostructure. Monolithic aerogel materials include those initially formed as having a single, interconnected gel or aerogel nanostructure, but subsequently broken, fractured, or segmented into non-monolithic aerogel nanostructures. Monolithic aerogel materials differ from particulate aerogel materials. The term "particulate aerogel material" refers to an aerogel material in which the majority (by weight) of the aerogel contained in the aerogel material is in the form of microparticles, particles, granules, beads, or powder, which may be assembled or compressed together. However, there is a lack of interconnected aerogel nanostructures between individual particles.

[0085] In the context of this disclosure, the term "wet gel" refers to a gel in which the mobile interstitial phase within an interconnected network of pores is primarily composed of a liquid (e.g., a conventional solvent), a liquefied gas (e.g., liquid carbon dioxide), or a combination thereof. Aerogels typically require the prior production of a wet gel, followed by innovative processing and extraction techniques to replace the mobile interstitial fluid in the gel with air. Examples of wet gels include, but are not limited to, alcohol gels, hydrogels, ketone gels, carbon gels, and any other wet gels known to those skilled in the art.

[0086] The aerogel compositions disclosed herein may include reinforced aerogel compositions. In the context of this disclosure, the term "reinforced aerogel composition" refers to an aerogel composition that includes a reinforcing phase within an aerogel material, wherein the reinforcing phase is not part of the aerogel skeleton itself. The reinforcing phase can be any material that provides increased flexibility, resilience, compliance, or structural stability to the aerogel material. Well-known examples of reinforcing materials include, but are not limited to, open-cell macroporous skeleton reinforcing materials, closed-cell macroporous skeleton reinforcing materials, open-cell membranes, honeycomb reinforcing materials, polymer reinforcing materials, and fiber reinforcing materials such as discrete fibers, woven materials, nonwoven materials, needle-knitted nonwoven materials, cotton wadding, mesh fabrics, mats, and felts.

[0087] The enhanced aerogel composition disclosed herein may comprise an aerogel composition reinforced with an open-pore macroporous framework material. In the context of this disclosure, the term "open-pore macroporous framework" or "OCMF" refers to a porous material comprising a framework of interconnected structures with a homogeneous basic composition, having a corresponding network of interconnected pores integrated within the framework; and characterized by an average pore size in the range of about 10 μm to about 700 μm. This average pore size can be measured using known techniques, including but not limited to microscopes with optical analysis capabilities. Therefore, the OCMF material disclosed herein includes any open-pore material that satisfies the defining elements set forth in this paragraph, including compounds that can be further classified as foams, foam-like materials, macroporous materials, etc. OCMF materials can be distinguished from materials comprising a framework with interconnected structures having void volumes within the framework and not having a homogeneous composition, such as an assembly of fibers and adhesives having void volumes within a fibrous matrix.

[0088] In the context of this disclosure, the term “substantially homogeneous composition” means the uniformity of the composition of the material referred to within a 10% tolerance.

[0089] In the context of this disclosure, the term "OCMF-reinforced aerogel composition" refers to a reinforced aerogel composition comprising an open-pore macroporous framework material as a reinforcing phase. Suitable OCMF materials for use in this disclosure include, but are not limited to, OCMF materials made from organic polymer materials. Examples include OCMF materials made from polyolefins, polyurethanes, phenolic resins, melamine, cellulose acetate, and polystyrene. In the context of this disclosure, the term "organic OCMF" refers to an OCMF material having a framework primarily composed of organic polymer materials. In some embodiments, OCMF materials made from melamine or melamine derivatives are also preferred. In the context of this disclosure, the terms "melamine OCMF" or "melamine-based OCMF" refer to an organic OCMF material having a framework primarily composed of polymer materials derived from reacting melamine with a condensing agent such as formaldehyde. Examples of OCMF materials made from melamine or melamine derivatives used in this disclosure are proposed in U.S. Patent Nos. 8,546,457, 4,666,948, and WO 2001 / 094436. The term "inorganic OCMF" refers to an OCMF material having a framework primarily composed of inorganic materials. Examples of inorganic OCMFs include, but are not limited to, cementitious materials, gypsum, and calcium silicate.

[0090] In the context of this invention, the term "foam" refers to a material comprising a skeleton of interconnected polymeric structures having a substantially homogeneous composition and having a corresponding network or set of pores integrated within the skeleton, and formed by dispersing a portion of gas in the form of bubbles into a liquid or resinous foam material such that, when the foam material solidifies into a solid structure, the bubbles remain as pores. Foams can typically be manufactured using a variety of methods—see, for example, U.S. Patent No. 6,147,134; U.S. Patent No. 6,147,134; and U.S. Patent No. 6,147,134; U.S. Patent No. 5,889,071; U.S. Patent No. 6,187,831; and U.S. Patent No. 5,229,429. Therefore, the foam materials disclosed herein include any material that satisfies the defining elements set forth in this paragraph, including compounds that can be further classified as OCMF materials, macroporous materials, etc. Foams as defined in this invention can be of the type of thermoplastic, elastomer, and thermosetting (rigid) plastic.

[0091] The pores within a solid framework can also be referred to as "pores." Cells can be separated by cell walls or cell membranes, thus forming a collection of independent, closed pores in a porous material. The term "closed-pore" refers to a porous material in which at least 50% of the pore volume is a closed pore surrounded by a membrane or wall. Cells within a material can also interconnect through cell openings, thus forming an interconnected network of open pores within the material. The term "open-pore" refers to a porous material in which at least 50% of the pore volume is open. Open-pore materials can include reticular open-pore materials, non-reticular open-pore materials, or combinations thereof. Reticular materials are open-pore materials produced through a reticularization process that eliminates or punctures the cell membranes within the porous material. Reticular materials typically have a higher open-pore concentration than non-reticular materials, but are often more expensive and difficult to produce. Generally, no porous material possesses only one type of pore structure (open-pore or closed-pore). A variety of methods can be used to manufacture porous materials, including the foam production methods proposed in U.S. Patent Nos. 6,147,134, 5,880,9071, 6,188,7031, 5,229,429, 4,454,248, and U.S. Patent Publication No. 20,070,213,417.

[0092] In the context of this disclosure, the terms "aerogel blanket" or "aerogel blanket composition" refer to an aerogel composition reinforced with continuous sheets of reinforcing material. Aerogel blanket compositions can be distinguished from other reinforced aerogel compositions reinforced with discontinuous reinforcing materials, such as discrete agglomerates or blocks of reinforcing material. Aerogel blanket compositions are particularly useful for applications requiring flexibility because of their high conformability and ability to be used like a blanket to cover surfaces with simple or complex geometries, while retaining the excellent thermal insulation properties of aerogel.

[0093] In the context of this disclosure, the terms “flexibility” and “flexibility” refer to the ability of an aerogel material or composition to be bent or flexed without visible structural damage. Aerogel compositions of this disclosure are capable of bending at least 5°, at least 25°, at least 45°, at least 65°, or at least 85° without visible damage; and / or with a bending radius 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 1 / 2 inch without visible damage. Similarly, the terms “high flexibility” or “high flexibility” refer to an aerogel material or composition capable of bending at least 90° and / or having a bending radius less than 1 / 2 inch without visible damage. Furthermore, the terms “flexible classification” and “flexible classification” refer to aerogel materials or compositions that can be classified as flexible according to ASTM C1101 (ASTM International, West Conshohocken, PA).

[0094] The aerogel compositions disclosed herein can be flexible, highly flexible, and / or classified as flexible. The aerogel compositions disclosed herein can also be draped. In the context of this disclosure, the terms "draped" and "draping" refer to the ability of an aerogel material or composition to bend or deflect to more than 90° with a radius of curvature of about 4 inches without visually perceptible damage. Aerogel materials or compositions according to certain embodiments of the invention are flexible, making the composition non-rigid and applicable to and conforming to three-dimensional surfaces or objects, or prefabricated into various shapes and configurations to simplify installation or application.

[0095] In the context of this disclosure, the terms "additive" or "additive element" refer to materials that can be added to the aerogel composition before, during, or after the production of the aerogel. Additives can be added to modify or improve desired properties in the aerogel, or to counteract undesirable properties in the aerogel. Additives are typically added to the aerogel material before gelation into a precursor liquid, during gelation into a transitional material, or after gelation into a solid or semi-solid material. Examples of additives include, but are not limited to, microfibers, fillers, reinforcing agents, stabilizers, thickeners, elastic compounds, opacifiers, coloring or dyeing compounds, radiation-absorbing compounds, radiation-reflecting compounds, fire-related additives, corrosion inhibitors, thermally conductive components, phase change materials, pH adjusters, redox regulators, HCN modifiers, exhaust gas modifiers, conductive compounds, dielectric compounds, magnetic compounds, radar-blocking components, hardeners, anti-shrinkage agents, and other aerogel additives known in the art.

[0096] In the context of this disclosure, the terms "thermal conductivity" and "TC" refer to measures of the ability of a material or composition to transfer heat between two surfaces on either side of the material or composition, given a temperature difference between them. Thermal conductivity is specifically measured as the amount of heat transferred per unit time and per unit surface area divided by the temperature difference. It is typically recorded in SI units as mW / m*K (milliwatts per meter per absolute temperature). The thermal conductivity of a material can be determined by test methods known in the art, including but not limited to: steady-state heat transfer property test methods using heat flow meter apparatus (ASTM C518, ASTM International, West Conshohocken, PA); steady-state heat flux measurement and heat transfer property test methods using protective heating plate apparatus (ASTM C177, ASTM International, West Conshohocken, PA); steady-state heat transfer performance test methods for pipe insulation (ASTM C335, ASTM International, West Conshohocken, PA); thermal conductivity test of thin heaters (ASTM C1114, ASTM International, West Conshohocken, PA); determination of thermal resistance using protective heating plate apparatus and heat flow meter method (EN 12667, British Standards Institution, UK); or determination of steady-state heat resistance and related properties using protective heating plate apparatus (ISO 8203, International Organization for Standardization, Switzerland). Because different methods can lead to different results, it should be understood that, in the context of this disclosure, unless otherwise explicitly stated, measurements according to ASTM C518 (Method for Testing Steady-State Heat Transfer Properties with a Heat Flow Meter Apparatus) are taken at a temperature of approximately 37.5°C, ambient atmospheric pressure, and a compressive load of approximately 2 psi. Measurements reported according to ASTM C518 are generally highly relevant to any measurements taken according to EN 12667 and any related adjustments to the compressive load. In some embodiments, the aerogel material or composition disclosed herein has a thermal conductivity of less than 40 mW / mK, less than 30 mW / mK, less than 25 mW / mK, less than 20 mW / mK, less than 18 mW / mK, less than 16 mW / mK, less than 14 mW / mK, less than 12 mW / mK, less than 10 mW / mK, less than 5 mW / mK, or a range between any two of these values.

[0097] Thermal conductivity measurements can also be obtained under compression at a temperature of approximately 10°C at atmospheric pressure. Thermal conductivity measurements at 10°C are typically 0.5 to 0.7 mW / mK lower than the corresponding thermal conductivity measurements at 37.5°C. In some embodiments, the aerogel material or composition disclosed herein has a thermal conductivity at 10°C of less than 40 mW / mK, less than 30 mW / mK, less than 25 mW / mK, less than 20 mW / mK, less than 18 mW / mK, less than 16 mW / mK, less than 14 mW / mK, less than 12 mW / mK, less than 10 mW / mK, less than 5 mW / mK, or between any two of these values.

[0098] In the context of this disclosure, the term "density" refers to a measure of the mass per unit volume of an aerogel material or composition. The term "density" generally refers to the apparent density of the aerogel material and the overall density of the aerogel composition. Density is typically recorded in kg / m³. 3 Or g / cc. The density of an aerogel material or composition can be determined by methods known in the art, including but not limited to standard test methods for the size and density of precast block and panel insulation materials (ASTM C303, ASTM International, West Conshohocken, PA); standard test methods for the thickness and density of blanket or felt insulation layers (ASTM C167, ASTM International, West Conshohocken, PA); determination of the apparent density of precast duct insulation materials (EN 13470, British Standards Institution, UK); or determination of the apparent density of precast duct insulation materials (ISO 18098, International Organization for Standardization, Switzerland). Because different methods can lead to different results, it should be understood that, in the context of this disclosure, unless otherwise stated, density measurements are performed according to ASTM C167 (Standard Test Method for the Thickness and Density of Insulation Layers of Blankets or Felt), and thickness measurements are performed at psi compression 2. In some embodiments, the aerogel material or composition disclosed herein has a density of less than 0.60 g / cc, less than 0.50 g / cc, less than 0.40 g / cc, less than 0.30 g / cc, less than 0.25 g / cc, less than 0.20 g / cc, less than 0.18 g / cc, less than 0.16 g / cc, less than 0.14 g / cc, less than 0.12 g / cc, less than 0.10 g / cc, less than 0.05 g / cc, less than 0.01 g / cc, or within a range of any two of these values.

[0099] 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.

[0100] The hydrophobicity of an aerogel material or composition can be expressed in terms of its capacity to absorb liquid water. In the context of this disclosure, the term "capacity to absorb liquid water" refers to a measure of the potential of an aerogel material or composition to absorb or retain liquid water. The capacity to absorb liquid water can be expressed as the percentage (by weight or volume) of water absorbed or retained by the aerogel material or composition when exposed to liquid water under certain measurement conditions. The liquid water absorption rate of an aerogel material or composition can be determined by methods known in the art, including, but not limited to, standard test methods for determining the water retention (drainage) properties of fiberglass insulation materials (ASTM C1511, ASTM International, West Conshohocken, PA); standard test methods for water absorption by immersion in insulation materials (ASTM C1763, ASTM International, West Conshohocken, PA); and for building insulation products: determination of short-term water absorption by partial immersion (EN 1609, British Standards Institution, UK). Because different methods can lead to different results, it should be understood that, in the context of this disclosure, measurements of liquid water absorption are obtained according to ASTM C1511 (Standard Test Method for Determining the Water Retention (Drainage) Properties of Fiberglass), unless otherwise stated, under ambient pressure and temperature. In some embodiments, the aerogel material or composition disclosed herein may have a liquid water absorption of less than about 50% by weight, less than about 40% by weight, less than about 30% by weight, less than about 20% by weight, less than about 15% by weight, less than about 10% by weight, less than about 8% by weight, less than about 3% by weight, less than about 2% by weight, less than about 1% by weight, less than about 0.1% by weight, or within any two of these values. An aerogel material or composition having improved liquid water absorption relative to another aerogel material or composition will have a lower percentage of liquid water absorption / retention relative to a reference aerogel material or composition.

[0101] The hydrophobicity of aerogel materials or compositions can be expressed in terms of water vapor absorption. In the context of this disclosure, the term "water vapor absorption" refers to a measure of the potential of an aerogel material or composition to absorb water vapor. Water vapor absorption can be expressed as the percentage (by weight) of water absorbed or retained by the aerogel material or composition when exposed to water vapor under certain measurement conditions. The water vapor absorption of an aerogel material or composition can be determined by methods known in the art, including but not limited to standard test methods for measuring the water vapor absorption of unprocessed mineral fiber insulation materials (ASTM C1104, ASTM International, West Conshohocken, PA); and for building insulation products: determination of long-term water absorption by diffusion (EN 12088, British Standards Institution, UK). Because different methods can lead to different results, it should be understood that, in the context of this disclosure, measurements of water vapor absorption are obtained at ambient pressure, 49°C, and 95% humidity for 24 hours (modified from 96 hours according to ASTM C1104), according to ASTM C1104 (Standard Test Method for Measuring Water Vapor Adsorption on Unprocessed Mineral Fibers), unless otherwise stated. In some embodiments, the aerogel material or composition disclosed herein may have a water vapor absorption of less than about 50 wt%, less than about 40 wt%, less than about 30 wt%, less than about 20 wt%, less than about 15 wt%, less than about 10 wt%, less than about 8 wt%, less than about 3 wt%, less than about 2 wt%, less than about 1 wt%, less than about 0.1 wt%, or in the range of any two of these values. An aerogel material or composition having improved water vapor absorption relative to another aerogel material or composition will have a lower percentage of water vapor absorption / retention relative to a reference aerogel material or composition.

[0102] The hydrophobicity of an aerogel material or composition can be expressed by measuring the equilibrium contact angle of a water droplet at the interface with the material surface. The aerogel materials or compositions disclosed herein may have a water contact angle of about 90° or more, about 120° or more, about 130° or more, about 140° or more, about 150° or more, about 160° or more, about 170° or more, about 175° or more, or within any two of these values.

[0103] In the context of this disclosure, the terms “heat of combustion,” “HOC (heat of combustion),” and “ΔHc” refer to a measure of the thermal energy released during the combustion or exothermic decomposition of a material or composition. Heat of combustion is typically recorded as calories (cal / g) of the thermal energy released per gram of aerogel material or composition, or megajoules (MJ / kg) of the thermal energy released per kilogram of material or composition. The heat of combustion of a material or composition can be determined by methods known in the art, including but not limited to the determination of the total heat of combustion (calorific value) by conducting a combustion test on the product (EN ISO 1716, International Organization for Standardization, Switzerland; adopted by EN). In the context of this disclosure, unless otherwise stated, measurements of heat of combustion are obtained according to the EN ISO 1716 standard (Reaction to a combustion test on a product – Measurement of the total heat of combustion (calorific value)). In some embodiments, the aerogel composition disclosed herein may have a heat of combustion of less than about 750 cal / g, less than about 717 cal / g, less than about 700 cal / g, less than about 650 cal / g, less than about 500 cal / g, less than 600 cal / g, less than about 575 cal / g, less than about 550 cal / g, less than about 500 cal / g, less than about 450 cal / g, less than about 400 cal / g, less than about 350 cal / g, less than about 300 cal / g, less than about 250 cal / g, less than about 200 cal / g, less than about 150 cal / g, less than about 100 cal / g, less than about 50 cal / g, less than about 25 cal / g, less than about 10 cal / g, or within any two of these values. An aerogel composition having an improved heat of combustion relative to another aerogel composition will have a lower heat of combustion value relative to a reference aerogel composition. In some embodiments disclosed herein, the HOC of the aerogel composite is improved by incorporating fire-based additives into the aerogel composite.

[0104] Within the scope of this disclosure, all thermal analyses and related definitions are referenced to measurements taken at room temperature in air, starting at 25°C and increasing at a rate of 20°C per minute to 1000°C. Therefore, any variations in these parameters must be considered (or re-performed under these conditions) when measuring and calculating the onset of thermal decomposition, peak exothermic temperature, peak endothermic temperature, etc. In the context of this disclosure, the terms "onset of thermal decomposition" and "T" are used interchangeably. D"Initial thermal decomposition" refers to the lowest temperature at which the ambient temperature is reached during a rapid exothermic reaction caused by the decomposition of organic matter in a material or composition. Thermogravimetric analysis (TGA) can be used to measure the initial thermal decomposition of organic matter in a material or composition. The TGA curve of a material describes the weight loss (mass percentage) of the material as the ambient temperature increases, thus indicating thermal decomposition. The initial thermal decomposition of a material is related to the intersection of the following tangents to the TGA curve: the line tangent to the baseline of the TGA curve, and the line tangent to the TGA curve at the point of maximum slope during rapid exothermic decomposition associated with the decomposition of organic matter. In the context of this disclosure, unless otherwise stated, the TGA analysis described in this paragraph is used to obtain measurements of the initial thermal decomposition of organic matter.

[0105] Differential scanning calorimetry (DSC) analysis can also be used to measure the initial thermal decomposition of materials. The DSC curve of a material describes the heat energy (mW / mg) released when the material is exposed to a gradually increasing ambient temperature. The initial thermal decomposition temperature of the material can be correlated with the point in the DSC curve where the ΔmW / mg (change in heat output) increases most significantly, indicating that the aerogel material is exothermic. In the context of this disclosure, unless otherwise explicitly stated, measurements of initial thermal decomposition using DSC, TGA, or both are obtained using a heating rate of 20 °C / min as further defined above. DSC and TGA both provide similar values ​​for this initial thermal decomposition, and often these tests are performed simultaneously, thus results can be obtained from both. In some embodiments, the aerogel material or composition disclosed herein has an initial thermal decomposition of about 300°C or higher, about 320°C or higher, about 340°C or higher, about 360°C or higher, about 380°C or higher, about 400°C or higher, about 420°C or higher, about 440°C or higher, about 460°C or higher, about 480°C or higher, about 500°C or higher, about 550°C or higher, about 600°C or higher, or within any two of these values. In the context of this document, for example, a first composition having an initial thermal decomposition higher than that of a second composition will be considered an improvement of the first composition relative to the second composition. This document anticipates that the initial thermal decomposition of a composition or material increases when one or more flammable additives are added, compared to a composition that does not contain any flammable additives.

[0106] In the context of this disclosure, the terms "initial endothermic decomposition" and "T" are used interchangeably. ED"Initial endothermic decomposition" refers to the measurement of the lowest temperature at which the material or composition undergoes an endothermic reaction with ambient heat during decomposition or dehydration. Thermogravimetric analysis (TGA) can be used to measure the initial endothermic decomposition of a material or composition. The TGA curve of a material describes the weight loss (mass percentage) of the material as the ambient temperature increases. The initial thermal decomposition of a material may be correlated with the intersection of the following tangents to the TGA curve: the line tangent to the baseline of the TGA curve, and the line tangent to the TGA curve at the point of maximum slope during rapid endothermic decomposition or dehydration of the material. In the context of this disclosure, unless otherwise stated, the TGA analysis described in this paragraph is used to obtain measurements of the initial endothermic decomposition of a material or composition.

[0107] In the context of this disclosure, the terms "furnace temperature rise" and "ΔT" are used interchangeably. R "T" refers to the highest temperature (T) of a material or component under thermal decomposition conditions. MAX The measured difference between the baseline temperature and the thermal decomposition temperature (typically the final temperature or T) under thermal decomposition conditions. FIN Changes in the material or composition under [the specified conditions]. Furnace temperature rise is typically recorded in degrees Celsius or °C. The furnace temperature rise of a material or composition can be determined by methods known in the art, including but not limited to the response to flammability tests for building and transport products: non-flammability test (EN ISO 1182, International Organization for Standardization, Switzerland; adopted by EN). In the context of this disclosure, unless otherwise stated, furnace temperature rise measurements are obtained under conditions equivalent to EN ISO 1182 (response to fire tests for building and transport products: non-flammability test). In some embodiments, the aerogel composition disclosed herein may have a furnace temperature rise of less than about 100°C, less than about 90°C, less than about 80°C, less than about 70°C, less than about 60°C, less than about 50°C, less than about 45°C, less than about 40°C, less than about 38°C, less than about 36°C, less than about 34°C, less than about 32°C, less than about 30°C, less than about 28°C, less than about 26°C, less than about 24°C, or between any two of these values. In terms of compositional stability at high temperatures, for example, a first composition having a lower furnace temperature rise than a second composition is considered an improvement of the first composition relative to the second composition. This document anticipates that, compared to a composition without any ignition source additives, the furnace temperature rise of the composition will decrease when one or more ignition source additives are added.

[0108] In the context of this disclosure, the terms "burn time" and "T" are used interchangeably. FLAME"Continuous combustion" refers to a measure of the sustained burning of a material or component under thermal decomposition conditions, where "sustained combustion" is the presence of a flame on a visible portion of the specimen for 5 seconds or longer under any circumstances. Burning time is typically recorded in seconds or minutes. The burning time of a material or component can be determined by methods known in the art, including but not limited to reactions to flammability tests on building and transport products: non-flammability testing (EN ISO 1182, International Organization for Standardization, Switzerland; adopted by EN). In the context of this disclosure, unless otherwise stated, the burning time is determined according to EN ISO... Burning time measurements are obtained under conditions equivalent to those of Standard 1182 (Reaction to Fire Testing of Building and Transport Products: Non-flammability Test). In some embodiments, the aerogel composition disclosed herein has a burning time of less than about 30 seconds, less than about 25 seconds, less than about 20 seconds, less than about 15 seconds, less than about 10 seconds, less than about 5 seconds, less than about 2 seconds, or within a range of any two of these values. In the context of this document, for example, a first composition having a shorter burning time than a second composition will be considered an improvement of the first composition relative to the second composition. This document anticipates that when one or more fire additives are added to a composition, the burning time of the composition is reduced compared to a composition that does not contain any fire additives.

[0109] In the context of this disclosure, the terms “mass loss” and “DM” refer to a measure of the amount of material, composition, or compound lost or burned under thermal decomposition conditions. Mass loss is typically recorded as a weight percentage or weight percent. The mass loss of a material, composition, or compound can be determined by methods known in the art, including but not limited to: reaction to fire tests of building and transport products: non-combustibility test (EN ISO 1182, Swiss Standard; adopted by EN). In the context of this disclosure, unless otherwise stated, the mass loss measurement is obtained under conditions equivalent to EN ISO 1182 (reaction to fire tests of building and transport products: non-combustibility test). In some embodiments, the aerogel composition of this disclosure may have a mass loss of less than 50%, less than 40%, less than 30%, less than 28%, less than 26%, less than 24%, less than 22%, less than 20%, less than 18%, less than 16%, or within a range of any two of these values. In the context of this paper, for example, a first component having a mass loss less than that of a second component will be considered an improvement of the first component relative to the second component. This paper anticipates that the mass loss of a component will be reduced when one or more ignition additives are added, compared to a component that does not contain any ignition additives.

[0110] In the context of this disclosure, the term "peak exothermic temperature" refers to a measurement of the ambient temperature at which the exothermic reaction from decomposition is at its maximum. The peak exothermic temperature of a material or composition can be measured using TGA analysis, differential scanning calorimetry (DSC), or a combination thereof. Both DSC and TGA provide similar values ​​for the peak exothermic temperature, and since many tests are performed simultaneously, results can be obtained from both. In a typical DSC analysis, heat flux is plotted against the rising temperature, and the peak exothermic temperature is the temperature at which the curve shows the highest peak. In the context of this disclosure, unless otherwise stated, the TGA analysis described in this paragraph is used to obtain measurements of the peak exothermic temperature of a material or composition.

[0111] In the context of endothermic materials, the term "peak endothermic temperature" refers to a measurement of the ambient temperature at which endothermic heat from decomposition is minimal. The peak endothermic temperature of a material or composition can be measured using TGA analysis, differential scanning calorimetry (DSC), or a combination thereof. In a typical DSC analysis, heat flux is plotted against rising temperatures, and the peak endothermic temperature is the temperature at which the curve shows its lowest peak. In the context of this disclosure, unless otherwise stated, the TGA analysis described in this paragraph is used to obtain measurements of the peak endothermic temperature of a material or composition.

[0112] In the context of this disclosure, the terms "low flammability" and "low combustibility" refer to materials or compositions that satisfy a combination of the following properties: i) furnace temperature rise below 50°C; ii) combustion time below 20 seconds; and iii) mass loss below 50% by weight. In the context of this disclosure, the terms "non-flammability" and "non-combustibility" refer to materials or compositions that satisfy a combination of the following properties: i) furnace temperature rise below 40°C; ii) combustion time below 2 seconds; and iii) mass loss below 30% by weight. As contemplated herein, the flammability of a composition (e.g., the combination of furnace temperature rise, combustion time, and mass loss) is reduced when one or more flammable additives are included.

[0113] In the context of this disclosure, the terms "low flammability" and "low combustibility" refer to low-flammability materials or compositions with a total heat of combustion (HOC) of less than or equal to 3 MJ / kg. In the context of this disclosure, the terms "non-flammable" and "non-combustible" refer to non-flammable materials or compositions with a heat of combustion (HOC) of less than or equal to 2 MJ / kg. As anticipated herein, the HOC of a composition is reduced when it contains one or more flammable additives.

[0114] Aerogels are described as the framework of interconnected structures, most typically composed of interconnected oligomers, polymers, or colloidal particles. Aerogel frameworks can be made from a variety of precursor materials, including inorganic precursor materials (e.g., precursors for the production of silica-based aerogels); organic precursor materials (such as precursors for the production of carbon-based aerogels); inorganic / organic mixed precursor materials; and combinations thereof. In the context of this disclosure, the term "amalgam aerogel" refers to an aerogel resulting from a combination of two or more different gel precursors. The corresponding precursors are referred to as "mixed precursors."

[0115] Inorganic aerogels are typically formed from metal oxides or metal alkoxides. These metal oxides or alkoxides can be based on oxides or alkoxides of any metal that can form oxides. Such metals include, but are not limited to, silicon, aluminum, titanium, zirconium, hafnium, yttrium, vanadium, and cerium. Inorganic silica aerogels are traditionally prepared by the hydrolysis and condensation of silica-based alkoxides (such as tetraethoxysilanes) or by the gelation of silicic acid or water glass. Other relevant inorganic precursor materials for the synthesis of silica-based aerogels include, but are not limited to, metal silicates of sodium silicate or potassium silicate, alkoxysilanes, partially hydrolyzed alkoxysilanes, tetraethoxysilanes (TEOS), partially hydrolyzed TEOS, TEOS condensates, tetramethoxysilanes (TMOS), partially hydrolyzed TMOS, TMOS condensates, tetra-n-propoxysilanes, partially hydrolyzed and / or condensates of tetra-n-propoxysilanes, polyethylsilicates, partially hydrolyzed polyethylsilicates, monomeric alkylalkoxysilanes, bis(trialkoxyalkyl) or arylsilanes, polyhedral siloxanes, or combinations thereof.

[0116] In certain embodiments disclosed herein, commercially available or pre-hydrolyzed TEOS, such as Silbond H-5 (SBH5, Silbond Corp.), which is hydrolyzed at a water / silica ratio of approximately 1.9 to 2, may be used. Commercially available or partially hydrolyzed TEOS or TMOS, such as polyethylsilicate (Silbond 40) or polymethylsilicate, which may be further hydrolyzed during the gelation process, may also be used.

[0117] Inorganic aerogels may also include gel precursors containing at least one hydrophobic group, such as alkyl metal alkoxides, cycloalkyl metal alkoxides, and aryl metal alkoxides, which can impart or improve certain properties of the gel, such as stability and hydrophobicity. Inorganic silica aerogels may specifically include hydrophobic precursors, such as alkylsilanes or arylsilanes. Hydrophobic gel precursors can be used as primary precursor materials to form the framework of the gel material. However, in the formation of hybrid aerogels, hydrophobic gel precursors are often combined with simple metal alkoxides as co-precursors. Hydrophobic inorganic precursor materials used for the synthesis of silica-based aerogels 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. Any derivative of any of the above precursors can be used, and specifically, certain polymers of other chemical groups can be added to or crosslinked to one or more of the above precursors. Aerogels can also be treated to impart or improve hydrophobicity. Hydrophobic treatment can be applied to sol-gel solutions, wet gels prior to liquid extraction, or aerogels after liquid extraction. Hydrophobic treatment is particularly common in the production of metal oxide aerogels, such as silica aerogels. An example of hydrophobic treatment of gels is discussed in more detail below, particularly in the case of treating wet silica gels. However, the specific examples and illustrations provided herein are not intended to limit the scope of this disclosure to any particular type of hydrophobic treatment procedure or aerogel matrix. This disclosure may include any gel or aerogel known to those skilled in the art, and related methods for hydrophobic treatment of aerogels in wet or dry aerogel form.

[0118] Hydrophobic treatment is achieved by reacting the hydroxyl groups on the gel (e.g., silanol groups (Si-OH) present on the silica gel backbone) with the functional groups of a hydrophobic agent. The resulting reaction converts the silanol groups and the hydrophobic agent into hydrophobic groups on the silica gel backbone. The hydrophobic agent compound can react with the hydroxyl groups on the gel according to the following reaction: R N MX 4-N (Hydrophobic agent) + MOH (silanol) → MOMR N (Hydrophobic group) + HX. Hydrophobic treatment can be performed on both the external macroscopic surface of the silica gel and the internal pore surfaces within the porous network of the gel.

[0119] The gel can be immersed in a mixture of a hydrophobic agent and an optional hydrophobic treatment solvent in which the hydrophobic agent is soluble and miscible with the gel solvent in the wet gel. A wide variety of hydrophobic treatment solvents can be used, including solvents such as methanol, ethanol, isopropanol, xylene, toluene, benzene, dimethylformamide, and hexane. Liquid or gaseous hydrophobic agents can also be brought into direct contact with the gel to impart hydrophobicity.

[0120] The hydrophobic treatment process may include mixing or stirring to help the hydrophobic agent penetrate into the wet gel. The hydrophobic treatment process may also include altering other conditions, such as temperature and pH, to further enhance and optimize the treatment reaction. After the reaction is complete, the wet gel is washed to remove unreacted compounds and reaction byproducts.

[0121] Hydrophobic agents used for hydrophobic treatment of aerogels are typically compounds of the following formula: R N MX 4-N The hydrophobic agent is defined as follows: 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 Cl. Specific examples of hydrophobic agents include, but are not limited to, trimethylchlorosilane (TMCS), triethylchlorosilane (TECS), triphenylchlorosilane (TPCS), dimethylchlorosilane (DMCS), dimethyldichlorosilane (DMDCS), etc. The hydrophobic agent may also have the following formula: Y(R3M)2; where 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 the hydrophobic agent include, but are not limited to, hexamethyldisilazane [HMDZ] and hexamethyldisilazane [HMDSO]. The hydrophobic agent may further include compounds of the following formula: R N MV 4-N V is a reactive or leaving group other than a halogen. Specific examples of the hydrophobic agent include, but are not limited to, vinyltriethoxysilane and vinyltrimethoxysilane.

[0122] The hydrophobic treatment of the present invention can also be performed during the removal, exchange, or drying of liquid in the gel. In one specific embodiment, the hydrophobic treatment can be performed in a supercritical fluid environment (e.g., but not limited to supercritical carbon dioxide) and can be combined with drying or extraction steps.

[0123] In the context of this disclosure, the term "hydrophobically bonded silicon" refers to silicon atoms within the framework of a gel or aerogel containing at least one hydrophobic group covalently bonded to silicon atoms. Examples of hydrophobically bonded silicon include, but are not limited to, silicon atoms in silica groups within a gel framework formed from a gel precursor (e.g., MTES or DMDS) containing at least one hydrophobic group. Hydrophobically bonded silicon may also include, but is not limited to, silicon atoms in the gel framework or on the gel surface, which are treated with a hydrophobic agent (e.g., HMDZ) to impart or improve hydrophobicity by introducing additional hydrophobic groups into the composition. Hydrophobic groups in this disclosure include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, octyl, phenyl, or other substituted or unsubstituted hydrophobic organic groups known in the art. For those skilled in the art, in the context of this disclosure, the terms "hydrophobic group," "hydrophobic organic material," and "hydrophobic organic content" specifically exclude readily hydrolyzable organosilicon-bonded alkoxy groups on the gel material framework, which are products of reactions between organic solvents and silanol groups. NMR analysis can distinguish these excluded groups from the hydrophobic organic compounds associated with those groups. The content of hydrophobically bound silicon in aerogels, such as CP / MAS, can be analyzed using NMR spectroscopy. 29 Si solid-state NMR. NMR analysis of aerogels can characterize and relatively quantify M-type hydrophobically bound silicon (monofunctional silica, such as TMS derivatives); D-type hydrophobically bound silicon (bifunctional silica, such as DMDS derivatives); T-type hydrophobically bound silicon (trifunctional silica, such as MTES derivatives); and Q-type silicon (tetrafunctional silica, such as TEOS derivatives). NMR analysis can also classify specific types of hydrophobically bound silicon into subtypes (e.g., classifying T-type hydrophobically bound silicon as T...). 1 Type, T 2 species and T 3 (Species) were used to analyze the bonding chemistry of hydrophobically bonded silicon in aerogels. Specific details relating to NMR analysis of silica materials can be found in Geppi et al.'s article "Applications of Solid-State NMR to the Study of Organic / Inorganic Multicomponent Materials," particularly pages 7–9 (Appl. Spec. Rev. (2008), 44-1: 1–89), which is incorporated herein by reference, according to the specific pages cited.

[0124] In CP / MAS 29 The characterization of hydrophobically bound silicon in Si NMR analysis can be based on the following chemical shift peaks: M 1 (30 to 10 ppm); and D 1(10 to -10 ppm), D 2 (-10 to -20 ppm); T 1 (-30 to -40ppm), T 2 (-40 to -50ppm), T 3 (-50 to -70ppm); Q 2 (-70 to -85ppm), Q 3 (-85 to -95ppm), Q 4 (-95 to -110 ppm). These chemical shift peaks are approximate and exemplary, and are not intended to be limiting or definitive. Precise chemical shift peaks attributable to various silicon species within a material may depend on the specific chemical composition of the material and can generally be identified by routine experiments and analyses performed by those skilled in the art.

[0125] In the context of this disclosure, the terms "hydrophobic organic content" or "hydrophobic content" or "hydrophobicity" refer to the amount of hydrophobic organic material bonded to the backbone in an aerogel material or composition. The hydrophobic organic content of an aerogel material or composition can be expressed as a weight percentage of the amount of hydrophobic organic material on the aerogel backbone relative to the total amount of material in the aerogel material or composition. The hydrophobic organic content can be calculated by those skilled in the art based on the properties and relative concentrations of the materials used to produce the aerogel material or composition. The content of hydrophobic organic material can also be measured using thermogravimetric analysis (TGA) of the subject material, preferably in an oxygen atmosphere (although TGA in an alternative gas environment is also useful). Specifically, the percentage of hydrophobic organic material in the aerogel can be correlated with the percentage weight loss of the hydrophobic aerogel material or composition when subjected to combustion heat temperatures during TGA analysis, and adjusted for losses of moisture, residual solvent, and readily hydrolyzable alkoxy groups during the TGA analysis. Other alternative techniques, such as differential scanning calorimetry, elemental analysis (especially carbon), chromatography, nuclear magnetic resonance spectroscopy, and other analytical techniques known to those skilled in the art, can be used to measure and determine the hydrophobic content in the aerogel composition of the products of the present invention. In some cases, a combination of known techniques may be useful or necessary in determining the hydrophobic content of the aerogel composition of the present invention.

[0126] The aerogel material or composition disclosed herein may have a hydrophobic organic content of less than 50% by weight, less than 40% by weight, less than 30% by weight, less than 25% by weight, less than 20% by weight, less than 15% by weight, less than 10% by weight, less than 8% by weight, less than 6% by weight, less than 5% by weight, less than 4% by weight, less than 3% by weight, less than 2% by weight, less than 1% by weight, or within any two of these values.

[0127] The term "fuel content" refers to the total amount of combustible material in an aerogel material or composition, which can be correlated with the total percentage of weight loss in the aerogel material or composition when subjected to the heat of combustion temperature during TGA or TG-DSC analysis, and adjusted for moisture loss. The fuel content of an aerogel material or composition may include the content of hydrophobic organic materials, as well as other combustible residual alcohol solvents, filler materials, reinforcing materials, and easily hydrolyzed alkoxy groups.

[0128] Organic aerogels are typically formed from carbon-based polymer precursors. These polymer materials include, but are not limited to, resorcinol-formaldehyde (RF), polyimide, polyacrylate, polymethyl methacrylate, acrylate oligomers, polyoxyethylene, polyurethane, polyphenol, polybutane, trialkoxysilyl-terminated polydimethylsiloxane, polystyrene, polyacrylonitrile, polyfurfural, melamine-formaldehyde, cresol-formaldehyde, phenol-furfural, polyether, polyol, polyisocyanate, polyhydroxybenzene, polyvinyl alcohol dialdehyde, polyisocyanate, polyacrylamide, various epoxy resins, agar, agarose, chitosan, and combinations thereof. As an example, organic RF aerogels are typically produced by sol-gel polymerization of resorcinol or melamine with formaldehyde under alkaline conditions.

[0129] The organic / inorganic hybrid aerogel is primarily composed of organically modified silica (“ormosil”) aerogel. The organically modified silica material includes organic components covalently bonded to the silica network, typically formed by the hydrolysis and condensation of organically modified silane R-Si(OX)3 with the conventional alkoxide alkoxide precursor Y(OX)4. In these chemical 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 the organically modified silica aerogel can also be dispersed or chemically bonded to the silica network.

[0130] In the context of this disclosure, the term "organically modified silica" encompasses the aforementioned materials and other organically modified materials, sometimes referred to as "organically modified ceramics." Organically modified silica is typically used as a coating in which a thin film of organically modified silica is cast onto a substrate, for example, via a sol-gel process. Other examples of organic-inorganic hybrid aerogels disclosed herein include, but are not limited to, silica-polyether, silica-PMMA, silica-chitosan, carbides, nitrides, and other combinations of the aforementioned organic and inorganic compounds that form aerogels. U.S. Patent Publication No. 20050192367 (paragraphs

[0022] -

[0038] and

[0044] through

[0058] ) includes teachings on such hybrid organic-inorganic materials and is incorporated herein by reference in accordance with separately cited sections and paragraphs.

[0131] In some embodiments, the aerogel disclosed herein is an inorganic silica aerogel formed primarily of a prepolymerized silica precursor, preferably as an oligomer, or a hydrolyzed silicate ester formed from a silanolate in an alcohol solvent. In some embodiments, such prepolymerized silica precursors or hydrolyzed silicates may be formed in situ from other precursors or silicates, such as alkoxysilanes or water glass. However, the present disclosure can be implemented in general with any other aerogel composition known to those skilled in the art, and is not limited to any single precursor material or a comprehensive mixture of precursor materials.

[0132] The production of aerogels typically involves the following steps: i) forming a sol-gel solution; ii) forming a gel from the sol-gel solution; and iii) extracting the solvent from the gel material using innovative processing and extraction techniques to obtain a dried aerogel material. The methods are discussed in more detail below, particularly regarding the formation of inorganic aerogels such as silica aerogels. However, the specific examples and illustrations provided herein are not intended to limit this disclosure to any particular type of aerogel and / or preparation method. Unless otherwise stated, this disclosure may include any aerogel formed by any relevant preparation method known to those skilled in the art.

[0133] The first step in forming inorganic aerogels typically involves the hydrolysis and condensation of silica precursors, such as, but not limited to, metal alkoxide precursors in alcohol-based solvents, to form a sol-gel solution. Key variables in inorganic aerogel formation include the type of alkoxide precursor contained in the sol-gel solution, the nature of the solvent, the processing temperature and pH of the sol-gel solution (which can be achieved by adding an acid or base), and the precursor / solvent / water ratio in the sol-gel solution. Controlling these variables during the formation of the sol-gel solution allows for control of the growth and aggregation of the gel skeleton during the subsequent transition of the gel material from a “sol” to a “gel” state. While the properties of the resulting aerogel are influenced by the pH of the precursor solution and the molar ratio of the reactants, any pH and molar ratio that allows for gel formation is permissible in this disclosure.

[0134] A sol-gel solution is formed by combining at least one gelling precursor with a solvent. Suitable solvents for forming the sol-gel solution include lower alcohols having 1 to 6 carbon atoms, particularly 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, etc. Multiple solvents can also be combined to achieve the desired dispersion level or optimize the properties of the gel material. Therefore, the selection of the optimal solvent for the sol-gel and gel formation steps depends on the incorporation of specific precursors, fillers, and additives into the sol-gel solution, the target processing conditions for gelation and liquid extraction, and the desired properties of the final aerogel material.

[0135] Water can also be present in the precursor solvent solution. Water can hydrolyze the metal alkoxide precursor into the metal hydroxide precursor. The hydrolysis reaction can be (e.g., using TEOS in an ethanol solvent): Si(OC2H5)4 + 4H2O → Si(OH)4 + 4(C2H5OH). The resulting hydrolyzed metal hydroxide precursor remains suspended in the solvent solution in a "sol" state as individual molecules or small polymeric (or oligomeric) colloidal clusters of molecules. For example, the polymerization / condensation of the Si(OH)4 precursor can occur as follows: 2Si(OH)4 = (OH)3Si-O-Si(OH)3 + H2O. This polymerization reaction can continue until colloidal clusters of polymeric (or oligomeric) SiO2 (silicon dioxide) molecules are formed.

[0136] Acids and bases can be incorporated into sol-gel solutions to control the pH of the solution and catalyze the hydrolysis and condensation reactions of precursor materials. While any acid can be used to catalyze the precursor reaction and obtain a lower pH solution, exemplary acids include HCl, H₂SO₄, H₃PO₄, oxalic acid, and acetic acid. Any base can be used to catalyze the precursor reaction and obtain a higher pH solution, with exemplary bases including NH₄OH.

[0137] The sol-gel solution may include additional co-gel precursors, as well as filler materials and other additives. Filler materials and other additives can be dispensed into the sol-gel solution at any time before or during gel formation. After gelation, filler materials and other additives can also be incorporated into the gel material using various techniques known to those skilled in the art. In some embodiments, the sol-gel solution containing the gel precursor, solvent, catalyst, water, filler, and other additives is a homogeneous solution capable of effectively forming a gel under suitable conditions.

[0138] Once the sol-gel solution is formed and optimized, the gel-forming components in the sol-gel can be transformed into a gel material. The process of transforming the gel-forming components into a gel material includes an initial gel-forming step, in which the gel solidifies until the gel point of the gel material. The gel point of the gel material can be considered as the point where the gel solution exhibits resistance to flowability throughout its entire volume and / or forms a substantially continuous polymer backbone. Various gel-forming techniques are known to those skilled in the art. Examples include, but are not limited to, holding the mixture in a static state for a sufficient time; adjusting the pH of the solution; adjusting the solution temperature; directing energy forms onto the mixture (ultraviolet, visible, infrared, microwave, ultrasonic, particle radiation, electromagnetic); or combinations thereof.

[0139] The process of transforming the gel-forming components (gel precursors) into a gel material can also include an aging step (also known as curing) prior to liquid extraction from the gel or solvent removal (also known as gel drying). Aging the gel material after reaching its gelation point can further enhance the gel skeleton by increasing the number of crosslinks in the network. The duration of gel aging can be adjusted to control various properties within the resulting aerogel material. This aging process can be used to prevent potential volume loss and shrinkage during liquid extraction. Aging may involve maintaining the gel for an extended period in a quiescent state (before extraction), keeping the gel at a high temperature, adding compounds that promote crosslinking, or any combination thereof. Preferred aging temperatures are typically between about 10°C and about 100°C, although other suitable temperatures are also anticipated herein. Aging of the gel material typically continues until liquid extraction of the wet gel material.

[0140] The time period for converting a gel-forming material (gel precursor) into a gel material includes the duration of initial gel formation (from the start of gelation until the gel point) and the duration of any subsequent curing, including the curing and aging of the gel material before solvent extraction from the liquid or removal from the gel (also known as gel drying) (from the gel point to the start of liquid extraction / solvent removal). The total time for converting a gel-forming material into a gel material is typically from about 1 minute to several days, typically less than about 30 hours, less than about 24 hours, less than about 15 hours, less than about 10 hours, less than about 6 hours, less than about 4 hours, less than about 2 hours, preferably less than about 1 hour, less than about 30 minutes, less than about 15 minutes, or less than about 10 minutes.

[0141] In another embodiment, the resulting gel material can be washed in a suitable second solvent instead of the first reaction solvent present in the wet gel. This second solvent can be a straight-chain monohydric alcohol having one or more aliphatic carbon atoms, a dihydric alcohol having two or more carbon atoms, a branched-chain alcohol, a cyclic alcohol, an alicyclic alcohol, an aromatic alcohol, a polyhydric alcohol, an ether, a ketone, a cyclic ether, or a derivative thereof. In another embodiment, the resulting gel material can be washed with an additional amount of the same solvent present in the gel material, which can remove any undesirable byproducts or other precipitates from the gel material.

[0142] Once the gel material has been formed and processed, extraction methods, including innovative processing and extraction techniques, can be used to at least partially extract the liquid from the wet gel to form an aerogel material. Liquid extraction plays a significant role, among other factors, in designing the properties of the aerogel (e.g., porosity and density) and related properties (e.g., thermal conductivity). Aerogels are typically obtained by extracting the liquid from the gel in a manner that minimizes shrinkage of the porous network and framework of the wet gel. This liquid extraction can also be referred to as desolventizing or drying.

[0143] An example of an alternative method for forming silica aerogels uses a metal oxide salt, such as sodium silicate, also known as water glass. A water glass solution is first produced by mixing sodium silicate with water and an acid to form a silicic acid precursor solution. Salt byproducts can be removed from the silicic acid precursor by ion exchange, surfactant separation, membrane filtration, or other chemical or physical separation techniques. The resulting sol can then be gelled, for example by adding a basic catalyst to produce a hydrogel. The hydrogel can be washed to remove any residual salts or reactants. Water can then be removed from the pores of the gel by exchanging with a polar organic solvent such as ethanol, methanol, or acetone. Innovative processing and extraction techniques are then used to at least partially extract the liquid from the gel. In one embodiment,

[0144] Aerogels are typically formed by removing the liquid mobile phase from a gel material at temperatures and pressures near or above the critical point of the liquid mobile phase. Once the critical point is reached (near the critical point) or exceeded (supercritical point) (i.e., the system pressure and temperature are equal to or above the critical pressure and critical temperature, respectively), a new supercritical phase appears in the fluid, which is distinct from the liquid or gas phase. The solvent can then be removed without introducing the liquid-vapor interface, capillary pressure, or any associated mass transfer limitations typically associated with the liquid-vapor boundary. Additionally, the supercritical phase is generally more miscible with organic solvents, thus exhibiting better extractability. Co-solvents and solvent exchange are also commonly used to optimize supercritical fluid drying processes.

[0145] If evaporation or extraction occurs below the critical point, 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 can reduce the negative effects of such capillary forces. In some embodiments disclosed herein, using near-critical conditions just below the critical point of the solvent system can allow the production of aerogel materials or compositions with sufficiently low shrinkage rates, resulting in commercially viable end products.

[0146] Several other aerogel extraction techniques are known in the art, including a range of different methods using supercritical fluids in dried aerogels. For example, Kistler (J. Phys. Chem. (1932) 36:52-64) describes a simple supercritical extraction process in which the gel solvent is maintained above its critical pressure and temperature, thereby reducing evaporative capillary forces and maintaining the structural integrity of the gel network. U.S. Patent No. 4,610,863 describes an extraction method in which the gel solvent is exchanged with liquid carbon dioxide, and then extraction is carried out under conditions where the carbon dioxide is in a supercritical state. U.S. Patent No. 6,704,702 teaches the production of aerogels by rapidly extracting liquid from the gel through solvent exchange by injecting supercritical (not liquid) carbon dioxide into an extractor that has been preheated and pre-pressurized to substantially supercritical conditions or above. U.S. Patent No. 5,962,539 describes a method for obtaining aerogels from polymeric materials in sol-gel form in organic solvents by exchanging an organic solvent for a fluid with a critical temperature below the polymer decomposition temperature, and for extracting the fluid / sol-gel using supercritical fluids (e.g., supercritical carbon dioxide, supercritical ethanol, or supercritical hexane). U.S. Patent No. 6,315,971 discloses a method for preparing a gel composition comprising drying a wet gel containing a gel solid and a desiccant to remove the desiccant under drying conditions sufficient to reduce gel shrinkage during drying. U.S. Patent No. 5,420,168 describes a method for producing resorcinol / formaldehyde aerogels using a simple air-drying procedure. U.S. Patent No. 5,565,142 describes a drying technique in which the gel surface is modified to be more robust and hydrophobic, such that the gel framework and pores resist collapse during ambient drying or subcritical extraction. Other examples of extracting liquids from aerogel materials can be found in U.S. Patents Nos. 5,275,796 and 5,395,805.

[0147] One embodiment of extracting liquid from a wet gel using a supercritical fluid, such as carbon dioxide, involves, for example, first substantially exchanging the main solvent present in the pore network of the gel with liquid carbon dioxide; then heating the wet gel (typically in an autoclave) to above the critical temperature of carbon dioxide (approximately 31.06°C), and then increasing the system pressure to above the critical pressure of carbon dioxide (approximately 1070 psig). The pressure around the gel material can be slightly fluctuated to facilitate the removal of liquid from the gel. Carbon dioxide can be recycled through the extraction system to further promote the continuous removal of the main solvent from the wet gel. Finally, the temperature and pressure are slowly returned to ambient conditions to produce a dried aerogel material. The carbon dioxide can also be pretreated to a supercritical state before being injected into the extraction chamber.

[0148] Another example of an alternative method for forming aerogels involves chemically modifying the matrix material in a wet gel state by converting surface hydroxyl groups to hydrophobic trimethylsilyl ethers, thereby reducing the destructive capillary pressure at the solvent / pore interface. Liquid is then extracted from the gel material at temperatures and pressures below the solvent's critical point.

[0149] In yet another embodiment, the liquid (solvent) in the gel material can be frozen at a lower temperature and then sublimated to remove the solvent from the gel material. Removal or drying of the solvent from the gel material is understood to be within the scope of this disclosure. Such removal largely preserves the gel structure, resulting in an aerogel with unique properties.

[0150] Large-scale production of aerogel materials or compositions can be complicated by difficulties associated with the continuous formation of gel materials on a large scale, and by the difficulty of extracting large quantities of liquid from gel materials using innovative processing and extraction technologies. In some embodiments, the aerogel materials or compositions disclosed herein are suitable for large-scale production. In some embodiments, the gel materials disclosed herein can be produced on a large scale via continuous casting and gelation processes. In some embodiments, the aerogel materials or compositions disclosed herein are produced on a large scale, requiring the use of large-scale extraction containers. The large-scale extraction containers disclosed herein may include containers with a volume of approximately 0.1 m³. 3 Above, approximately 0.25m 3 Above, approximately 0.5m 3 Above or approximately 0.75m 3 The above are extraction containers.

[0151] The thickness of the aerogel composition of the present invention can be less than 15 mm, less than 10 mm, less than 5 mm, less than 3 mm, less than 2 mm, or less than 1 mm.

[0152] Aerogel compositions can be reinforced with a variety of reinforcing materials to obtain composite products with greater flexibility, elasticity, and compliance. Reinforcing materials can be added to the gel at any point during the gelation process to produce a wet, reinforced gel composition. The wet gel composition can then be dried to produce a reinforced aerogel composition.

[0153] Aerogel compositions can be reinforced with various open-cell macroporous framework reinforcing materials (OCMF) to obtain composite products with greater flexibility, elasticity, and compliance. OCMF reinforcing materials can be added to the gel at any stage prior to gelation to produce a wet, reinforced gel composition. The wet gel composition can then be dried to produce an OCMF-reinforced aerogel composition. OCMF reinforcing materials can be formed from organic polymer materials such as melamine or melamine derivatives and exist in the form of continuous sheets or plates.

[0154] Melamine-formaldehyde OCMF materials can be prepared from melamine-formaldehyde precondensation solutions. The aqueous solution of the melamine-formaldehyde condensation product is prepared by mixing the melamine-formaldehyde precondensate with a solvent, emulsifier / dispersant, curing agent (e.g., acid), and foaming agent (e.g., C5 to C7 hydrocarbons). The melamine-formaldehyde solution or resin is then cured at a temperature above the boiling point of the foaming agent to produce an OCMF comprising multiple interconnected three-dimensional branched melamine structures, with a corresponding interconnected network of pores integrated within the framework. The molar ratio of formaldehyde to melamine in the melamine-formaldehyde precondensate is typically in the range of 5:1 to 1.3:1, and usually in the range of 3.5:1 to 1.5:1. The precondensate can be in powder, spray, resin, or solution form. The solvent contained in the melamine-formaldehyde precondensation solution may contain alcohols, such as methanol, ethanol, or butanol.

[0155] Emulsifiers / dispersants included in the melamine-formaldehyde precondensation solution may comprise anionic surfactants, cationic emulsifiers, or nonionic surfactants. Useful anionic surfactants include, but are not limited to, diphenyl ether sulfonates, alkane and alkylbenzene sulfonates, alkylnaphthalene sulfonates, olefin sulfonates, alkyl ether sulfonates, fatty alcohol sulfates, ether sulfates, α-sulfonyl fatty acid esters, acylamino alkyl sulfonates, acyl hydroxyethanesulfonates, alkyl ether carboxylates, N-acylsarcosine salts, and alkyl and alkyl ether phosphates. Useful cationic emulsifiers include, but are not limited to, alkyl triammonium salts, alkyl benzyl dimethylammonium salts, or alkyl pyridinium salts. Useful nonionic surfactants include, but are not limited to, alkylphenol polyethylene glycol ethers, fatty alcohol polyethylene glycol ethers, fatty acid polyethylene glycol ethers, fatty acid alkanolamides, ethylene oxide-propylene oxide block copolymers, amine oxides, glycerol fatty acid esters, dehydrated sorbitan esters, and alkyl polysaccharides. Based on the melamine-formaldehyde precondensate, the amount of emulsifier / dispersant added can be 0.2-5% by weight.

[0156] The curing agent contained in the melamine-formaldehyde precondensation solution may contain acidic compounds. Based on the melamine-formaldehyde precondensate, the amount of these curing agents typically ranges from 0.01% to 20% by weight, and generally from 0.05% to 5% by weight. Useful acidic compounds include, but are not limited to, organic and inorganic acids, such as those selected from hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, formic acid, acetic acid, oxalic acid, toluenesulfonic acid, aminosulfonic acid, acid anhydrides, and mixtures thereof.

[0157] The blowing agent contained in the melamine-formaldehyde precondensation solution may include physical blowing agents or chemical blowing agents. Useful physical blowing agents include, but are not limited to, hydrocarbons such as pentane and hexane; halogenated hydrocarbons, more particularly chlorinated and / or fluorinated hydrocarbons such as dichloromethane, chloroform, trichloroethane, chlorofluorocarbons, and hydrochlorofluorocarbons (HCFCs); alcohols such as methanol, ethanol, n-propanol, or isopropanol; ethers, ketones, and esters such as methyl formate, ethyl formate, methyl acetate, or ethyl acetate; and gases such as air, nitrogen, or carbon dioxide. In some embodiments, it is preferable to add a physical blowing agent with a boiling point between 0°C and 80°C. Useful chemical blowing agents include, but are not limited to, isocyanates mixed with water (releasing carbon dioxide as an active blowing agent); carbonates and / or bicarbonates mixed with acids (releasing carbon dioxide as an active blowing agent); and azo compounds such as azodicarbonamide. The amount of the blowing agent in the melamine-formaldehyde precondensation solution is from 0.5 to 60% by weight, particularly from 1 to 40% by weight, and in some embodiments, the amount of the blowing agent based on the melamine-formaldehyde precondensate is 1.5 to 30% by weight.

[0158] Melamine-formaldehyde precondensation solutions can be heated to temperatures typically above the boiling point of the blowing agent used to form melamine OCMF materials, thereby creating OCMFs comprising multiple interconnected three-dimensional branched melamine structures and integrating an interconnected open microporous network within the framework. Thermal energy can be introduced via electromagnetic radiation, for example, through high-frequency radiation in the frequency range of 0.2 to 100 GHz, or more specifically 0.5 to 10 GHz, at a rate of 5 to 400 kW, or, in some embodiments, 9 to 120 kW per kilogram of mixture. Magnetrons are useful dielectric radiation sources; one magnetron can be used, or two or more magnetrons can be used simultaneously.

[0159] OCMF materials can be dried to remove residual liquids (water, solvents, foaming agents). Post-treatment can also be used to hydrophobize OCMF materials. This post-treatment can use hydrophobic coating agents with high thermal stability and / or low flammability, such as silicones, silicates, or fluorinated compounds.

[0160] The density of melamine OCMF is typically in the range of 0.005 to 0.3 g / cc, for example, in the range of 0.01 to 0.2 g / cc, in some embodiments in the range of 0.03 to 0.15 g / cc, or most specifically, in the range of 0.05 to 0.15 g / cc. The average pore size of melamine OCMF is typically in the range of 10 pm to about 1000 pm, particularly in the range of 50 to 700 pm.

[0161] In one embodiment, an OCMF-reinforcing material is incorporated as a continuous sheet into an aerogel composition. The method includes first fabricating a continuous OCMF-reinforcing gel sheet by casting or impregnating a gel precursor solution into the continuous OCMF-reinforcing material sheet, and then forming the material into a reinforced gel composite sheet. Liquid can then be at least partially extracted from the OCMF-reinforcing gel composite sheet to produce a sheet-like OCMF-reinforcing aerogel composition.

[0162] Aerogel compositions may contain opaque agents to reduce the radiative component of heat transfer. At any time prior to gel formation, an opaque compound or its precursor may be dispersed into the mixture containing the gel precursor. Examples of opaque compounds include, but are not limited to, boron carbide (B4C), diatomaceous earth, manganese ferrite, MnO, NiO, SnO, Ag2O, and B. 12 O3, carbon black, titanium dioxide, ferric titanium dioxide, titanium dioxide, aluminum oxide, zirconium silicate, zirconium oxide, iron(II), iron(III), manganese dioxide, titanium iron oxide (ilmenite), chromium oxide, carbides (e.g., SiC, TiC, or WC), or mixtures thereof. Examples of opaque compound precursors include, but are not limited to, TiOSO4 or TiOCl2.

[0163] The aerogel composition may contain one or more pyrophoric additives. In the context of this disclosure, the term "pyrophoric additive" refers to a material that has an endothermic effect when reacting with fire and can be incorporated into the aerogel composition. Furthermore, in some embodiments, the endothermic decomposition (Ef) of the pyrophoric additive... D The initial value is higher than the thermal decomposition (T) of the aerogel composition containing fire-resistant additives. d The initial temperature shall not exceed 100°C, and in some embodiments, E D It is also more than the T of aerogel compositions containing fire-related additives. d The temperature should not exceed 50℃. In other words, the E of fire-related additives... D The range is (T) d -50℃ to (T d +100℃):

[0164]

[0165] Before, during, or even after incorporation or mixing with a sol (e.g., silica sol prepared in various ways from alkyl silicates or water glass as understood in the art), pyrophoric additives may be mixed with or otherwise incorporated into a medium containing ethanol and up to 10% by volume water. The mixture may be mixed and / or stirred as needed to achieve a substantially uniform dispersion of the additive in the medium. Unbound by theory, the aforementioned clays and other pyrophoric additives in their hydrated forms can provide additional endothermic effects. For example, halloysite clay (available from Applied Minerals, Inc. or from Imerys under the trade name DRAGONITE, simply referred to as halloysite), kaolinite clay, is an aluminosilicate clay whose hydrated form has an endothermic effect (gas dilution) by releasing hydrated water at high temperatures. As another example, hydrated carbonates can release carbon dioxide when heated or elevated at elevated temperatures.

[0166] In the context of this disclosure, the term "heat of dehydration" refers to the amount of heat required to evaporate water (and dihydroxylate, if applicable) from a hydrated material without exposure to high temperatures. Heat of dehydration is typically expressed per unit weight.

[0167] In some embodiments, the pyrophoric additive of the present invention has an initial thermal decomposition temperature of about 350°C or higher, about 400°C or higher, about 450°C or higher, about 500°C or higher, about 550°C or higher, about 600°C or higher, about 650°C or higher, about 700°C or higher, about 750°C or higher, about 800°C or higher, or between these values. In some embodiments, the pyrophoric additive of the present invention has an initial thermal decomposition temperature of about 440°C or 570°C. In some embodiments, the pyrophoric additive disclosed herein has a higher Tg than an aerogel composition incorporating the pyrophoric additive (without the pyrophoric additive). d The initial thermal decomposition is within the range of 50°C or less, or 40°C or less, or 30°C or less, or 20°C or less, or 10°C or less, or 5°C or less, or between any two of these values.

[0168] The fire-related additives disclosed herein include clay materials, such as, but not limited to, layered silicate clays (e.g., illite), kaolinite (aluminum silicate; Al2Si2O5(OH)4), halloysite (aluminum silicate; Al2Si2O5(OH)4), endellite (aluminum silicate; Al2Si2O5(OH)4), mica (silica mineral), alumina, gibbsite (aluminum hydroxide), montmorillonite, aluminum bentonite, and pyrophyllite (aluminum silicate; Al2Si4O5). 10(OH)2), chlorite, bleaching mica, bentonite, kaolinite, palygorskite, chlorite, magnesium aluminum sepiolite, green opal, chrome bentonite, aluminum quartz, calcium aluminum bentonite, chloroflammable crystal, granodiolite, chrome aluminum quartz, luminous aluminum quartz, terrazzo and orthorhombic quartz, magnesium hydroxide (or magnesium dihydroxyl, "MDH"), alumina trihydrate ("ATH"), carbonates, such as, but not limited to, dolomite and lithium carbonate. In the clay materials, certain embodiments of this disclosure use clay materials having at least a partially layered structure. In certain embodiments of this disclosure, the clay material used as a pyrophoretic additive in the aerogel composition has at least some water, for example, in a hydrated form. The additive can be in a hydrated crystalline form, or it can be hydrated during the manufacture / processing of the composition of the invention. In some embodiments, the pyrophoretic additive also includes a low-melting-point additive that absorbs heat without altering the chemical composition. An example of this is a low-melting-point glass, such as inert glass beads. Other additives that may be used in the composition disclosed herein include, but are not limited to, wollastonite (calcium silicate) and titanium dioxide (TiO2). In some embodiments, other additives may include infrared shading agents, such as, but not limited to, titanium dioxide or silicon carbide; ceramicizing agents, such as, but not limited to, low-melting-point glass powder, calcium silicate; or carburizing agents, such as, but not limited to, phosphates and sulfates. In some embodiments, additives may require special processing considerations, such as techniques to ensure that the additives are uniformly distributed and do not agglomerate excessively, leading to changes in product performance. Processing techniques may involve additional static and dynamic mixers, stabilizers, adjustments to process conditions, and other techniques known in the art. The amount of additives in the final aerogel composition can depend on various other performance requirements and can vary from 5% by weight to about 70% by weight. In some embodiments, the amount of additives in the final aerogel composition is 10% to 60% by weight, and in some preferred embodiments, it is 20% to 40% by weight. In some embodiments, the additives may be of more than one type. One or more fire-based additives may also be present in the final aerogel composition. In some preferred embodiments, including aluminum silicate fire-resistant additives, the additive content in the final aerogel composition is about 60 to 70% by weight.

[0169] In some embodiments of this disclosure, methods are provided for preparing OCMF-reinforced aerogel compositions with flammability. The flammability compositions of these embodiments also possess sufficient hydrophobicity, as measured by water absorption and low thermal conductivity, to help meet growing energy conservation requirements for use as insulation materials in industrial environments. Simply adding additives, or even flammability additives, is unsuccessful in achieving this combination of desirable properties. While one can try various permutations and combinations or various additives and obtain optimal solutions, such efforts are not always successful, and there are feasible manufacturing risks in achieving repeatable quality control of these desired properties. An important aspect of these embodiments is evaluating the thermal behavior of the composition (evaluated by thermogravimetric analysis or differential scanning calorimetry) to ensure that the composition provides all the desired properties except for flammability, taking into account the decomposition of the basic components by flammability additives closely matching the occurrence of heat, or the temperature at which flammability additives release the most heat or absorb the majority of heat when thermal decomposition begins.

[0170] In some embodiments, the desired flammability of the final composition may include not only inherent properties, such as heat of combustion (ISO 1716), but also system flammability, such as the response to flammability according to ISO 1182. In the case of ISO 1182, weight loss, furnace temperature rise, and combustion time are evaluated when exposed to a temperature of about 750°C.

[0171] OCMF-reinforced aerogel compositions can contain a variety of components that add fuel to the system. Additionally, it may contain various other components that, while not used as fuel, may interfere with combustion when exposed to fire. Thus, the combustion behavior of such a system cannot be predicted simply based on its constituent elements. In some embodiments where multiple properties are required, the composition should be obtained without considering its ignition performance, and the thermal properties of such the resulting composition should be evaluated to find suitable flammability additives that will provide ignition performance without intending to impair other properties intended to be provided by the starting composition.

[0172] In some embodiments, the initial thermal decomposition is a critical property of the composition. In other embodiments, the peak exothermic temperature may be a critical property for the purpose of developing enhanced flammable aerogel (OCMF) compositions. When multiple fuel components are present in the composition as determined by multiple peaks in the DSC curve, such compositions can be well utilized to release heat at 140°C, 120°C, 100°C, or 80°C by matching the peak exothermic temperature of the OCMF-enhanced aerogel composition with that of a flammable additive having an endothermic peak temperature. In many embodiments, the endothermic peak exothermic temperature is below 50°C.

[0173] The aerogel materials and compositions of the present invention have shown to be highly effective as thermal insulation materials. However, the applications of the methods and materials disclosed herein are not limited to applications related to insulation. The methods and materials disclosed herein can be applied to any system or application, which will benefit from the unique combination of properties or processes provided by the materials and methods disclosed herein.

[0174] Example

[0175] The following examples provide various non-limiting embodiments and characteristics of this disclosure. In the examples below, additive weight % refers to 100% by weight of the silica and hydrophobic components of the aerogel composition. Thermal analysis, TGA, and DSC were performed using a Netzsch STA449 FL Jupitor simultaneous thermal analyzer, starting at 25°C and increasing to 1000°C in air at ambient pressure at a rate of 20°C per minute. Any reference to the hydrophobic content of the sol refers to the weight of the solid material in the final aerogel composition, derived from the hydrophobic alkyl silane in the sol, as a percentage of the final aerogel composition by weight.

[0176] Example 1

[0177] Polyethyl silicate sol was prepared by hydrolyzing TEOS (tetraethoxysilane) in ethanol and water using a sulfuric acid catalyst, followed by stirring at ambient temperature for approximately 16 hours. Polymethylsilsesquioxane sol was prepared by hydrolyzing MTES (methyltriethoxysilane) and DMDES (dimethyldiethoxysilane) in ethanol and water using a phosphoric acid catalyst (molar ratio approximately 4:1), followed by stirring at room temperature for at least 16 hours. Polyethyl silicate and polymethylsilsesquioxane (MTES+DMDES) sols were mixed (approximately 2:1 by weight) to form a precursor sol, the precursor sol being designed to contain 30 to 40% by weight of total hydrophobicity in the final aerogel composition prepared from the sol. The combined precursor sols were stirred at ambient temperature for at least 2 hours.

[0178] Example 2

[0179] A sample of melamine OCMF material (BASOTECT UF from BASF) is provided. The sample is 10 mm thick and has a density of approximately 6 kg / m³. 3A substantially homogeneous mixture of 70 g of magnesium hydroxide (fire additive; MDH) in approximately 450 mL of ethanol (containing up to 10% by volume water) was mixed with approximately 540 mL of the silica sol from Example 1 and stirred for less than 5 minutes. Then, approximately 10 mL of a 28% by weight NH4OH solution was added, and the sol mixture was stirred for at least 1 minute. The sol mixture was then infiltrated into the melamine OCMF material and gelled, which occurred within 2 minutes. The resulting gel composition was allowed to stand and solidify for approximately 10 minutes. The gel composition was then aged for 16 hours at 68°C in an ethanol aging solution containing 10% by volume H2O and 1.1% by weight / volume NH4OH (1.1 g NH4OH per 100 mL of fluid), with a fluid-to-gel composition ratio of approximately 1.5:1. The aging temperature and aging solution composition can be further varied to alter the overall aging time.

[0180] The aerogel composition sample was then extracted with supercritical CO2 and dried at 120°C for 4 hours. The target silica density was 0.07 g / cc, and the material density of the resulting aerogel composite was 0.159 g / cc. The hydrophobic content of the aerogel composition was approximately 4.34% by weight.

[0181] Example 3

[0182] The gel composition was prepared using the same procedure as in Example 2, except that 72 g of MDH in about 529 mL of ethanol (containing up to 10% by volume water) was mixed with about 460 mL of silica sol from Example 1. The silica density was 0.06 g / cc, and the material density of the resulting aerogel composition was 0.185 g / cc. The hydrophobic content of the aerogel composition was about 3.97% by weight.

[0183] Example 4

[0184] The gel composition was prepared using the same procedure as in Example 2, except that a substantially homogeneous mixture of 96 g of MDH in approximately 376 mL of ethanol (containing up to 10% by volume water) was mixed with approximately 614 mL of silica sol from Example 1. The target silica density was 0.08 g / cc, and the material density of the resulting aerogel composition was 0.178 g / cc. The hydrophobic content of the aerogel composition was approximately 3.97% by weight.

[0185] Example 5

[0186] The gel composition was prepared using the same procedure as in Example 2, except that a substantially homogeneous mixture of 84 g of MDH in about 539 mL of ethanol (containing up to 10% by volume water) was mixed with about 460 mL of the silica sol from Example 1. The target silica density was 0.06 g / cc, and the material density of the resulting aerogel composition was 0.142 g / cc. The hydrophobic content of the aerogel composition was about 3.6% by weight.

[0187] Example 6

[0188] The gel composition was prepared using the same procedure as in Example 2, except that a substantially homogeneous mixture of about 529 mL of ethanol (containing up to 10% water by volume; no fire-resistant additives) was mixed with about 460 mL of silica sol from Example 1. The target silica density was 0.06 g / cc, and the material density of the resulting aerogel composition was 0.074 g / cc. The hydrophobic content of the aerogel composition was about 8.3% by weight.

[0189] Example 7

[0190] The gel composition was prepared using the same procedure as in Example 2, except that 72 g of inert glass beads (fire-resistant additive) were mixed substantially uniformly in approximately 529 mL of ethanol (containing up to 10% by volume of water). 460 mL of silica sol from Example 1 was also used. The target silica density was 0.06 g / cc, and the material density of the resulting aerogel composition was 0.141 g / cc. The hydrophobic content of the aerogel composition was approximately 3.93% by weight.

[0191] Example 8

[0192] The gel composition was prepared using the same procedure as in Example 2, except that a substantially homogeneous mixture of 60 g of wollastonite (commercially available as NY AD) in approximately 529 mL of ethanol solvent was mixed with approximately 460 mL of the silica sol from Example 1. The silica density was 0.06 g / cc, and the resulting aerogel composition had a material density of 0.161 g / cc. The hydrophobic content of the aerogel composition was approximately 3.95% by weight.

[0193] Example 9

[0194] The gel composition was prepared using the same procedure as in Example 2, except that a substantially homogeneous mixture of 72 g of titanium dioxide (fire additive; TiO2) in about 529 mL of ethanol (containing up to 10% by volume water) was mixed with about 460 mL of silica sol from Example 1. The target silica density was 0.06 g / cc, and the material density of the resulting aerogel composition was 0.159 g / cc. The hydrophobic content of the aerogel composition was about 3.95% by weight.

[0195] Example 10

[0196] It provides a size of 10mm and a density of approximately 23kg / m³. 3 A sample of polyurethane OCMF material was prepared. A substantially homogeneous mixture of 60 g of MDH (fire additive) in approximately 529 mL of ethanol (containing up to 10% by volume water) was mixed with approximately 460 mL of the silica sol from Example 1 and stirred for at least 5 minutes. Then, approximately 10 mL of a 28% by volume NH4OH solution was added, and the sol mixture was stirred for at least 1 minute. The sol mixture was then infiltrated into the polyurethane OCMF material and allowed to gel, which occurred within 2 minutes. The resulting gel composite was allowed to stand and cure for approximately 10 minutes. The gel composite was then aged for 16 hours in an ethanol aging solution at 68°C, where the fluid-to-gel ratio was approximately 1.5:1.

[0197] The aerogel composition sample was then extracted with supercritical CO2 and dried at 120°C for 4 hours. The target silica density was 0.06 g / cc, and the material density of the resulting aerogel composition was 0.165 g / cc. The hydrophobic content of the aerogel composition was approximately 3.95% by weight.

[0198] Example 11

[0199] Polyethyl silicate sol was prepared by hydrolyzing TEOS in EtOH and H2O using a sulfuric acid catalyst, followed by stirring at ambient temperature for at least 16 hours. Polymethyl silsesquioxane sol was prepared by hydrolyzing MTES and DMDES (approximately 8:1 molar ratio) in EtOH and H2O using an acetic acid catalyst, followed by stirring at ambient temperature for at least 16 hours. Polyethyl silicate (TEOS) and polymethyl silsesquioxane (MTES+DMDES) sols were mixed (approximately 10:1 by weight) to form a silica sol, aiming for a hydrophobic content of approximately 12% by weight in the final aerogel composition. The combined silica sols were stirred at ambient temperature for at least 2 hours.

[0200] Example 12

[0201] Provide a sample of melamine OCMF material, with a thickness of 10 mm and a density of approximately 6 kg / m³. 3A substantially homogeneous mixture of 60 g of MDH (fire additive) in approximately 718 mL of ethanol (containing up to 10% by volume water) was mixed with approximately 266 mL of the silica sol from Example 11 and stirred for at least 5 minutes. Then, approximately 10 mL of a 28% by weight NH4OH solution was added, and the sol mixture was stirred for at least 1 minute. The sol mixture was then infiltrated into the melamine OCMF material and gelled, which occurred within 2 minutes. The resulting gel composite was allowed to stand and solidify for approximately 10 minutes. The gel composition was then treated in ethanol at 68°C for 16 hours, the ethanol containing 0.12 M of a trimethylsilyl derivative of hexamethyldisilazane (TMS), 8% H2O, and 0.8 g of NH4OH3 (per 100 mL of ethanol), with a fluid-to-gel composition ratio of approximately 1.5:1.

[0202] The aerogel composition sample was then extracted with supercritical CO2 and dried at 120°C for 4 hours. The target silica density was 0.05 g / cc, and the material density of the obtained aerogel composition was 0.176 g / cc.

[0203] Example 13

[0204] The gel composition was prepared using the same steps as in Example 12, except that a substantially homogeneous mixture of about 718 mL of ethanol solvent (without fire-resistant additives) was mixed with about 256 mL of silica sol from Example 8, resulting in a material density of 0.081 g / cc.

[0205] Example 14

[0206] The gel complex was prepared using the same steps as in Example 11, except that polyethyl silicate (TEOS) and polymethylsilsesquioxane (MTES+DMDES) sol were mixed in a weight ratio of about 7:1 to form a silica sol in the final aerogel composition for a total hydrophobic content of 16% by weight.

[0207] Example 15

[0208] The gel composition was prepared using the same procedure as in Example 12, except that a substantially homogeneous mixture of 72 g of MDH (firework additive) in approximately 668 mL of ethanol solvent was mixed with approximately 317 mL of silica sol from Example 14. The target silica density was 0.06 g / cc, and the material density of the resulting aerogel composition was 0.195 g / cc. Thermogravimetric analysis (TGA) revealed an onset temperature of 399.5 °C, and DSC revealed a peak exothermic temperature of 439.6 °C. The extrapolated onset temperature of thermal decomposition of the composition containing the firework additive was measured using TGA at 395.8 °C, and the peak exothermic temperature was measured using DSC at 560.9 °C.

[0209] For comparison, it was found that the composition in this embodiment without any flammable additives had a thermal decomposition extrapolation start of 369.4°C, and the peak exothermic temperature measured using DSC curves was 607.9°C, as measured by thermogravimetric analysis.

[0210] Example 16

[0211] The gel composition was prepared using the same procedure as in Example 12, except that approximately 668 mL of a mixture of ethanol solvent (flammable additive-free) was mixed with approximately 317 mL of silica sol from Example 14. The target silica density was 0.06 g / cc, and the material density of the resulting aerogel composition was 0.092 g / cc.

[0212] Example 17

[0213] Polyethyl silicate sol was prepared by hydrolyzing TEOS in ethanol and water using a sulfuric acid catalyst, followed by stirring at ambient temperature for approximately 16 hours. This non-hydrophobic sol was used without the addition of any polymethylsilsesquioxane sol or other hydrophobic materials.

[0214] Example 18

[0215] The gel composite was prepared using the same procedures as in Example 12, except that approximately 662 mL of a mixture of ethanol solvent (without fire-resistant additives) was mixed with approximately 328 mL of silica sol from Example 17 and allowed to gel. The gel was treated with an ethanol solution containing 0.3 M TMS (8 vol% H2O and 0.8 g NH4OH per 100 mL of ethanol, with a fluid-to-gel composite ratio of approximately 1.5:1) for 68 hours, with a duration of 16 hours. The target silica density was 0.06 g / cc, and the material density of the resulting aerogel composite was 0.086 g / cc.

[0216] Example 19

[0217] The gel composite was prepared using the same procedures as in Example 12, except that approximately 662 mL of a mixture of ethanol solvent (without fire-resistant additives) was mixed with approximately 328 mL of silica sol from Example 17 and allowed to gel. The gel was treated at 68°C for 16 hours with a solution containing 0.6 M MTES (8 vol% H₂O and 0.8 g NH₄OH per 100 mL of ethanol, with a fluid-to-gel composite ratio of approximately 1.5:1). The target silica density was 0.06 g / cc, and the material density of the resulting aerogel composite was 0.103 g / cc.

[0218] Example 20

[0219] The aerogel composite was prepared using the same procedure as in Example 2, except that 112 g of halloysite clay (fire additive; DRAGONITE) was mixed with approximately 537 mL of silica sol from Example 1 in approximately 453 mL of a substantially homogeneous mixture in approximately 453 mL of ethanol (containing up to 8% by volume water). The target silica density was 0.07 g / cc, and the resulting aerogel composite had a material density of 0.196 g / cc. The hydrophobic content of the aerogel composition was approximately 3.37% by weight.

[0220] Example 21

[0221] The aerogel composite was prepared using the same procedures as in Example 2, except that approximately 72 mL of halloysite clay (fire additive; DRAGONITE) was mixed with approximately 460 mL of silica sol from Example 1 in approximately 529 mL of ethanol (containing up to 10% by volume water). The target silica density was 0.06 g / cc, and the material density of the resulting aerogel composite was 0.128 g / cc. The hydrophobic content of the aerogel composition was approximately 3.91% by weight. The initial thermal decomposition was measured using thermogravimetric analysis (TGA) at 492.9 °C, and the peak exothermic temperature was measured using DSC at 565.9 °C. The extrapolated initial thermal decomposition temperature of the composition containing the fire additive was measured using TGA at 370.9 °C, and the peak exothermic temperature was measured using DSC at 565.9 °C.

[0222] For comparison, the composition in the embodiments without any flammable additives was found to have an inferred initial thermal decomposition temperature of 369.4°C using thermogravimetric analysis and a peak exothermic temperature of 607.9°C using DSC analysis.

[0223] Example 22

[0224] The aerogel composite was produced using the same steps as in Example 2, except that a substantially homogeneous mixture of two fire-based additives (36 g of halloysite clay and 36 g of alumina trihydrate) was prepared in approximately 529 mL of ethanol (containing up to 10% by volume water). Up to 10% (by volume) of water was mixed with approximately 460 mL of the silica sol from Example 1. The target silica density was 0.06 g / cc, and the material density of the resulting aerogel composite was 0.149 g / cc. The hydrophobic content of the aerogel composition was approximately 3.94% by weight.

[0225] Example 23

[0226] The aerogel composite was prepared using the same procedure as in Example 2, except that 72 g of alumina trihydrate (ATH) in approximately 529 mL of ethanol (containing up to 10% by volume water) was mixed with approximately 460 mL of the silica sol from Example 1. The target silica density was 0.06 g / cc, and the resulting aerogel composite had a material density of 0.152 g / cc. The hydrophobic content of the aerogel composition was approximately 3.94% by weight. The thermal decomposition onset temperature, measured using thermogravimetric analysis, was 289.8 °C, and the peak exothermic temperature, measured using DSC, was 334.1 °C.

[0227] For comparison, the composition in the embodiments without any flammable additives was inferred to have an initial thermal decomposition temperature of 369.4°C using thermogravimetric analysis and a peak exothermic temperature of 607.9°C using DSC analysis.

[0228] Example 24

[0229] The aerogel composite was prepared using the same procedure as in Example 12, except that a substantially homogeneous mixture of 100 g of halloysite clay in approximately 558 mL of ethanol (up to 10% water by volume) was mixed with approximately 426 mL of ethanol. The silica sol from Example 11 was incorporated to a target hydrophobic content of 28% by weight. The target silica density was 0.083 g / cc, and the resulting aerogel composite had a material density of 0.184 g / cc.

[0230] Example 25

[0231] The gel composition was prepared using the same procedure as in Example 2, except that 56 g of halloysite clay (DRAGONITE from Applied Minerals, Inc.) and 56 g of ATH were mixed substantially uniformly in about 453 mL of ethanol (up to 8% by volume of water). Water was mixed with about 537 mL of the silica sol from Example 1. The target silica density was 0.07 g / cc, and the material density of the resulting aerogel composite was 0.196 g / cc. The hydrophobic content of the aerogel composition was about 3.36% by weight.

[0232] Table 1 below shows the composition of the foregoing embodiments. The term "weight % loading" refers to the amount of additive loaded into the composition based on the amount of silica present. For example, 120% "weight % loading" means that for every 100g of silica in the composition, 120g of additive is loaded.

[0233] Table 1. Components of the Embodiment

[0234]

[0235] Table 2 lists the measured values ​​of density, TC, liquid water absorption, HOC, FTR, combustion time, and mass loss for the exemplary composites in Table 1.

[0236] Table 2. Result Properties of the Example

[0237]

[0238] Referring to Table 2, density measurements were performed according to ASTM C167. The measured density of all aerogel components was less than 0.2 g / cc. TC measurements were performed according to ASTM C518 at a temperature of approximately 37.5°C and a compressive force of 2 psi. The measured thermal conductivity of all aerogel components was less than 20.1 mW / m*K. Liquid water absorption was measured according to ASTM C 1511 (after immersion under ambient conditions for 15 minutes). The liquid water absorption of all aerogel components was less than 5% by weight. HOC measurements were performed according to ISO 1716. The HOC of all aerogel components was less than 690 cal / g. FTR measurements were performed according to ISO 1182 A.1. The FTR of all aerogel components was less than 50°C. Burning time measurements were performed according to ISO 1182 A.2. The measured burning time for all these samples was 20 seconds. Mass loss measurements were performed according to ISO 1182 A.3. All other aerogel component samples experienced a mass loss of less than 50% by weight.

[0239] The aforementioned advantages, as well as those obvious from the foregoing description, are effectively achieved. Since certain changes can be made to the above-described structure without departing from the scope of the invention, it is intended that everything contained in the foregoing description or shown in the drawings be interpreted as illustrative rather than restrictive.

[0240] It should be understood that the following claims are intended to cover all general and specific features of the invention described herein, and for linguistic purposes, all statements within the scope of the invention may be said to fall within it.

Claims

1. An enhanced aerogel composition comprising: i) Enhanced silica-based aerogel materials, comprising: (a) Reinforcing materials, including open-pore macroporous skeleton materials; (b) Silica-based aerogel materials; and ii) Fire-related additives; and in: The open-pore macroporous framework material refers to a porous material comprising a framework of uniform interconnected structures, having a corresponding network of interconnected pores integrated within the framework; and is characterized in that the average pore diameter is in the range of 10 μm to 700 μm. The enhanced silica-based aerogel material has an initial thermal decomposition temperature; and The pyrophoric additive refers to a material that has an endothermic effect when reacting with fire and can be incorporated into the enhanced aerogel composition, wherein the pyrophoric additive has an initial thermal decomposition temperature within 50°C of the initial thermal decomposition temperature of the enhanced silica-based aerogel material.

2. An enhanced aerogel composition comprising: i) Enhanced silica-based aerogel materials, comprising: (a) Reinforcing materials, including open-pore macroporous skeleton materials; (b) Silica-based aerogel materials; and ii) Fire-related additives; and in: The open-pore macroporous framework material refers to a porous material comprising a framework of uniform interconnected structures, having a corresponding network of interconnected pores integrated within the framework; and is characterized in that the average pore diameter is in the range of 10 μm to 700 μm. The enhanced silica-based aerogel material has a first decomposition heat release; and The fire additive refers to a material that has an endothermic effect when reacting with fire and can be incorporated into the enhanced aerogel composition, wherein the fire additive has at least 30% of the first decomposition heat release and the second decomposition heat release.

3. The enhanced aerogel composition according to claim 1 or 2, wherein, The silica-based aerogel material permeates into the open-pore macroporous framework material.

4. The enhanced aerogel composition according to claim 1 or 2, wherein, The fire-related additives are incorporated into the enhanced aerogel composition.

5. The enhanced aerogel composition according to claim 1 or 2, wherein, The fire-related additive is an endothermic fire-related additive.

6. The enhanced aerogel composition according to claim 1 or 2, wherein, The fire-related additives are present in the enhanced aerogel composition at a concentration of 5% to 70% by weight.

7. The enhanced aerogel composition according to claim 1 or 2, wherein, The open-pore macroporous framework material includes organic open-pore macroporous framework materials.

8. The enhanced aerogel composition according to claim 1 or 2, wherein, The open-pore macroporous framework material includes melamine-based open-pore macroporous framework materials.

9. The enhanced aerogel composition according to claim 1 or 2, wherein, The open-pore macroporous skeleton material includes sheets of open-pore macroporous skeleton material.

10. The enhanced aerogel composition according to claim 1 or 2, wherein, The open-pore macroporous skeleton material includes foam material.

11. The enhanced aerogel composition according to claim 1 or 2, wherein, The open-pore macroporous framework material accounts for 2% to 10% by weight of the reinforced aerogel composition.

12. The enhanced aerogel composition according to claim 1 or 2, wherein, The enhanced silica-based aerogel material also includes hydrophobic components.

13. The enhanced aerogel composition according to claim 1 or 2, wherein, The perforated macroporous skeleton material includes combustible materials.

14. The enhanced aerogel composition according to claim 1 or 2, wherein, The enhanced aerogel composition has an initial thermal decomposition of 350°C to 390°C.

15. The enhanced aerogel composition according to claim 1 or 2, wherein, The enhanced aerogel composition has an initial thermal decomposition of 280°C to 390°C.

16. The enhanced aerogel composition according to claim 1 or 2, wherein, The fire-related additives include halloysite clay.

17. The enhanced aerogel composition according to claim 1 or 2, wherein, The fire-related additives do not include kaolinite or hydrated alumina.

18. The enhanced aerogel composition according to claim 1 or 2, wherein, The initial thermal decomposition temperature of the fire-related additive corresponds to the heat required for dehydration or dihydroxylation.

19. The enhanced aerogel composition according to claim 1 or 2, wherein, The enhanced aerogel composition is characterized by: i) The amount of liquid water absorbed is less than 20% by weight; as well as ii) According to ASTM C518, the thermal conductivity is less than 30 mW / M·K at a temperature of 37.5°C, in ambient environment, at atmospheric pressure, and under a compressive load of 2 psi.

20. The enhanced aerogel composition according to claim 2, wherein, According to EN ISO 1716, the heat of pyrolysis of the first decomposition of the reinforced silica-based aerogel material is 625 cal / g to 700 cal / g.

21. The enhanced aerogel composition according to claim 1 or 2, further comprising at least two fire-related additives, wherein, The initial thermal decomposition of each of the at least two fire-related additives is separated by at least 10°C.

22. The enhanced aerogel composition according to claim 1 or 2, wherein, The silica-based aerogel material incorporated into the reinforcing material has a density of 2 kg / m³. 3 and 25 kg / m 3 The density between.

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