Aerogel Fiber

Abstract

To provide improved ultralight fibers with high air porosities that can be fabricated using sustainable resources.SOLUTION: An aerogel fiber includes an aerogel polymer selected from the group consisting of polylactic acid (PLA), sodium alginate, cellulose, oxidized cellulose, and a mixture thereof, wherein the aerogel polymer is optionally crosslinked with a crosslinking agent and the aerogel fiber has a linear density of 0.20 tex or less, a fiber tenacity of 5 to 20 cN / tex, an elongation at break of 3 to 20%, and an average diameter between 5 μm to 200 μm.SELECTED DRAWING: None

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority from U.S. Provisional Patent Application No. 63 / 482,075, filed January 30, 2023, which is incorporated by reference in its entirety.

[0002] Technical Field Provided herein are aerogel fibers useful for preparing lightweight textiles with high thermal insulation properties. [Background technology]

[0003] There is a need for fibers that are sustainable, ultra-lightweight, and can provide a warming sensation when incorporated into clothing or other textiles.

[0004] Responsible wool is becoming an increasingly important material in outdoor fashion clothing due to the benefits it provides to the user. Wool fabrics require a thicker construction for use in extreme weather conditions. Additionally, wool's moisture content is higher compared to most synthetic fabrics. These properties limit the use of wool in ultra-lightweight performance activewear for use in cold and extreme weather conditions.

[0005] Ultralight hollow fibers with high porosity are available on the market for their thermal insulation properties. However, heat loss from these fibers is significant due to convection from their microscale hollow core through the sheath structure. Furthermore, commercially available hollow fibers are generally available as insulating fillers and are not suitable for knitted fabrics. They are synthetic in nature and therefore not sustainable. Hollow fibers made from regenerated cellulose are also available on the market, but their high water retention capacity makes them unsuitable for use in insulation applications. They are more ideal for use as moisture management fabrics and wound dressings. Summary of the Invention [Problem to be solved by the invention]

[0006] There is a need for improved ultralightweight fibers with high porosity that can be produced using sustainable resources. These fibers, when properly knitted into fabrics with conventional fibers, can provide lightweight fabrics with high insulation performance against extreme weather, and can be used in outdoor fashion apparel and performance activewear for use in cold and extreme weather conditions. [Means for solving the problem]

[0007] In a first aspect, there is provided an aerogel fiber comprising an aerogel polymer selected from the group consisting of polylactic acid (PLA), sodium alginate, cellulose, oxidized cellulose, and mixtures thereof, wherein the aerogel polymer is optionally crosslinked with a crosslinking agent, the aerogel fiber having a linear density of 0.20 tex or less, a fiber tenacity of 5 to 20 cN / tex, an elongation at break of 3 to 20%, and an average diameter of 5 μm to 200 μm.

[0008] In certain embodiments, the aerogel polymer comprises cellulose, 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO)-oxidized cellulose, microfibrillated cellulose, TEMPO-oxidized microfibrillated cellulose, cellulose nanofibrils, or mixtures thereof.

[0009] In certain embodiments, the aerogel polymer is crosslinked with a crosslinker selected from the group consisting of methyltrimethoxysilane, 1,4-butanediol diglycidyl ether (BDDE), trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, salts, and mixtures thereof.

[0010] In certain embodiments, the aerogel polymer is crosslinked with calcium chloride.

[0011] In certain embodiments, the aerogel polymer comprises sodium alginate.

[0012] In certain embodiments, the aerogel fibers further comprise a hydrophobic alkylsilane, an aliphatic ester, or a combination thereof grafted onto the outer surface of the aerogel fibers.

[0013] In certain embodiments, the aerogel fibers have an average diameter of 5 to 30 μm.

[0014] In certain embodiments, the aerogel fibers have a fiber tenacity of 15 to 20 cN / tex.

[0015] In certain embodiments, the aerogel fibers have a linear density of 0.1 to 0.2 tex.

[0016] In certain embodiments, the aerogel is mesoporous, nanoporous, or microporous.

[0017] In certain embodiments, the aerogel fibers contain pores with an average diameter of 100 to 250 nm.

[0018] In certain embodiments, the aerogel fibers comprise sodium alginate, the aerogel fibers have a fiber tenacity of 15-20 cN / tex, an average diameter of 15 μm-20 μm, a linear density of 0.15-0.2 tex, and the aerogel fibers comprise pores with an average diameter of 100-250 nm.

[0019] In a second aspect, there is provided a textile comprising the aerogel fibers described herein.

[0020] In certain embodiments, the aerogel fibers comprise sodium alginate, the aerogel fibers have a fiber tenacity of 15-20 cN / tex, an average diameter of 15 μm-20 μm, and a linear density of 0.15-0.20 tex, and the aerogel fibers comprise pores with an average diameter of 100-250 nm.

[0021] In certain embodiments, the textile is selected from the group consisting of staple fibers, yarns, fabrics, clothing, linens, curtains, upholstery materials, and combinations thereof.

[0022] In certain embodiments, the textile further comprises one or more additional fibers selected from the group consisting of natural fibers, synthetic fibers, semi-synthetic fibers, and combinations thereof.

[0023] In certain embodiments, the aerogel fibers and the one or more additional fibers are present in the textile in a weight ratio of 1:9 to 9:1.

[0024] In certain embodiments, the textile further comprises wool, and the textile has a higher thermal resistance and a lower mass compared to a comparable textile made of wool.

[0025] In a third aspect, there is provided a method of preparing an aerogel fiber as described herein, the method including providing a spinning solution comprising an aerogel polymer; wet-spinning the spinning solution to form filaments comprising the aerogel polymer; wet-stretching the filaments to form wet-stretched filaments; and freeze-drying the wet-stretched filaments to form the aerogel fibers.

[0026] In certain embodiments, the step of wet-spinning the spinning solution includes passing the spinning solution through a multifilament spinneret at a flow rate of 0.1 to 5 meters / minute into a coagulation bath containing calcium chloride.

[0027] In certain embodiments, the wet drawing step comprises drawing the filaments at a temperature of 30-60°C at a total draw ratio of 100-500%.

[0028] In certain embodiments, wet-spinning the aerogel polymer comprises passing the solution through a 50-100 micron diameter multifilament spinneret at a temperature of 70-90°C and a flow rate of 2.5-3 meters / minute into a coagulation bath containing calcium chloride, and wet-drawing comprises drawing the filaments at a total draw ratio of 300-350% at 40-50°C. [Effects of the Invention]

[0029] The above and other objects and features of the present disclosure will become apparent from the following description of the disclosure when considered in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0030] [Figure 1] 1 illustrates a cross-sectional view of an aerogel fiber according to certain embodiments described herein. [Figure 2-1] Figure 1 shows a cross-section of an aerogel fiber prepared at a freezing temperature of -20°C and a 5% w / w coagulation bath. [Figure 2-2] Figure 1 shows a cross-section of an aerogel fiber prepared at a freezing temperature of -20°C and a 5% w / w coagulation bath. [Figure 2-3] Figure 1 shows a cross-section of an aerogel fiber prepared at a freezing temperature of -20°C and a 5% w / w coagulation bath. [Figure 3-1] Figure 1 shows a cross-sectional view of an aerogel fiber prepared at a freezing temperature of -20°C and a 10% w / w coagulation bath. [Figure 3-2] Figure 1 shows a cross-sectional view of an aerogel fiber prepared at a freezing temperature of -20°C and a 10% w / w coagulation bath. [Figure 3-3] Figure 1 shows a cross-sectional view of an aerogel fiber prepared at a freezing temperature of -20°C and a 10% w / w coagulation bath. [Figure 4-1] Figure 1 shows a cross-section of an aerogel fiber prepared at a freezing temperature of -50°C and a 5% w / w coagulation bath. [Figure 4-2] Figure 1 shows a cross-section of an aerogel fiber prepared at a freezing temperature of -50°C and a 5% w / w coagulation bath. [Figure 4-3]Figure 1 shows a cross-section of an aerogel fiber prepared at a freezing temperature of -50°C and a 5% w / w coagulation bath. DETAILED DESCRIPTION OF THE INVENTION

[0031] definition Throughout this application, when a composition is described as having, including, or comprising particular components, or a process is described as having, including, or comprising particular process steps, it is contemplated that a composition of the present teachings can consist essentially of or consist of the recited components, and a process of the present teachings can consist essentially of or consist of the recited process steps.

[0032] When an element or component is referred to in this application as being included in and / or selected from a list of described elements or components, it should be understood that the element or component can be any one of the described elements or components, or that the element or component can be selected from a group consisting of two or more of the described elements or components. Furthermore, it should be understood that the elements and / or features of the compositions or methods described herein, whether expressly or implicitly stated herein, can be combined in various ways without departing from the spirit and scope of the present teachings.

[0033] It should be understood that the order of steps or order for performing certain actions is immaterial so long as the present teachings remain operable. Moreover, two or more steps or actions may be conducted simultaneously.

[0034] The use of the singular herein includes the plural (and vice versa) unless specifically stated otherwise. In addition, when the term "about" is used before a quantitative value, the present teachings also include the particular quantitative value itself, unless specifically stated otherwise.

[0035] As used herein, the term "about" refers to a variation of ±10%, ±7%, ±5%, ±3%, ±1%, or ±0% from the nominal value, unless otherwise stated or inferred.

[0036] Provided is an aerogel fiber comprising an aerogel polymer selected from the group consisting of polylactic acid (PLA), sodium alginate, cellulose, oxidized cellulose, and mixtures thereof, wherein the aerogel polymer is optionally crosslinked with a crosslinking agent, and the aerogel fiber has a linear density of 0.20 tex or less, a fiber tenacity of 5 to 20 cN / tex, an elongation at break of 3 to 20%, and an average diameter of 5 μm to 200 μm.

[0037] In certain embodiments, the aerogel polymer comprises cellulose, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose, microfibrillated cellulose, TEMPO-oxidized microfibrillated cellulose, cellulose nanofibrils, or mixtures thereof. In certain embodiments, the aerogel polymer does not comprise polyvinyl alcohol or polypyrrole.

[0038] In certain embodiments, the aerogel polymer comprises sodium alginate having a viscosity of 500-600 mPa·s (1% in water), which can be optionally crosslinked with a crosslinking agent.

[0039] In certain embodiments, the aerogel polymer comprises PLA having an average molecular weight of 170 kg / mol, hi certain embodiments, the aerogel polymer comprises PLA sold under the trade name Luminy® L130 by TotalEnergies Corbion.

[0040] The aerogel polymer can be derived from any source, in certain embodiments, the aerogel polymer is prepared from cellulose obtained from one or more of spent corn husks, paper pulp, wood pulp, rice husks, and fruit peels.

[0041] In certain embodiments, the aerogel polymer is crosslinked by a crosslinker. The crosslinker can be any crosslinker containing two, three, four, five, or more electrophilic species capable of reacting with nucleophiles present in the aerogel polymer. In certain embodiments, the crosslinker is selected from the group consisting of methyltrimethoxysilane, 1,4-butanediol diglycidyl ether (BDDE), trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, 1,6-hexanediol diglycidyl ether, poly(ethylene glycol) diglycidyl ether, diglycidyl ether of bisphenol A, and mixtures thereof. In certain embodiments, the crosslinker is BDDE.

[0042] In certain embodiments, the crosslinker is a salt comprising at least one cation and at least one anion, where the cation has a charge of +1, +2, +3, +4, or +5, and the salt can bond with one or more substituents present in the aerogel polymer through ionic and / or hydrogen bonding interactions. + , Ca 2+ , Mg 2+ , Cu 1+ , Cu 2+ , Zn 2+ , or Al 3+ The salt may comprise any anion. Suitable anions include, but are not limited to, halide, nitrate, phosphate, carbonate, sulfate, acetate, alkoxide, and the like. In certain embodiments, the crosslinker is selected from the group consisting of calcium chloride, lithium chloride, copper chloride, zinc chloride, and aluminum chloride. In certain embodiments, the crosslinker is calcium chloride.

[0043] Aerogel fibers can be microporous (<2 nm), mesoporous, nanoporous (2-50 nm), macroporous (>50 nm), or a combination thereof. In certain embodiments, aerogel fibers are nanoporous (1-100 nm). In certain embodiments, aerogel fibers comprise pores having an average size of 1-20 nm, 20-100 nm, 100-500 nm, 500-1,000 nm, or 1,000-3,000 nm, or a combination thereof. In certain embodiments, aerogel fibers comprise pores having an average size of 100-250 nm.

[0044] The water resistance of aerogel fibers can be improved by surface modification with a hydrophobic agent selected from alkylsilanes, aliphatic esters, and mixtures thereof. The hydrophobic agent can react with the outer surface of the aerogel fiber, thereby lowering the surface energy of the aerogel fiber and increasing the water contact angle. Any hydrophobic agent can be used that can react with a nucleophile present on the surface of the aerogel fiber to result in a reduction in surface energy. Exemplary hydrophobic agents include C8-C 20 Alkyl acyl halides, C8-C 20 Alkyl anhydrides (C8-C 20 trialkyl)(halo)silanes, and mixtures thereof.

[0045] In certain embodiments, the aerogel fibers further comprise vitamins, humectants, surfactants, fragrances, sunscreens, color stabilizers, pigments, or mixtures thereof.

[0046] Advantageously, the aerogel fibers described herein can have an average diameter of 5 to 200 μm, which can provide improved hand feel. In certain embodiments, the aerogel fibers described herein can have an average diameter of 5 to 200 μm, 5 to 150 μm, 5 to 100 μm, 5 to 75 μm, 5 to 50 μm, 5 to 40 μm, 5 to 30 μm, 10 to 30 μm, 10 to 25 μm, 10 to 20 μm, 15 to 20 μm, 16 to 20 μm, 17 to 20 μm, or 18 to 19 μm. In certain embodiments, the aerogel fibers have an average diameter of about 18.81 μm.

[0047] The aerogel fibers can have a fiber tenacity of 5-20 cN / tex, 6-20 cN / tex, 7-20 cN / tex, 8-20 cN / tex, 9-20 cN / tex, 10-20 cN / tex, 11-20 cN / tex, 12-20 cN / tex, 13-20 cN / tex, 14-20 cN / tex, 15-20 cN / tex, 16-20 cN / tex, 17-20 cN / tex, 17-19 cN / tex, or 17-18 cN / tex. In a particular embodiment, the aerogel fibers have a fiber tenacity of about 17.1 cN / tex.

[0048] In certain embodiments, the aerogel fibers have an elongation to break of 0.1-10%, 0.5-10%, 1-10%, 1-9%, 1-8%, 1-7%, 1-6%, 1-5%, 1-4%, 2-4%, 3-4%, 3-3.5%, 0.1-9%, 0.1-8%, 0.1-7%, 0.1-6%, 0.1-5%, 0.5-5%, 0.5-4.5%, 0.5-4%, 0.5-3.5%, 1-3.5%, 1.5-3.5%, 2-3.5%, or 2.5-3.5%. In certain embodiments, the aerogel fibers have an elongation to break of about 3.3%.

[0049] In certain embodiments, the aerogel fibers have a linear density of 0.01-0.2 tex, 0.05-0.2 tex, 0.1-0.2 tex, 0.11-0.2 tex, 0.12-0.2 tex, 0.13-0.2 tex, 0.14-0.2 tex, 0.15-0.2 tex, 0.16-0.2 tex, 0.17-0.2 tex, 0.17-0.19 tex, or 0.17-0.18 tex. In certain embodiments, the aerogel fibers have a linear density of about 0.174 tex.

[0050] The present disclosure also provides textiles comprising the aerogel fibers described herein. The textile is not particularly limited. In certain embodiments, the textile is selected from the group consisting of staple fibers, yarns, fabrics, clothing, linens, curtains, upholstery materials, or combinations thereof.

[0051] Yarns can include, for example, multiple twisted staple fibers, juxtaposed filaments without twist, juxtaposed filaments with some twist, and single filaments with or without twist. Yarns can be textured or untextured. Suitable fabrics can similarly include, for example, woven fabrics, knitted fabrics, and nonwoven fabrics. Apparel can be apparel and industrial garments. Fabrics and textiles can include household items such as linens, curtains, and upholstery materials (including automotive, marine, and aircraft).

[0052] In certain embodiments, the textile further comprises one or more additional fibers selected from the group consisting of natural fibers, synthetic fibers, semi-synthetic fibers, and combinations thereof.

[0053] Natural organic fibers can be of any plant or animal origin, but include, for example, fibrous materials obtained from natural products containing cellulose, such as any one or combination of wood, bamboo, cotton, banana, piña, hemp ramie, linen, coconut, soy, milk, khoya, bagasse, kenaf, retting, mudrar, silk, wool, cashmere, alpaca, angora wool, mohair, shearling, vicuña, shahtoosh, and the like.

[0054] Semi-synthetic fibers may include, for example, any one or combination of viscose, cuprammonium, rayon, polynosic, lyocell, cellulose acetate, and the like.

[0055] Synthetic fibers can include, for example, acrylic, Kevlar, modacrylic, Nomex, spandex, nylon, polyester, acrylic, rayon, acetate, and the like.

[0056] In certain embodiments, the textile comprises aerogel fibers described herein and one or more additional fibers in a weight ratio of 1:9 to 9:1, 1:9 to 4:1, 1:9 to 7:3, 1:9 to 3:2, 1:9 to 1:1, 1:4 to 1:1, 3:7 to 1:1, 3:7 to 2:3, 1:4 to 4:1, 3:7 to 7:3, 2:3 to 3:2, or 9:11 to 11:9. In certain embodiments, the textile comprises aerogel fibers described herein and one or more additional fibers in a weight ratio of about 1:1. In certain embodiments, the textile comprises aerogel fibers described herein and wool fibers in a weight ratio of 1:9 to 9:1, 1:9 to 4:1, 1:9 to 7:3, 1:9 to 3:2, 1:9 to 1:1, 1:4 to 1:1, 3:7 to 1:1, 3:7 to 2:3, 1:4 to 4:1, 3:7 to 7:3, 2:3 to 3:2, or 9:11 to 11:9. In certain embodiments, the textile comprises aerogel fibers described herein and wool fibers in a weight ratio of about 1:1.

[0057] In certain embodiments, a textile comprises aerogel fibers described herein and wool. Advantageously, a textile comprising wool and aerogel fibers described herein exhibits higher thermal resistance and reduced weight compared to a comparable textile comprising only wool (e.g., in certain embodiments, the comparable textile is comprised of wool, has the same or substantially the same (e.g., ±4%, ±3%, ±2%, ±1%, or ±0.5% of a reference value) yarn diameter, void volume, yarn count, is constructed using the same knitting technique, etc.). The thermal resistance of the textiles described herein can be measured using any method known in the art, such as GB11048-89, Method A.

[0058] For example, a textile comprising aerogel fibers and wool can have a thermal resistance that is 1-50%, 5-50%, 5-45%, 5-40%, 5-35%, 5-30%, 5-25%, 5-20%, 5-15%, 5-10%, 10-50%, 15-50%, 20-50%, 25-50%, 30-50%, 40-50%, 45-50%, 10-25%, 15-25%, 20-25%, 10-45%, 15-40%, 20-35%, or 25-30% greater than a comparable textile made of wool. In certain embodiments, a textile comprising aerogel fibers and wool in a 2:3 to 3:2 weight ratio can have a thermal resistance that is 9-25%, 10-24%, 11-23%, 12-22%, 13-21%, 14-20%, 15-20%, 15-19%, 15-18%, 15-17%, 15-16%, 16-18%, or 16-17% higher than a comparable textile comprised of wool. In certain embodiments, a textile comprising aerogel fibers and wool in a 1:1 weight ratio can have a thermal resistance that is about 16.7% higher than a comparable textile comprised of wool.

[0059] A textile containing aerogel fibers and wool in a weight ratio of 2:3 to 3:2 can have a weight that is 24 to 36% lower than a comparable textile made of wool. In a specific embodiment, a textile containing aerogel fibers and wool in a weight ratio of about 1:1 can have a weight that is about 29% lower than a comparable textile made of wool.

[0060] The insulating properties of the textiles described herein are not significantly affected by washing the textiles, for example, the insulating properties of the textiles described herein may change by no more than 20%, no more than 15%, no more than 10%, or no more than 5% after 10 washes.

[0061] Also provided is a method of preparing the aerogel fibers described herein, the method including providing a spinning solution comprising an aerogel polymer, wet-spinning the spinning solution to form filaments comprising the aerogel polymer, wet-stretching the filaments to form wet-stretched filaments, and freeze-drying the wet-stretched filaments to form the aerogel fibers.

[0062] The spinning solution can include any solvent in which the aerogel polymer dissolves. Suitable solvents include, but are not limited to, water, organic solvents, or mixtures thereof. Organic solvents can include dimethylacetamide, dimethylformamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, acetone, acetonitrile, methanol, ethanol, isopropanol, or combinations thereof. In certain embodiments, the spinning solution includes water. In certain embodiments, the spinning solution does not include an ice regulator, such as one or more of sodium chloride, ethylene glycol, and dimethyl sulfoxide.

[0063] The step of wet-spinning the spinning solution can include passing the spinning solution through a spinneret (e.g., a multifilament spinneret) and into a coagulation bath.

[0064] The coagulation bath may comprise any solvent in which the aerogel polymer has low solubility. In certain embodiments, the coagulation bath may comprise Li + , Ca 2+ , Mg 2+ , Cu 1+ , Cu 2+ , Zn 2+ , and Al 3+ and one or more anions selected from the group consisting of halide anions, nitrate anions, phosphate anions, carbonate anions, sulfate anions, acetate anions, alkoxide anions, etc. In certain embodiments, the coagulation bath comprises calcium chloride.

[0065] The salt and aerogel polymer can be combined in any weight ratio sufficient to at least partially solidify the aerogel polymer under wet spinning conditions. In certain embodiments, the salt and aerogel polymer are present in a weight ratio of 1:100-100:1, 1:9-9:1, 1:5-5:1, 1:4-4:1, 1:3-3:1, 2:3-3:2, 1:1-9:1, 3:2-9:1, 7:3-9:1, or 4:1-9:1, respectively. In certain embodiments, the salt and aerogel polymer are present in a weight ratio of about 8:1.

[0066] When the aerogel polymer comprises sodium alginate, oxidized cellulose, or a mixture thereof, the anionic moieties present in the aerogel polymer can be crosslinked in situ by the salt present in the coagulation bath, thereby crosslinking the aerogel polymer.

[0067] The spinning solution can be forced through the spinneret at a flow rate of 0.1 to 5, 0.5 to 5, 0.5 to 4.5, 1.0 to 4.0, 1.5 to 3.5, 2.0 to 3.5, 2.5 to 3.5, or 2.5 to 3.0 meters / minute. In certain embodiments, the spinning solution is forced through the spinneret at a rate of about 2.8 meters / minute.

[0068] The wet-drawing step can include drawing the filaments at a total draw ratio of 100-500%, 150-500%, 200-500%, 200-450%, 200-400%, 250-400%, 250-350%, or 300-350%. In certain embodiments, the wet-drawing step includes drawing the filaments at a total draw ratio of about 320%.

[0069] The wet drawing step can include drawing the filaments and can be carried out at a temperature of 30-60° C., 40-60° C., or 40-50° C. In certain embodiments, the wet drawing step can include drawing the filaments and can be carried out at a temperature of about 45° C.

[0070] The wet-stretched filaments are subjected to a freeze-drying process to form aerogel fibers. Freeze-drying can be achieved by reducing the temperature of the wet-stretched filaments (e.g., to -100°C to -20°C) and then reducing the pressure, which removes the liquid present in the wet-stretched filaments, thereby forming aerogel fibers. [Example]

[0071] Example 1 Aerogel fibers containing sodium alginate were prepared as follows. A 5% w / w aqueous solution of sodium alginate was wet-spun through a 70-micron diameter multifilament spinneret (500F) at 80°C with a flow rate of 2.8 m / min using a calcium chloride aqueous solution (10% w / w) as a coagulation bath at room temperature. Calcium chloride was used as a cross-linking agent for the sodium alginate. The resulting fibers were wet-drawn in water at 45°C to a total draw ratio of 320%. The fibers were then frozen at -80°C for 3 hours and freeze-dried for 48 hours to provide aerogel fibers with a fiber tenacity of 17.1 cN / tex and an elongation at break of 3.3% (determined according to GB / T4711-84), a fiber diameter of 18.81 microns (determined according to ASTM D2130-13), and a linear density of 1.57 denier (0.17 tex, determined according to ASTM D1577-07). Figure 1 provides a cross-sectional view of the fibers. In these SEM images, a nanoporous structure was observed, with pore sizes ranging from 100 to 250 nm.

[0072] In comparison, mercerized wool fibers have a diameter of 18 microns, a linear density of 3 denier (0.33 tex), a fiber tenacity of 1.99 cN / tex, and an elongation to break of 37.7%.

[0073] Example 2 A composite yarn containing 50% w / w of the aerogel fibers prepared in Example 1 was produced by blending mercerized wool fibers and aerogel fibers through a carding process. This was reinforced into strips on a folding machine. These strips were twisted into rovings at 30-40 turns per meter, which were then twisted at 610 turns per meter into a yarn with a yarn count of 26 Nm. Two yarns were twisted together and folded into a single yarn with a yarn count of 2 / 26 Nm, and steamed under pressure. The yarn was determined to have an average diameter of 316±10 microns.

[0074] Example 3 The single jersey knit fabric containing the composite yarn obtained in Example 2 was 0.035 m 2Thermal resistance in K / W (determined according to GB11048-89, Method A), Claw value of 0.23, and 343 g / m 2 In comparison, the single jersey knit fabric containing wool yarn of Comparative Example 2 had a basis weight of 0.03 m 2 K / W thermal resistance, 0.2 Claw value, and 485.9 g / m 2 The sheet had a basis weight of 1.0001.

[0075] Comparative Example 1 A 5% w / w aqueous sodium alginate solution (1 kg of dope solution containing 5% w / w sodium alginate) was wet-spun through a 70 micron diameter multifilament spinneret (500F) at 80°C with a flow rate of 2.8 m / min using an aqueous calcium chloride solution (4 kg of water containing 10% w / w calcium chloride) as a coagulation bath at room temperature. The resulting fiber was wet-drawn in water at 45°C to a total draw ratio of 320%. It was dried at 60°C to provide a fiber with a fiber tenacity of 19.5 cN / tex, an elongation to break of 3.3%, a fiber diameter of 23.06 microns, and a linear density of 0.31 tex.

[0076] Comparative Example 2 A wool yarn containing 100% w / w mercerized wool fibers was produced by a carding process. It was reinforced into strips by a folding machine. These strips were twisted into rovings at 30-40 turns per meter, which were then twisted at 650 turns per meter into a 20 Nm yarn. Two yarns were folded and twisted together into a single 2 / 20 Nm yarn and steamed under pressure. The measured average diameter of this yarn was 281±16 microns.

[0077] Comparative Example 3 A 5% w / w aqueous solution of sodium alginate was wet-spun at 80°C through a 70-micron diameter multifilament spinneret (500F) at a flow rate of 2.8 m / min using a calcium chloride aqueous solution (5% w / w) as a coagulation bath at room temperature. Calcium chloride was used as a cross-linking agent for the sodium alginate. The resulting fibers were wet-stretched in water at 45°C to a total draw ratio of 320%. The fibers were then frozen at -20°C for 3 hours and freeze-dried for 48 hours to provide aerogel fibers with a fiber tenacity of 20 cN / tex, an elongation at break of 3.22%, a fiber diameter of 20.18 microns, and a linear density of 0.25 tex. Figures 2-1 through 2-3 provide cross-sectional views of the fibers thus formed.

[0078] Comparative Example 4 A 5% w / w aqueous solution of sodium alginate was wet-spun at 80°C through a 70-micron diameter multifilament spinneret (500F) at a flow rate of 2.8 m / min using a calcium chloride aqueous solution (10% w / w) as a coagulation bath at room temperature. Calcium chloride was used as a cross-linking agent for the sodium alginate. The resulting fibers were wet-drawn in water at 45°C to a total draw ratio of 320%. These fibers were then frozen at -20°C for 3 hours and freeze-dried for 48 hours to provide aerogel fibers with a fiber tenacity of 18 cN / tex, an elongation at break of 3.38%, a fiber diameter of 19.37 microns, and a linear density of 0.24 tex. Figures 3-1 through 3-3 provide cross-sectional views of the fibers thus formed.

[0079] Comparative Example 5 A 5% w / w aqueous solution of sodium alginate was wet-spun at 80°C through a 70-micron diameter multifilament spinneret (500F) at a flow rate of 2.8 m / min using a calcium chloride aqueous solution (5% w / w) as a coagulation bath at room temperature. Calcium chloride was used as a cross-linking agent for the sodium alginate. The resulting fibers were wet-drawn in water at 45°C to a total draw ratio of 320%. These fibers were then frozen at -50°C for 3 hours and freeze-dried for 48 hours to provide aerogel fibers with a fiber tenacity of 20 cN / tex, an elongation at break of 3.15%, a fiber diameter of 17.92 microns, and a linear density of 0.25 tex. Figures 4-1 through 4-3 provide cross-sectional views of the fibers thus formed.

[0080] [Table 1]

Claims

1. 1. An aerogel fiber comprising an aerogel polymer, wherein the aerogel polymer is sodium alginate cross-linked with calcium chloride, the aerogel fiber having a linear density of 0.20 tex or less, a fiber tenacity of 5 to 20 cN / tex, an elongation at break of 3 to 20%, and an average diameter of 5 μm to 200 μm, and the aerogel fiber having a nanoporous structure including pores having an average diameter of 100 to 250 nm.

2. 10. The aerogel fiber of claim 1, wherein the aerogel fiber further comprises a hydrophobic alkylsilane, an aliphatic ester, or a combination thereof grafted to the outer surface of the aerogel fiber.

3. 10. The aerogel fiber of claim 1, wherein the aerogel fiber has an average diameter of 5 to 30 μm.

4. 10. The aerogel fiber of claim 1, wherein the aerogel fiber has a fiber tenacity of 15 to 20 cN / tex.

5. 10. The aerogel fiber of claim 1, wherein the aerogel fiber has a linear density of 0.1 to 0.2 tex.

6. The aerogel fiber of claim 1, wherein the aerogel fiber has a fiber tenacity of 15 to 20 cN / tex, an average diameter of 15 μm to 20 μm, a linear density of 0.15 to 0.2 tex, and the aerogel fiber contains pores with an average diameter of 100 to 250 nm.

7. A textile comprising the aerogel fiber of claim 1.

8. The textile of claim 7, wherein the aerogel fibers have a fiber tenacity of 15 to 20 cN / tex, an average diameter of 15 μm to 20 μm, and a linear density of 0.15 to 0.20 tex, and the aerogel fibers contain pores with an average diameter of 100 to 250 nm.

9. 8. The textile of claim 7, selected from the group consisting of staple fibers, yarns, fabrics, garments, linens, curtains, upholstery materials, and combinations thereof.

10. 8. The textile of claim 7, further comprising one or more additional fibers selected from the group consisting of natural fibers, synthetic fibers, semi-synthetic fibers, and combinations thereof.

11. 11. The textile of claim 10, wherein the aerogel fibers and the one or more additional fibers are present in the textile in a weight ratio of 1:9 to 9:

1.

12. 8. The textile of claim 7 further comprising wool.

13. 8. The textile of claim 7, further comprising wool, wherein the aerogel fibers and the wool are present in the textile in a mass ratio of 2:3 to 3:2, respectively.

14. 10. A method of preparing the aerogel fiber of claim 1, comprising: providing a spinning solution comprising the aerogel polymer; wet-spinning the spinning solution to form filaments comprising the aerogel polymer; wet-drawing the filaments to form wet-drawn filaments; and freeze-drying the wet-drawn filaments to form the aerogel fiber.

15. 15. The method of claim 14, wherein the step of wet-spinning the spinning solution comprises flowing the spinning solution through a multifilament spinneret at a flow rate of 0.1 to 5 meters per minute into a coagulation bath comprising calcium chloride.

16. 15. The method of claim 14, wherein the wet drawing step comprises drawing the filaments at a total draw ratio of 100 to 500% at 30 to 60°C.

17. 15. The method of claim 14, wherein wet-spinning the aerogel polymer comprises passing the solution through a multifilament spinneret of 50-100 microns in diameter at a temperature of 70-90°C and a flow rate of 2.5-3 meters / minute into a coagulation bath containing calcium chloride, and wet-drawing comprises drawing the filaments at a total draw ratio of 300-350% at 40-50°C.

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