High-resilience and hydrophobic aromatic polyamide aerogel fiber as well as preparation method and application thereof
Through the hydrophobic modification and annealing treatment of aromatic polyamide aerogel fiber, the problems of its resilience and water absorption collapse are solved, and the high resilience and hydrophobic fibers are achieved, which expands its potential in various application fields. .
Patent Information
- Application Number
- CN202411663770.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-20
- Publication Date
- 2025-01-03
AI Technical Summary
The existing aromatic polyamide aerogel fibers have poor elasticity, are prone to deformation under external forces and are difficult to recover, and their hydrophilicity leads to water absorption and collapse under normal temperature and pressure, limiting their application.
The aromatic polyamide aerogel fiber is surface modified and annealed to improve its elasticity and hydrophobicity.
Aromatic polyamide aerogel fiber with high resilience and surface hydrophobicity can be restored 100% after compression, bending and folding, and the surface water contact angle is between 90° and 160°. It is suitable for smart fabrics and wearable devices. and thermal insulation and other fields.
Smart Images
Figure CN119243474A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of nanoporous materials and functional fibers, and relates to an aromatic polyamide aerogel fiber, in particular to a highly resilient and hydrophobic aromatic polyamide aerogel fiber and a preparation method and application thereof. Background Art
[0002] In 2021, the 250th issue of Science, a top international academic journal, listed ten new materials that could change the world. Aerogels hold many world records and are ranked first among the top ten new materials. Aerogels play a huge role in thermal insulation, adsorption separation, sound absorption and noise reduction based on their unique properties such as extremely high porosity, extremely low density, high specific surface area and ultra-high pore volume. At present, research on aerogels mainly focuses on block or membrane materials. Due to their fragility and poor reprocessability, the development of aerogel materials has been seriously hindered. Aerogels are prepared into fibers, which not only maintain their aerogel properties, but also give them the characteristics of slender and soft fibers, which will further broaden the application areas of aerogel materials. Aerogel fibers have the advantages of easy large-scale preparation, excellent flexibility and reprocessability, and have development potential that cannot be underestimated in the fields of wearable devices, flexible devices, thermal insulation fabrics, smart fabrics and portable devices. Therefore, more and more researchers are focusing on aerogel fibers, especially aromatic polyamide aerogel fibers.
[0003] Aromatic polyamide aerogel fibers have the advantages of excellent thermal stability, ultra-high mechanical strength and low thermal conductivity, and are one of the most likely aerogel fibers to be used in practical applications. The resilience of aerogel fibers is the basis for ensuring durability and cyclic stability in practical applications. Due to the high porosity and high softness of aromatic polyamide aerogel fibers, aerogel fibers are easily squeezed or bent in practical applications, such as as thermal insulation fibers or smart fabrics. However, most aromatic polyamide aerogel fibers prepared by current methods have poor resilience. In addition, due to the presence of a large number of amide bonds in the aromatic polyamide structure, the surface wettability of aromatic polyamide aerogel fibers is hydrophilic (the static contact angle of water is about 65°), which means that they must be used in a dry and water-free environment. Otherwise, the porous structure of the aerogel is easy to absorb water at room temperature and pressure, causing the skeleton to shrink and collapse, and the specific surface area gradually decreases. Therefore, surface hydrophobic modification of aramid nano aerogel fibers is a necessary part of their practical application. Patent CN110468461A reports a polyamide aerogel fiber, which is obtained by dissolving polyamide in an organic solvent / strong alkali mixture for a long time to obtain polyamide nanofibers, and further using it as a spinning solution to obtain a polyamide aerogel fiber through spinning technology and drying technology. Patent CN 115522285 A reports an aromatic polyamide aerogel fiber, which is obtained by dissolving aromatic polyamide polymer in concentrated acid to obtain an aromatic polyamide molecular solution, and then obtaining an aromatic polyamide wet gel fiber through wet spinning and dry-jet wet spinning processes, and finally the aromatic polyamide wet gel fiber is subjected to solvent exchange and special drying to obtain an aromatic polyamide aerogel fiber. The above two patents do not further anneal the aerogel fiber, and the obtained aerogel fiber is compressed, bent, folded, and deformed under the action of external force. After radial loading and unloading, it cannot return to 100% of its original appearance after the external force disappears, and it is easy to cause irreversible deformation in the radial direction of the aerogel fiber, which hinders its practical application. In addition, the high-performance polymer fiber-based aerogel fiber reported in patent CN 116815357 A and the superelastic aramid nanofiber aerogel reported in patent CN 114907609 A both mention high-temperature treatment of aerogels, but the effect of high-temperature treatment on the radial resilience of aerogel fibers is not described in the patents, and the above two patents do not further perform surface hydrophobic treatment on aramid aerogels, which will cause the mesoporous structure to easily absorb water and collapse in practical applications and be not resistant to water washing, resulting in poor durability and cyclic stability. The preparation of aromatic polyamide aerogel fibers with resilience and surface hydrophobicity is of great significance for their practical application.
[0004] More importantly, it is found in the practice of technicians in this field that it is more difficult to achieve surface hydrophobicity for aromatic polyamide aerogel fibers that have been thermally annealed than for aromatic polyamide aerogel fibers that have not been annealed. This is mainly because the high-temperature heat treatment almost removes the oxygen-containing functional groups on the surface of aromatic polyamide, which makes it difficult for some hydrophobic modifiers to combine with aromatic polyamide through chemical or physical effects. In summary, it is challenging to prepare aromatic polyamide aerogel fibers with resilience and hydrophobic surface, and such aromatic polyamide aerogel fibers with resilience and hydrophobic surface have a necessity and importance that cannot be ignored in practical applications. Summary of the invention
[0005] The main purpose of the present invention is to provide a highly resilient and hydrophobic aromatic polyamide aerogel fiber and a preparation method thereof, so as to solve the thorny problem that the aromatic polyamide aerogel fiber, due to its hydrophilicity, has a porous structure that easily absorbs water at room temperature and pressure, causing skeleton shrinkage and collapse.
[0006] Another object of the present invention is to provide an application of the highly resilient and hydrophobic aromatic polyamide aerogel fiber.
[0007] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes: The embodiment of the present invention provides a method for preparing a highly resilient and hydrophobic aromatic polyamide aerogel fiber, which comprises: The surface of aromatic polyamide aerogel fiber is modified by using a hydrophobic modifier to obtain modified aromatic polyamide aerogel fiber; The modified aromatic polyamide aerogel fiber is annealed to obtain highly resilient and hydrophobic aromatic polyamide aerogel fiber.
[0008] In some embodiments, the hydrophobic modifier includes any one of fluorocarbon resin, silane compound, and silane polymer, or a combination of two or more thereof.
[0009] In some embodiments, the heating rate of the annealing treatment is 1°C / min~20°C / min, the maximum temperature is maintained at 150~650°C, the annealing time is 1min~10h, and the cooling rate is 1°C / min~20°C / min.
[0010] The embodiment of the present invention also provides a highly resilient and hydrophobic aromatic polyamide aerogel fiber prepared by the above-mentioned preparation method.
[0011] Furthermore, the high-resilience and hydrophobic aromatic polyamide aerogel fiber has high resilience, and can recover 100% after being compressed, bent, and folded. The radial maximum compression rebound limit of the high-resilience and hydrophobic aromatic polyamide aerogel fiber is 1 to 99%; the surface wettability of the high-resilience and hydrophobic aromatic polyamide aerogel fiber is hydrophobic, and the static contact angle of water is 90° to 160°.
[0012] The embodiments of the present invention also provide applications of the highly resilient and hydrophobic aromatic polyamide aerogel fiber in the fields of smart fabrics, wearable devices, human thermal management, environmental management, sensing, sound absorption and noise reduction, thermal insulation or fiber flakes.
[0013] Compared with the prior art, the beneficial effects of the present invention include at least: 1) The highly resilient and hydrophobic aromatic polyamide aerogel fiber prepared by the present invention has excellent resilience and surface hydrophobicity compared to the aromatic polyamide aerogel fiber prepared by the previous technology. While achieving resilience, it can also achieve surface hydrophobicity; 2) The highly resilient and hydrophobic aromatic polyamide aerogel fiber provided by the present invention has a unique three-dimensional porous network structure, low thermal conductivity, high porosity, high tensile strength and elongation at break, excellent skeleton structure stability, water washability and self-cleaning ability, and can meet practical applications, such as textile and other fields; 3) The preparation method provided by the present invention can obtain highly resilient and hydrophobic aromatic polyamide aerogel fibers, which fills the gap in the research of aromatic polyamide aerogel fibers and promotes the practical application of aromatic polyamide aerogel fibers in the fields of smart fabrics, wearable devices, thermal insulation and fiber flakes. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0015] Figure 1 is a digital photo of the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained in Example 1 of the present invention; Figure 2a and Figure 2b They are respectively nitrogen adsorption-desorption curves of the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained in Example 1 of the present invention; Figure 3Schematic diagram of radial loading-unloading of the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained in Example 1 of the present invention; Figure 4 is a water contact angle diagram of the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained in Example 1 of the present invention; Figure 5 is a radial compression cycle diagram of the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained in Example 2 of the present invention; Figure 6 is a microscopic morphology of the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained in Example 3 of the present invention; Figure 7 is a thermogravimetric curve of the highly resilient and hydrophobic aromatic polyamide hydrogel fiber obtained in Example 4 of the present invention; Figure 8 is a microscopic morphology of the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained in Example 5 of the present invention; Fig. 9 is a water contact angle diagram of the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained in Example 6 of the present invention; Fig.10 is a water contact angle diagram of the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained in Example 7 of the present invention; Fig.11 is a water contact angle diagram of the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained in Example 8 of the present invention; Fig.12 is a water contact angle diagram of the aromatic polyamide aerogel fiber obtained in Comparative Example 1 of the present invention; Fig.13 is a water contact angle diagram of the aromatic polyamide aerogel fiber obtained in Comparative Example 2 of the present invention; Fig.14 This is a compression test diagram of the aromatic polyamide aerogel fiber obtained in Comparative Example 3 of the present invention. DETAILED DESCRIPTION
[0016] In view of the deficiencies in the prior art, in order to solve the thorny problems that aromatic polyamide aerogel fibers have poor resilience, the obtained aerogel fibers are compressed, bent, folded, etc. under the action of external forces, and cannot return to 100% of their original appearance after the external force disappears, and are prone to irreversible deformation, resulting in their inability to be applied, the inventor of this case has proposed the technical solution of the present invention after long-term research and extensive practice, which mainly provides an aromatic polyamide aerogel fiber with resilience and surface hydrophobicity and a preparation method thereof, which can achieve both resilience and surface hydrophobicity. The technical solution, its implementation process and principle, etc. will be further explained as follows.
[0017] As one aspect of the technical solution of the present invention, a method for preparing a highly resilient and hydrophobic aromatic polyamide aerogel fiber includes: The surface of aromatic polyamide aerogel fiber is modified by using a hydrophobic modifier to obtain modified aromatic polyamide aerogel fiber; The modified aromatic polyamide aerogel fiber is annealed to obtain highly resilient and hydrophobic aromatic polyamide aerogel fiber.
[0018] In some embodiments, the hydrophobic modifier may include any one or a combination of two of fluorocarbon resin, silane compound, etc., but is not limited thereto.
[0019] In some more preferred embodiments, the fluorocarbon resin includes any one or a combination of two or more of polytetrafluoroethylene series resins, polyvinylidene fluoride series resins, alternating copolymer resins of fluoroolefins and alkyl vinyl ethers, and chlorotrifluoroethylene copolymer series resins, but is not limited thereto.
[0020] In some more preferred embodiments, the silane compound includes any one or a combination of two or more of trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, trimethoxysilane, dimethyldiethoxysilane, trimethylethoxysilane, γ-aminopropyltriethoxysilane, vinyltrimethoxysilane, vinylmethyldiethoxysilane, octamethylcyclotetrasiloxane, tridecafluorooctyltriethoxysilane, perfluorooctyltrimethoxysilane, silane polymers, etc., but is not limited thereto.
[0021] In some more preferred embodiments, the silane-based polymer may include any one or a combination of two or more of silane-modified polyether, silane-modified polyurethane, polydimethylsiloxane, silicone resin, etc., but is not limited thereto.
[0022] In some embodiments, the surface modification treatment includes any one or a combination of two or more of chemical vapor deposition technology, cold plasma treatment technology, surface immersion coating technology, etc., but is not limited thereto.
[0023] In some embodiments, the heating rate of the annealing treatment is 1°C / min~20°C / min, the maximum temperature is maintained at 150~650°C, the annealing time is 1min~10h, and the cooling rate is 1°C / min~20°C / min.
[0024] In some embodiments, the annealing treatment is performed in a protective atmosphere, and the protective gas used to form the protective atmosphere may include any one or a combination of two or more of nitrogen, argon, helium, and carbon dioxide, but is not limited thereto.
[0025] In some embodiments, the preparation method specifically comprises: The aromatic polyamide spinning solution is subjected to a spinning technology to obtain aromatic polyamide wet gel fibers; The aromatic polyamide wet gel fiber is dried to obtain the aromatic polyamide aerogel fiber.
[0026] In some more preferred embodiments, the method for preparing the highly resilient and hydrophobic aromatic polyamide aerogel fiber comprises the following steps: Firstly, aromatic polyamide spinning solution is used to obtain aromatic polyamide wet gel fiber through spinning technology; Then, the aromatic polyamide wet gel fiber is dried to obtain the aromatic polyamide aerogel fiber; The surface wettability of the aromatic polyamide aerogel fiber is modified again by a surface modification process using a hydrophobic modifier; Finally, the aromatic polyamide aerogel fiber is annealed to obtain highly resilient and hydrophobic aromatic polyamide aerogel fiber.
[0027] In some embodiments, the aromatic polyamide spinning solution includes an aromatic polyamide molecular solution consisting of aromatic polyamide and concentrated sulfuric acid.
[0028] Furthermore, the concentration of the aromatic polyamide spinning solution is 0.1-20 wt %. Preferably, the concentration of the aromatic polyamide spinning solution is 1-10 wt %.
[0029] In other embodiments, the aromatic polyamide spinning solution includes a homogeneous aromatic polyamide nanofiber dispersion formed from aromatic polyamide, an organic solvent and a base.
[0030] In some embodiments, the aromatic polyamide may include any one or a combination of two or more of all-para aromatic polyamide, all-para aromatic polyamide copolymer, all-meta aromatic polyamide, meta aromatic amide copolymer containing methyl substituents, etc., but is not limited thereto.
[0031] In some preferred embodiments, the aromatic polyamide may include any one or a combination of two or more of poly(p-phenylene terephthalamide), poly(m-phenylene isophthalamide), poly(p-phenylene terephthalamide), poly(s-phenylene terephthalamide), poly(p-phenylene terephthalamide-co-o-phenylene terephthalamide), etc., but is not limited thereto.
[0032] In some more preferred embodiments, the aromatic polyamide may be any one or a combination of two or more of Kevlar, Nomex, Technora, Twaron, Terlon and Taparan, but is not limited thereto.
[0033] In some embodiments, the organic solvent may include any one or a combination of two or more of dimethyl sulfoxide, cyclopentane, dibutyl sulfone, diethyl sulfone, ethyl methyl sulfone, N,N-dimethylformamide, N,N-dimethylacetamide, etc., but is not limited thereto.
[0034] In some embodiments, the base may include any one or a combination of two or more of sodium hydroxide, potassium hydroxide, sodium tert-butoxide, potassium tert-butoxide, sodium amide, lithium amide, lithium chloride, calcium chloride, etc., but is not limited thereto.
[0035] In some embodiments, the spinning technology may include any one or a combination of two or more of gel spinning technology, wet spinning technology, dry spinning technology, dry-jet wet spinning technology, dry-freeze spinning technology, 3D printing technology, mold filamentation technology, coaxial wet spinning technology, coaxial 3D printing technology, coaxial dry-freeze spinning technology, etc., but is not limited to these.
[0036] Furthermore, the spinning technology is wet spinning technology and / or coaxial wet spinning technology.
[0037] In some more preferred embodiments, the wet spinning technology includes: providing an aromatic polyamide spinning solution of selected concentration, and extruding the aromatic polyamide spinning solution into a coagulation bath through a spinneret or a dispensing needle to form aromatic polyamide wet gel fibers.
[0038] Furthermore, the process conditions adopted by the wet spinning technology are: the concentration of the aromatic polyamide spinning solution is 0.1~20wt%, the diameter of the extrusion needle is 10~5000 μm, and the extrusion speed is 5~5000 μL / min.
[0039] In some more preferred embodiments, the coaxial wet spinning technology includes: providing an aromatic polyamide spinning solution of a selected concentration as the first spinning solution (also referred to as spinning solution A), using a coagulation bath as the second spinning solution (also referred to as spinning solution B), and simultaneously extruding the first spinning solution (also referred to as spinning solution A) and the second spinning solution (also referred to as spinning solution B) into the coagulation bath through a hollow spinneret or a coaxial needle to obtain aromatic polyamide wet gel fibers.
[0040] Furthermore, the process conditions adopted by the coaxial wet spinning technology are: the concentration of the aromatic polyamide spinning solution is 0.1~20wt%, the extrusion speed of the first spinning solution is 5~5000 μL / min, and the extrusion speed of the second spinning solution is 5~5000 μL / min.
[0041] Furthermore, the inner needle model of the coaxial needle is 10G-30G, and the outer needle model of the coaxial needle is 8G-28G.
[0042] In some more preferred embodiments, the coagulation bath includes a main component and an auxiliary component, the main component includes any one or a combination of two or more of water, ethanol, acetone, dimethyl sulfoxide, nitrogen methyl pyrrolidone, ethyl acetate, dimethyl silicone oil, N,N-dimethylformamide, etc.; the auxiliary component includes any one or a combination of two or more of sulfuric acid, hydrochloric acid, ascorbic acid, calcium chloride, ferric chloride, etc., but is not limited to these.
[0043] In some preferred embodiments, the mass ratio of the main component to the auxiliary component is 1:0~1:99.
[0044] In some more preferred embodiments, the preparation method comprises: first replacing the non-drying solvent in the aromatic polyamide wet gel fiber with an easy-drying solvent, and then drying the replaced aromatic polyamide wet gel fiber.
[0045] Furthermore, the easy-to-dry solvent may include any one or a combination of two or more of water, methanol, ethanol, tert-butyl alcohol, acetone, propylene glycol, isopropyl alcohol, etc., but is not limited thereto.
[0046] In some embodiments, the drying process includes any one or a combination of two or more of supercritical fluid drying, vacuum freeze drying, and reduced pressure drying, but is not limited thereto.
[0047] In some embodiments, the aromatic polyamide aerogel fibers include any one or a combination of two or more of aerogel fibers and non-aerogel fibers, but are not limited thereto.
[0048] In summary, the preparation process of the aromatic polyamide aerogel fiber provided by the embodiment of the present invention is simple, the reaction conditions are mild, controllable, low energy consumption, green and pollution-free, suitable for large-scale production, and has broad application prospects. Because giving aromatic polyamide aerogel fibers resilience and surface hydrophobicity is of considerable necessity and importance in practical applications, it is also challenging to prepare aramid aerogel fibers with resilience and surface hydrophobicity.
[0049] As another aspect of the technical solution of the present invention, it relates to a highly resilient and hydrophobic aromatic polyamide aerogel fiber prepared by the above method.
[0050] In some embodiments, the high-resilience and hydrophobic aromatic polyamide aerogel fiber has high resilience and can recover 100% after being deformed by compression, bending, folding, etc. The radial maximum compression rebound limit of the high-resilience and hydrophobic aromatic polyamide aerogel fiber is 1 to 99%.
[0051] Furthermore, the surface wettability of the highly resilient and hydrophobic aromatic polyamide aerogel fiber is hydrophobic, and the static contact angle between the surface and water is 90° to 160°.
[0052] In some embodiments, the high resilience and hydrophobic aromatic polyamide aerogel fiber has a tensile strength of 0.1-300 MPa and an elongation at break of 1-80%.
[0053] In some embodiments, the highly resilient and hydrophobic aromatic polyamide aerogel fiber includes a continuous three-dimensional multilevel porous network structure formed by overlapping aromatic polyamide nanofibers, and the three-dimensional multilevel porous network structure includes micropores with a pore size of less than 2 nm, mesopores with a pore size of 2 to 50 nm, and macropores with a pore size of 50 nm to 100 nm.
[0054] In some embodiments, the density of the highly resilient and hydrophobic aromatic polyamide aerogel fiber is 0.001-1 g / cm 3 The porosity is 1.0~99.9%, and the specific surface area is 1~1000 m 2 / g. The highly resilient and hydrophobic aromatic polyamide aerogel fiber provided by the present invention has a unique three-dimensional porous network structure, low thermal conductivity, high porosity, high tensile strength and elongation at break, excellent skeleton structure stability, water washability and self-cleaning ability, and can meet practical applications, such as in the textile and other fields.
[0055] As another aspect of the technical solution of the present invention, it also relates to the application of the highly resilient and hydrophobic aromatic polyamide aerogel fiber.
[0056] Furthermore, the highly resilient and hydrophobic aromatic polyamide aerogel fiber prepared by the present invention has excellent resilience and surface hydrophobicity compared to the aromatic polyamide aerogel fiber prepared by the previous technology, and can achieve surface hydrophobicity while achieving resilience.
[0057] The preparation method provided by the present invention can obtain highly resilient and hydrophobic aromatic polyamide aerogel fibers, which fills the gap in the research of aromatic polyamide aerogel fibers and promotes the practical application of aromatic polyamide aerogel fibers in the fields of smart fabrics, wearable devices, thermal insulation, and fiber flakes.
[0058] Furthermore, an embodiment of the present invention also provides the application of the aforementioned high resilience and hydrophobic aromatic polyamide aerogel fiber in the fields of preparing smart fabrics, wearable devices, human thermal management, environmental governance, sensing, sound absorption and noise reduction, thermal insulation and fiber flakes.
[0059] The technical scheme of the present invention is further described in detail below in conjunction with several preferred embodiments and the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work belong to the scope of protection of the present invention. The experimental methods in the following embodiments that do not specify specific conditions are usually carried out under conventional conditions or under conditions recommended by the manufacturer.
[0060] Example 1 (1) A 5.0 wt% aromatic polyamide spinning solution was used to obtain hollow aromatic polyamide wet gel fibers by a coaxial wet spinning method. Specifically, a mixed solution of 5.0 wt% Kevlar, DMSO, and potassium hydroxide was used as spinning solution A, and water was used as spinning solution B. The spinning solution A and the spinning solution B were simultaneously extruded into a water coagulation bath through a coaxial needle (inner 19G-outer 14G) at an extrusion rate of 600 μL / min to obtain hollow aromatic polyamide wet gel fibers.
[0061] (2) The hollow aromatic polyamide wet gel fiber of step (1) is subjected to solvent replacement (the easily dry solvent used is ethanol), and then supercritical drying is performed to obtain the hollow aromatic polyamide aerogel fiber.
[0062] (3) The hollow aromatic polyamide aerogel fiber of step (2) is subjected to hydrophobic modification by cold plasma, specifically, the hollow aromatic polyamide aerogel fiber is placed in a chamber, and vacuumized, filled with argon, discharged and activated, filled with gasified octamethylcyclotetrasiloxane for modification, and the sample is taken out to obtain the hydrophobic hollow aromatic polyamide aerogel fiber.
[0063] (4) The hydrophobic hollow aromatic polyamide aerogel fiber prepared in step (3) was annealed at 350°C for 50 min in a nitrogen atmosphere with a heating rate of 5°C / min and a cooling rate of 20°C / min to obtain a highly resilient and hydrophobic hollow aromatic polyamide aerogel fiber.
[0064] After the above steps, the physical picture of the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained in this embodiment is shown in FIG1 , and the nitrogen adsorption-desorption curve and pore size distribution diagram of the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained in this embodiment are shown in FIG1 . Figure 2a and Figure 2bAs shown in the figure, the compression resilience of the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained in this embodiment is shown in Figure 3 As shown in the figure, the water contact angle test diagram of the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained in this embodiment is as follows Figure 4 shown.
[0065] Example 2 (1) A 3.0 wt% aromatic polyamide spinning solution was used to obtain hollow aromatic polyamide wet gel fibers by a coaxial wet spinning method. Specifically, a mixed solution of 3.0 wt% Kevlar, DMSO, and potassium hydroxide was used as spinning solution A, and water was used as spinning solution B. The spinning solution A and the spinning solution B were simultaneously extruded into a water coagulation bath through a coaxial needle (inner 21G-outer 16G) at an extrusion rate of 400 μL / min to obtain hollow aromatic polyamide wet gel fibers.
[0066] (2) After the hollow aromatic polyamide wet gel fiber of step (1) is subjected to solvent replacement (the easily dry solvent used is water), the hollow aromatic polyamide aerogel fiber is obtained by vacuum freeze drying.
[0067] (3) The hollow aromatic polyamide aerogel fiber of step (2) is subjected to hydrophobic modification by cold plasma, specifically, the hollow aromatic polyamide aerogel fiber is placed in a chamber, and vacuumized, filled with argon, discharged and activated, filled with vaporized trimethoxysilane for modification, and the sample is taken out to obtain the hydrophobic hollow aromatic polyamide aerogel fiber.
[0068] (4) The hydrophobic hollow aromatic polyamide aerogel fiber prepared in step (3) was annealed at 350°C for 50 min in a nitrogen atmosphere with a heating rate of 10°C / min and a cooling rate of 10°C / min to obtain a highly resilient and hydrophobic hollow aromatic polyamide aerogel fiber.
[0069] After the above steps, the radial compression cycle of the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained in this embodiment is as follows: Figure 5 shown.
[0070] Example 3 (1) Aromatic polyamide wet gel fibers were obtained by wet spinning a 0.5 wt% aromatic polyamide spinning solution. Specifically, a 0.5 wt% Kevlar sulfuric acid solution was extruded through a spinning needle with a diameter of 500 μm at an extrusion rate of 200 μL / min and then entered into a deionized water coagulation bath to obtain aromatic polyamide wet gel fibers.
[0071] (2) The aromatic polyamide wet gel fiber of step (1) is subjected to solvent replacement (the easily dry solvent used is acetone), and then supercritical drying is performed to obtain aromatic polyamide aerogel fiber.
[0072] (3) The aromatic polyamide aerogel fiber of step (2) is subjected to hydrophobic modification by cold plasma, specifically, the aromatic polyamide aerogel fiber is placed in a chamber, and vacuumized, filled with argon, discharged and activated, filled with gasified octamethylcyclotetrasiloxane for modification, and the sample is taken out to obtain the hydrophobic aromatic polyamide aerogel fiber.
[0073] (4) The hydrophobic aromatic polyamide aerogel fiber prepared in step (3) is annealed at 400°C for 30 min in an argon atmosphere with a heating rate of 5°C / min and a cooling rate of 5°C / min to obtain a highly resilient and hydrophobic aromatic polyamide aerogel fiber.
[0074] After the above steps, the microscopic morphology of the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained in this embodiment is as follows: Figure 6 shown.
[0075] Example 4 (1) Aromatic polyamide wet gel fibers were obtained by wet spinning a 7 wt% aromatic polyamide spinning solution. Specifically, a mixed solution of 7 wt% Kevlar, DMSO, and potassium tert-butoxide was extruded through a spinning needle with a diameter of 300 μm at an extrusion rate of 300 μL / min and then entered into an ethanol coagulation bath to obtain aromatic polyamide wet gel fibers.
[0076] (2) The aromatic polyamide wet gel fiber of step (1) is subjected to solvent replacement (the easily dry solvent used is tert-butyl alcohol), and then the aromatic polyamide aerogel fiber is obtained by reduced pressure drying.
[0077] (3) The aromatic polyamide aerogel fiber of step (2) is subjected to hydrophobic modification by a vapor deposition method. Specifically, the aromatic polyamide aerogel fiber is placed in a chamber, and vacuumized, filled with argon, filled with vaporized perfluorooctyltrimethoxysilane for modification, and the sample is taken out to obtain the hydrophobic aromatic polyamide aerogel fiber.
[0078] (4) The hydrophobic aromatic polyamide aerogel fiber prepared in step (3) is annealed at 300°C for 120 min in an argon atmosphere, with a heating rate of 3°C / min and a cooling rate of 20°C / min to obtain a highly resilient and hydrophobic aromatic polyamide aerogel fiber.
[0079] After the above steps, the thermal weight loss curve of the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained in this embodiment is as follows: Figure 7 shown.
[0080] Example 5 (1) A 5.0 wt% aromatic polyamide spinning solution was used to obtain hollow aromatic polyamide wet gel fibers by a coaxial wet spinning method. Specifically, a 5.0 wt% Kevlar sulfuric acid solution was used as spinning solution A, and ethanol was used as spinning solution B. The spinning solution A and the spinning solution B were simultaneously extruded into a water coagulation bath through a coaxial needle (inner 18G-outer 14G) at an extrusion rate of 1000 μL / min to obtain hollow aromatic polyamide wet gel fibers.
[0081] (2) The hollow aromatic polyamide wet gel fiber of step (1) is subjected to solvent replacement (the easily dry solvent used is ethanol), and then supercritical drying is performed to obtain the hollow aromatic polyamide aerogel fiber.
[0082] (3) The hollow aromatic polyamide aerogel fiber of step (2) is subjected to hydrophobic modification by cold plasma, specifically, the hollow aromatic polyamide aerogel fiber is placed in a chamber, and vacuumized, filled with argon, discharged and activated, filled with vaporized trimethoxysilane for modification, and the sample is taken out to obtain the hydrophobic hollow aromatic polyamide aerogel fiber.
[0083] (4) The hydrophobic hollow aromatic polyamide aerogel fiber prepared in step (3) was annealed at 500°C for 10 min in a nitrogen atmosphere, with a heating rate of 5°C / min and a cooling rate of 20°C / min to obtain a high-resilience and hydrophobic hollow aromatic polyamide aerogel fiber.
[0084] After the above steps, the microscopic morphology of the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained in this embodiment is as follows: Figure 8 shown.
[0085] Example 6 (1) Aromatic polyamide wet gel fibers were obtained by wet spinning a 4 wt% aromatic polyamide spinning solution. Specifically, a mixed solution of 4 wt% Kevlar, DMSO, and potassium tert-butoxide was extruded through a spinning needle with a diameter of 500 μm at an extrusion rate of 500 μL / min and then entered into a water coagulation bath to obtain aromatic polyamide wet gel fibers.
[0086] (2) The aromatic polyamide wet gel fiber of step (1) is subjected to solvent replacement (the easily dry solvent used is methanol), and then aromatic polyamide aerogel fiber is obtained by supercritical drying.
[0087] (3) The aromatic polyamide aerogel fiber of step (2) is hydrophobically modified by using a PDMS surface coating. Specifically, the aromatic polyamide aerogel fiber is placed in a mixed solution of 1 wt% PDMS monomer, a crosslinking agent, and n-hexane. After soaking for a period of time, the aromatic polyamide aerogel fiber is placed in an 80° C. vacuum oven and dried for 4 hours. The sample is taken out to obtain a hydrophobic aromatic polyamide aerogel fiber.
[0088] (4) The hydrophobic aromatic polyamide aerogel fiber prepared in step (3) is annealed at 400°C for 30 min in an argon atmosphere with a heating rate of 5°C / min and a cooling rate of 10°C / min to obtain a highly resilient and hydrophobic aromatic polyamide aerogel fiber.
[0089] After the above steps, the water contact angle test of the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained in this embodiment is as follows: Fig. 9 shown.
[0090] Example 7 (1) A 3.0 wt% aromatic polyamide spinning solution was used to obtain hollow aromatic polyamide wet gel fibers by a coaxial wet spinning method. Specifically, a mixed solution of 3.0 wt% Kevlar, DMSO, and potassium tert-butoxide was used as spinning solution A, and water was used as spinning solution B. The spinning solution A and the spinning solution B were simultaneously extruded into a water coagulation bath through a coaxial needle (inner 21G-outer 16G) at an extrusion rate of 400 μL / min to obtain hollow aromatic polyamide wet gel fibers.
[0091] (2) The aromatic polyamide wet gel fiber of step (1) is subjected to solvent replacement (the easily dry solvent used is isopropanol), and then the aromatic polyamide aerogel fiber is obtained by vacuum freeze drying.
[0092] (3) The aromatic polyamide aerogel fiber of step (2) is hydrophobically modified by using a PDMS surface coating. Specifically, the aromatic polyamide aerogel fiber is placed in a mixed solution of PDMS monomer, crosslinking agent, and n-hexane. After soaking for a period of time, the aromatic polyamide aerogel fiber is placed in a vacuum oven at 80° C. and dried for 4 hours. The sample is taken out to obtain a hydrophobic aromatic polyamide aerogel fiber.
[0093] (4) The hydrophobic aromatic polyamide aerogel fiber prepared in step (3) was annealed at 150° C. for 10 h in an argon atmosphere with a heating rate of 1° C. / min and a cooling rate of 1° C. / min to obtain a highly resilient and hydrophobic aromatic polyamide aerogel fiber.
[0094] After the above steps, the water contact angle test of the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained in this embodiment is as follows: Fig.10 shown.
[0095] Example 8 (1) 8.0 wt% aromatic polyamide spinning solution was used to obtain hollow aromatic polyamide wet gel fibers by a coaxial wet spinning method. Specifically, a mixed solution of 8.0 wt% Kevlar, DMSO, and potassium tert-butoxide was used as spinning solution A, and water was used as spinning solution B. The spinning solution A and the spinning solution B were simultaneously extruded into a water coagulation bath through a coaxial needle (inner 15G-outer 10G) at an extrusion rate of 2000 μL / min to obtain hollow aromatic polyamide wet gel fibers.
[0096] (2) The hollow aromatic polyamide wet gel fiber of step (1) is subjected to solvent replacement (the easily dry solvent used is propylene glycol), and then vacuum freeze-dried to obtain the hollow aromatic polyamide aerogel fiber.
[0097] (3) The hollow aromatic polyamide aerogel fiber of step (2) is subjected to hydrophobic modification by cold plasma, specifically, the hollow aromatic polyamide aerogel fiber is placed in a chamber, and vacuumized, filled with argon, discharged and activated, filled with gasified octamethylcyclotetrasiloxane for modification, and the sample is taken out to obtain the hydrophobic hollow aromatic polyamide aerogel fiber.
[0098] (4) The hydrophobic hollow aromatic polyamide aerogel fiber prepared in step (3) was annealed at 650°C for 1 min in a nitrogen atmosphere, with a heating rate of 20°C / min and a cooling rate of 20°C / min to obtain a high-resilience and hydrophobic hollow aromatic polyamide aerogel fiber.
[0099] After the above steps, the water contact angle test of the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained in this embodiment is as follows: Fig.11 shown.
[0100] Example 9 Aromatic polyamide wet gel fiber was obtained by wet spinning 20 wt% aromatic polyamide spinning solution. Specifically, a mixed solution of 20 wt% poly(m-phenylene isophthalamide), cyclopentane sulfone and lithium amide was extruded through a spinning needle with a diameter of 5000 μm at an extrusion rate of 5000 μL / min and then entered into an ethanol coagulation bath to obtain aromatic polyamide wet gel fiber.
[0101] (2) The aromatic polyamide wet gel fiber of step (1) is subjected to solvent replacement (the easily dry solvent used is tert-butyl alcohol), and then vacuum freeze-dried to obtain aromatic polyamide aerogel fiber.
[0102] (3) The aromatic polyamide aerogel fiber of step (2) is subjected to hydrophobic modification by cold plasma, specifically, the aromatic polyamide aerogel fiber is placed in a chamber, and vacuumized, filled with argon, discharged and activated, filled with vaporized vinyltrimethoxysilane for modification, and the sample is taken out to obtain the hydrophobic aromatic polyamide aerogel fiber.
[0103] (4) The hydrophobic aromatic polyamide aerogel fiber prepared in step (3) is annealed at 350°C for 50 min in a helium atmosphere with a heating rate of 10°C / min and a cooling rate of 10°C / min to obtain a highly resilient and hydrophobic aromatic polyamide aerogel fiber.
[0104] Example 10 (1) A 0.1 wt% aromatic polyamide spinning solution was subjected to a coaxial wet spinning method to obtain hollow aromatic polyamide wet gel fibers. Specifically, a mixed solution of 0.1 wt% poly(phenylene terephthalamide), ethyl methyl sulfone, and sodium hydroxide was extruded through a spinning needle with a diameter of 10 μm at an extrusion rate of 5 μL / min and then entered into an acetone coagulation bath to obtain aromatic polyamide wet gel fibers.
[0105] (2) The aromatic polyamide wet gel fiber of step (1) is subjected to solvent replacement (the easily dry solvent used is tert-butyl alcohol), and then vacuum freeze-dried to obtain aromatic polyamide aerogel fiber.
[0106] (3) The aromatic polyamide aerogel fiber of step (2) is subjected to hydrophobic modification by using polytetrafluoroethylene resin. Specifically, the aromatic polyamide aerogel fiber is immersed in polytetrafluoroethylene resin, and a sample is taken out to obtain a hydrophobic aromatic polyamide aerogel fiber.
[0107] (4) The hydrophobic aromatic polyamide aerogel fiber prepared in step (3) is annealed at 350°C for 50 min in a carbon dioxide atmosphere, with a heating rate of 10°C / min and a cooling rate of 10°C / min to obtain a highly resilient and hydrophobic aromatic polyamide aerogel fiber.
[0108] Embodiment 11 (1) A 1.0 wt% aromatic polyamide spinning solution was used to obtain hollow aromatic polyamide wet gel fibers by a coaxial wet spinning method. Specifically, a mixed solution of 1.0 wt% Technora, N,N-dimethylformamide and lithium chloride was used as spinning solution A, and a 5% calcium chloride aqueous solution was used as spinning solution B. The spinning solution A and the spinning solution B were simultaneously extruded into a 5% calcium chloride aqueous solution coagulation bath through a coaxial needle (inner 18G-outer 14G) at an extrusion speed of 1000 μL / min to obtain hollow aromatic polyamide wet gel fibers.
[0109] (2) The hollow aromatic polyamide wet gel fiber of step (1) is subjected to solvent replacement (the easily dry solvent used is ethanol), and then supercritical drying is performed to obtain the hollow aromatic polyamide aerogel fiber.
[0110] (3) The hollow aromatic polyamide aerogel fiber of step (2) is subjected to hydrophobic modification by cold plasma, specifically, the hollow aromatic polyamide aerogel fiber is placed in a chamber, and vacuumized, filled with argon, discharged and activated, filled with gasified tridecafluorooctyl triethoxysilane for modification, and the sample is taken out to obtain the hydrophobic hollow aromatic polyamide aerogel fiber.
[0111] (4) The hydrophobic hollow aromatic polyamide aerogel fiber prepared in step (3) was annealed at 500°C for 10 min in a nitrogen atmosphere, with a heating rate of 5°C / min and a cooling rate of 20°C / min to obtain a high-resilience and hydrophobic hollow aromatic polyamide aerogel fiber.
[0112] Example 12 (1) A 3 wt% aromatic polyamide spinning solution was subjected to a coaxial wet spinning method to obtain hollow aromatic polyamide wet gel fibers. Specifically, a mixed solution of 3 wt% Kevlar, dimethyl sulfoxide, and potassium tert-butoxide was extruded through a spinning needle with a diameter of 300 μm at an extrusion rate of 200 μL / min and then entered into a water coagulation bath to obtain aromatic polyamide wet gel fibers.
[0113] (2) The aromatic polyamide wet gel fiber of step (1) is subjected to solvent replacement (the easily dry solvent used is tert-butyl alcohol), and then vacuum freeze-dried to obtain aromatic polyamide aerogel fiber.
[0114] (3) The aromatic polyamide aerogel fiber of step (2) is hydrophobically modified by using a polyvinylidene fluoride series resin. Specifically, the aromatic polyamide aerogel fiber is immersed in the polyvinylidene fluoride series resin, and a sample is taken out to obtain a hydrophobic aromatic polyamide aerogel fiber.
[0115] (4) The hydrophobic aromatic polyamide aerogel fiber prepared in step (3) is annealed at 350°C for 50 min in a carbon dioxide atmosphere, with a heating rate of 10°C / min and a cooling rate of 10°C / min to obtain a highly resilient and hydrophobic aromatic polyamide aerogel fiber.
[0116] Comparative Example 1 (without hydrophobic modification) (1) A 5.0 wt% aromatic polyamide spinning solution was used to obtain hollow aromatic polyamide wet gel fibers by a coaxial wet spinning method. Specifically, a mixed solution of 5.0 wt% Kevlar, DMSO, and potassium hydroxide was used as spinning solution A, and water was used as spinning solution B. The spinning solution A and the spinning solution B were simultaneously extruded into a water coagulation bath through a coaxial needle (inner 19G-outer 14G) at an extrusion rate of 600 μL / min to obtain hollow aromatic polyamide wet gel fibers.
[0117] (2) The hollow aromatic polyamide wet gel fiber of step (1) is subjected to solvent replacement (the easily dry solvent used is ethanol), and then supercritical drying is performed to obtain the hollow aromatic polyamide aerogel fiber.
[0118] (3) The hollow aromatic polyamide aerogel fiber of step (2) is annealed at 350° C. for 50 min in a nitrogen atmosphere to obtain a highly resilient and hydrophilic hollow aromatic polyamide aerogel fiber.
[0119] After the above steps, the water contact angle of the aromatic polyamide aerogel fiber obtained in this comparative example is as follows: Fig.12 As shown, it is impossible to obtain a highly resilient and hydrophobic hollow aromatic polyamide aerogel fiber.
[0120] Comparative Example 2 (annealing followed by hydrophobic modification) (1) A 5.0 wt% aromatic polyamide spinning solution was used to obtain hollow aromatic polyamide wet gel fibers by a coaxial wet spinning method. Specifically, a mixed solution of 5.0 wt% Kevlar, DMSO, and potassium hydroxide was used as spinning solution A, and water was used as spinning solution B. The spinning solution A and the spinning solution B were simultaneously extruded into a water coagulation bath through a coaxial needle (inner 19G-outer 14G) at an extrusion rate of 600 μL / min to obtain hollow aromatic polyamide wet gel fibers.
[0121] (2) The hollow aromatic polyamide wet gel fiber of step (1) is subjected to solvent replacement (the easily dry solvent used is ethanol), and then supercritical drying is performed to obtain the hollow aromatic polyamide aerogel fiber.
[0122] (3) The hollow aromatic polyamide aerogel fiber of step (2) is annealed at 350° C. for 50 min in a nitrogen atmosphere to obtain a high resilience hollow aromatic polyamide aerogel fiber.
[0123] (4) The high resilience hollow aromatic polyamide aerogel fiber prepared in step (3) is subjected to hydrophobic modification by cold plasma, specifically, the hollow aromatic polyamide aerogel fiber is placed in a chamber, and vacuumized, filled with argon, discharged and activated, filled with gasified octamethylcyclotetrasilane for modification, and the sample is taken out.
[0124] After the above steps, the water contact angle test of the aromatic polyamide aerogel fiber obtained in this comparative example is as follows: Fig.13 As shown, it is impossible to obtain a highly resilient and hydrophobic hollow aromatic polyamide aerogel fiber.
[0125] Comparative Example 3 (without high temperature treatment) (1) A 5.0 wt% aromatic polyamide spinning solution was used to obtain hollow aromatic polyamide wet gel fibers by a coaxial wet spinning method. Specifically, a mixed solution of 5.0 wt% Kevlar, DMSO, and potassium hydroxide was used as spinning solution A, and water was used as spinning solution B. The spinning solution A and the spinning solution B were simultaneously extruded into a water coagulation bath through a coaxial needle (inner 19G-outer 14G) at an extrusion rate of 600 μL / min to obtain hollow aromatic polyamide wet gel fibers.
[0126] (2) The hollow aromatic polyamide wet gel fiber of step (1) is subjected to solvent replacement (the easily dry solvent used is ethanol), and then supercritical drying is performed to obtain the hollow aromatic polyamide aerogel fiber.
[0127] (3) The hollow aromatic polyamide aerogel fiber of step (2) is subjected to hydrophobic modification by cold plasma, specifically, the hollow aromatic polyamide aerogel fiber is placed in a chamber, and vacuumized, filled with argon, discharged and activated, filled with vaporized octamethylcyclotetrasilane for modification, and the sample is taken out.
[0128] After the above steps, the compression test results of the aromatic polyamide aerogel fiber obtained in this comparative example are as follows: Fig.14 As shown, it is impossible to obtain a highly resilient and hydrophobic hollow aromatic polyamide aerogel fiber.
[0129] Through Examples 1-12 and Comparative Examples 1-3, it can be found that the highly resilient and hydrophobic aromatic polyamide aerogel fiber obtained by the above technical scheme of the present invention is composed of a continuous three-dimensional multi-level pore network structure formed by overlapping aromatic polyamide nanofibers, and has high resilience. After the fiber is deformed by compression, bending, folding, etc., the fiber can recover 100%, and the radial maximum compression rebound limit of the fiber is 1 ~ 99%. The surface wettability is hydrophobic, the specific surface area is large, the porosity is high, the pore size distribution and morphology are controllable, and the preparation process is simple, and it is easy to realize large-scale production. It can be used in human thermal management, smart fabrics, wearable devices, environmental governance, sensing, sound absorption and noise reduction, thermal insulation and fiber flakes and other fields.
[0130] In addition, the inventors of the present invention also conducted experiments with other raw materials and conditions listed in this specification in accordance with the methods of Examples 1-12, and also prepared highly resilient and hydrophobic aromatic polyamide aerogel fibers.
[0131] The various aspects, embodiments, features and examples of the present invention should be considered as illustrative in all aspects and are not intended to limit the present invention, the scope of the present invention is defined only by the claims. Other embodiments, modifications and uses will be apparent to those skilled in the art without departing from the spirit and scope of the claimed invention.
[0132] The use of headings and sections in this disclosure is not meant to limit the disclosure; each section may apply to any aspect, embodiment, or feature of the disclosure.
[0133] Throughout this disclosure, where a composition is described as having, containing, or comprising particular components, or where a process is described as having, containing, or comprising particular process steps, it is contemplated that the compositions taught by the present invention also consist essentially of or consist of the recited components, and that the processes taught by the present invention also consist essentially of or consist of the recited process steps.
[0134] It should be understood that the order of the various steps or the order in which a particular action is performed is not very important, as long as the teachings of the present invention remain operable. In addition, two or more steps or actions may be performed simultaneously.
[0135] Although the present invention has been described with reference to illustrative embodiments, it will be appreciated by those skilled in the art that various other changes, omissions and / or additions may be made and that elements of the described embodiments may be substituted with substantial equivalents without departing from the spirit and scope of the present invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present invention without departing from the scope of the present invention. Therefore, it is not intended herein to limit the present invention to the specific disclosed embodiments for carrying out the present invention, but rather it is intended that the present invention will include all embodiments within the scope of the appended claims.
Claims
1. A method for preparing highly resilient and hydrophobic aromatic polyamide aerogel fibers, characterized in that: include: The surface of aromatic polyamide aerogel fiber is modified by using a hydrophobic modifier to obtain modified aromatic polyamide aerogel fiber; The modified aromatic polyamide aerogel fiber is annealed to obtain highly resilient and hydrophobic aromatic polyamide aerogel fiber.
2. The preparation method according to claim 1, characterized in that: The hydrophobic modifier includes any one or a combination of two of fluorocarbon resin and silane compound; Preferably, the fluorocarbon resin includes any one or a combination of two or more of polytetrafluoroethylene series resins, polyvinylidene fluoride series resins, alternating copolymer resins of fluoroolefins and alkyl vinyl ethers, and trifluorochloroethylene copolymer series resins; Preferably, the silane compound includes any one or a combination of two or more of trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, trimethoxysilane, dimethyldiethoxysilane, trimethylethoxysilane, γ-aminopropyltriethoxysilane, vinyltrimethoxysilane, vinylmethyldiethoxysilane, octamethylcyclotetrasiloxane, tridecafluorooctyltriethoxysilane, perfluorooctyltrimethoxysilane, and silane polymers; Preferably, the silane polymer includes any one or a combination of two or more of silane-modified polyether, silane-modified polyurethane, polydimethylsiloxane, and silicone resin.
3. The preparation method according to claim 1, characterized in that: The surface modification treatment includes any one or a combination of two or more of chemical vapor deposition technology, cold plasma treatment technology, and surface immersion coating technology.
4. The preparation method according to claim 1, characterized in that: The heating rate of the annealing treatment is 1°C / min~20°C / min, the maximum temperature is maintained at 150~650°C, the annealing time is 1min~10h, and the cooling rate is 1°C / min~20°C / min; and / or, the annealing treatment is carried out in a protective atmosphere, and the protective gas used to form the protective atmosphere includes any one of nitrogen, argon, helium and carbon dioxide or a combination of two or more thereof.
5. The preparation method according to claim 1, characterized in that: include: The aromatic polyamide spinning solution is subjected to a spinning technology to obtain aromatic polyamide wet gel fibers; The aromatic polyamide wet gel fiber is dried to obtain the aromatic polyamide aerogel fiber.
6. The preparation method according to claim 5, characterized in that: The aromatic polyamide spinning solution comprises an aromatic polyamide molecular solution composed of aromatic polyamide and concentrated sulfuric acid; and / or, the aromatic polyamide spinning solution comprises a homogeneous aromatic polyamide nanofiber dispersion formed by aromatic polyamide, an organic solvent and an alkali; Preferably, the concentration of the aromatic polyamide spinning solution is 0.1-20 wt %; particularly preferably, the concentration of the aromatic polyamide spinning solution is 1-10 wt %; Preferably, the aromatic polyamide includes any one of all-para aromatic polyamide, all-para aromatic polyamide copolymer, all-meta aromatic polyamide, meta aromatic amide copolymer containing methyl substituents, or a combination of two or more thereof; particularly preferably, the aromatic polyamide includes any one of poly(p-phenylene terephthalamide), poly(m-phenylene isophthalamide), poly-p-phenylene terephthalamide, poly(s-phenylene terephthalamide), poly(p-phenylene terephthalamide) copolymer, or a combination of two or more thereof; particularly preferably, the aromatic polyamide includes any one of Kevlar, Nomex, Technora, Twaron, Terlon, and Taparan, or a combination of two or more thereof; The organic solvent includes any one or a combination of two or more of dimethyl sulfoxide, cyclopentane, dibutyl sulfone, diethyl sulfone, ethyl methyl sulfone, N,N-dimethylformamide, and N,N-dimethylacetamide; The base includes any one of sodium hydroxide, potassium hydroxide, sodium tert-butoxide, potassium tert-butoxide, sodium amide, lithium amide, lithium chloride, and calcium chloride, or a combination of two or more thereof.
7. The preparation method according to claim 5, characterized in that: The spinning technology includes any one or a combination of two or more of gel spinning technology, wet spinning technology, dry spinning technology, dry-jet wet spinning technology, dry-freeze spinning technology, 3D printing technology, mold filamentation technology, coaxial wet spinning technology, coaxial 3D printing technology, and coaxial dry-freeze spinning technology, preferably wet spinning technology and / or coaxial wet spinning technology; Preferably, the wet spinning technology comprises: providing an aromatic polyamide spinning solution of a selected concentration, extruding the aromatic polyamide spinning solution into a coagulation bath through a spinneret or a dispensing needle, and forming an aromatic polyamide wet gel fiber; wherein the process conditions adopted by the wet spinning technology are: the concentration of the aromatic polyamide spinning solution is 0.1-20wt%, the diameter of the extrusion needle is 10-5000 μm, and the extrusion speed is 5-5000 μL / min; Preferably, the coaxial wet spinning technology comprises: providing an aromatic polyamide spinning solution of a selected concentration as a first spinning solution, using a coagulation bath as a second spinning solution, and simultaneously extruding the first spinning solution and the second spinning solution into the coagulation bath through a hollow spinneret or a coaxial needle to obtain an aromatic polyamide wet gel fiber; wherein the process conditions adopted by the coaxial wet spinning technology are: the concentration of the aromatic polyamide spinning solution is 0.1-20wt%, the extrusion speed of the first spinning solution is 5-5000 μL / min, and the extrusion speed of the second spinning solution is 5-5000 μL / min; Preferably, the coagulation bath comprises a main component and an auxiliary component, wherein the main component comprises any one or a combination of two or more of water, ethanol, acetone, dimethyl sulfoxide, nitrogen methyl pyrrolidone, ethyl acetate, dimethyl silicone oil, and N,N-dimethylformamide; the auxiliary component comprises any one or a combination of two or more of sulfuric acid, hydrochloric acid, ascorbic acid, calcium chloride, and ferric chloride; particularly preferably, the mass ratio of the main component to the auxiliary component is 1:0 to 1:99; And / or, the preparation method comprises: first replacing the non-drying solvent in the aromatic polyamide wet gel fiber with an easy-drying solvent, and then drying the replaced aromatic polyamide wet gel fiber; preferably, the easy-drying solvent comprises any one of water, methanol, ethanol, tert-butanol, acetone, propylene glycol and isopropanol, or a combination of two or more thereof; And / or, the drying process includes any one or a combination of two or more of supercritical fluid drying, vacuum freeze drying and reduced pressure drying; And / or, the aromatic polyamide aerogel fiber includes any one of aerogel fibers and non-aerogel fibers, or a combination of two or more thereof.
8. The high-resilience and hydrophobic aromatic polyamide aerogel fiber prepared by the preparation method according to any one of claims 1 to 7, wherein the high-resilience and hydrophobic aromatic polyamide aerogel fiber has high resilience, can recover 100% after being compressed, bent, folded and deformed, and has a radial maximum compression rebound limit of 1 to 99%; the surface wettability of the high-resilience and hydrophobic aromatic polyamide aerogel fiber is hydrophobic, and the static contact angle of water is 90° to 160°.
9. The highly resilient and hydrophobic aromatic polyamide aerogel fiber according to claim 8, characterized in that: The highly resilient and hydrophobic aromatic polyamide aerogel fiber has a tensile strength of 0.1 to 300 MPa and an elongation at break of 1 to 80%; And / or, the highly resilient and hydrophobic aromatic polyamide aerogel fiber comprises a continuous three-dimensional multilevel pore network structure formed by overlapping aromatic polyamide nanofibers, wherein the three-dimensional multilevel pore network structure comprises micropores with a pore size of less than 2 nm, mesopores with a pore size of 2 to 50 nm, and macropores with a pore size of 50 nm to 100 nm; the density of the highly resilient and hydrophobic aromatic polyamide aerogel fiber is 0.001 to 1 g / cm 3 The porosity is 1.0~99.9%, and the specific surface area is 1~1000 m 2 / g.
10. Application of the highly resilient and hydrophobic aromatic polyamide aerogel fiber according to claim 8 or 9 in the fields of smart fabrics, wearable devices, human thermal management, environmental management, sensing, sound absorption and noise reduction, thermal insulation or fiber flakes.