Graphene modified fiber functional composite fabric as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of textile materials, and particularly relates to a graphene modified fiber functional composite fabric and a preparation method and application thereof. The functional composite fabric comprises a fabric base material as well as a moisture conducting layer, a temperature and humidity response layer and a super-hydrophobic layer which are applied to the fabric base material, wherein the moisture conducting layer comprises a continuous hydrophilic liquid guide channel formed by graphene and polyvinyl alcohol; the temperature and humidity response layer based on the N-isopropylacrylamide copolymerization system is directionally applied to the air side, so that environment temperature and humidity induction and liquid regulation and transportation can be realized; and the super-hydrophobic layer constructs a compact low-surface-energy micro-nano structure through nano silicon dioxide sol, a fluorosilicone modifier and the like, so that excellent drainage and antifouling characteristics are realized. Through the synergistic effect of the three layers of functional structures, the fabric is endowed with excellent hygroscopicity, quick-drying property and moisture penetrability, the wearing comfort of the fabric in a low-temperature and high-humidity environment is greatly improved, and the fabric is suitable for being applied to various outdoor or sports functional textiles and has the application prospect of large-scale production.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of textile materials, and particularly relates to a graphene modified fiber functional composite fabric and a preparation method and application thereof. BACKGROUND

[0002] With the rapid development of sports, outdoor and leisure apparel market, the requirements for comfort and multi-scene applicability of functional textiles continue to improve, especially higher standards for moisture absorption, sweat wicking, air permeability and fast drying performance are proposed. For this reason, various moisture absorption and fast drying finishing technologies are widely researched and applied, and currently mainly include different technical routes such as hydrophilic and hydrophobic / super-hydrophobic types.

[0003] The existing hydrophilic finishing method usually improves the adsorption and diffusion capacity of fabric to sweat by introducing hydrophilic groups or coating hydrophilic polymers, thereby improving the moisture absorption rate at room temperature. However, this kind of method lacks dynamic adaptability adjustment to environmental temperature and humidity conditions, and once saturated with water in low wind speed or high humidity environment, the fabric will produce sticky and damp feeling, and it is difficult to achieve continuous and efficient sweat wicking and fast drying. The pure hydrophobic or super-hydrophobic finishing technology usually constructs a high contact angle layer on the surface of the fabric to achieve the effect of repelling rainwater and liquid drops, but its adsorption and spreading capacity to trace amounts of sweat is limited, and it is difficult to effectively and quickly absorb and diffuse the sweat discharged by the human body, and often leads to sweat accumulation under high-intensity exercise or high-temperature conditions, even the phenomenon of “back seepage” or “slippery” occurs, thereby affecting the comfort of wearing.

[0004] In view of the above problems, in order to overcome the limitations of traditional single hydrophilic or hydrophobic finishing method, researchers have also developed composite finishing technology by designing membrane layer structure to realize waterproof and moisture permeable and fast drying performance. For example, Chinese patent application CN111607973A discloses a preparation method of moisture absorption and fast drying textile, which uses cotton fiber doped with graphene fiber as the fabric substrate, and combines a microporous film prepared by taking polytetrafluoroethylene as the main body and adding graphene oxide and nano silicon dioxide, to obtain a textile with waterproof and breathable and certain fast drying effect. This technology mainly relies on the pore size distribution of the microporous film layer to block liquid water drops while allowing water vapor molecules to pass through, thereby having the functions of anti-splashing water and air permeability on the outer layer, and relying on air flow to promote sweat evaporation. However, this kind of microporous membrane composite fabric also has significant deficiencies: the preparation process of microporous film is complex, the requirements for equipment and process control are high, and the pore size distribution is strict, which results in high production cost; the attachment of the membrane layer reduces the overall softness and air permeability uniformity of the fabric, affecting the wearing comfort; and the microporous film has obvious blocking effect on liquid water, which needs to be converted into water vapor before being discharged, resulting in the phenomenon of “internal humidity and external dryness” under high humidity or intense exercise conditions, which is easy to produce sticky and stuffy feeling; in addition, with the increase of wearing and washing times, the waterproof and moisture permeable performance of the film layer is also prone to decline.

[0005] In summary, the prior art in improving the moisture absorption and quick drying performance of the fabric, often only in hydrophilic moisture absorption, diffusion and hydrophobic drainage, quick drying, lack of a comprehensive solution that can realize multi-functional integration in the finished fabric finishing process, with layered collaborative structure and comfortable in different environmental conditions. Therefore, it is urgent to develop a new fabric finishing method with simple process, suitable for existing textile production line, which can achieve a good balance between moisture absorption, moisture transfer, drainage and quick drying performance, to meet the higher demand for functional textiles in multiple scenarios and all weather conditions. SUMMARY

[0006] In view of the above problems existing in the prior art, the purpose of the present application is to provide a graphene modified fiber functional composite fabric and its preparation method and application. The graphene modified fiber functional composite fabric of the present application realizes multiple functions of efficient moisture absorption and liquid transfer, temperature and humidity self-adaptive adjustment, and outer layer rapid drainage and stain prevention by sequentially constructing a moisture transfer layer, a temperature and humidity response layer and a super-hydrophobic layer on the fabric substrate. The present application has reasonable structure design and controllable material ratio. The step-by-step preparation process between the layers not only realizes functional complementation, but also avoids the problems of delamination or pollution between the layers, and endows the fabric with excellent wearing comfort, moisture permeability and quick drying performance in low temperature and high humidity environment.

[0007] To solve the above problems, the technical scheme adopted by the present application is as follows: A graphene modified fiber functional composite fabric, comprising a fabric substrate, a moisture transfer layer applied to the fabric substrate, and a temperature and humidity response layer and a super-hydrophobic layer sequentially applied to the air side surface of the moisture transfer layer. The moisture transfer layer comprises a coating layer formed by graphene and its derivative dispersion and polyvinyl alcohol. The temperature and humidity response layer comprises a coating layer formed by a temperature and humidity responsive high molecular copolymer. The super-hydrophobic layer comprises a coating layer formed by nano-silica sol, siloxane coupling agent and fluorosilicon modifier. After the fabric substrate is treated by applying the moisture transfer layer, the temperature and humidity response layer and the super-hydrophobic layer are sequentially applied to the air side surface of the moisture transfer layer, and the graphene modified fiber functional composite fabric is obtained.

[0008] The graphene and its derivative dispersion includes a uniform dispersion system of graphene, graphene oxide, reduced graphene oxide and other graphene derivatives in a solvent.

[0009] The present application aims to solve the problem that the existing textile is difficult to realize rapid moisture absorption, dynamic sweat removal and efficient waterproof of the outer layer at the same time in the movement sweating scene, and provides a structured graphene modified fiber functional composite fabric. The fabric comprises a fabric substrate, a moisture guide layer applied to the fabric substrate, and a temperature and humidity responsive layer and a super-hydrophobic layer applied in sequence on the air side surface of the moisture guide layer, and the three layers cooperatively construct a hierarchical regulated water management system.

[0010] Specifically, the moisture guide layer of the present application utilizes the hydrophilic film-forming property of graphene and its derivative dispersion and polyvinyl alcohol (PVA) to construct an efficient adsorption and diffusion network, quickly guiding sweat from the skin side into the inner layer of the fabric; the temperature and humidity responsive layer located in the middle layer forms a dynamic open and close hydrogel coating, which responds to changes in humidity and temperature, and can dynamically open and close the water absorption and release channels according to environmental changes, realizing intelligent regulation of sweat flow rate and distribution, and avoiding sticky retention in low ventilation or high humidity environment; the super-hydrophobic layer constructs a dense nano microstructure and a low surface energy interface through the synergistic effect of nano silicon dioxide, siloxane coupling agent and fluorosilicon modifier, effectively expelling water and preventing external liquid penetration. Through the synergistic effect of the three-layer structure, the sweat is absorbed from the skin side, guided to the middle layer, the humidity of the middle layer is adjusted in response to the flow and the water is released to the outer layer, and then the water is efficiently drained from the outer layer, forming a continuous moisture guide and sweat removal path from rapid moisture absorption on the skin side to efficient drainage on the outer layer, overcoming the problem of functional exclusion and poor durability in traditional single-layer finishing or simple superposition finishing technology, and realizing long-term comfortable wearing performance under complex movement or climate conditions.

[0011] Further, the temperature and humidity responsive copolymer is a copolymer of N-isopropyl acrylamide, acrylic acid and acrylamide; the mass ratio of the N-isopropyl acrylamide, acrylic acid and acrylamide is (60-80):(10-30):(5-15).

[0012] The present application can effectively adjust the balance of hydrophilic and hydrophobic levels and electrolyte effect of molecular segments, and break the problem of narrow phase transition temperature interval (about 31-33℃) of pure N-isopropyl acrylamide homopolymer by designing a specific proportion range of N-isopropyl acrylamide, acrylic acid and acrylamide copolymer system. The introduction of acrylic acid monomer can enhance the overall hydrophilicity through ionization of carboxyl and hydrogen bond competition, form a diversified microenvironment, and make the local segment swell and shrink at a lower temperature; and the non-ionic hydrophilicity of acrylamide monomer and the flexible segment structure balance the strong ionic effect, avoid swelling out of control and improve the uniformity of crosslinking, and through the three copolymer structure, a hydrogel network with distributed LCST behavior is formed, so that the phase transition is no longer concentrated at a single temperature point, but shows a continuous, adjustable and distributed hydrophilic and hydrophobic change within 25-40℃, thereby giving the temperature and humidity responsive layer dynamic adaptability and wide temperature zone humidity regulating and transporting capacity in the fabric, so that the fabric can continuously and dynamically adjust the moisture absorption and transportation in a wide environmental temperature range, better adapt to the temperature and humidity fluctuations in the human activity process, and realize the synchronous improvement of comfort and functionality.

[0013] Further, the preparation method of the temperature and humidity responsive polymer copolymer comprises the following steps: dissolving N-isopropyl acrylamide, acrylic acid and acrylamide in a solvent to form a monomer solution; then adding a crosslinking agent, an initiator and an assistant initiator, stirring and reacting to obtain a temperature and humidity responsive polymer copolymer; the mass ratio of the N-isopropyl acrylamide, acrylic acid, acrylamide, crosslinking agent, initiator and assistant initiator is (60-80):(10-30):(5-15):(0.3-0.6):(0.5-0.8):(0.3-0.6).

[0014] The ternary copolymerization modification method of the temperature and humidity responsive polymer copolymer can realize uniform crosslinking of the polymer chain structure and controlled molecular weight distribution, obtain a temperature and humidity sensitive coating material with stable response performance, make the temperature and humidity responsive layer reversibly control the gel state when absorbing the moisture introduced by the moisture guiding layer, avoid overflow or local fluid accumulation, and moderately release to the super-hydrophobic layer to ensure uniform water drainage, overcome the problem of fixed LCST and single response performance of the existing NIPAM monomer system, and improve the adaptability of the fabric to body temperature fluctuations, sweat state and external ventilation conditions in practical application; and the temperature and humidity responsive layer, the moisture guiding layer and the super-hydrophobic layer cooperatively form a three-phase moisture absorption and quick-drying structure, which can still maintain efficient sweat and dry experience under different environmental conditions.

[0015] Further, the crosslinking agent is N,N'-methylene bisacrylamide; the initiator is ammonium persulfate; and the assistant initiator is NaHSO3.

[0016] Further, the mass ratio of graphene and its derivatives and polyvinyl alcohol is (5-20):(70-85); the mass ratio of nano-silica sol, siloxane coupling agent and fluorosilicon modifier is (40-60):(5-15):(20-30).

[0017] The raw materials in the above ratio range can effectively ensure that the moisture guide layer has excellent hydrophilic liquid guide capacity and good film layer flexibility and adhesion; at the same time, the synergistic effect of nano-skeleton support and low surface energy modification in the super-hydrophobic layer is realized, forming a dense and durable hydrophobic surface structure. And the overall synergistic function between the layers is optimized by this ratio: the moisture guide layer quickly adsorbs and diffuses moisture, the temperature and humidity response layer dynamically adjusts the swelling and perspiration process, and the super-hydrophobic layer quickly drains water and forms a closed water barrier, effectively preventing the back infiltration of sweat.

[0018] Furthermore, the application also provides a preparation method of the graphene modified fiber functional composite fabric as described above, comprising the following steps: Step (1): the finishing liquid formed by graphene and its derivatives dispersion and polyvinyl alcohol is applied to the fabric substrate by padding, coating or spraying, and drying or heat treatment is performed to form a moisture guide layer; Step (2): the finishing liquid formed by the temperature and humidity responsive polymer copolymer is applied to the air side surface of the moisture guide layer of the fabric substrate by coating or spraying, and drying or heat treatment is performed to form a temperature and humidity response layer; Step (3): the nano-super-hydrophobic finishing liquid formed by nano-silica sol, siloxane coupling agent and fluorosilicon modifier is further applied to the temperature and humidity response layer by coating or spraying, and drying, heat treatment or photocuring is performed to form a super-hydrophobic layer; finally, the fabric is placed at room temperature for post-curing to obtain the graphene modified fiber functional composite fabric.

[0019] Firstly, the application forms continuous hydrophilic moisture guide channels by graphene-PVA padding and drying; secondly, the temperature and humidity responsive coating is applied to the air side of the moisture guide layer in a directional manner, and drying and crosslinking are performed to ensure the stability of the structure in the layer; finally, the super-hydrophobic coating or spraying process is used to finely control the finishing liquid load, and a dense hydrophobic layer is formed by heat treatment or photocuring, which effectively avoids the mutual pollution and peeling risk between the layers through the step-by-step processing method, ensures the firm interfacial bonding between the three layers and maintains the independent functions of each layer, and realizes the efficient synergistic mechanism of moisture guide, intermediate temperature and humidity adjustment and outer layer waterproof drainage.

[0020] Further, the step (1) comprises: Moisture-conducting finishing liquid preparation: graphene and its derivatives are added to deionized water, ultrasonic, graphene and its derivative dispersion is obtained, heated to 80-90℃; Then polyvinyl alcohol is added, stirred, cooled to room temperature; Then add phosphoric acid and stir for 20-30min, obtain the moisture-conducting finishing liquid formed by graphene and its derivatives dispersion and polyvinyl alcohol; Pad operation: the pretreated fabric is dipped in the moisture-conducting finishing liquid by two-dip-two-pad method, the pick-up rate is controlled at 75±5%, and the pad line speed is controlled at 15-18m / min; Drying and curing: the fabric is dried at 90-100℃ for 3-5min; Then cured at 115-125℃ for 3-5min, forming a moisture-conducting layer.

[0021] The present application optimizes the pretreatment, padding, drying and curing process of graphene and its derivatives and polyvinyl alcohol, ensures the compactness and adhesion of the moisture-conducting layer, and improves the hydrophilic and liquid-conducting performance. At the same time, the process lays a good interface foundation for the attachment of the subsequent temperature and humidity responsive layer and the super-hydrophobic layer, realizes the stable combination and functional synergy between the multi-layer coatings, and finally enhances the overall moisture-conducting, adjusting and water-repellent integrated effect of the fabric.

[0022] Further, the step (2) comprises: Copolymer finishing liquid preparation: N-isopropyl acrylamide, acrylic acid and acrylamide are dissolved in a solvent to form a monomer solution; Then add crosslinking agent, initiator and co-initiator, continue to stir at room temperature for 25-35min to obtain temperature and humidity responsive copolymer, forming a copolymer finishing liquid; Application method: the fabric obtained in step (1) is flattened, and then the copolymer finishing liquid is uniformly coated on the air side of the moisture-conducting layer of the fabric, and the loading amount is controlled at 0.5-1.0g / m 2 ; Drying and polymerization: first dry the fabric at 75-85℃ for 3-5min; Then heat treated at 100-145℃ for 3-10min to form a temperature and humidity responsive layer.

[0023] The temperature and humidity responsive copolymer finishing liquid of the present application is precisely applied to the air side surface of the moisture-conducting layer, so that the layer is directly exposed to the environmental humidity and heat changes, thereby realizing more sensitive body sensing adjustment response. This position layout is different from the traditional temperature control material hidden inside the fabric, so that it realizes rapid switching between moisture absorption and expansion and moisture release and shrinkage. And the layer cooperates with the bottom moisture-conducting layer to guide the sweat outward from inside, and regulates the water transport rate through responsive adjustment; At the same time, it provides dynamic water input for the super-hydrophobic layer on the surface, so that the functions of the three layers are linked and progressive, and the overall function of "fast moisture absorption-intelligent adjustment-high efficiency drainage" is realized.

[0024] Further, the step (3) comprises: Preparation of the nanometer super-hydrophobic finishing liquid: add nanometer silica sol in ethanol and ultrasonic; add siloxane coupling agent and stir for 20-30 min; then add fluorosilicon modifier and continue to stir for 20-30 min, then adjust pH to 4-5, and stir for 25-35 min to obtain the nanometer super-hydrophobic finishing liquid; Application method: place the fabric obtained in step (2) upside down, use a low-pressure spray gun to spray, and control the load to be 0.5-1.0 g / m 2 ; Drying and curing: first dry the fabric at 75-85 DEG C for 3-5 min; then heat treat at 110-150 DEG C for 2-10 min to form a super-hydrophobic layer; finally, place the fabric at room temperature for post-curing to obtain the graphene modified fiber functional composite fabric.

[0025] Moreover, the application also provides the application of the graphene modified fiber functional composite fabric, and the clothing made of the graphene modified fiber functional composite fabric.

[0026] Compared with the prior art, the application has the following beneficial effects: (1) The graphene modified fiber functional composite fabric provided by the application forms a multi-functional gradient structure with layer-by-layer synergistic effect by sequentially constructing a moisture conducting layer, a temperature and humidity responsive layer and a super-hydrophobic layer on the same fabric substrate. The moisture conducting layer uses the dispersed network formed by graphene and its derivatives and polyvinyl alcohol to construct a continuous hydrophilic channel and enhance the moisture absorption and liquid conducting capacity; the temperature and humidity responsive layer uses a copolymer with a specific monomer ratio to realize dynamic response to the change of the environment temperature and humidity and moisture transport regulation; and the super-hydrophobic layer forms a dense low-surface-energy micro-nano structure through the synergistic effect of nanometer silicon dioxide, siloxane coupling agent and fluorosilicon modifier to realize high-efficiency water repellency and rapid drainage function. Overall, the product structure design is scientific, the functions of the layers are complementary, and the interface is firmly combined, thus solving the problem that the existing single hydrophilic or hydrophobic finishing technology cannot consider both moisture absorption and quick drying, and significantly improving the comfort and durability of the textile wear.

[0027] (2) The multi-layer finishing process of the application avoids the problems of cross contamination between the multi-layer coatings, poor adhesion and interface delamination through the systematic and step-by-step dipping, coating, spraying and heat treatment process. First, the graphene-PVA moisture conducting layer is applied on the pretreated fabric to ensure that the hydrophilic liquid conducting channel of the bottom layer is uniform and continuous; then the temperature and humidity responsive layer is precisely applied on the air side to form an intermediate layer with dynamic regulation function; finally, the dense super-hydrophobic layer is constructed through fine spraying and heat treatment or light curing, which not only ensures the stable film formation and interface bonding force of each coating, but also realizes the gradient progression and synergy of the functions between the multi-layers, and improves the controllability, applicability and scale promotion value of the overall production process. DETAILED DESCRIPTION

[0028] The application is further described by the following description of specific embodiments, which are not intended to limit the application, and which will be apparent to those skilled in the art from consideration of the application as a whole, and from the further description as follows. Various modifications and improvements can be made to the embodiments described without departing from the spirit of the application. It is intended that the scope of the application should only be limited by the appended claims.

[0029] In the following examples and comparative examples, the methods used are those of the prior art unless otherwise specified; reagents not specifically named are conventional reagents, which can be purchased from conventional reagent production and sales companies.

[0030] Example 1 Preparation method of graphene modified fiber functional composite fabric First, the polyester knitted fabric was pretreated by being placed in a soaping solution at 60°C for continuous washing for 10 min to remove oil stains and impurities, then rinsed thoroughly with clean water, and finally dried in a hot air oven at 80°C to constant weight for standby use.

[0031] Next, the moisture conducting layer was prepared: First, 5 g of graphene oxide (GO) water was added to 400 mL of deionized water and ultrasonically treated for 10 min to ensure uniform dispersion. Then, 70 g of polyvinyl alcohol (PVA, molecular weight 80-90 kDa) was slowly added while stirring under heating to 80°C. After stirring until completely dissolved to form a uniform transparent solution, the solution was cooled to room temperature, and 2 g of 85% phosphoric acid was added and stirred for 20 min to obtain a GO-PVA finishing solution.

[0032] Then, the pretreated and dried polyester fabric was immersed in the above GO-PVA finishing solution, with a mass ratio of fabric to finishing solution of 1:15. A two-dip-two-nip process was used for padding, with the squeezing rate controlled at 70% by roller after each dip, and the dip line speed being 15 m / min. After completing the padding, the fabric was spread flat and placed in a hot air setting machine. First, it was dried at 90°C for 3 min to remove water, and then heat treated at 115°C for 3 min to promote the crosslinking reaction of PVA and the hydrogen bond network of graphene oxide to be fixed, thereby forming a stable moisture conducting layer on the polyester fabric.

[0033] Next, the temperature and humidity responsive layer was prepared: First, 60 g of N-isopropyl acrylamide (NIPAAm), 10 g of acrylic acid (AA), and 5 g of acrylamide (AAm) were dissolved in 300 mL of deionized water to form a monomer solution. Then, 0.3 g of N,N'-methylenebisacrylamide (MBAAm) was added as a crosslinking agent, and 0.5 g of ammonium persulfate (APS) and 0.3 g of sodium bisulfite (NaHSO3) were added as a redox initiation system. The solution was stirred at room temperature for 25 min to form a copolymer finishing solution.

[0034] The fabric with completed moisture guide layer treatment was flattened, and then the copolymer finishing solution was uniformly coated on the air side of the moisture guide layer of the fabric, with a controlled load of 0.5 g / m 2 After coating, the fabric was dried at 75°C for 3 min, and then heat treated at 100°C for 3 min to form the temperature and humidity responsive layer.

[0035] After the temperature and humidity responsive layer was completed, the super-hydrophobic layer was prepared: First, the concentration of 40 g of nano-silica sol (silica content in the stock solution is 30 wt%, the same below) was diluted to 15 wt%, and then added to 400 mL of ethanol, ultrasonic dispersed for 10 min to make it uniform; then 5 g of siloxane coupling agent KH-570 was added, stirred for 20 min; then 20 g of fluorosilane trifluoropropyl trimethoxysilane was slowly added, and a small amount of acetic acid was used to adjust the pH of the system to 5, and continue to stir for 25 min to promote the hydrolysis and condensation reaction; finally, 1 wt% of polytetrafluoroethylene (PTFE) micro powder was added and ultrasonic dispersed for 5 min again to prepare a uniform and transparent super-hydrophobic coating solution.

[0036] The fabric with completed temperature and humidity responsive layer treatment was placed flat on the air side, and a low-pressure spray gun was used for spraying, with a controlled load of 0.5 g / m 2 ; then the fabric was dried at 75°C for 3 min; then heat treated at 110°C for 10 min to form the super-hydrophobic layer; finally, the fabric was placed at room temperature for post-curing to obtain the graphene modified fiber functional composite fabric.

[0037] Preparation method of graphene modified fiber functional composite fabric First, the polyester knitted fabric was pretreated, first washed in a soaping solution at 60°C for 10 min to remove oil and impurities, then rinsed thoroughly with water, and finally dried in a hot air oven at 80°C to constant weight for standby.

[0038] Next, the moisture guide layer was prepared: First, 20 g of graphene oxide (GO) water was added to 600 mL of deionized water and ultrasonic treated for 10 min to ensure uniform dispersion. Then, while stirring, 85 g of polyvinyl alcohol (PVA, molecular weight 80-90 thousand) was slowly added while heating to 90°C. After stirring to completely dissolve and form a uniform transparent solution, it was cooled to room temperature, and 10 g of 85% phosphoric acid was added and stirred for 30 min to obtain a GO-PVA finishing solution.

[0039] Then the pretreated and dried polyester fabric is immersed in the above GO-PVA finishing liquor, with a mass ratio of fabric to finishing liquor of 1:20, using a two-dip-two-nip process. After each dip, the nip roller is used to control the squeezing rate at 80%, and the dip line speed is 18 m / min. After the dipping process is completed, the fabric is spread out and placed in a hot air setting machine. First, it is dried at 100°C for 5 min to remove moisture, and then it is heat treated at 125°C for 5 min to promote the cross-linking reaction of PVA and the hydrogen bond network of graphene oxide, thereby forming a stable moisture transfer layer on the polyester fabric.

[0040] Next, a temperature and humidity responsive layer is prepared: First, 80 g of N-isopropyl acrylamide (NIPAAm), 30 g of acrylic acid (AA), and 15 g of acrylamide (AAm) are dissolved in 500 mL of deionized water, and stirred to obtain a monomer solution. Then, 0.6 g of N,N'-methylene bisacrylamide (MBAAm) is added as a crosslinking agent, and 0.8 g of ammonium persulfate (APS) and 0.6 g of sodium bisulfite (NaHSO3) are added as a redox initiation system. The mixture is continuously stirred at room temperature for 35 min to form a copolymer finishing liquor.

[0041] The fabric with the moisture transfer layer is spread out, and the copolymer finishing liquor is evenly applied to the air side of the fabric's moisture transfer layer, with a loading amount of 1.0 g / m 2 After the application is complete, the fabric is dried at 85°C for 5 min, and then heat treated at 145°C for 3 min to form a temperature and humidity responsive layer.

[0042] After the temperature and humidity responsive layer is completed, an ultra-hydrophobic layer is prepared: First, 60 g of nano-silica sol is diluted to a concentration of 25 wt%, and then added to 400-600 mL of ethanol and ultrasonically dispersed for 10 min to make it uniform. Then, 15 g of siloxane coupling agent KH-570 is added and stirred for 30 min. Then, 30 g of fluorosilane trifluoropropyl trimethoxysilane is slowly added, and a small amount of acetic acid is used to adjust the pH of the system to 4. The mixture is continuously stirred for 35 min to promote the hydrolysis and condensation reaction. Finally, 1 wt% of polytetrafluoroethylene (PTFE) powder is added and ultrasonically dispersed for another 5 min to obtain a uniform and transparent ultra-hydrophobic coating solution.

[0043] The fabric with the temperature and humidity responsive layer is spread out and placed on the air side, and a low-pressure spray gun is used for spraying, with a loading amount of 1.0 g / m 2 Then the fabric is dried at 85°C for 5 min, and then heat treated at 150°C for 2 min to form an ultra-hydrophobic layer. Finally, the fabric is left to cure at room temperature to obtain a graphene-modified fiber functional composite fabric.

[0044] Preparation method of graphene modified fiber functional composite fabric Firstly, the polyester knitted fabric was pretreated. It was first put into a soaping solution at 60°C for continuous washing for 10 min to remove oil stains and impurities, then rinsed thoroughly with clean water, and finally dried in a hot air oven at 80°C to constant weight for standby use.

[0045] Next, the moisture conducting layer was prepared: First, 10 g of graphene oxide (GO) water was added to 600 mL of deionized water and ultrasonically treated for 10 min to ensure uniform dispersion. Then, 70 g of polyvinyl alcohol (PVA, molecular weight 80-90 kDa) was slowly added while stirring under heating to 85°C. After stirring until completely dissolved to form a uniform transparent solution, it was cooled to room temperature, and 6 g of 85% phosphoric acid was added and stirred for 30 min to obtain a GO-PVA finishing solution.

[0046] Then, the pretreated and dried polyester fabric was immersed in the above GO-PVA finishing solution, with a mass ratio of fabric to finishing solution of 1:20. A two-dip-two-nip process was used, with the squeezing rate controlled at 75% by the nip roller after each dip, and the dip line speed was 18 m / min. After completing the dip-nip, the fabric was spread flat and placed in a hot air setting machine. It was first dried at 90°C for 5 min to remove moisture, and then heat treated at 115°C for 5 min to promote the crosslinking reaction of PVA and the hydrogen bond network of graphene oxide, thereby forming a stable moisture conducting layer on the polyester fabric.

[0047] Next, the temperature and humidity responsive layer was prepared: First, 70 g of N-isopropyl acrylamide (NIPAAm), 20 g of acrylic acid (AA), and 10 g of acrylamide (AAm) were dissolved in 500 mL of deionized water to form a monomer solution. Then, 0.4 g of N,N'-methylene bisacrylamide (MBAAm) was added as a crosslinking agent, and 0.6 g of ammonium persulfate (APS) and 0.6 g of sodium bisulfite (NaHSO3) were added as a redox initiation system. The solution was stirred at room temperature for 35 min to form a copolymer finishing solution.

[0048] The fabric with the moisture conducting layer was then spread flat, and the copolymer finishing solution was uniformly coated on the air side of the moisture conducting layer, with a loading amount of 1.0 g / m 2 After coating, the fabric was dried at 85°C for 3 min, and then heat treated at 100°C for 10 min to form the temperature and humidity responsive layer.

[0049] After the temperature and humidity responsive layer was completed, the superhydrophobic layer was prepared: First, 50 g of nano-silica sol was diluted to 20 wt% and then added to 600 mL of ethanol, and ultrasonic dispersion was performed for 10 min to make it uniform. Then, 10 g of siloxane coupling agent KH-570 was added, and stirring was performed for 30 min. Then, 20 g of fluorosilane trifluoropropyl trimethoxysilane was slowly added, and a small amount of acetic acid was used to adjust the pH of the system to 4, and stirring was continued for 35 min to promote the hydrolysis and condensation reaction. Finally, 1 wt% of polytetrafluoroethylene (PTFE) powder was added and ultrasonic dispersion was performed for 5 min again, and a uniform and transparent super-hydrophobic coating solution was prepared.

[0050] The fabric on which the temperature and humidity response layer treatment was completed was placed flat on the air side, and a low-pressure spray gun was used for spraying, and the load was controlled to be 1.0 g / m 2 ; then the fabric was dried at 85°C for 3 min; then it was heat treated at 110°C for 10 min to form a super-hydrophobic layer; finally, the fabric was placed at room temperature for post-curing to obtain a graphene modified fiber functional composite fabric.

[0051] Comparative Example 1 The difference from Example 3 is that the temperature and humidity response layer is not coated on the air side of the moisture guide layer, but is coated on both sides, and then dried and heat treated, and the other steps and preparation processes are the same as those of Example 3.

[0052] Comparative Example 2 The difference from Example 3 is that the preparation step of the temperature and humidity response layer is omitted, and the fabric is directly treated with the super-hydrophobic layer after the moisture guide layer treatment is completed, and the other steps and preparation processes are the same as those of Example 3.

[0053] Comparative Example 3 The difference from Example 3 is that the addition of acrylic acid (AA) and acrylamide (AAm) is omitted in the temperature and humidity response layer monomer solution, and the other steps and preparation processes are the same as those of Example 3.

[0054] Comparative Example 4 The difference from Example 3 is that the GO-PVA finishing liquid, the copolymer finishing liquid, and the super-hydrophobic coating liquid are prepared respectively, and then mixed, and then the polyester knitted fabric is placed in the mixed liquid for one pad treatment, and after the pad treatment is completed, the fabric is placed flat in a hot air setting machine, and first dried at 90°C for 5 min to remove water, and then heat treated at 115°C for 5 min, and the other steps and preparation processes are the same as those of Example 3.

[0055] Comparative Example 5 The difference from Example 3 is that only graphene oxide (GO) is contained in the finishing liquid for preparing the moisture guide layer, and polyvinyl alcohol (PVA) is not added, and the remaining steps and process parameters are the same as those of Example 3.

[0056] Test Example: 1. Test method: according to GB / T 21655.1-2008 Textiles - Assessment of the moisture management performance - Part 1: determination of basic properties.

[0057] 2. Test object: graphene modified fiber functional composite fabric obtained from examples 1-3 and comparative examples 1-5.

[0058] 3. Test results: Table 1

[0059] From the above results, the graphene modified fiber functional composite fabric prepared according to the method of the application can meet or significantly exceed the requirements of the GB / T 21655.1-2008 national standard in terms of water absorption, drop diffusion time, wicking height, evaporation rate and moisture permeability, which shows that the hydrophilic liquid channel of the graphene-PVA moisture conducting layer, the dynamic transport and adjustment function of the temperature and humidity response layer, and the drainage barrier of the super-hydrophobic layer form a synergistic moisture conducting-adjusting-waterproof layered structure under step-by-step preparation.

[0060] Comparative example 1 does not direct the temperature and humidity response layer on the air side of the moisture conducting layer, which destroys the one-way gradient response structure, making the humidity adjustment and transport not directional, resulting in performance decline. Comparative example 2 omits the temperature and humidity response layer, so the material loses the ability to adapt to changes in environmental temperature and humidity, and only relies on the surface drainage, so the water absorption and wicking capacity decrease, the diffusion time becomes longer, and the moisture permeability also decreases. Comparative example 3 does not use acrylic acid (AA) and acrylamide (AAm) for modification, so the temperature and humidity response layer has a narrow LCST range and weak adjustment capacity, which limits the performance. In comparative example 4, the three layers are mixed and applied at one time, resulting in mixed functions and disordered structure between the layers, which cannot form a continuous hydrophilic moisture conducting path and a clear adjustment barrier, and the performance is deteriorated. In comparative example 5, PVA is not introduced into the moisture conducting layer, which loses the support of the flexible hydrophilic matrix, and the graphene is unevenly distributed, resulting in decreased moisture conductivity, and the moisture absorption rate and diffusion speed are also slow.

[0061] In summary, the application not only optimizes the performance in each functional layer, but also forms a ordered gradient synergistic system of moisture conducting-humidity adjusting-waterproofing between the layers, which significantly improves the moisture absorption and quick drying comprehensive performance of the composite fabric in complex environments.

[0062] The above examples only illustrate the principles and effects of the application, and are not intended to limit the application. Any person skilled in the art can modify or change the above examples without departing from the spirit and scope of the application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical thought disclosed by the application should be covered by the claims of the application.

Claims

1. A graphene-modified fiber functional composite fabric, characterized in that, The functional composite fabric comprises a fabric substrate, a moisture conducting layer applied to the fabric substrate, and a temperature and humidity responsive layer and a super-hydrophobic layer applied to the air side surface of the moisture conducting layer in sequence. The moisture conducting layer comprises a coating layer formed by graphene and its derivative dispersion and polyvinyl alcohol; The temperature and humidity responsive layer comprises a coating layer formed by a temperature and humidity responsive polymer copolymer; The super-hydrophobic layer comprises a coating layer formed by nano-silica sol, siloxane coupling agent and fluorosilicon modifier; The fabric substrate is treated by applying the moisture conducting layer, and then the temperature and humidity responsive layer and the super-hydrophobic layer are applied to the air side surface of the moisture conducting layer in sequence, thereby obtaining the graphene modified fiber functional composite fabric.

2. The graphene-modified fiber functional composite fabric according to claim 1, wherein, The temperature and humidity responsive polymer copolymer is a copolymer of N-isopropyl acrylamide, acrylic acid and acrylamide; the mass ratio of the N-isopropyl acrylamide, the acrylic acid and the acrylamide is (60-80):(10-30):(5-15).

3. The graphene-modified fiber functional composite fabric according to claim 1, wherein, The preparation method of the temperature and humidity responsive polymer copolymer comprises the following steps: dissolving N-isopropyl acrylamide, acrylic acid and acrylamide in a solvent to form a monomer solution; then adding a crosslinking agent, an initiator and an assistant initiator, and stirring and reacting to obtain the temperature and humidity responsive polymer copolymer; the mass ratio of the N-isopropyl acrylamide, the acrylic acid, the acrylamide, the crosslinking agent, the initiator and the assistant initiator is (60-80):(10-30):(5-15):(0.3-0.6):(0.5-0.8):(0.3-0.6).

4. The graphene-modified fiber functional composite fabric according to claim 3, wherein, The crosslinking agent is N,N'-methylene bisacrylamide; the initiator is ammonium persulfate; and the assistant initiator is NaHSO3.

5. The graphene-modified fiber functional composite fabric according to claim 1, wherein the graphene-modified fiber functional composite fabric is a graphene-modified fiber functional composite fabric for a wearable device. The mass ratio of the graphene and its derivative and the polyvinyl alcohol is (5-20):(70-85); and the mass ratio of the nano-silica sol, the siloxane coupling agent and the fluorosilicon modifier is (40-60):(5-15):(20-30).

6. The method for preparing graphene-modified fiber functional composite fabric according to any one of claims 1-5, characterized in that, The method comprises the following steps: Step (1): applying a finishing liquid formed by graphene and its derivative dispersion and polyvinyl alcohol to the fabric substrate by padding, coating or spraying, and drying or heat treating to form a moisture conducting layer; Step (2): applying a finishing liquid formed by a temperature and humidity responsive polymer copolymer to the air side surface of the moisture conducting layer of the fabric substrate by coating or spraying, and drying or heat treating to form a temperature and humidity responsive layer; Step (3): applying a nano-super-hydrophobic finishing liquid formed by nano-silica sol, siloxane coupling agent and fluorosilicon modifier to the temperature and humidity responsive layer by coating or spraying, and drying, heat treating or light curing to form a super-hydrophobic layer; and finally placing the fabric at room temperature for post-curing to obtain the graphene modified fiber functional composite fabric.

7. The method for preparing the graphene-modified fiber functional composite fabric as described in claim 6, characterized in that, The step (1) comprises: Moisture conducting finishing liquid preparation: adding graphene and its derivative into deionized water, and ultrasonicating to obtain graphene and its derivative dispersion; heating to 80-90℃; then adding polyvinyl alcohol, stirring and cooling to room temperature; and then adding phosphoric acid and stirring for 20-30 min to obtain a moisture conducting finishing liquid formed by graphene and its derivative dispersion and polyvinyl alcohol; Padding operation: the pretreated fabric is padded in the moisture-conducting finishing liquid by two-dip-two-pad method, the pick-up is controlled at 75±5%, and the line speed is controlled at 15-18 m / min; Drying and curing: the fabric is dried at 90-100 ℃ for 3-5 min, and then cured at 115-125 ℃ for 3-5 min to form the moisture-conducting layer.

8. The method for preparing the graphene-modified fiber functional composite fabric as described in claim 6, characterized in that, The step (2) comprises: Preparation of copolymer finishing liquid: N-isopropyl acrylamide, acrylic acid and acrylamide are dissolved in a solvent to form a monomer solution by stirring; then a crosslinking agent, an initiator and an assistant initiator are added, and the stirring is continued at room temperature for 25-35 min to form the copolymer finishing liquid; Application method: The fabric obtained in step (1) is flattened, and the copolymer finishing solution is uniformly coated or sprayed on the air side of the moisture conducting layer of the fabric, with the loading amount controlled to be 0.5-1.0 g / m 2 ; Drying and polymerization: the fabric is dried at 75-85 ℃ for 3-5 min, and then heat-treated at 100-145 ℃ for 3-10 min to form the warm and humid response layer.

9. The method for preparing the graphene-modified fiber functional composite fabric as described in claim 6, characterized in that, The step (3) comprises: Preparation of nano-super-hydrophobic finishing liquid: nano-silica sol is added in ethanol and ultrasonically treated; a siloxane coupling agent is added and stirred for 20-30 min; a fluorosilicon modifier is added and continuously stirred for 20-30 min; then the pH is adjusted to 4-5, and the stirring is continued for 25-35 min to obtain the nano-super-hydrophobic finishing liquid; Application method: the fabric obtained in step (2) is placed with the air side upward, and the nano super-hydrophobic finishing liquid is sprayed or coated, with the loading amount controlled to be 0.5-1.0 g / m 2 ; Drying and curing: the fabric is dried at 75-85 ℃ for 3-5 min, and then heat-treated at 110-150 ℃ for 2-10 min to form the super-hydrophobic layer; finally, the fabric is placed at room temperature for post-curing to obtain the graphene-modified fiber functional composite fabric.

10. Use of graphene-modified fiber functional composite fabric, characterized in that, Clothing made of the graphene-modified fiber functional composite fabric according to any one of claims 1-5. Clothing made of the graphene-modified fiber functional composite fabric according to any one of claims 1-5.

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