A method for preparing a high-conductivity flexible liquid crystal state polyarylate nanofiber membrane by in-situ self-assembly

Abstract

The application relates to a method for preparing a high-conductivity flexible liquid crystal state polyarylate nanofiber membrane by in-situ self-assembly, which comprises the following steps: S1. grafting active groups on the surface of conductive nanoparticles; S2. preparing conductive nanoparticles grafted with ionic organic long chains; S3. preparing a conductive liquid crystal state polyarylate resin; S4. preparing a conductive liquid crystal state polyarylate fiber; S5. preparing a conductive liquid crystal state polyarylate nanofiber dispersion liquid; S6. preparing a conductive flexible liquid crystal state polyarylate nanofiber membrane; and S7. in-situ growing metal particles on the surface of the nanofiber membrane and then electroplating, and the method is completed. The method provided by the application solves the problems of the prior art, such as the need for pretreatment of the surface of a fiber fabric, damage to the fiber, a complicated process and low mechanical strength of a prepared conductive membrane material, and the prepared metal fiber membrane has excellent flexibility, mechanical properties, flame retardancy and super-low water absorption and other comprehensive performances, and can be used for manufacturing anti-radiation clothes.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of thin film materials, and particularly relates to a method for preparing a high-conductivity flexible liquid crystal state polyarylate nanofiber film by in-situ self-assembly. BACKGROUND

[0002] Liquid crystal polymer (LCP) has unique one-dimensional or two-dimensional long-range molecular orientation, and is compatible with both polymer and liquid crystal characteristics, so that it has excellent properties such as high heat resistance, high modulus, low melt viscosity, extremely small thermal expansion coefficient, low dielectric loss, high strength, and rapid development. Heat-induced LCP fibers also develop rapidly and have excellent performance in terms of ultraviolet resistance, dye compatibility, mechanical strength, and wear resistance, and have been applied in aerospace, heavy ships, special ropes, etc. For example, Vectran HT fiber launched by Kuraray Company in 2008 and chitinous LCP fiber which has been highly researched. In addition, the current common method for metalizing the surface of fiber fabric is chemical plating of fiber fabric, such as Chinese patents CN101550546A and CN112779480A. However, chemical plating itself has the problems of complicated process flow and complex operation, and the pretreatment process of chemical plating may cause damage to the fiber itself. Therefore, it is necessary to find a simple and efficient method for metalizing the surface of fiber fabric, while ensuring high uniformity of the metalized fiber surface and high conductivity, high heat resistance, high flame retardance and high mechanical strength of the obtained metalized fiber film. SUMMARY

[0003] The present application provides a method for preparing a high-conductivity flexible liquid crystal state polyarylate nanofiber film by in-situ self-assembly, which aims to overcome the problems of complicated process and low efficiency in the surface metalization of fiber fabric in the prior art, and the defects of general conductivity, low heat resistance, poor flame retardance and low strength of the existing conventional conductive film.

[0004] The technical solution of the present application to solve the above technical problems is as follows: a method for preparing a high-conductivity flexible liquid crystal state polyarylate nanofiber film by in-situ self-assembly, which comprises the following steps:

[0005] S1. grafting active groups on the surface of conductive nanoparticles by physical or chemical methods;

[0006] S2. adding the prepared surface-modified conductive nanoparticles to an ionic organic long-chain compound solution to prepare conductive nanoparticles grafted with ionic organic long chains;

[0007] S3. uniformly dispersing the conductive nanoparticles grafted with ionic organic long chains in liquid crystal state polyarylate resin by using the repulsion effect between like charges through a double screw melt blending method to prepare conductive liquid crystal state polyarylate resin;

[0008] S4. Spinning the conductive liquid crystal state polyarylate resin into a conductive liquid crystal state polyarylate fiber by melt spinning;

[0009] S5. Adding the conductive liquid crystal state polyarylate fiber into a hydroquinone aqueous solution, and then dissociating the conductive liquid crystal state polyarylate fiber into a conductive liquid crystal state polyarylate nanofiber dispersion liquid through an ultrasonic kneading device;

[0010] S6. Preparing the conductive liquid crystal state polyarylate nanofiber dispersion liquid into a conductive liquid crystal state polyarylate nanofiber nascent paper through suction filtration, and then preparing the nanofiber nascent paper into a conductive flexible liquid crystal state polyarylate nanofiber membrane through hot-pressing consolidation;

[0011] S7. Immersing the conductive flexible liquid crystal state polyarylate nanofiber membrane into a metal complex solution, growing metal particles on the surface of the liquid crystal state polyarylate nanofiber membrane in situ through an oxidation-reduction reaction, and then growing an ultra-thin and firm metal conductive layer on the surface of the metal particles on the fiber membrane through electroplating, to obtain a high-conductive flexible liquid crystal state polyarylate nanofiber membrane.

[0012] On the basis of the above technical solutions, the application can also be further specifically selected or more optimally selected as follows.

[0013] Specifically, the physical or chemical method used in S1 is plasma treatment, hydrothermal treatment or acid-base liquid treatment, and the active groups grafted on the surface of the conductive nanoparticles are one or more of hydroxyl, amino, carboxyl, sulfonic acid group, alkyne group, aldehyde group and carbonyl group.

[0014] Specifically, the conductive nanoparticles in S1 are one or more of graphene nanosheets, carbon nanotubes, MXene, carbon nanofibers, gold nanoparticles, silver nanoparticles, silver nanowires and copper nanoparticles.

[0015] Specifically, the particle size of the conductive nanoparticles in S1 is 5-200 nm.

[0016] Specifically, the ionic organic long-chain compound in S2 is hexamethonium hydroxide, tetra(3-mercaptopropionic acid) pentaerythritol ester, pentaerythritol allyl ether, pentaerythritol triacrylate, (2-aminoethyl) trimethylammonium chloride hydrochloride, dimethyloctadecyl [3-(trimethoxysilyl) propyl] ammonium chloride, nitrogen-site-trimethoxysilylpropyl-nitrogen, nitrogen, nitrogen-site-trimethylammonium chloride, (3-triethoxysilylpropyl) trimethylammonium chloride, dimethyl(3-trimethoxysilylpropyl) tetraacetate ammonium, N-(trimethoxysilylpropyl) ethylenediamine triacetate sodium salt.

[0017] Specifically, the concentration of the ionic organic long-chain compound solution in S2 is 1-25 wt%, and the ratio of the surface-modified conductive nanoparticles to the ionic organic long-chain compound solution is 0.2-0.8 g:100 mL.

[0018] Specifically, the mass ratio of the surface-grafted ionic organic long-chain conductive nanoparticles to the liquid crystal state polyarylate resin in S3 is 0.1:100-1000; the temperature of the double-screw melt blending in S3 is 250-500 ℃, and the shear rate is 0.5-200 r / min.

[0019] Specifically, the spinning temperature in S4 is 180-550 ℃, the drawing temperature is 60-350 ℃, the setting temperature is 150-450 ℃, the nozzle drawing ratio is 1:1-1:50, the drawing ratio is 1:1-1:20, and the winding speed is 50-3000 m / s.

[0020] Specifically, the concentration of the phenylenediamine aqueous solution in S5 is 5-85 wt%, the ultrasonic frequency of the ultrasonic kneading device is 25-150 KHz, and the kneading frequency is 10-200 r / min; the hot-pressing temperature in S6 is 50-350 ℃, and the hot-pressing pressure is 5-100 MPa.

[0021] Specifically, the metal complex solution in S7 is a copper ammonia solution or a silver ammonia solution, and the concentration is 0.5 mg / L; the ratio of the conductive flexible liquid crystal state polyarylate nanofiber membrane to the metal complex solution is 0.5 g:100-300 mL; the electroplating process is copper electroplating, silver electroplating or nickel electroplating, and the thickness of the formed metal conductive layer is 0.05-0.10 mm.

[0022] Compared with the prior art, the beneficial effects of the present application are:

[0023] The present application utilizes the characteristics of high flame retardance and good mechanical strength of liquid crystal state polyarylate, before spinning, ion type long chain conductive nanoparticles are added to the liquid crystal state polyarylate resin, and the homocharges are repelled, the conductive liquid crystal state polyarylate with uniformly dispersed conductive nanoparticles is obtained by using double screw melt blending, on this basis, melt spinning and ultrasonic kneading are carried out to obtain liquid crystal state polyarylate nanofiber, after filtration, heat pressing is carried out to make the film, and the mechanical strength and heat resistance of the polyarylate fiber are further enhanced, finally, a layer of ultra-thin and firm metal conductive layer is formed on the surface of the fiber film by growing metal particles on the film surface in situ and then electroplating, which solves the problems of roughening pretreatment of the fiber fabric surface, damage to the fiber, complex process and low mechanical strength of the prepared conductive film material. The metal fiber film prepared by the present application has excellent softness, mechanical properties, chemical resistance, heat resistance, flame retardance, ultra-low water absorption and ultra-low water vapor transmission rate, has excellent dimensional stability and processing formability, and can be used to manufacture anti-radiation clothes. DETAILED DESCRIPTION

[0024] The present application will be further described in detail below in combination with specific examples, and the examples are only used to explain the present application and not to limit the scope of the present application.

[0025] For the sake of brevity, the solvents or the remaining raw materials used in the following examples are all commercially available products if not specifically stated, and the methods used are all conventional methods in the art if not specifically stated.

[0026] Example 1

[0027] A method for preparing high-conductivity flexible liquid crystal state polyarylate nanofiber film by in-situ self-assembly, comprising the following steps:

[0028] S1. The conductive nanoparticles are subjected to plasma treatment to graft active groups on the surface of the conductive nanoparticles, the active groups including one or more combinations of hydroxyl, amino, carboxyl, sulfonic acid, alkyne, aldehyde, carbonyl and the like; the conductive nanoparticles are silver nanoparticles with a particle size of 80-130 nm.

[0029] S2. An ion type long chain compound solution is prepared, the temperature of the solution is controlled at 80℃, the surface modified conductive silver nanoparticles are added to the ion type long chain compound solution, the temperature is raised to 90℃ and maintained at this temperature for 36h of continuous stirring to prepare the surface grafted ion type long chain conductive nanoparticles; the ion type long chain compound solution is a hexamethonium hydroxide aqueous solution with a concentration of 25wt%, and the amount ratio of the surface modified conductive nanoparticles to the ion type long chain compound solution is 0.4g:100mL.

[0030] S3. Utilizing the repulsion effect between same charges, the surface grafted ion type organic long chain conductive silver nanoparticles are uniformly dispersed in the liquid crystal state polyarylate resin by double screw melt blending, to obtain a conductive liquid crystal state polyarylate resin; wherein the mass ratio of the surface grafted ion type organic long chain conductive nanoparticles to the liquid crystal state polyarylate resin is 0.1:100, the double screw melt blending temperature is 250-300℃, and the shear rate is 50-80r / min.

[0031] S4. The conductive liquid crystal state polyarylate resin is spun into a conductive liquid crystal state polyarylate fiber by melt spinning; the spinning temperature is 180-250℃; the drawing temperature is 60-150℃; the setting temperature is 150-260℃; the nozzle drawing ratio is 1:5-10; the drawing ratio is 1:5-8; and the winding speed is 50-100m / s.

[0032] S5. The conductive liquid crystal state polyarylate fiber is added into a hydroquinone aqueous solution, and then the conductive liquid crystal state polyarylate fiber is dissociated into a conductive liquid crystal state polyarylate nanofiber dispersion liquid by an ultrasonic kneading device; the concentration of the hydroquinone aqueous solution is 25wt%, the ultrasonic frequency of the ultrasonic kneading device is 130KHz, and the kneading frequency is 80-100r / min.

[0033] S6. The conductive liquid crystal state polyarylate nanofiber dispersion liquid is prepared into a conductive liquid crystal state polyarylate nanofiber primary paper by suction filtration, and then the nanofiber primary paper is made into a conductive flexible liquid crystal state polyarylate nanofiber film by hot pressing consolidation (hot pressing temperature is 350℃, hot pressing pressure is 100 MPa), and the thickness of the film is 0.213 mm.

[0034] S7. The conductive flexible liquid crystal state polyarylate nanofiber film is immersed into a metal complex solution (silver ammine solution 0.5mg / L), and metal particles are in-situ grown on the surface of the liquid crystal state polyarylate nanofiber film by an oxidation-reduction reaction under alkaline conditions, and the dosage ratio of the liquid crystal state polyarylate nanofiber film to the metal complex solution is 0.5 g:100 mL. Then the film is further immersed into a silver ion solution to grow an ultra-thin and firm metal conductive layer on the surface of the metal particles on the film by electroplating (silver ions in the solution are reduced by using electric current), and the thickness of the metal conductive layer is 0.089 mm, thereby obtaining a high-conductive flexible liquid crystal state polyarylate nanofiber film.

[0035] The obtained high-conductive flexible liquid crystal state polyarylate nanofiber film has a water absorption rate as low as 1%, is strong in heat resistance and flame resistance, has a flame resistance level of UL94V-0, can achieve self-extinguishing away from an open flame, has a low coating rate (the metal conductive layer is not continuous, does not cover the film completely, and is relatively dispersed on the surface of the film), but has excellent electrical conductivity, an electrical conductivity of 152 s / cm, and good bending resistance, and can be repeatedly folded more than 50 times without obvious damage.

[0036] Example 2

[0037] A method for preparing a high-conductivity flexible liquid crystal state polyarylate nanofiber membrane by in-situ self-assembly, comprising the following steps:

[0038] S1. Plasma treatment is performed on conductive nanoparticles to graft active groups on the surface of the conductive nanoparticles, the active groups including one or more combinations of hydroxyl, amino, carboxyl, sulfonic acid, alkyne, aldehyde, carbonyl and the like; the conductive nanoparticles are copper nanoparticles with a particle size of 30-80 nm.

[0039] S2. An ionic organic long-chain compound solution is prepared, the temperature of the solution is controlled at 50°C, the surface-modified conductive gold nanoparticles prepared are added to the ionic organic long-chain compound solution, the temperature is raised to 90°C and maintained at this temperature for 36 h of continuous stirring to prepare conductive nanoparticles grafted with ionic organic long chains; the ionic organic long-chain compound solution is a hexamethonium hydroxide aqueous solution with a concentration of 15 wt%, the amount ratio of the surface-modified conductive nanoparticles to the ionic organic long-chain compound solution is 0.4 g:100 mL.

[0040] S3. The conductive nanoparticles grafted with ionic organic long chains are uniformly dispersed in a liquid crystal state polyarylate resin by a double screw melt blending method through the repulsion effect between like charges to prepare a conductive liquid crystal state polyarylate resin; the mass ratio of the conductive nanoparticles grafted with ionic organic long chains to the liquid crystal state polyarylate resin is 0.1:200, the double screw melt blending temperature is 350-500°C, and the shear rate is 80-100 r / min.

[0041] S4. The conductive liquid crystal state polyarylate resin is spun into a conductive liquid crystal state polyarylate fiber by melt spinning; the spinning temperature is 280-350°C; the drawing temperature is 150-230°C; the setting temperature is 260-300°C; the nozzle drawing ratio is 1:15-20; the drawing ratio is 1:15-20; and the winding speed is 100-300 m / s.

[0042] S5. The conductive liquid crystal state polyarylate fiber is added to a hydroquinone aqueous solution, and then the conductive liquid crystal state polyarylate fiber is dissociated into a conductive liquid crystal state polyarylate nanofiber dispersion liquid by an ultrasonic kneading device; the concentration of the hydroquinone aqueous solution is 45 wt%, the ultrasonic frequency of the ultrasonic kneading device during ultrasonic kneading is 100 KHz, and the kneading frequency is 150 r / min.

[0043] S6. The conductive liquid crystalline polyarylate nanofiber dispersion is prepared into a conductive liquid crystalline polyarylate nanofiber nascent paper by suction filtration, and then the nanofiber nascent paper is consolidated into a conductive flexible liquid crystalline polyarylate nanofiber membrane by hot pressing (hot pressing temperature is 250°C, hot pressing pressure is 80 MPa), and the thickness of the conductive flexible liquid crystalline polyarylate nanofiber membrane is 0.288 mm;

[0044] S7. The conductive flexible liquid crystalline polyarylate nanofiber membrane is immersed into a metal complex solution (silver-ammonia solution 0.5 mg / L), and metal particles are in-situ grown on the surface of the liquid crystalline polyarylate nanofiber membrane by an oxidation-reduction reaction under alkaline conditions, and the dosage ratio of the liquid crystalline polyarylate nanofiber membrane to the metal complex solution is 0.5 g:150 mL. Then, a super-thin and firm metal conductive layer is grown on the surface of the metal particles on the fiber membrane by copper electroplating, and the thickness of the metal conductive layer is 0.073 mm, thereby obtaining a high-conductive flexible liquid crystalline polyarylate nanofiber membrane.

[0045] The mechanical strength of the prepared high-conductive flexible liquid crystalline polyarylate nanofiber membrane is 1 kg / cm 2 , the flame-retardant level is UL94 V-0, the water absorption is as low as 1%, the electrical conductivity is 102 s / cm, the coating rate is low, but the electrical conductivity is excellent, and the bending resistance is better, and the liquid crystalline polyarylate nanofiber membrane can be repeatedly folded more than 50 times without obvious damage.

[0046] Example 3

[0047] A method for preparing a high-conductive flexible liquid crystalline polyarylate nanofiber membrane by in-situ self-assembly, comprising the following steps:

[0048] S1. The conductive nanoparticles are subjected to plasma treatment to graft active groups on the surface of the conductive nanoparticles, and the active groups include one or more combinations of hydroxyl, amino, carboxyl, sulfonic acid, alkyne, aldehyde, carbonyl and the like; the conductive nanoparticles are copper nanoparticles with a particle size of 120-200 nm.

[0049] S2. An ionic organic long-chain compound solution is prepared, the temperature of the solution is controlled at 60°C, the prepared surface-modified conductive nanoparticles are added into the ionic organic long-chain compound solution, the temperature is raised to 90°C and maintained for 36 h of continuous stirring at this temperature, and the conductive nanoparticles with ionic organic long-chain groups grafted on the surface are prepared; the ionic organic long-chain compound solution is a (3-triethoxysilylpropyl) trimethylammonium chloride aqueous solution with a concentration of 5 wt%, and the dosage ratio of the surface-modified conductive nanoparticles to the ionic organic long-chain compound solution is 0.8 g:100 mL.

[0050] S3. Utilizing the repulsion effect between same charges, the surface grafted ion type organic long chain conductive nanoparticles are uniformly dispersed in the liquid crystal state polyarylate resin by double screw melt blending method to obtain the conductive liquid crystal state polyarylate resin; wherein the mass ratio of the surface grafted ion type organic long chain conductive nanoparticles to the liquid crystal state polyarylate resin is 0.1:400, the double screw melt blending temperature is 250-300℃, and the shear rate is 25-60r / min.

[0051] S4. The conductive liquid crystal state polyarylate resin is spun into a conductive liquid crystal state polyarylate fiber by melt spinning; the spinning temperature is 180-200℃; the drawing temperature is 60-90℃; the setting temperature is 150-200℃; the nozzle drawing ratio is 1:5-10; the drawing ratio is 1:5-10; and the winding speed is 50-80m / s.

[0052] S5. The conductive liquid crystal state polyarylate fiber is added into a hydroquinone aqueous solution, and then the conductive liquid crystal state polyarylate fiber is dissociated into a conductive liquid crystal state polyarylate nanofiber dispersion liquid by an ultrasonic kneading device; the concentration of the hydroquinone aqueous solution is 60wt%, the ultrasonic frequency of the ultrasonic kneading device is 25-50KHz, and the kneading frequency is 100-140r / min.

[0053] S6. The conductive liquid crystal state polyarylate nanofiber dispersion liquid is prepared into a conductive liquid crystal state polyarylate nanofiber primary paper by suction filtration, and then the nanofiber primary paper is made into a conductive flexible liquid crystal state polyarylate nanofiber membrane by hot pressing consolidation (hot pressing temperature is 150℃, hot pressing pressure is 75MPa), and the thickness is 0.258 mm.

[0054] S7. The conductive flexible liquid crystal state polyarylate nanofiber membrane is immersed into a metal complex solution (silver ammine solution 0.5mg / L), metal particles are in-situ grown on the surface of the liquid crystal state polyarylate nanofiber membrane by an oxidation-reduction reaction, the dosage ratio of the liquid crystal state polyarylate nanofiber membrane to the metal complex solution is 0.5 g:200mL, and then a super-thin and firm metal conductive layer is grown on the surface of the metal particles on the fiber membrane by copper electroplating, and the thickness of the metal conductive layer is 0.095 mm, thereby obtaining a high-conductive flexible liquid crystal state polyarylate nanofiber membrane.

[0055] The mechanical strength of the obtained high-conductive flexible liquid crystal state polyarylate nanofiber membrane is 1kg / cm 2 , the flame retardant level is UL94V-0, the water absorption is as low as 1%, the conductivity is 123 s / cm, the coating rate is low, but the conductivity is excellent, and the bending resistance is better, and the membrane can be repeatedly folded more than 50 times without obvious damage.

[0056] Example 4

[0057] A method for preparing a high-conductivity flexible liquid crystal state polyarylate nanofiber membrane by in-situ self-assembly, comprising the following steps:

[0058] S1. Plasma treatment is performed on conductive nanoparticles to graft active groups on the surface of the conductive nanoparticles, the active groups including one or more combinations of hydroxyl, amino, carboxyl, sulfonic acid, alkyne, aldehyde, carbonyl and the like; the conductive nanoparticles are graphene nanoplates with a particle size of 70-120 nm.

[0059] S2. An ionic organic long-chain compound solution is prepared, the temperature of the solution is controlled at 80℃, the prepared surface-modified conductive nanoparticles are added to the ionic organic long-chain compound solution, the temperature is raised to 90℃ and maintained for 36 h of stirring at the temperature, to prepare conductive nanoparticles grafted with ionic organic long chains; the ionic organic long-chain compound solution is a (3-triethoxysilylpropyl) trimethylammonium chloride solution with a concentration of 5 wt%, and the amount ratio of the surface-modified conductive nanoparticles to the ionic organic long-chain compound solution is 0.6 g:100 mL.

[0060] S3. The surface-grafted conductive nanoparticles with ionic organic long chains are uniformly dispersed in a liquid crystal state polyarylate resin by a double-screw melt blending method through the repulsion effect between like charges, to prepare a conductive liquid crystal state polyarylate resin; the mass ratio of the surface-grafted conductive nanoparticles with ionic organic long chains to the liquid crystal state polyarylate resin is 0.1:500, the double-screw melt blending temperature is 450-500℃, and the shear rate is 160-200 r / min.

[0061] S4. The conductive liquid crystal state polyarylate resin is spun into a conductive liquid crystal state polyarylate fiber by melt spinning; the spinning temperature is 500-550℃; the drawing temperature is 280-350℃; the setting temperature is 400-450℃; the nozzle drawing ratio is 1:40-50; the drawing ratio is 1:16-20; and the winding speed is 500-1000 m / s.

[0062] S5. The conductive liquid crystal state polyarylate fiber is added to a hydroquinone aqueous solution, and then the conductive liquid crystal state polyarylate fiber is dissociated into a conductive liquid crystal state polyarylate nanofiber dispersion liquid by an ultrasonic kneading device; the concentration of the hydroquinone aqueous solution is 75 wt%, the ultrasonic frequency of the ultrasonic kneading device during ultrasonic kneading is 150 KHz, and the kneading frequency is 200 r / min.

[0063] S6. The conductive liquid crystalline polyarylate nanofiber dispersion is prepared into a conductive liquid crystalline polyarylate nanofiber nascent paper by suction filtration, and then the nanofiber nascent paper is prepared into a conductive flexible liquid crystalline polyarylate nanofiber membrane by hot pressing consolidation (hot pressing temperature is 350°C, hot pressing pressure is 100 MPa), and the thickness is 0.357 mm;

[0064] S7. The conductive flexible liquid crystalline polyarylate nanofiber membrane is immersed into a metal complex solution (silver amine solution 0.5 mg / L), and metal particles are in-situ grown on the surface of the liquid crystalline polyarylate nanofiber membrane by an oxidation-reduction reaction, and the dosage ratio of the liquid crystalline polyarylate nanofiber membrane to the metal complex solution is 0.5 g:240 mL, and then a super-thin and firm metal conductive layer is grown on the surface of the metal particles on the fiber membrane by copper electroplating, and the thickness of the metal conductive layer is 0.078 mm, and a high-conductive flexible liquid crystalline polyarylate nanofiber membrane is obtained.

[0065] The water absorption rate of the prepared high-conductive flexible liquid crystalline polyarylate nanofiber membrane is as low as 1%, the heat resistance and flame resistance are strong, the self-extinguishing away from open flame can be realized, the conductivity is excellent, the electrical conductivity is 172 s / cm, the bending resistance is better, and the fiber membrane can be repeatedly folded more than 50 times without obvious damage.

[0066] Example 5

[0067] A method for preparing a high-conductive flexible liquid crystalline polyarylate nanofiber membrane by in-situ self-assembly, comprising the following steps:

[0068] S1. The conductive nanoparticles are subjected to plasma treatment to graft active groups on the surface of the conductive nanoparticles, and the active groups include one or more combinations of hydroxyl, amino, carboxyl, sulfonic acid, alkyne, aldehyde, carbonyl and the like; the conductive nanoparticles are graphene nanosheets with a particle size of 150-200 nm.

[0069] S2. An ionic organic long-chain compound solution is prepared, the solution temperature is controlled at 75°C, the prepared surface-modified conductive nanoparticles are added into the ionic organic long-chain compound solution, the temperature is raised to 90°C and maintained at this temperature for 36 h of continuous stirring to prepare the conductive nanoparticles grafted with ionic organic long-chain; the ionic organic long-chain compound solution is a hexamethonium hydroxide aqueous solution with a concentration of 10 wt%, and the dosage ratio of the surface-modified conductive nanoparticles to the ionic organic long-chain compound solution is 0.8 g:100 mL.

[0070] S3. Utilizing the repulsion effect between same charges, the surface grafted ion type organic long chain conductive nanoparticles are uniformly dispersed in the liquid crystal state polyarylate resin by double screw melt blending method to obtain a conductive liquid crystal state polyarylate resin; wherein the mass ratio of the surface grafted ion type organic long chain conductive nanoparticles to the liquid crystal state polyarylate resin is 0.1:1000, the double screw melt blending temperature is 350-400℃, and the shear rate is 80-120 r / min.

[0071] S4. The conductive liquid crystal state polyarylate resin is spun into a conductive liquid crystal state polyarylate fiber by melt spinning; the spinning temperature is 300-400℃; the drawing temperature is 180-240℃; the setting temperature is 270-320℃; the nozzle drawing ratio is 1:25-30; the drawing ratio is 1:10-15; and the winding speed is 2500-3000 m / s.

[0072] S5. The conductive liquid crystal state polyarylate fiber is added into a hydroquinone aqueous solution, and then the conductive liquid crystal state polyarylate fiber is dissociated into a conductive liquid crystal state polyarylate nanofiber dispersion liquid by an ultrasonic kneading device; the concentration of the hydroquinone aqueous solution is 60 wt%, the ultrasonic frequency of the ultrasonic kneading device is 125 KHz, and the kneading frequency is 100 r / min.

[0073] S6. The conductive liquid crystal state polyarylate nanofiber dispersion liquid is prepared into a conductive liquid crystal state polyarylate nanofiber primary paper by suction filtration, and then the nanofiber primary paper is made into a conductive flexible liquid crystal state polyarylate nanofiber membrane by hot pressing consolidation (hot pressing temperature is 300℃, hot pressing pressure is 75 MPa), and the thickness is 0.318 mm.

[0074] S7. The conductive flexible liquid crystal state polyarylate nanofiber membrane is immersed into a metal complex solution (silver ammine solution 0.5 mg / L), metal particles are in-situ grown on the surface of the liquid crystal state polyarylate nanofiber membrane by an oxidation-reduction reaction, the dosage ratio of the liquid crystal state polyarylate nanofiber membrane to the metal complex solution is 0.5 g:300 mL, and then a super-thin and firm metal conductive layer is grown on the surface of the metal particles on the fiber membrane by copper electroplating, and the thickness of the metal conductive layer is 0.086 mm, thereby obtaining a high-conductive flexible liquid crystal state polyarylate nanofiber membrane.

[0075] The high-conductive flexible liquid crystal state polyarylate nanofiber membrane has a water absorption rate as low as 1%, is strong in heat resistance and flame resistance, can realize self-extinguishing away from an open flame, has excellent conductivity with an electrical conductivity of 162 s / cm, and has good bending resistance and can be repeatedly folded more than 50 times without obvious damage.

[0076] The above merely describes preferred embodiments of the present application, and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a high conductive flexible liquid crystalline state polyarylate nanofiber membrane by in-situ self-assembly, characterized in that, It comprises the following steps: S1. Grafting active groups on the surface of conductive nanoparticles by physical or chemical methods; S2. Adding the prepared surface-modified conductive nanoparticles to an ionic organic long-chain compound solution to prepare surface-grafted ionic organic long-chain conductive nanoparticles; S3. Using the repulsion effect between like charges, the surface-grafted ionic organic long-chain conductive nanoparticles are uniformly dispersed in liquid crystal state polyarylate resin by double screw melt blending to prepare conductive liquid crystal state polyarylate resin; S4. The conductive liquid crystal state polyarylate resin is spun into conductive liquid crystal state polyarylate fiber by melt spinning; S5. The conductive liquid crystal state polyarylate fiber is added to a hydroquinone aqueous solution, and then the conductive liquid crystal state polyarylate fiber is dissociated into a conductive liquid crystal state polyarylate nanofiber dispersion liquid by an ultrasonic kneading device; S6. The conductive liquid crystal state polyarylate nanofiber dispersion liquid is prepared into a conductive liquid crystal state polyarylate nanofiber primary paper by suction filtration, and then the nanofiber primary paper is made into a conductive flexible liquid crystal state polyarylate nanofiber membrane by hot pressing consolidation; S7. The conductive flexible liquid crystal state polyarylate nanofiber membrane is immersed into a metal complex solution, and metal particles are in-situ grown on the surface of the liquid crystal state polyarylate nanofiber membrane by an oxidation-reduction reaction, and then a super-thin and firm metal conductive layer is grown on the surface of the metal particles on the fiber membrane by electroplating, thereby obtaining a high-conductive flexible liquid crystal state polyarylate nanofiber membrane; In S2, the ionic organic long-chain compound is hexamethonium hydroxide, (2-aminoethyl) trimethylammonium chloride hydrochloride, dimethyloctadecyl [3-(trimethoxysilyl) propyl] ammonium chloride, nitrogen-site-trimethoxysilyl propyl-nitrogen, nitrogen, nitrogen-site-trimethylammonium chloride, (3-triethoxysilyl propyl) trimethylammonium chloride, dimethyl (3-trimethoxysilyl propyl) ammonium tetraacetate, and N-(trimethoxysilyl propyl) ethylenediamine triacetate sodium salt.

2. The method of claim 1, wherein the in-situ self-assembly method of preparing high conductive flexible liquid crystalline polyarylate nanofiber membranes is characterized by, The physical or chemical method used in S1 is plasma treatment, hydrothermal treatment, or acid-base liquid treatment, and the active groups grafted on the surface of the conductive nanoparticles are one or more of hydroxyl, amino, carboxyl, sulfonic acid group, alkyne group, aldehyde group, and carbonyl group.

3. The method of claim 1, wherein the in-situ self-assembly method of preparing high conductive flexible liquid crystalline polyarylate nanofiber membranes is characterized by, The conductive nanoparticles in S1 are one or more of graphene nanosheets, carbon nanotubes, MXene, carbon nanofiber, gold nanoparticles, silver nanoparticles, silver nanowires, and copper nanoparticles.

4. The method of claim 1, wherein the in-situ self-assembly method of preparing high conductive flexible liquid crystalline polyarylate nanofiber membranes is characterized by, The particle size of the conductive nanoparticles in S1 is 5-200 nm.

5. The method of claim 1, wherein the in-situ self-assembly method of preparing high conductive flexible liquid crystalline polyarylate nanofiber membranes is characterized by, The concentration of the ionic organic long-chain compound solution in S2 is 1-25 wt%, and the dosage ratio of the surface-modified conductive nanoparticles to the ionic organic long-chain compound solution is 0.2-0.8 g:100 mL.

6. The method of claim 1, wherein the in-situ self-assembly method of preparing high conductive flexible liquid crystalline polyarylate nanofiber membranes is characterized by, The mass ratio of the surface-grafted ionic organic long-chain conductive nanoparticles to the liquid crystal state polyarylate resin in S3 is 0.1:100-1000, the double screw melt blending temperature is 250-500 ℃, and the shear rate is 0.5-200 r / min.

7. The method of claim 1, wherein the in-situ self-assembly method of preparing high conductive flexible liquid crystalline polyarylate nanofiber membranes is characterized by, The spinning temperature in S4 is 180-550 DEG C, the drawing temperature is 60-350 DEG C, the setting temperature is 150-450 DEG C, the nozzle drawing ratio is 1:1-1:50, the drawing ratio is 1:1-1:20, and the winding speed is 50-3000 m / s.

8. The method of claim 1, wherein the in-situ self-assembly method of preparing high conductive flexible liquid crystalline polyarylate nanofiber membranes is characterized by, The concentration of the phenylenediamine aqueous solution in S5 is 5-85 wt%, the ultrasonic frequency of the ultrasonic kneading device is 25-150 KHz, and the kneading frequency is 10-200 r / min; the hot-pressing temperature in S6 is 50-350 DEG C, and the hot-pressing pressure is 5-100 MPa.

9. The method of claim 1, wherein the in-situ self-assembly method of preparing high conductive flexible liquid crystalline polyarylate nanofiber membranes is characterized by, The metal complex solution in S7 is a copper ammonia solution or a silver ammonia solution, the concentration is 0.5 mg / L, and the dosage ratio of the conductive flexible liquid crystal state polyarylate nanofiber membrane to the metal complex solution is 0.5 g:100-300 mL; the electroplating process is copper electroplating, silver electroplating or nickel electroplating, and the thickness of the metal conductive layer formed is 0.05-0.10 mm.