Preparation method of antibacterial and heat-preserving graphene quantum dot cloud velvet

Abstract

The present invention discloses a preparation method of antibacterial and warm graphene quantum dot cloud fluff, which relates to the technical field of cloud fluff. First, monolayer graphene is prepared by a chemical method, and then monolayer graphene quantum dots are prepared through an electrochemical reaction. Not only does it reach the nanometer level in terms of size, but its monolayer structure is also sharper, which can improve the sterilization effect; it is modified to make its surface rich in carboxyl groups, which are attached to cellulose to improve the agglomeration problem; secondly, the strong interaction between ball milling and polar solvents rich in hydroxyl groups is utilized, combined with ultrasound to break the intermolecular hydrogen bonds of cellulose macromolecules; then it is combined with hydroxy cashew phenol with a hydroxyl group in the side chain, and synergistically and efficiently catalyzes the generation of reactive oxygen with the graphene quantum dots attached to cellulose to achieve the sterilization effect; then the modified nanocellulose is prepared into an aerogel, which is added into polyester as an antibacterial masterbatch to prepare cloud fluff, improving the warming effect. The cloud fluff prepared by the present invention has antibacterial and warming effects.

Description

Technical Field

[0001] The present invention relates to the technical field of cloud velvet, and specifically to a preparation method of antibacterial and warm graphene quantum dot cloud velvet. Background Art

[0002] Cloud velvet is actually a kind of fiber made by a new process. It has good warmth retention and high elasticity, is comfortable and soft. Usually, cloud velvet can be processed and applied in many fields such as clothing and household items. Cloud velvet is a completely new fiber different from the traditional ones. It adopts a brand-new polyester production process and the technology of blending multiple PET polymer materials. After being processed into spherical velvet, it feels very comfortable to the touch, giving a feeling like congealed fat. When you hold it with both hands, it also has a sense of fullness. Now cloud velvet can be used as the filling of many items, including pillows, quilts, fabric dolls, sofas, soft beds, etc.

[0003] However, there are still many defects in the preparation of cloud velvet at present. Firstly, for antibacterial cellulose, cellulose nanofibers are first prepared and then physically combined with antibacterial agents. The process is cumbersome, the operation is complex, the separation of intermediate products is difficult, and the yield is low. Since the antibacterial agent is only dispersed on the surface of nanofibers, it is easy to fall off, the antibacterial persistence is poor, it is difficult to reuse, the stability is poor, and the addition of a single inorganic antibacterial agent makes the antibacterial effect limited. Secondly, the addition of graphene quantum dots is prone to aggregation due to π-π conjugate bonds. While the performance of the produced cloud velvet is poor, the bactericidal effect of graphene quantum dots is also greatly reduced. Therefore, the present invention proposes a preparation method to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of antibacterial and warm graphene quantum dot cloud velvet to solve the problems existing in the prior art.

[0005] To solve the above technical problems, the present invention provides the following technical solution: A preparation method of antibacterial and warm graphene quantum dot cloud velvet, including the following preparation steps:

[0006] (1)Take 3 portions of natural graphite powder, add 12 portions of concentrated sulfuric acid, 2 - 3 portions of potassium persulfate, and 2 - 3 portions of phosphorus pentoxide, mix them evenly at 80°C, and let the reaction proceed for 4 - 6 h; after the reaction is completed, cool it to room temperature, then add 10 portions of deionized water for dilution and let it stand for 24 h, then separate by membrane filtration, wash the solid with deionized water 3 times, and then let it stand for 24 h to obtain pre-oxidized graphite; slowly add the pre-oxidized graphite to 120 - 140 portions of a cooled mixed solution at 0°C while stirring, with a stirring speed of 60 rpm, stir at 35°C for 2 h, then dilute with 250 portions of deionized water, continue stirring for 2 h, then add 600 portions of deionized water, and then add 15 - 25 portions of hydrogen peroxide solution after stirring for another 2 h; filter, wash the solid with a dilute hydrochloric acid aqueous solution with a concentration of 8% 2 times, then wash with deionized water 3 times, and then dialyze the product for one week to obtain oxidized graphite; prepare the obtained oxidized graphite into an aqueous solution with a concentration of 0.5 mg / ml, and perform ultrasonic treatment in an ultrasonic machine for 30 min, with an ultrasonic power of 35 kHz, to obtain a single-layer oxidized graphite sheet solution; then place the single-layer oxidized graphite sheet solution in a high-speed centrifuge for centrifugal separation, with a centrifugal speed of 15000 rpm and a time of 20 min, and vacuum-dry the obtained solid at 0.085 MPa for 2 h; disperse the dried graphene oxide solid in dimethyl sulfoxide solution, with a dosage ratio of 1:1, stir at 150 rpm for 20 min until evenly mixed, then transfer it to a reaction kettle, and react at 160 - 200°C for 10 - 14 h, after filtration, wash with deionized water 3 times, and vacuum-dry at 0.085 MPa for 2 h to obtain single-layer graphene; weigh 2 portions of single-layer graphene, place 1 portion in each centrifuge tube with holes, put a dialysis bag with a molecular weight cut-off of 1000 Da outside the centrifuge tube, and use them as positive and negative electrode materials respectively, with a distance of 2 cm between the two electrode materials; take 20 portions of 1-butyl-3-methyltetrafluoroborate ionic liquid and mix it with 20 portions of deionized water as the electrolyte, soak the electrodes for 1 h, then start to connect the DC power supply, with a DC voltage of 10 V; during the power-on process, exchange the positive and negative electrodes every 2 h, stop power-on after reacting for 10 h; place the electrolyzed electrolyte in a centrifuge tube, centrifuge at a speed of 8000 - 10000 rpm for 30 min to obtain the bottom precipitate, after dialysis, place the liquid in the dialysis bag in a hydrothermal kettle and keep it at 180°C for 3 h; then centrifuge the solution at a speed of 8000 - 10000 rpm for 30 min, wash the solid with deionized water 2 times, and then dry it at normal temperature and pressure for 5 h to prepare single-layer graphene quantum dots; mix 1 portion of single-layer graphene quantum dots with 100 portions of deionized water, then add 10 - 20 portions of bromoacetic acid, ultrasonicate at a power of 30 kHz for 10 - 30 min, and then react at room temperature for 5 h; after the reaction is completed, centrifuge at a speed of 8000 - 10000 rpm for 30 min, wash the solid with deionized water 3 times, and then freeze-dry at -40°C for 2 h to obtain carboxyl-functionalized single-layer graphene quantum dots;

[0007] (2) First, mix the nano-cellulose raw material and montmorillonite at a mass ratio of 0.2-1:1, and perform ball milling. The ball milling speed is 300-600 rpm, and the ball milling time is 3-8 h; prepare a pretreatment solution, adjust the pH to 7, raise the temperature to 40-50 °C, completely immerse the ball-milled nano-cellulose in the pretreatment solution and soak for 12-24 h, with a solid-liquid mass ratio of 1:10. Then raise the temperature of the pretreatment solution to 50-60 °C, adjust the pH to 8, soak for another 1-2 h, and perform low-frequency short-time ultrasonic oscillation at the current temperature to obtain pretreated nano-cellulose; mix the pretreated nano-cellulose, hydroxy-cashew phenol with hydroxyl groups on the micro and side chains, and ethanol at a mass ratio of 2-4:1:10, place them in a reaction kettle, heat to 100-140 °C and react for 2-4 h. After the reaction, centrifuge and wash with deionized water 3 times at a centrifuge speed of 10,000 rpm, collect the upper suspension, and obtain modified nano-cellulose; mix the modified nano-cellulose and deionized water in proportion to prepare a modified nano-fiber dispersion with a mass fraction of 1.0%, and stir evenly at a speed of 150 rpm for 30 min; take 10 parts of the modified nano-fiber dispersion, add an appropriate amount of glacial acetic acid to adjust the pH value of the dispersion to 4, then stir at a speed of 150 rpm for 1 h, and then add carboxyl-functionalized monolayer graphene quantum dots to the dispersion and mix and stir at 150 rpm for 3 h to obtain a uniform solution; finally, pour the solution into a polytetrafluoroethylene mold and freeze in liquid nitrogen for 3 min, and continue vacuum freeze-drying the frozen solid sample at -60 °C and 1 Pa for 48 h to obtain a 0.1-1.5 mm composite aerogel masterbatch;

[0008] (3) Mix terephthalic acid, ethylene glycol, and the composite aerogel masterbatch at a mass ratio of 1:0.9-1.1:0.1-0.3 for esterification reaction and polycondensation reaction. The temperature of the esterification reaction is 180 °C, the pressure is 0.01 MPa, and the time is 2 h; after the esterification reaction, carry out polycondensation reaction in stages: the temperature of the first-stage polycondensation is 220 °C, the pressure is 0.4-0.8 kPa, and the time is 0.5-1.5 h; the temperature of the second-stage polycondensation is 240 °C, the pressure is 20-80 Pa, and the time is 1-3 h; extrude and melt the polycondensed polyester raw material through a screw, and the ejected fiber is quickly shaped by high-speed stretching and ring blowing air cooling, and flows into a reciprocating machine for barrel bundling. When the total denier of the composite production reaches 600 denier, perform rapid drawing through an oil bath, and then enter a steam box for micro-stretching. The temperature of the steam box is 120 °C, and the micro-stretching time is 2 s. Carry out three-dimensional curling inside to fully form, and then enter a cutting machine for cutting. After cutting, put it into a three-layer oven for heat setting to make cloud velvet.

[0009] Further, the concentration of concentrated sulfuric acid in step (1) is 92-98%.

[0010] Further, the filter membrane in the step (1) is a cellulose acetate membrane with pores of 0.2 microns.

[0011] Further, the mixed solution in the step (1) is composed of concentrated sulfuric acid with a concentration of 95% and potassium permanganate in a mass ratio of 8:1.

[0012] Further, the concentration of the dilute hydrochloric acid aqueous solution in the step (1) is 8%.

[0013] Further, the dialysis process in the step (1) is to place the bottom precipitate in a dialysis bag with a molecular weight cut-off of 1000 Da, use water as the dialysis solution, dialyze for 3 days, and change the water every 8 hours.

[0014] Further, the pretreatment liquid in the step (2) is prepared by mixing a sodium hydroxide solution with a mass concentration of 2 - 10% and a n-butanol solution with a mass concentration of 45 - 75% in a volume ratio of 1:1 - 5.

[0015] Further, the ultrasonic conditions adopted in the step (2) are: frequency 20 - 50 kHz, power 200 - 600 W, and ultrasonic time 10 - 20 min.

[0016] Further, the mass ratio of the carboxyl-functionalized monolayer graphene quantum dots to the dispersion liquid in the step (2) is 0.01 - 0.05:1.

[0017] Further, the heat setting temperature in the step (3) is 180 °C.

[0018] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0019] The present invention prepares an aerogel antibacterial masterbatch by combining monolayer graphene quantum dots with modified cashew phenol nanocellulose, and adds it into polyester to make cloud velvet to achieve the effects of antibacterial and warming.

[0020] First of all, the present invention uses a chemical method to prepare graphene with a single-layer two-dimensional structure, that is, monolayer graphene; using this monolayer graphene as a raw material, graphene nano quantum dots with a single-layer structure are prepared through an electrochemical reaction; compared with ordinary graphene quantum dots, the graphene quantum dots prepared by the present invention not only reach the nanoscale in terms of size, can increase the contact area between the quantum dots and bacterial cells, and interact with the phospholipid molecules on the bacterial cell membrane to kill bacteria; its single-layer two-dimensional structure also makes the edges of the quantum dots sharper, which can improve the effect and success rate of cutting and damaging the cell walls of bacteria; on this basis, the monolayer graphene quantum dots are functionalized and modified to make their surfaces rich in carboxyl groups, and are attached to the surface of cellulose through the connection of carboxyl groups with nanocellulose, greatly improving the aggregation problem of graphene quantum dots;

[0021] Secondly, utilize the mechanochemical effect generated during the ball milling process to disrupt the physical structure of nanocellulose. Then, through the strong action of a polar solvent rich in hydroxyl groups and combined with ultrasonic waves to break the intermolecular hydrogen bonds of cellulose macromolecules, causing its dissociation. Then combine it with hydroxy cashew phenol with a hydroxyl group in the side chain, and utilize its photosensitive property of releasing reactive oxygen under sunlight to synergistically and efficiently catalyze the production of reactive oxygen with graphene quantum dots attached to cellulose, thereby achieving the sterilization effect. Then prepare the modified nanocellulose into an aerogel and add it as an antibacterial masterbatch into polyester to prepare cloud velvet, which solves the problem of the dispersibility of cellulose and effectively improves the heat preservation effect of cloud velvet. Specific embodiments

[0022] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0023] In order to more clearly illustrate the method provided by the present invention, the following examples are used for detailed description. The test methods for various indicators of an antibacterial and heat-preserving graphene quantum dot cloud velvet prepared in the following examples are as follows:

[0024] Antibacterial property: The antibacterial properties of the examples and comparative examples were tested in accordance with the national standard GB / T20944.3-2008 "Evaluation of Antibacterial Properties of Textiles - Part 3: Oscillation Method". The test bacteria used were Escherichia coli ATCC25922 and Staphylococcus aureus ATCC6538.

[0025] Heat preservation property: The heat preservation properties of the examples and comparative examples were tested in accordance with GB / T11048-2008-T "Determination of Thermal Resistance and Moisture Resistance of Textiles under Steady-State Conditions of Physiological Comfort".

[0026] Example 1; (1) Take 3 parts of natural graphite powder, add 12 parts of concentrated sulfuric acid with a concentration of 92%, 2 parts of potassium persulfate and 2 parts of phosphorus pentoxide, and mix evenly at 80 °C to react for 4 h; after the reaction, cool to room temperature, then add 10 parts of deionized water for dilution and let stand for 24 h, then filter and separate with a cellulose acetate membrane with a pore size of 0.2 μm, wash the solid with deionized water 3 times, and then let stand for 24 h to obtain pre-oxidized graphite; while stirring, slowly add the pre-oxidized graphite to 120 parts of a cooled mixed solution at 0 °C, which is composed of concentrated sulfuric acid with a concentration of 95% and potassium permanganate in a mass ratio of 8:1, the stirring speed is 60 rpm, stir at 35 °C for 2 h, then dilute with 250 parts of deionized water, continue to stir for 2 h, then add 600 parts of deionized water, and then add 15 parts of hydrogen peroxide solution after stirring for another 2 h; filter, wash the solid with a dilute hydrochloric acid aqueous solution with a concentration of 8% 2 times, then wash with deionized water 3 times, and then dialyze the product for one week to obtain oxidized graphite; prepare the obtained oxidized graphite into an aqueous solution with a concentration of 0.5 mg / ml, and perform ultrasonic treatment in an ultrasonic machine for 30 min, the ultrasonic power is 35 kHz, to obtain a single-layer oxidized graphite sheet solution; then centrifuge the single-layer oxidized graphite sheet solution in a high-speed centrifuge, the centrifugation speed is 15000 rpm, and the time is 20 min, and vacuum-dry the obtained solid at 0.085 MPa for 2 h; disperse the dried graphene oxide solid in a dimethyl sulfoxide solution, the dosage ratio of the two is 1:1, stir evenly at 150 rpm for 20 min, then transfer it to a reaction kettle, and react at 160 °C for 10 h, after filtration, wash with deionized water 3 times, 0.Single-layer graphene was obtained by vacuum drying at 0.85 MPa for 2 h; 2 portions of single-layer graphene were weighed and placed in centrifuge tubes with holes, 1 portion in each tube. A dialysis bag with a molecular weight cut-off of 1000 Da was put outside the centrifuge tubes, which were used as the positive and negative electrode materials respectively, and the distance between the two electrode materials was 2 cm; 20 portions of 1-butyl-3-methyltetrafluoroborate ionic liquid and 20 portions of deionized water were mixed as the electrolyte. After soaking the electrodes for 1 h, a DC power supply was turned on, and the DC voltage used was 10 V; During the power-on process, the positive and negative electrodes were exchanged every 2 h. After reacting for 10 h, the power supply was turned off; The electrolyzed electrolyte was placed in a centrifuge tube and centrifuged at 8000 rpm for 30 min to obtain the bottom precipitate. The bottom precipitate was placed in a dialysis bag with a molecular weight cut-off of 1000 Da, and water was used as the dialysis solution. Dialysis was carried out for 3 d, and the water was changed every 8 h. The liquid in the bag was placed in a hydrothermal autoclave and maintained at 180 °C for 3 h; Then the solution was centrifuged at 8000 rpm for 30 min, and the solid was washed twice with deionized water and then dried at normal temperature and pressure for 5 h to obtain single-layer graphene quantum dots; 1 portion of single-layer graphene quantum dots was mixed with 100 portions of deionized water, then 10 portions of bromoacetic acid were added, and ultrasonic treatment was carried out at a power of 30 kHz for 10 min, and then the reaction was carried out at room temperature for 5 h; After the reaction, it was centrifuged at 8000 rpm for 30 min, and the solid was washed three times with deionized water and then freeze-dried at -40 °C for 2 h to obtain carboxyl-functionalized single-layer graphene quantum dots;.

[0027] (2)First, mix the nano-cellulose raw material and montmorillonite at a mass ratio of 0.2:1, and conduct ball milling treatment. The ball milling speed is 300 rpm, and the ball milling time is 3 h. Mix a sodium hydroxide solution with a mass concentration of 2% and a n-butanol solution with a mass concentration of 45% according to a volume ratio of 1:1 to prepare a pretreatment solution. Adjust the pH to 7, heat up to 40 °C, and completely immerse the ball-milled nano-cellulose in the pretreatment solution for 12 h. The solid-liquid mass ratio is 1:10. Then, raise the temperature of the pretreatment solution to 50 °C, adjust the pH to 8, and soak for another 1 h. Conduct low-frequency short-time ultrasonic oscillation at the current temperature. The ultrasonic conditions are: frequency 20 kHz, power 200 W, and ultrasonic time 10 min to obtain pretreated nano-cellulose. Mix the pretreated nano-cellulose, hydroxy cashew phenol with hydroxyl groups on the micro and side chains, and ethanol at a mass ratio of 2:1:10, place them in a reaction kettle, heat to 100 °C and react for 2 h. After the reaction, conduct centrifugal washing with deionized water 3 times. The centrifugal speed is 10,000 rpm, and collect the upper suspension to obtain modified nano-cellulose. Mix the modified nano-cellulose and deionized water in proportion to prepare a modified nano-fiber dispersion with a mass fraction of 1.0%, and stir evenly at a speed of 150 rpm for 30 min. Take 10 parts of the modified nano-fiber dispersion, add an appropriate amount of glacial acetic acid to adjust the pH value of the dispersion to 4, then stir at a speed of 150 rpm for 1 h. Then add carboxyl-functionalized single-layer graphene quantum dots to the dispersion and mix and stir at 150 rpm for 3 h to obtain a homogeneous solution. The mass ratio of the carboxyl-functionalized single-layer graphene quantum dots to the dispersion is 0.01:1. Finally, pour the solution into a polytetrafluoroethylene mold and freeze it in liquid nitrogen for 3 min. The frozen solid sample is further vacuum freeze-dried at -60 °C and 1 Pa for 48 h to obtain a 0.1 mm composite aerogel masterbatch;

[0028] (3)Mix terephthalic acid, ethylene glycol, and the composite aerogel masterbatch at a mass ratio of 1:0.9:0.1 for esterification reaction and polycondensation reaction. The temperature of the esterification reaction is 180 °C, the pressure is 0.01 MPa, and the time is 2 h. After the esterification reaction, conduct polycondensation reaction in stages: the temperature of the first-stage polycondensation is 220 °C, the pressure is 0.4 kPa, and the time is 0.5 h; the temperature of the second-stage polycondensation is 240 °C, the pressure is 20 Pa, and the time is 1 h. Extrude and melt the polycondensed polyester raw material through a screw, and the ejected fibers are quickly shaped by high-speed stretching and air cooling with a ring blower. Then, it flows into a reciprocating machine for barrel bundling. When the total denier of the composite production reaches 600 denier, conduct rapid drawing through an oil bath, and then enter a steam box for micro-stretching. The temperature of the steam box is 120 °C, and the micro-stretching time is 2 s. Conduct three-dimensional curling inside to fully form, and then enter a cutting machine for cutting. After cutting, put it into a three-layer oven for heat setting. The heat setting temperature is 180 °C to make cloud velvet.

[0029] Example 2; (1) Take 3 parts of natural graphite powder, add 12 parts of concentrated sulfuric acid with a concentration of 95%, 2.5 parts of potassium persulfate and 2.5 parts of phosphorus pentoxide, and uniformly mix them at 80 °C to react for 5 h; after the reaction, cool to room temperature, then add 10 parts of deionized water for dilution and let stand for 24 h, then filter and separate with a cellulose acetate membrane with a pore size of 0.2 μm, wash the solid with deionized water 3 times, and then let stand for 24 h to obtain pre-oxidized graphite; while stirring, slowly add the pre-oxidized graphite into 130 parts of a cooled mixed solution at 0 °C, which is composed of concentrated sulfuric acid with a concentration of 95% and potassium permanganate in a mass ratio of 8:1, the stirring speed is 60 rpm, stir at 35 °C for 2 h, then dilute with 250 parts of deionized water, continue to stir for 2 h, then add 600 parts of deionized water, and then add 20 parts of hydrogen peroxide solution after stirring for another 2 h; filter, wash the solid with a dilute hydrochloric acid aqueous solution with a concentration of 8% 2 times, then wash with deionized water 3 times, and then dialyze the product for one week to obtain oxidized graphite; prepare the obtained oxidized graphite into an aqueous solution with a concentration of 0.5 mg / ml, and perform ultrasonic treatment in an ultrasonic machine for 30 min, the ultrasonic power is 35 kHz, to obtain a single-layer oxidized graphite sheet solution; then centrifuge the single-layer oxidized graphite sheet solution in a high-speed centrifuge, the centrifugation speed is 15,000 rpm, and the time is 20 min, and vacuum-dry the obtained solid at 0.085 MPa for 2 h; disperse the dried graphene oxide solid in a dimethyl sulfoxide solution, the dosage ratio of the two is 1:1, stir evenly at 150 rpm for 20 min, then transfer it to a reaction kettle, and react at 180 °C for 12 h, after filtration, wash with deionized water 3 times, 0.Single-layer graphene was obtained by vacuum drying at 0.85 MPa for 2 h; 2 portions of single-layer graphene were weighed and each was placed in a centrifuge tube with holes, and a dialysis bag with a molecular weight cut-off of 1000 Da was sleeved outside the centrifuge tube, serving as the positive and negative electrode materials respectively, and the distance between the two electrode materials was 2 cm; 20 portions of 1-butyl-3-methyltetrafluoroborate ionic liquid were mixed with 20 portions of deionized water as the electrolyte. After the electrodes were immersed for 1 h, a DC power supply was turned on, and the DC voltage used was 10 V; during the power-on process, the positive and negative electrodes were exchanged every 2 h. After reacting for 10 h, the power supply was turned off; the electrolyzed electrolyte was placed in a centrifuge tube and centrifuged at 9000 rpm for 30 min to obtain the bottom precipitate. The bottom precipitate was placed in a dialysis bag with a molecular weight cut-off of 1000 Da, and water was used as the dialysis solution. Dialysis was carried out for 3 d, and the water was changed every 8 h. The liquid in the bag was placed in a hydrothermal autoclave and maintained at 180 °C for 3 h; then the solution was centrifuged at 9000 rpm for 30 min, and the solid was washed 2 times with deionized water and then dried at normal temperature and pressure for 5 h to obtain single-layer graphene quantum dots; 1 portion of single-layer graphene quantum dots was mixed with 100 portions of deionized water, then 15 portions of bromoacetic acid were added, and ultrasonic treatment was carried out at a power of 30 kHz for 20 min, and then the reaction was carried out at room temperature for 5 h; after the reaction was completed, it was centrifuged at 9000 rpm for 30 min, and the solid was washed 3 times with deionized water and then freeze-dried at -40 °C for 2 h to obtain carboxyl-functionalized single-layer graphene quantum dots.

[0030] (2) First, mix the nano-cellulose raw material and montmorillonite at a mass ratio of 0.6:1 and conduct ball milling treatment. The ball milling speed is 450 rpm and the ball milling time is 5.5 h. Mix a sodium hydroxide solution with a mass concentration of 6% and a n-butanol solution with a mass concentration of 60% at a volume ratio of 1:3 to prepare a pretreatment solution, adjust the pH to 7, raise the temperature to 45 °C, and completely immerse the ball-milled nano-cellulose in the pretreatment solution for 18 h with a solid-liquid mass ratio of 1:10. Then raise the temperature of the pretreatment solution to 55 °C, adjust the pH to 8, and soak for another 1.5 h. Conduct ultrasonic low-frequency short-time oscillation at the current temperature. The ultrasonic conditions are: frequency 35 kHz, power 400 W, and ultrasonic time 15 min to obtain pretreated nano-cellulose. Mix the pretreated nano-cellulose, hydroxy cashew phenol with hydroxyl groups on the micro and side chains, and ethanol at a mass ratio of 3:1:10, place them in a reaction kettle, heat to 120 °C and react for 3 h. After the reaction, conduct centrifugal washing with deionized water 3 times at a centrifugal speed of 10,000 rpm, collect the upper suspension to obtain modified nano-cellulose. Mix the modified nano-cellulose and deionized water in proportion to prepare a modified nanofiber dispersion with a mass fraction of 1.0%, and stir evenly at a speed of 150 rpm for 30 min. Take 10 parts of the modified nanofiber dispersion, add an appropriate amount of glacial acetic acid to adjust the pH value of the dispersion to 4, then stir at a speed of 150 rpm for 1 h. Then add carboxyl-functionalized monolayer graphene quantum dots to the dispersion and mix and stir at 150 rpm for 3 h to obtain a homogeneous solution. The mass ratio of the carboxyl-functionalized monolayer graphene quantum dots to the dispersion is 0.03:1. Finally, pour the solution into a polytetrafluoroethylene mold and freeze it in liquid nitrogen for 3 min. The frozen solid sample is further vacuum freeze-dried at -60 °C and 1 Pa for 48 h to obtain a 0.8 mm composite aerogel masterbatch.

[0031] (3) Mix terephthalic acid, ethylene glycol, and the composite aerogel masterbatch at a mass ratio of 1:1:0.2 for esterification reaction and polycondensation reaction. The temperature of the esterification reaction is 180 °C, the pressure is 0.01 MPa, and the time is 2 h. After the esterification reaction, conduct polycondensation reaction in stages: the temperature of the first-stage polycondensation is 220 °C, the pressure is 0.6 kPa, and the time is 1 h; the temperature of the second-stage polycondensation is 240 °C, the pressure is 50 Pa, and the time is 2 h. Extrude and melt the polycondensed polyester raw material through a screw, and the ejected fibers are quickly shaped by high-speed stretching and ring blowing air cooling, and flow into a reciprocating machine for barrel bundling. When the total denier of the composite production reaches 600 denier, conduct rapid drawing through an oil bath tank, and then enter a steam box for micro-stretching. The temperature of the steam box is 120 °C, and the micro-stretching time is 2 s. Conduct three-dimensional curling inside to fully form, and then enter a cutting machine for cutting. After cutting, put it into a three-layer oven for heat setting. The heat setting temperature is 180 °C to make cloud velvet.

[0032] Example 3; (1) Take 3 parts of natural graphite powder, add 12 parts of concentrated sulfuric acid with a concentration of 98%, 3 parts of potassium persulfate and 3 parts of phosphorus pentoxide, and mix evenly at 80 °C to make it react for 6 h; after the reaction, cool to room temperature, then add 10 parts of deionized water for dilution and let stand for 24 h, then filter and separate with a cellulose acetate membrane with a pore size of 0.2 microns, take the solid and wash it 3 times with deionized water, and then let stand for 24 h to obtain pre-oxidized graphite; while stirring the pre-oxidized graphite, slowly add it to 140 parts of a cooled mixed solution at 0 °C, which is composed of concentrated sulfuric acid with a concentration of 95% and potassium permanganate in a mass ratio of 8:1, the stirring speed is 60 rpm, stir at 35 °C for 2 h and then dilute with 250 parts of deionized water, continue to stir for 2 h and then add 600 parts of deionized water, and then add 25 parts of hydrogen peroxide solution after stirring for another 2 h; filter, take the solid and wash it 2 times with a dilute hydrochloric acid aqueous solution with a concentration of 8%, then wash it 3 times with deionized water, and then dialyze the product for one week to obtain oxidized graphite; prepare the obtained oxidized graphite into an aqueous solution with a concentration of 0.5 mg / ml and perform ultrasonic treatment in an ultrasonic machine for 30 min, the ultrasonic power is 35 kHz, to obtain a single-layer oxidized graphite sheet solution; then centrifuge the single-layer oxidized graphite sheet solution in a high-speed centrifuge, the centrifugation speed is 15,000 rpm, and the time is 20 min, and vacuum-dry the obtained solid at 0.085 MPa for 2 h; disperse the dried graphene oxide solid in dimethyl sulfoxide solution, the dosage ratio of the two is 1:1, stir evenly at 150 rpm for 20 min and then transfer it to a reaction kettle, and react at 200 °C for 14 h, after filtration, wash it 3 times with deionized water, 0.Single-layer graphene was obtained by vacuum drying at 0.85 MPa for 2 h; 2 portions of single-layer graphene were weighed and each was placed in a centrifuge tube with holes, and a dialysis bag with a molecular weight cut-off of 1000 Da was sleeved outside the centrifuge tube, serving as the positive and negative electrode materials respectively, and the distance between the two electrode materials was 2 cm; 20 portions of 1-butyl-3-methyltetrafluoroborate ionic liquid were mixed with 20 portions of deionized water as the electrolyte. After soaking the electrodes for 1 h, a DC power supply was turned on, and the DC voltage used was 10 V; During the power-on process, the positive and negative electrodes were exchanged every 2 h. After reacting for 10 h, the power supply was turned off; The electrolyzed electrolyte was placed in a centrifuge tube and centrifuged at 10000 rpm for 30 min to obtain a bottom precipitate. The bottom precipitate was placed in a dialysis bag with a molecular weight cut-off of 1000 Da, and water was used as the dialysis solution. Dialysis was carried out for 3 d, and the water was changed every 8 h. The liquid in the bag was placed in a hydrothermal autoclave and maintained at 180 °C for 3 h; Then the solution was centrifuged at 10000 rpm for 30 min, and the solid was washed twice with deionized water and then dried at normal temperature and pressure for 5 h to obtain single-layer graphene quantum dots; 1 portion of single-layer graphene quantum dots was mixed with 100 portions of deionized water, then 20 portions of bromoacetic acid were added, and ultrasonic treatment was carried out at a power of 30 kHz for 30 min, and then the reaction was carried out at room temperature for 5 h; After the reaction, it was centrifuged at 10000 rpm for 30 min, and the solid was washed three times with deionized water and then freeze-dried at -40 °C for 2 h to obtain carboxyl-functionalized single-layer graphene quantum dots.

[0033] (2) First, mix the nanocellulose raw material and montmorillonite in a mass ratio of 1:1 and conduct ball milling treatment. The ball milling speed is 600 rpm and the ball milling time is 8 h. Mix a sodium hydroxide solution with a mass concentration of 10% and a n-butanol solution with a mass concentration of 75% in a volume ratio of 1:5 to prepare a pretreatment solution, adjust the pH to 7, raise the temperature to 50 °C, completely immerse the ball-milled nanocellulose in the pretreatment solution and soak for 24 h. The solid-liquid mass ratio is 1:10. Then raise the temperature of the pretreatment solution to 60 °C, adjust the pH to 8, and soak for another 2 h. Conduct low-frequency short-time ultrasonic oscillation at the current temperature. The ultrasonic conditions are: frequency 50 kHz, power 600 W, and ultrasonic time 20 min to obtain pretreated nanocellulose. Mix the pretreated nanocellulose, hydroxy cashew phenol with hydroxyl groups on the micro and side chains, and ethanol in a mass ratio of 4:1:10, place them in a reaction kettle, heat to 140 °C and react for 4 h. After the reaction, conduct centrifugal washing with deionized water 3 times. The centrifugal speed is 10,000 rpm, and collect the upper suspension to obtain modified nanocellulose. Mix the modified nanocellulose and deionized water in proportion to prepare a modified nanofiber dispersion with a mass fraction of 1.0%, and stir evenly at a speed of 150 rpm for 30 min. Take 10 parts of the modified nanofiber dispersion, add an appropriate amount of glacial acetic acid to adjust the pH value of the dispersion to 4, then stir at a speed of 150 rpm for 1 h. Then add carboxyl-functionalized monolayer graphene quantum dots to the dispersion and mix and stir at 150 rpm for 3 h to obtain a homogeneous solution. The mass ratio of the carboxyl-functionalized monolayer graphene quantum dots to the dispersion is 0.05:1. Finally, pour the solution into a polytetrafluoroethylene mold and freeze in liquid nitrogen for 3 min. The frozen solid sample is further vacuum freeze-dried at -60 °C and 1 Pa for 48 h to obtain a 1.5 mm composite aerogel masterbatch.

[0034] (3) Mix terephthalic acid, ethylene glycol, and the composite aerogel masterbatch in a mass ratio of 1:1.1:0.3 for esterification reaction and polycondensation reaction. The temperature of the esterification reaction is 180 °C, the pressure is 0.01 MPa, and the time is 2 h. After the esterification reaction, conduct polycondensation reaction in stages: the temperature of the first-stage polycondensation is 220 °C, the pressure is 0.8 kPa, and the time is 1.5 h; the temperature of the second-stage polycondensation is 240 °C, the pressure is 80 Pa, and the time is 3 h. Extrude and melt the polycondensed polyester raw material through a screw, and the ejected fibers are quickly shaped by high-speed stretching and ring blowing air cooling, and flow into a reciprocating machine for barrel bundling. When the total denier of the composite production reaches 600 denier, conduct rapid drawing through an oil bath, and then enter a steam box for micro-drawing. The temperature of the steam box is 120 °C, and the micro-drawing time is 2 s. Conduct three-dimensional curling inside to fully form, and then enter a cutting machine for cutting. After cutting, put it into a three-layer oven for heat setting. The heat setting temperature is 180 °C to make cloud velvet.

[0035] Comparative Example 1; The difference between Comparative Example 1 and Example 2 lies in the differences in steps (1) and (2). Steps (1) and (2) are changed to: (1) Weigh 2 parts of micron-sized graphene, with 1 part in each centrifuge tube with holes. A dialysis bag with a molecular weight cut-off of 1000 Da is sleeved outside the centrifuge tube, serving as the positive and negative electrode materials respectively. The distance between the two electrode materials is 2 cm; Take 20 parts of 1-butyl-3-methyltetrafluoroborate ionic liquid and mix it with 20 parts of deionized water as the electrolyte. After soaking the electrodes for 1 h, start connecting the DC power supply, and the DC voltage used is 10 V; During the power-on process, every 2 h, reverse the positive and negative electrodes. After reacting for 10 h, stop the power supply; Place the electrolyzed electrolyte in a centrifuge tube and centrifuge at 9000 rpm for 30 min to obtain the bottom precipitate. Place the bottom precipitate in a dialysis bag with a molecular weight cut-off of 1000 Da, use water as the dialysis solution, and dialyze for 3 d, changing the water every 8 h. Place the liquid in the dialysis bag in a hydrothermal reactor and maintain it at 180 °C for 3 h; Then centrifuge the solution at 9000 rpm for 30 min, take the solid and wash it twice with deionized water, and then dry it at normal temperature and pressure for 5 h to obtain monolayer graphene quantum dots; Mix 1 part of monolayer graphene quantum dots with 100 parts of deionized water, then add 15 parts of bromoacetic acid, sonicate at a power of 30 kHz for 20 min, and then react at room temperature for 5 h; After the reaction, centrifuge at 9000 rpm for 30 min, take the solid and wash it three times with deionized water, and then freeze-dry at -40 °C for 2 h to obtain carboxyl-functionalized monolayer graphene quantum dots;

[0036] (2)First, mix the nano-cellulose raw material and montmorillonite at a mass ratio of 0.6:1, and conduct ball milling treatment. The ball milling speed is 450 rpm, and the ball milling time is 5.5 h. Mix a sodium hydroxide solution with a mass concentration of 6% and a n-butanol solution with a mass concentration of 60% according to a volume ratio of 1:3 to prepare a pretreatment solution, adjust the pH to 7, heat up to 45 °C, completely immerse the ball-milled nano-cellulose in the pretreatment solution and soak for 18 h, with a solid-liquid mass ratio of 1:10. Then, heat the pretreatment solution to 55 °C, adjust the pH to 8, soak for another 1.5 h, and perform low-frequency short-time ultrasonic oscillation at the current temperature. The ultrasonic conditions are: frequency 35 kHz, power 400 W, and ultrasonic time 15 min to obtain pretreated nano-cellulose. Mix the pretreated nano-cellulose, hydroxy cardanol with hydroxyl groups on the micro and side chains, and ethanol at a mass ratio of 3:1:10, place them in a reaction kettle, heat to 120 °C and react for 3 h. After the reaction, centrifuge and wash with deionized water 3 times, with a centrifuge speed of 10,000 rpm, and collect the upper suspension to obtain modified nano-cellulose. Mix the modified nano-cellulose and deionized water in proportion to prepare a modified nanofiber dispersion with a mass fraction of 1.0%, and stir evenly at a speed of 150 rpm for 30 min. Take 10 parts of the modified nanofiber dispersion, add an appropriate amount of glacial acetic acid to adjust the pH value of the dispersion to 4, then stir at a speed of 150 rpm for 1 h. Then add carboxyl-functionalized graphene quantum dots to the dispersion and mix and stir at 150 rpm for 3 h to obtain a homogeneous solution. The mass ratio of carboxyl-functionalized graphene quantum dots to the dispersion is 0.03:1. Finally, pour the solution into a polytetrafluoroethylene mold and freeze in liquid nitrogen for 3 min. The frozen solid sample is further vacuum freeze-dried at -60 °C and 1 Pa for 48 h to obtain a 0.8 mm composite aerogel masterbatch. The remaining steps are the same as in Example 2.

[0037] Comparative Example 2; The difference between Comparative Example 2 and Example 2 lies in the differences in steps (1) and (2). Steps (1) and (2) are changed to: (1) Take 3 parts of natural graphite powder, add 12 parts of concentrated sulfuric acid with a concentration of 95%, 2.5 parts of potassium persulfate, and 2.5 parts of phosphorus pentoxide, and mix evenly at 80 °C to react for 5 h; After the reaction, cool to room temperature, then add 10 parts of deionized water for dilution and let it stand for 24 h, then filter and separate with a cellulose acetate membrane with a pore size of 0.2 μm, take the solid and wash it 3 times with deionized water, and then let it stand for 24 h to obtain pre-oxidized graphite; While stirring, slowly add the pre-oxidized graphite into 130 parts of a cooled mixed solution at 0 °C, which is composed of concentrated sulfuric acid with a concentration of 95% and potassium permanganate in a mass ratio of 8:1, the stirring speed is 60 rpm, stir for 2 h at 35 °C, then dilute with 250 parts of deionized water, continue to stir for 2 h, then add 600 parts of deionized water, and then add 20 parts of hydrogen peroxide solution after stirring for another 2 h; Filter, take the solid and wash it 2 times with a dilute hydrochloric acid aqueous solution with a concentration of 8%, then wash it 3 times with deionized water, and then dialyze the product for one week to obtain oxidized graphite; Prepare the obtained oxidized graphite into an aqueous solution with a concentration of 0.5 mg / ml and perform ultrasonic treatment in an ultrasonic machine for 30 min, the ultrasonic power is 35 kHz, to obtain a single-layer graphene oxide sheet solution; Then centrifuge and separate the single-layer graphene oxide sheet solution in a high-speed centrifuge, the centrifugation speed is 15,000 rpm, and the time is 20 min. Vacuum-dry the obtained solid at 0.085 MPa for 2 h; Disperse the dried graphene oxide solid in dimethyl sulfoxide solution, the dosage ratio of the two is 1:1, stir evenly at 150 rpm for 20 min, then transfer it to a reaction kettle, and react at 180 °C for 12 h. After filtration, wash it 3 times with deionized water and vacuum-dry it at 0.085 MPa for 2 h to obtain single-layer graphene; Mix 1 part of single-layer graphene with 100 parts of deionized water, then add 15 parts of bromoacetic acid, sonicate at a power of 30 kHz for 20 min, and then react at room temperature for 5 h; After the reaction, centrifuge at a speed of 9000 rpm for 30 min, take the solid and wash it 3 times with deionized water, and then freeze-dry at -40 °C for 2 h to obtain carboxyl-functionalized single-layer graphene;

[0038] (2) First, mix the nano-cellulose raw material and montmorillonite at a mass ratio of 0.6:1, and carry out ball milling treatment. The ball milling speed is 450 rpm and the ball milling time is 5.5 h. Mix a sodium hydroxide solution with a mass concentration of 6% and a n-butanol solution with a mass concentration of 60% according to a volume ratio of 1:3 to prepare a pretreatment solution, adjust the pH to 7, raise the temperature to 45 °C, and completely immerse the ball-milled nano-cellulose in the pretreatment solution for 18 h. The solid-liquid mass ratio is 1:10. Then raise the temperature of the pretreatment solution to 55 °C, adjust the pH to 8, and soak for another 1.5 h. Carry out low-frequency short-time ultrasonic oscillation at the current temperature. The ultrasonic conditions are: frequency 35 kHz, power 400 W, and ultrasonic time 15 min to obtain pretreated nano-cellulose. Mix the pretreated nano-cellulose, hydroxy cardanol with hydroxyl groups on the micro and side chains, and ethanol at a mass ratio of 3:1:10, place them in a reaction kettle, heat to 120 °C and react for 3 h. After the reaction, centrifuge and wash 3 times with deionized water. The centrifuge speed is 10,000 rpm, and collect the upper suspension to obtain modified nano-cellulose. Mix the modified nano-cellulose and deionized water in proportion to prepare a modified nanofiber dispersion with a mass fraction of 1.0%, and stir evenly at a speed of 150 rpm for 30 min. Take 10 parts of the modified nanofiber dispersion, add an appropriate amount of glacial acetic acid to adjust the pH value of the dispersion to 4, and then stir at a speed of 150 rpm for 1 h. Then add carboxyl-functionalized single-layer graphene into the dispersion and mix and stir at 150 rpm for 3 h to obtain a homogeneous solution. The mass ratio of carboxyl-functionalized single-layer graphene to the dispersion is 0.03:1. Finally, pour the solution into a polytetrafluoroethylene mold and freeze it in liquid nitrogen for 3 min. The frozen solid sample is further vacuum freeze-dried at -60 °C and 1 Pa for 48 h to obtain a 0.8 mm composite aerogel masterbatch. The remaining steps are the same as in Example 2.

[0039] Comparative Example 3; The difference between Comparative Example 3 and Example 2 lies in the differences in steps (1) and (2). Steps (1) and (2) are changed to: (1) Take 3 parts of natural graphite powder, add 12 parts of concentrated sulfuric acid with a concentration of 95%, 2.5 parts of potassium persulfate, and 2.5 parts of phosphorus pentoxide, and mix evenly at 80 °C to react for 5 h; After the reaction, cool to room temperature, then add 10 parts of deionized water for dilution and let it stand for 24 h, then filter and separate with a cellulose acetate membrane with a pore size of 0.2 microns, take the solid and wash it 3 times with deionized water, and then let it stand for 24 h to obtain pre-oxidized graphite; While stirring, slowly add the pre-oxidized graphite to 130 parts of a cooled mixed solution at 0 °C, which is composed of concentrated sulfuric acid with a concentration of 95% and potassium permanganate in a mass ratio of 8:1, and the stirring speed is 60 rpm. After stirring at 35 °C for 2 h, dilute it with 250 parts of deionized water, continue to stir for 2 h, then add 600 parts of deionized water, and then add 20 parts of hydrogen peroxide solution after stirring for another 2 h; Filter, take the solid and wash it 2 times with a dilute hydrochloric acid aqueous solution with a concentration of 8%, then wash it 3 times with deionized water, and then dialyze the product for one week to obtain oxidized graphite; Prepare the obtained oxidized graphite into an aqueous solution with a concentration of 0.5 mg / ml, and perform ultrasonic treatment in an ultrasonic machine for 30 min, with an ultrasonic power of 35 kHz, to obtain a single-layer graphene oxide sheet solution; Then centrifuge the single-layer graphene oxide sheet solution in a high-speed centrifuge, with a centrifugation speed of 15,000 rpm and a time of 20 min, and vacuum-dry the obtained solid at 0.085 MPa for 2 h; Disperse the dried graphene oxide solid in a dimethyl sulfoxide solution, with a dosage ratio of 1:1 for both, stir at 150 rpm for 20 min until evenly mixed, then transfer it to a reaction kettle, and react at 180 °C for 12 h. After filtration, wash it 3 times with deionized water, and vacuum-dry it at 0.085 MPa for 2 h to obtain single-layer graphene; Weigh 2 parts of single-layer graphene, put 1 part in each of the centrifuge tubes with holes, and put a dialysis bag with a molecular weight cut-off of 1000 Da outside the centrifuge tubes, which are used as positive and negative electrode materials respectively, and the distance between the two electrode materials is 2 cm; Take 20 parts of 1-butyl-3-methyltetrafluoroborate ionic liquid and mix it with 20 parts of deionized water as the electrolyte, soak the electrodes for 1 h, then start to connect the DC power supply, and the DC voltage used is 10 V; During the power-on process, exchange the positive and negative electrodes every 2 h. After reacting for 10 h, stop power-on; Place the electrolyzed electrolyte in a centrifuge tube, centrifuge at a speed of 9000 rpm for 30 min to obtain the bottom precipitate. Place the bottom precipitate in a dialysis bag with a molecular weight cut-off of 1000 Da, use water as the dialysis solution, dialyze for 3 d, change the water every 8 h, and place the liquid in the bag in a hydrothermal kettle and keep it at 180 °C for 3 h; Then centrifuge the solution at a speed of 9000 rpm for 30 min, take the solid and wash it 2 times with deionized water, and then dry it at normal temperature and pressure for 5 h to prepare single-layer graphene quantum dots;

[0040] (2) First, mix the nano-cellulose raw material and montmorillonite at a mass ratio of 0.6:1, and carry out ball milling treatment. The ball milling speed is 450 rpm, and the ball milling time is 5.5 h. Mix the sodium hydroxide solution with a mass concentration of 6% and the n-butanol solution with a mass concentration of 60% according to a volume ratio of 1:3 to prepare a pretreatment solution, adjust the pH to 7, heat up to 45 °C, and completely immerse the ball-milled nano-cellulose in the pretreatment solution for 18 h. The solid-liquid mass ratio is 1:10. Then, heat the pretreatment solution to 55 °C, adjust the pH to 8, and soak for another 1.5 h. Perform low-frequency short-time ultrasonic oscillation at the current temperature. The ultrasonic conditions are: frequency 35 kHz, power 400 W, and ultrasonic time 15 min to obtain pretreated nano-cellulose. Mix the pretreated nano-cellulose, hydroxy cardanol with hydroxyl groups on the micro and side chains, and ethanol at a mass ratio of 3:1:10, place them in a reaction kettle, heat to 120 °C and react for 3 h. After the reaction, centrifuge and wash with deionized water 3 times. The centrifuge speed is 10,000 rpm, and collect the upper suspension to obtain modified nano-cellulose. Mix the modified nano-cellulose and deionized water in proportion to prepare a modified nano-fiber dispersion with a mass fraction of 1.0%, and stir at a speed of 150 rpm for 30 min to make it uniform. Take 10 parts of the modified nano-fiber dispersion, add an appropriate amount of glacial acetic acid to adjust the pH value of the dispersion to 4, and then stir at a speed of 150 rpm for 1 h. Then add monolayer graphene quantum dots to the dispersion and mix and stir at 150 rpm for 3 h to obtain a uniform solution. The mass ratio of monolayer graphene quantum dots to the dispersion is 0.03:1. Finally, pour the solution into a polytetrafluoroethylene mold and freeze it in liquid nitrogen for 3 min. The frozen solid sample is further vacuum freeze-dried at -60 °C and 1 Pa for 48 h to obtain a 0.8 mm composite aerogel masterbatch. The remaining steps are the same as in Example 2.

[0041] Comparative Example 4; The difference between Comparative Example 4 and Example 2 lies in step (2). Step (2) is changed to: Mix micro-nano cellulose, hydroxy cashew phenol with a hydroxyl group in the side chain and ethanol at a mass ratio of 3:1:10, place them in a reaction kettle, heat to 120 °C and react for 3 h. After the reaction, centrifuge and wash with deionized water three times at a centrifuge speed of 10,000 rpm, collect the upper suspension to obtain modified nano cellulose; Mix the modified nano cellulose and deionized water in proportion to prepare a modified nano fiber dispersion with a mass fraction of 1.0%, stir evenly at a speed of 150 rpm for 30 min; Take 10 parts of the modified nano fiber dispersion, add an appropriate amount of glacial acetic acid to adjust the pH value of the dispersion to 4, then stir at a speed of 150 rpm for 1 h, and then add carboxyl-functionalized monolayer graphene quantum dots to the dispersion and mix and stir at 150 rpm for 3 h to obtain a homogeneous solution. The mass ratio of carboxyl-functionalized monolayer graphene quantum dots to the dispersion is 0.03:1; Finally, pour the solution into a polytetrafluoroethylene mold and freeze in liquid nitrogen for 3 min. The frozen solid sample is further vacuum freeze-dried at -60 °C and 1 Pa for 48 h to obtain a 0.8 mm composite aerogel masterbatch; The remaining steps are the same as those in Example 2.

[0042] Comparative Example 5; The difference between Comparative Example 5 and Example 2 lies in step (2). Step (2) is changed to: First, mix the nano cellulose raw material and montmorillonite at a mass ratio of 0.6:1, and perform ball milling treatment. The ball milling speed is 450 rpm and the ball milling time is 5.5 h; Mix a sodium hydroxide solution with a mass concentration of 6% and a n-butanol solution with a mass concentration of 60% in a volume ratio of 1:3 to prepare a pretreatment solution, adjust the pH to 7, raise the temperature to 45 °C, completely immerse the ball-milled nano cellulose in the pretreatment solution and soak for 18 h. The solid-liquid mass ratio is 1:10. Then raise the temperature of the pretreatment solution to 55 °C, adjust the pH to 8, and soak for another 1.5 h. Perform low-frequency short-time ultrasonic oscillation at the current temperature. The ultrasonic conditions are: frequency 35 kHz, power 400 W, and ultrasonic time 15 min to obtain modified nano cellulose; Mix the modified nano cellulose and deionized water in proportion to prepare a modified nano fiber dispersion with a mass fraction of 1.0%, stir evenly at a speed of 150 rpm for 30 min; Take 10 parts of the modified nano fiber dispersion, add an appropriate amount of glacial acetic acid to adjust the pH value of the dispersion to 4, then stir at a speed of 150 rpm for 1 h, and then add carboxyl-functionalized monolayer graphene quantum dots to the dispersion and mix and stir at 150 rpm for 3 h to obtain a homogeneous solution. The mass ratio of carboxyl-functionalized monolayer graphene quantum dots to the dispersion is 0.03:1; Finally, pour the solution into a polytetrafluoroethylene mold and freeze in liquid nitrogen for 3 min. The frozen solid sample is further vacuum freeze-dried at -60 °C and 1 Pa for 48 h to obtain a 0.8 mm composite aerogel masterbatch; The remaining steps are the same as those in Example 2.

[0043] Comparative Example 6; The difference between Comparative Example 6 and Example 2 lies in step (2). Step (2) is changed to: First, mix the nano-cellulose raw material and montmorillonite at a mass ratio of 0.6:1, and conduct ball milling treatment. The ball milling speed is 450 rpm, and the ball milling time is 5.5 h; Mix a sodium hydroxide solution with a mass concentration of 6% and a n-butanol solution with a mass concentration of 60% according to a volume ratio of 1:3 to prepare a pretreatment solution, adjust the pH to 7, raise the temperature to 45 °C, completely immerse the ball-milled nano-cellulose in the pretreatment solution and soak for 18 h, with a solid-liquid mass ratio of 1:10. Then raise the temperature of the pretreatment solution to 55 °C, adjust the pH to 8, and soak for another 1.5 h. Conduct ultrasonic low-frequency short-time oscillation at the current temperature. The ultrasonic conditions are: frequency 35 kHz, power 400 W, and ultrasonic time 15 min to obtain pretreated nano-cellulose; Mix the pretreated nano-cellulose, hydroxy cashew phenol with hydroxyl groups on the micro and side chains, and ethanol at a mass ratio of 3:1:10, place them in a reaction kettle, heat to 120 °C and react for 3 h. After the reaction, conduct centrifugal washing with deionized water 3 times, with a centrifugal speed of 10,000 rpm, collect the upper suspension to obtain modified nano-cellulose; Mix the modified nano-cellulose and deionized water in proportion to prepare a modified nano-fiber dispersion with a mass fraction of 1.0%, and stir evenly at a speed of 150 rpm for 30 min; Take 10 parts of the modified nano-fiber dispersion, add an appropriate amount of glacial acetic acid to adjust the pH value of the dispersion to 4, then stir at a speed of 150 rpm for 1 h. Then add carboxyl-functionalized monolayer graphene quantum dots to the dispersion and mix and stir at 150 rpm for 3 h to obtain a homogeneous solution. The mass ratio of carboxyl-functionalized monolayer graphene quantum dots to the dispersion is 0.03:1; Finally, centrifuge the solution at a speed of 10,000 rpm for 20 min, take the solid and dry it at normal temperature and pressure for 5 h to obtain a composite aerogel masterbatch; The remaining steps are the same as those in Example 2.

[0044] Effect Example

[0045] Table 1 below gives the performance analysis results of an antibacterial and warm graphene quantum dot cloud fluff using Examples 1 to 3 and Comparative Examples 1 to 6 of the present invention.

[0046] Table 1

[0047]

[0048] From the comparison of the experimental data on the antibacterial properties of the examples and the comparative examples, it can be found that the present invention uses a chemical method to prepare graphene with a single-layer two-dimensional structure, namely single-layer graphene; using this single-layer graphene as a raw material, graphene quantum dots with a single-layer structure are prepared through an electrochemical reaction; compared with ordinary graphene quantum dots, the graphene quantum dots prepared by the present invention not only reach the nanometer level in terms of size, can increase the contact surface area between the quantum dots and bacterial cells, and interact with the phospholipid molecules on the bacterial cell membrane, thereby killing bacteria; its single-layer two-dimensional structure also makes the edges of the quantum dots sharper, which can improve the effect and success rate of cutting and damaging the cell walls of bacteria; on this basis, the single-layer graphene quantum dots are functionally modified to make their surfaces rich in carboxyl groups, and are attached to the surface of cellulose by connecting with nanocellulose through carboxyl groups, greatly improving the aggregation problem of graphene quantum dots. Secondly, the present invention uses the mechanochemical action generated during the ball milling process to destroy the physical structure of nanocellulose, and then through the strong action of a polar solvent rich in hydroxyl groups, combined with ultrasonic waves to break the intermolecular hydrogen bonds of cellulose macromolecules, causing them to dissociate. Then it is combined with hydroxy cashew phenol with a hydroxyl group in the side chain, and using its photosensitive property of releasing reactive oxygen under sunlight, it synergistically and efficiently catalyzes the generation of reactive oxygen with the graphene quantum dots attached to the cellulose to achieve the effect of sterilization. From the comparison of the experimental data on the antibacterial properties of the examples and the comparative examples, it can be found that the present invention prepares the modified nanocellulose into an aerogel, adds it as an antibacterial masterbatch into polyester to prepare cloud velvet, solves the problem of the dispersibility of cellulose, and effectively improves the heat preservation effect of cloud velvet.

[0049] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be construed as limiting the claimed claim.

Claims

1. A method for preparing antibacterial and heat-retaining graphene quantum dot cloud velvet, characterized in that: The method comprises the following preparation steps: (1) Take 3 parts of natural graphite powder, add 12 parts of concentrated sulfuric acid, 2-3 parts of potassium persulfate and 2-3 parts of phosphorus pentoxide, mix them evenly at 80°C, and react for 4-6 hours; after the reaction is completed, cool to room temperature, add 10 parts of deionized water to dilute, let stand for 24 hours, and then separate by membrane filtration, take the solid and wash it with deionized water 3 times, and then let stand for 24 hours to obtain pre-oxidized graphite; slowly add the pre-oxidized graphite to 120-140 parts of a cooled 0°C mixed solution while stirring, the mixed solution is composed of 95% concentrated sulfuric acid and potassium permanganate in a mass ratio of 8:1, the stirring speed is 60rpm, stir at 35°C for 2 hours, dilute with 250 parts of deionized water, continue stirring for 2 hours, add 600 parts of deionized water, and then add 15-25 parts of hydrogen peroxide solution after stirring for 2 hours; filter, take the solid and use 8% The obtained graphene oxide was washed twice with a dilute hydrochloric acid aqueous solution, and then washed three times with deionized water, and then the product was dialyzed for one week to obtain graphite oxide; the obtained graphite oxide was prepared into an aqueous solution with a concentration of 0.5 mg / ml, and ultrasonically treated in an ultrasonic machine for 30 minutes with an ultrasonic power of 35 kHz to obtain a single-layer graphite oxide sheet solution; the single-layer graphite oxide sheet solution was then centrifuged in a high-speed centrifuge at a centrifugal speed of 15000 rpm for 20 minutes, and the obtained solid was vacuum dried at 0.085 MPa for 2 hours; the dried graphene oxide solid was dispersed in a dimethyl sulfoxide solution at a dosage ratio of 1:1, and the mixture was stirred at 150 rpm for 20 minutes to be uniform, and then transferred to a reactor and reacted at 160-200°C for 10-14 hours, filtered, washed three times with deionized water, 0.085MPa vacuum drying for 2h to obtain single-layer graphene; weigh 2 parts of single-layer graphene, put 1 part each in a centrifuge tube with holes, put a 1000Da dialysis bag on the outside of the centrifuge tube, use them as positive and negative electrode materials respectively, and the distance between the two electrode materials is 2cm; take 20 parts of 1-butyl-3-methyl tetrafluoroborate ionic liquid and 20 parts of deionized water as electrolyte, soak the electrodes for 1h, start to connect the DC power supply, and the DC voltage used is 10V; during the power-on process, the positive and negative electrodes are exchanged every 2h, and the power is stopped after the reaction for 10h; the electrolyte after electrolysis is placed in a centrifuge tube, and centrifuged at 8000-10000rpm for 30min to obtain a bottom precipitate, After dialysis, the liquid in the bag was placed in a hydrothermal autoclave and maintained at 180°C for 3 hours; the solution was then centrifuged at 8000-10000 rpm for 30 minutes, the solid was washed twice with deionized water, and then dried at room temperature and pressure for 5 hours to obtain a single-layer graphene quantum dot; 1 part of the single-layer graphene quantum dot was mixed with 100 parts of deionized water, and then 10-20 parts of bromoacetic acid were added, and ultrasonicated at 30kHz power for 10-30 minutes, and then reacted at room temperature for 5 hours; after the reaction was completed, it was centrifuged at 8000-10000 rpm for 30 minutes, the solid was washed three times with deionized water, and then freeze-dried at -40°C for 2 hours to obtain a carboxyl-functionalized single-layer graphene quantum dot;. (2) First, the mass ratio of the nanocellulose raw material and montmorillonite is 0.2-1:1, and the ball milling treatment is performed. The ball milling speed is 300-600 rpm, and the ball milling time is 3-8 hours. Prepare a pretreatment solution, which is prepared by mixing a sodium hydroxide solution with a mass concentration of 2-10% and a n-butanol solution with a mass concentration of 45-75% in a volume ratio of 1:1-5, adjust the pH to 7, and heat it to 40-50°C. The ball-milled nanocellulose is completely immersed in the pretreatment solution for 12-24 hours, and the solid-liquid mass ratio is 1:

10. Then, the pretreatment solution is heated to 50-60°C, the pH is adjusted to 8, and it is immersed for another 1-2 hours. Ultrasonic low-frequency short-time oscillation is performed at the current temperature to obtain pretreated nanocellulose. Pretreated nanocellulose, hydroxycardanol containing hydroxyl groups on the side chain and ethanol were mixed in a mass ratio of 2-4:1:10, placed in a reactor, heated to 100-140°C for reaction for 2-4h, and after the reaction, centrifuged and washed three times with deionized water at a centrifugal speed of 10000rpm, and the upper suspension was collected to obtain modified nanocellulose; the modified nanocellulose and deionized water were mixed in proportion to prepare a modified nanofiber dispersion with a mass fraction of 1.0%, and stirred at 150rpm for 30min; 10 portions of the modified nanofiber dispersion were taken, an appropriate amount of glacial acetic acid was added to adjust the pH value of the dispersion to 4, and then stirred at 150rpm for 1h, and then carboxyl functionalized single-layer graphene quantum dots were added to the dispersion, mixed and stirred at 150rpm for 3h to obtain a uniform solution; finally, the solution was poured into a polytetrafluoroethylene mold and frozen in liquid nitrogen for 3min, and the frozen solid sample was continued to be vacuum freeze-dried at -60°C and 1Pa for 48h to obtain a 0.1-1.5mm composite aerogel masterbatch; (3) Terephthalic acid, ethylene glycol and composite aerogel masterbatch are mixed in a mass ratio of 1:0.9-1.1:0.1-0.3 for esterification reaction and polycondensation reaction. The temperature of the esterification reaction is 180°C, the pressure is 0.01MPa, and the time is 2h. After the esterification reaction is completed, the polycondensation reaction is carried out in stages: the first stage polycondensation temperature is 220°C, the pressure is 0.4-0.8kPa, and the time is 0.5-1.5h; the second stage polycondensation temperature is 240°C, the pressure is 20-80Pa, and the time is 1- 3h; the polyester raw material after polycondensation is melted by screw extrusion, and the ejected fiber is quickly shaped by high-speed stretching and ring-blown air cooling, and flows into the reciprocating machine for barrel bundling. When the bundling reaches the total denier of 600 denier for composite production, it is quickly stretched by an oil bath, and then enters the steam box for micro-stretching. The steam box temperature is 120°C, and the micro-stretching time is 2s. Three-dimensional curling is performed inside to fully form it, and then it enters the cutting machine. After cutting, it is placed in a three-layer oven for heat setting to make cloud velvet.

2. The method for preparing the antibacterial and heat-retaining graphene quantum dot cloud velvet according to claim 1, characterized in that: The concentration of concentrated sulfuric acid in step (1) is 92-98%.

3. The method for preparing the antibacterial and heat-retaining graphene quantum dot cloud velvet according to claim 1, characterized in that: The filter membrane in step (1) is a cellulose acetate membrane with a pore size of 0.2 micrometers.

4. The method for preparing the antibacterial and heat-retaining graphene quantum dot cloud velvet according to claim 1, characterized in that: The concentration of the dilute hydrochloric acid aqueous solution in step (1) is 8%.

5. The method for preparing the antibacterial and heat-retaining graphene quantum dot cloud velvet according to claim 1, characterized in that: The dialysis process in step (1) is to place the bottom precipitate in a dialysis bag with a molecular weight cutoff of 1000Da, use water as the dialysis fluid, and dialyze for 3 days, changing the water every 8 hours.

6. The method for preparing the antibacterial and heat-retaining graphene quantum dot cloud velvet according to claim 1, characterized in that: The ultrasonic conditions used in step (2) are: frequency 20-50 kHz, power 200-600 W, and ultrasonic time 10-20 min.

7. The method for preparing the antibacterial and heat-retaining graphene quantum dot cloud velvet according to claim 1, characterized in that: In the step (2), the mass ratio of carboxyl functionalized single-layer graphene quantum dots to the dispersion is 0.01-0.05:

1.

8. The method for preparing the antibacterial and heat-retaining graphene quantum dot cloud velvet according to claim 1, characterized in that: The heat setting temperature in step (3) is 180°C.

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