WO2023221299A1

WO2023221299A1 - Method for preparing silver nanowires at room temperature on the basis of micromolecular phenolic acid

Info

Publication number: WO2023221299A1
Application number: PCT/CN2022/109870
Authority: WO
Inventors: 邢丽丽; 邢铁玲; 卢神州; 陈国强
Original assignee: 苏州大学
Priority date: 2022-05-20
Filing date: 2022-08-03
Publication date: 2023-11-23
Also published as: CN114985756B; CN114985756A

Abstract

A method for preparing silver nanowires at room temperature on the basis of a micromolecular phenolic acid. A micromolecular phenolic acid is used as a reducing agent and polyvinylpyrrolidone is used as a template, and a silver source is reduced under a room temperature condition to prepare silver nanowires; the silver nanowires are deposited on a surface of a cotton fabric by means of an impregnation-rolling-drying method to prepare a conductive cotton fabric, the sheet resistance of the conductive cotton fabric being 0.23-0.54 Ω/sq. The method for preparing silver nanowires at room temperature on the basis of a micromolecular phenolic acid has a simple process and can be carried out at room temperature; compared with existing main silver nanowire preparation methods such as a polyol method and a solvothermal method, the method avoids high temperature and high pressure conditions, is environmentally-friendly, saves energy, and reduces energy consumption. In addition, the method involves a simple apparatus and low apparatus cost, has no limit for the material size, and can realize large-scale production.

Description

Method for preparing silver nanowires at room temperature based on small molecule phenolic acid

Technical field

The invention belongs to the technical field of silver nanowires and relates to a method for preparing silver nanowires at room temperature based on small molecule phenolic acid.

Background technique

At present, the preparation methods of silver nanowires mainly include ultraviolet (UV) light irradiation method, template method, solvothermal method and polyol method. The ultraviolet irradiation method is a photoreduction method that adds an appropriate surfactant as a protective agent to induce the reduction of the silver source under ultraviolet irradiation conditions. However, only the reactants in contact with UV light can be triggered and reduced to the final product, which is prone to problems such as uneven products and low reduction efficiency. The template method adjusts the shape of the final product by controlling the shape of the template, and is divided into hard template method and soft template method. The hard template method has strong controllability, but requires prefabricated templates, and the purification process is more complicated. The soft template method has a convenient purification process, but the form of the product is difficult to control. The polyol method and the solvothermal method have simple processes, high yields, and can be produced on a large scale. They are currently the two main methods for industrial production of silver nanowires. However, these two methods often require conditions such as high temperature and high pressure, and most of them introduce a large amount of chemical reagents that are easy to pollute the environment, such as ethylene glycol, propylene glycol or glycerol as reducing agents and solvents. In recent years, as environmental problems have become increasingly prominent, the concept of green development has been deeply rooted in the hearts of the people. Energy conservation, emission reduction, and green and environmentally friendly high-efficiency preparation processes have become a research hotspot among modern scholars.

CN113385686A discloses a method for preparing high aspect ratio silver nanowires with the assistance of organic amine hydrochloride. Add the silver nitrate-ethylene glycol solution to the mixed solution, heat to 110-180°C and react for 2-12 hours, then cool to room temperature, collect the precipitate, and obtain high aspect ratio silver nanowires; the mixed solution is made of polyethylene It is obtained by uniformly mixing pyrrolidone-ethylene glycol solution and organic amine hydrochloride-ethylene glycol solution; the diameter of the prepared silver nanowires is mainly 100-150nm, and the length is more than 80μm. However, the entire synthesis process requires high Temperature and time, high energy consumption.

CN111922359A discloses a preparation method of pure silver nanowires. First prepare solution A (ethylene glycol solution of polydienedimethylammonium chloride) and solution B (ethylene glycol solution of silver nitrate), then add an equal volume of solution B dropwise to solution A under magnetic stirring. Stir the mixed solution magnetically at room temperature for 10 to 20 minutes, then heat to 160 to 200°C, and react for 6 to 10 hours to obtain the product; cool the product at room temperature and separate it with a centrifuge. The centrifuged product is washed. Dispersed in ethanol; the prepared silver nanowire surface is very pure and has good conductivity and light transmittance. However, the long-term high-temperature reaction consumes a lot of energy in production, poses safety risks, makes the reaction process difficult to control, and results in silver nanowires with large size differences. At the same time, more harmful organic solvents are used, causing certain environmental pollution.

CN113210623A discloses a preparation method for microwave-assisted synthesis of pure silver nanowires with controllable aspect ratio, which includes the following steps: heating ethylene glycol and uniformly mixing it with an ethylene glycol solution of halide and an ethylene glycol solution of nitrate and keeping warm. ; Then mix it with the ethylene glycol solution of silver nitrate, put it into a microwave digestion instrument, and microwave it at a temperature of 110 to 150°C. The microwave frequency is 300w to 900w, and the microwave time is 30 to 60 minutes. The resulting solution is washed, centrifuged, and redispersed. Pure silver nanowires were obtained in solvent. Higher microwave temperatures bring more energy consumption, and the economic benefits are not high.

Therefore, developing a method that has a simple synthesis process, is energy-saving and environmentally friendly, does not require high pressure and high temperature, and can synthesize high aspect ratio silver nanowires under mild conditions has become one of the directions that researchers urgently need to break through.

Contents of the invention

The purpose of the present invention is to solve the above problems existing in the prior art and provide a method for preparing silver nanowires at room temperature based on small molecule phenolic acid.

In order to achieve the above objects, the technical solutions adopted by the present invention are as follows:

Based on the method of preparing silver nanowires at room temperature from small molecule phenolic acid, small molecule phenolic acid is used as a reducing agent, polyvinylpyrrolidone (PVP) is used as a template agent, and the silver source is reduced at room temperature (25-30°C) to prepare silver nanowires. .

As the preferred technical solution:

The method for preparing silver nanowires at room temperature is based on the above-mentioned small molecule phenolic acid, which is caffeic acid, ferulic acid or chlorogenic acid.

As described above, the molecular weight of polyvinylpyrrolidone is 20,000 to 1,300,000 Daltons based on the method of preparing silver nanowires at room temperature based on small molecule phenolic acid.

As described above, the method for preparing silver nanowires at room temperature is based on small molecule phenolic acid. The silver source is silver nitrate, silver bromide or silver sulfate.

According to the above method for preparing silver nanowires at room temperature based on small molecule phenolic acid, the diameter of the silver nanowires is 40~60nm and the length is 40~60μm; the silver nanowires are deposited to A conductive cotton fabric is prepared on the surface of the cotton fabric. The square resistance of the conductive cotton fabric is 0.23-0.54Ω/sq. Compared with the existing technology, the conductive performance of the conductive cotton fabric finished with silver nanowires prepared by the method of the present invention is better. better.

The specific steps for using silver nanowires for conductive finishing of cotton fabrics are as follows:

(1) Boil and clean the cotton fabric to remove natural and man-made impurities on its surface, and dry it naturally after washing;

(2) Immerse the cotton fabric in step (1) into water and treat it with room temperature ultrasonic treatment for 10 to 20 minutes. The acoustic cavitation effect of ultrasonic waves makes the fiber surface rough, and also discharges the residual air in the interwoven structure of the fabric, which greatly enhances the strength of the cotton fabric. The adsorption effect on the surface of the fabric is beneficial to the contact and combination between it and the silver nanowires;

(3) Configure the synthesized silver nanowires into a silver nanowire aqueous solution with a mass concentration of 6 to 12g/L, and disperse it with ultrasonic waves for 3 to 5 minutes; immerse the cotton fabric treated in step (2) into the silver nanowire solution, Maintain 80°C in an oscillating water bath for 20 to 30 minutes, take out the padding solution, and then dry it in an oven at 60°C. Repeat the dipping-padding-drying process 2 to 3 times; finally, immerse the fabric obtained in the chloride aqueous solution for 30 to 30 minutes. 60s, and wash with deionized water for 10-20s, repeat twice, and dry at 60°C to obtain a conductive cotton fabric (the prepared conductive cotton fabric is further soaked in a chloride ion solution, and the chloride ions and dissolved oxygen molecules present in the solution, The silver ions are dissolved from the surface of the silver nanowires and freed through the solution to be redeposited at the nodes, reducing the node resistance and the surface resistance of the cotton fabric).

The temperature of ultrasonic dispersion in step (3) is room temperature, and the ultrasonic frequency is 40-60KHz; the rolling residue rate when rolling off the solution is 100-150%; the chloride is sodium chloride, potassium chloride or Lithium chloride has an aqueous solution mass fraction of 10 to 20%.

The method for preparing silver nanowires at room temperature based on small molecule phenolic acid as mentioned above, the specific preparation steps are as follows:

(1) Prepare respectively a silver source solution with a concentration of 0.5~3mol/L, a small molecule phenolic acid aqueous solution with a concentration of 2~3g/L, and a polyvinylpyrrolidone solution with a concentration of 0.01~0.05g/L;

(2) Add the silver source solution to the polyvinylpyrrolidone solution, stir and mix evenly to obtain a mixed solution;

(3) Add a small molecule phenolic acid aqueous solution to the mixed solution obtained in step (2), stir and react at room temperature for 5 to 10 minutes, then raise the temperature to 28 to 30°C and let it stand for 3 to 4 hours;

(4) Centrifuge the solution after the reaction in step (3), remove the lower precipitate and clean it, repeat the centrifugation and cleaning steps 2 to 4 times to obtain silver nanowires.

According to the above method for preparing silver nanowires at room temperature based on small molecule phenolic acid, in step (2), the volume ratio of the silver source solution to the polyvinylpyrrolidone solution is 1:40 to 80;

In step (3), the volume ratio of the small molecule phenolic acid aqueous solution to the mixed solution is 7:41 to 81.

As mentioned above, in the method of preparing silver nanowires at room temperature based on small molecule phenolic acid, the stirring speed in step (2) is 500~600r/min. The rapid stirring in this step is to quickly disperse the silver source solution evenly. The mixing time 15~20min;

The stirring speed in step (3) is 100~300r/min. The purpose of slow stirring in this step is to prevent the reducing agent from quickly contacting the silver source due to too fast stirring, causing the reaction to be too fast, and a large number of silver ions to be reduced to silver atoms in a short period of time. , and quickly agglomerate into large silver crystal nuclei, causing the final synthesized solution to contain not only nanowires, but also silver particles or short and thick silver nanorods. Slow stirring is beneficial to the acquisition of silver nanowires, and this result was also verified through the control variable method in the experiment.

As described above, in the method of preparing silver nanowires at room temperature based on small molecule phenolic acid, in step (3), the small molecule phenolic acid aqueous solution is added dropwise, and the dropping speed is 2.8 to 20 mL/min.

According to the above method for preparing silver nanowires at room temperature based on small molecule phenolic acid, the cleaning in step (4) means: first cleaning with ethanol, and then cleaning with deionized water.

The principle of the present invention is as follows:

The carboxyl group in the biomass small molecule phenolic acid can easily capture the positively charged Ag ions from the solution and form a relatively stable complex with them. However, due to the reducing nature of the phenolic hydroxyl group in the phenolic acid, the silver ions trapped in the complex will be reduced to silver atoms and released. Silver atoms begin to nucleate slowly and unevenly. As the reaction continues, more and more silver atoms are reduced and aggregate into primary silver crystals. Subsequently, the oxygen in C=O in the polyvinylpyrrolidone structure forms a silver-oxygen bond with Ag (silver crystal). Since the surface free energy of the Ag(111) crystal face is smaller than the Ag(100) crystal face, polyvinylpyrrolidone will contain Covered on the Ag(100) crystal surface, that is, the Ag(100) surface forms a silver-oxygen bond with polyvinylpyrrolidone and is covered. Since polyvinylpyrrolidone is a polymer chain, the continuously newly generated silver elemental (100) surface will combine with the oxygen in the C=O on polyvinylpyrrolidone, and the Ag(111) surface will be connected to other Ag(111) surfaces. , thereby promoting the one-dimensional linear growth of the generated silver twins along the (111) plane, and gradually generating silver nanowires.

The method of the present invention can prepare silver nanowires at room temperature. This is because: firstly, alcohols such as ethylene glycol are mainly used as reducing agents in the prior art. In contrast, small molecule phenolic acids in the present invention More reductive. Due to the presence of double bonds on the benzene ring and benzene ring side chain in the structure of phenolic acid compounds, a large conjugated system is often formed in the molecule, and due to the presence of carboxyl groups, the conjugated system has a greater electron-attracting ability. In the phenolic hydroxyl COH structure, the oxygen atom contains a lone pair of p electrons. The p electron cloud and the large π electron cloud in the conjugated system overlap from the side. Due to the electron-attracting effect of the conjugated system, the p electron cloud on the oxygen atom moves toward The benzene ring is transferred, and the electron cloud between the hydrogen and oxygen atoms is transferred to the direction of the oxygen atom. As a result, the OH bond on the phenolic hydroxyl group is easily broken and oxidized to form an o-phthaloquinone structure. The alcoholic hydroxyl group is generally connected to an alkane or alkene, and at most it can only be p-π conjugated in a small range. Its OH bond energy is large and it is difficult to be oxidized. The dissociation energy (BED) of the OH bond in the phenolic hydroxyl group of phenolic acid compounds is much smaller than the dissociation energy of the alcoholic hydroxyl group in ethylene glycol (the BED of the OH bond in the phenolic hydroxyl group of commonly used phenolic acid compounds is 200kJ /mol～400kJ/mol range). Therefore, phenolic acid compounds are more reducible than alcohols and can more easily reduce metal ions to elemental substances, so they do not require a higher reaction temperature like alcohols. Second, the carboxyl anion in the small molecule phenolic acid captures the positively charged Ag ⁺ from the solution through electrostatic complexation. The freely displaced electrons between the conjugated ring and the side chain double bond are affected by the electrostatic force. Gradually approaching Ag ⁺ , Ag ⁺ easily obtains electrons and is reduced to silver atoms, which to a certain extent can promote the rapid and orderly reduction of silver ions without the need for higher environmental energy. In summary, the present invention can produce silver nanowires at room temperature without requiring high-temperature reaction conditions.

Beneficial effects:

(1) The method for preparing silver nanowires at room temperature based on small molecule phenolic acid of the present invention has a simple process flow and can be carried out at room temperature. Compared with the current main silver nanowire preparation methods such as polyol method and solvothermal method, It avoids high temperature and high pressure conditions, is green and environmentally friendly, saves energy and reduces energy consumption;

(2) The preparation method used in the present invention requires simple equipment, no restrictions on material size, low equipment cost, and can be produced on a large scale;

(3) In the present invention, polyvinylpyrrolidone is added as a surfactant and protective agent in the reaction mixture. The coating of PVP can prevent the agglomeration of silver particles during the reduction of silver ions into nanosilver particles. At the same time, PVP also serves as a capping agent and soft template to promote the growth of silver twins into a one-dimensional structure.

Description of the drawings

Figure 1 is an SEM image of the silver nanowires prepared in Example 1;

Figure 2 is a TEM image of the silver nanowires prepared in Example 2;

Figure 3 is an XRD pattern of the silver nanowires prepared in Example 3;

Figure 4 shows the test results of the electrical conductivity and washability of AgNW/cotton fabrics in Examples 8 to 11 measured by the ST-2258C multifunctional digital four-probe tester.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

In the following examples, room temperature refers to 25°C.

Example 1

A method for preparing silver nanowires at room temperature based on small molecule phenolic acid (caffeic acid). The specific preparation steps are as follows:

(1) Prepare respectively a silver nitrate solution with a concentration of 1mol/L, a caffeic acid aqueous solution with a concentration of 2.4g/L, and a polyvinylpyrrolidone solution with a concentration of 0.04g/L;

Among them, the molecular weight of polyvinylpyrrolidone is 40,000 Daltons;

(2) Add the silver nitrate solution to the polyvinylpyrrolidone solution, stir for 20 minutes at a speed of 600 r/min, and mix evenly to obtain a mixed solution;

Among them, the volume ratio of silver nitrate solution and polyvinylpyrrolidone solution is 1:60;

(3) Add caffeic acid aqueous solution dropwise to the mixed solution obtained in step (2) at a speed of 2.8 mL/min, stir and react at room temperature at a speed of 280 r/min for 5 min, then raise the temperature to 28°C and let it stand for 4 hours;

The volume ratio of caffeic acid aqueous solution and mixed solution is 7:61;

(4) Centrifuge the solution after the reaction in step (3) at a centrifugal speed of 5000 rpm. Remove the precipitate and wash it first with ethanol and then with deionized water. Repeat the centrifugation and cleaning steps twice to obtain silver nanowires;

The diameter of the prepared silver nanowire is 46±2nm and the length is 49±3μm. Its scanning electron microscope picture is shown in Figure 1.

Example 2

(1) Prepare respectively a silver nitrate solution with a concentration of 1mol/L, a caffeic acid aqueous solution with a concentration of 2.4g/L, and a polyvinylpyrrolidone solution with a concentration of 0.03g/L;

Among them, the molecular weight of polyvinylpyrrolidone is 58,000 Daltons;

(3) Add caffeic acid aqueous solution dropwise to the mixed solution obtained in step (2) at a speed of 2.8 mL/min, stir and react at room temperature at a speed of 280 r/min for 5 min, then raise the temperature to 28°C and let it stand for 3.5 h;

The volume ratio of caffeic acid aqueous solution and mixed solution is 7:61;

(4) Centrifuge the solution after the reaction in step (3) at a centrifugal speed of 5000 rpm. Remove the precipitate and wash it with ethanol and then with deionized water. Repeat the centrifugation and cleaning steps three times to obtain silver nanowires;

The diameter of the prepared silver nanowire is 50±3nm and the length is 52±2μm. Its transmission electron microscope picture is shown in Figure 2.

Example 3

(1) Prepare respectively a silver nitrate solution with a concentration of 1mol/L, a caffeic acid aqueous solution with a concentration of 2.4g/L, and a polyvinylpyrrolidone solution with a concentration of 0.02g/L;

Among them, the molecular weight of polyvinylpyrrolidone is 40,000 Daltons;

The volume ratio of caffeic acid aqueous solution and mixed solution is 7:61;

(4) Centrifuge the solution after the reaction in step (3) at a centrifugal speed of 5000 rpm. Remove the precipitate and wash it first with ethanol and then with deionized water. Repeat the centrifugation and cleaning steps 4 times to obtain silver nanowires;

The diameter of the prepared silver nanowire is 54±5nm and the length is 46±4μm. Its X-ray diffraction pattern is shown in Figure 3.

It can be seen from Figure 3 that the X-ray diffraction peaks are very clear, and the peak shapes all show the characteristics of narrow peaks and high intensity, indicating that the prepared silver nanowires have good crystallinity; 4 obvious diffraction patterns appear in the XRD pattern Peaks, each peak corresponds to the number 04-0783 in the JCPDS standard card, and respectively corresponds to the crystal plane diffraction peaks of (111), (200), (220), (311) and (222) of elemental silver in the face-centered cubic crystal system , there are no other impurity peaks in the figure; in addition, from the data in Figure 3, it can be calculated that the ratio of the relative diffraction peak intensity of the (111) plane peak and the (200) plane peak is 4.95, which is greater than the theoretical (111) plane and (200) plane The relative diffraction peak strength of The growth rate is one-dimensional, and silver nanowires are obtained by one-dimensional growth.

Example 4

(1) Prepare respectively a silver nitrate solution with a concentration of 1mol/L, a caffeic acid aqueous solution with a concentration of 2.4g/L, and a polyvinylpyrrolidone solution with a concentration of 0.01g/L;

Among them, the molecular weight of polyvinylpyrrolidone is 1,300,000 Daltons;

The volume ratio of caffeic acid aqueous solution and mixed solution is 7:61;

The diameter of the prepared silver nanowire is 56±2nm and the length is 59±3μm.

Example 5

A method for preparing silver nanowires at room temperature based on small molecule phenolic acid (ferulic acid). The specific preparation steps are as follows:

(1) Prepare respectively a silver bromide solution with a concentration of 0.5mol/L, a ferulic acid aqueous solution with a concentration of 2g/L, and a polyvinylpyrrolidone solution with a concentration of 0.05g/L;

Among them, the molecular weight of polyvinylpyrrolidone is 40,000 Daltons;

(2) Add the silver bromide solution to the polyvinylpyrrolidone solution, stir for 15 minutes at a speed of 500 r/min, and mix evenly to obtain a mixed solution;

Among them, the volume ratio of silver bromide solution and polyvinylpyrrolidone solution is 1:40;

(3) Add ferulic acid aqueous solution dropwise to the mixed solution obtained in step (2) at a speed of 10 mL/min, stir and react at room temperature at a speed of 100 r/min for 10 min, then raise the temperature to 30°C and let it stand for 3.5 h;

The volume ratio of ferulic acid aqueous solution to mixed solution is 7:41;

The diameter of the prepared silver nanowire is 44±3nm and the length is 51±2μm.

Example 6

A method for preparing silver nanowires at room temperature based on small molecule phenolic acid (chlorogenic acid). The specific preparation steps are as follows:

(1) Prepare respectively a silver sulfate solution with a concentration of 2mol/L, a chlorogenic acid aqueous solution with a concentration of 3g/L, and a polyvinylpyrrolidone solution with a concentration of 0.02g/L;

Among them, the molecular weight of polyvinylpyrrolidone is 40,000 Daltons;

(2) Add the silver sulfate solution to the polyvinylpyrrolidone solution, stir for 15 minutes at a speed of 500 r/min, and mix evenly to obtain a mixed solution;

Among them, the volume ratio of silver sulfate solution and polyvinylpyrrolidone solution is 1:80;

(3) Add the chlorogenic acid aqueous solution dropwise to the mixed solution obtained in step (2) at a speed of 20 mL/min, stir and react at room temperature at a speed of 200 r/min for 10 min, then raise the temperature to 28°C and let it stand for 3 hours;

The volume ratio of chlorogenic acid aqueous solution and mixed solution is 7:81;

The diameter of the prepared silver nanowire is 53±4nm and the length is 47±4μm.

Example 7

(1) Prepare respectively a silver nitrate solution with a concentration of 3mol/L, a ferulic acid aqueous solution with a concentration of 2.4g/L, and a polyvinylpyrrolidone solution with a concentration of 0.03g/L;

Among them, the molecular weight of polyvinylpyrrolidone is 58,000 Daltons;

(3) Add ferulic acid aqueous solution dropwise to the mixed solution obtained in step (2) at a speed of 15 mL/min, stir and react at room temperature at a speed of 300 r/min for 5 min, then raise the temperature to 30°C and let it stand for 3 hours;

The volume ratio of ferulic acid aqueous solution and mixed solution is 7:61;

The diameter of the prepared silver nanowire is 51±2nm and the length is 51±3μm.

Example 8

A method for using silver nanowires for conductive finishing of cotton fabrics. The specific steps are as follows:

(1) Cleaning of cotton fabrics:

Prepare 2g/L soap solution with a liquor ratio of 1:60, boil the cotton fabric at 100°C for 30 minutes, and wash it with deionized water three times to remove natural and man-made impurities on its surface. After washing, dry it naturally;

(2) Cotton fabric pretreatment:

Cut the cotton fabric in step (1) into 4×4cm pieces, immerse it in water and treat it ultrasonically at room temperature for 10 minutes;

(3) Conductive finishing:

The silver nanowires synthesized in Example 1 were configured into a silver nanowire aqueous solution with a mass concentration of 6g/L, and ultrasonically dispersed at room temperature for 3 minutes at a frequency of 40KHz; the cotton fabric treated in step (2) was impregnated into the silver nanowires In the solution, keep it in a oscillating water bath at 80°C for 30 minutes, take out the pad and remove the solution, and then dry it in an oven at 60°C. Repeat the dipping-padding-drying process three times; finally, immerse the fabric obtained in the sodium chloride aqueous solution for 45 seconds. And wash with deionized water for 20 seconds, repeat twice, and dry at 60°C to obtain conductive cotton fabric;

Among them, the rolling residue rate when rolling off the solution is 150%; the mass fraction of sodium chloride aqueous solution is 10%;

The ST-2258C multifunctional digital four-probe tester was used to test the square resistance of the conductive cotton fabric. The measured square resistance of the conductive cotton fabric was 0.54±0.06Ω/sq.

Example 9

(1) Cleaning of cotton fabrics:

(2) Cotton fabric pretreatment:

(3) Conductive finishing:

The silver nanowires synthesized in Example 2 were configured into a silver nanowire aqueous solution with a mass concentration of 8g/L, and ultrasonically dispersed at room temperature for 3 minutes at a frequency of 50KHz; the cotton fabric treated in step (2) was impregnated into the silver nanowires In the solution, keep it in an oscillating water bath at 80°C for 30 minutes, take out the pad and remove the solution, and then dry it in an oven at 60°C. Repeat the dipping-pad-drying process three times; finally, immerse the fabric obtained in the potassium chloride aqueous solution for 45 seconds. And wash with deionized water for 20 seconds, repeat twice, and dry at 60°C to obtain conductive cotton fabric;

Among them, the rolling residue rate when rolling off the solution is 150%; the mass fraction of potassium chloride aqueous solution is 10%;

The ST-2258C multifunctional digital four-probe tester was used to test the square resistance of the conductive cotton fabric. The measured square resistance of the conductive cotton fabric was 0.33±0.09Ω/sq.

Example 10

(1) Cleaning of cotton fabrics:

(2) Cotton fabric pretreatment:

Cut the cotton fabric in step (1) into 4×4cm pieces, immerse it in water and treat it ultrasonically at room temperature for 20 minutes;

(3) Conductive finishing:

The silver nanowires synthesized in Example 3 were configured into a silver nanowire aqueous solution with a mass concentration of 10g/L, and ultrasonic dispersed at room temperature for 5 minutes at a frequency of 60KHz; the cotton fabric treated in step (2) was impregnated into the silver nanowires In the solution, keep it in a oscillating water bath at 80°C for 30 minutes, take out the pad and remove the solution, and then dry it in an oven at 60°C. Repeat the dipping-padding-drying process twice; finally, immerse the fabric obtained in the lithium chloride aqueous solution for 45 seconds. And wash with deionized water for 20 seconds, repeat twice, and dry at 60°C to obtain conductive cotton fabric;

Among them, the rolling residue rate when rolling off the solution is 150%; the mass fraction of lithium chloride aqueous solution is 10%;

The ST-2258C multifunctional digital four-probe tester was used to test the square resistance of the conductive cotton fabric. The measured square resistance of the conductive cotton fabric was 0.26±0.04Ω/sq.

Example 11

(1) Cleaning of cotton fabrics:

(2) Cotton fabric pretreatment:

(3) Conductive finishing:

The silver nanowires synthesized in Example 4 were configured into a silver nanowire aqueous solution with a mass concentration of 12g/L, and ultrasonically dispersed at room temperature for 5 minutes at a frequency of 60KHz; the cotton fabric treated in step (2) was impregnated into the silver nanowires In the solution, keep it in a oscillating water bath at 80°C for 30 minutes, take out the pad and remove the solution, and then dry it in an oven at 60°C. Repeat the dipping-pad-drying process twice; finally, immerse the fabric obtained in the sodium chloride aqueous solution for 60 seconds. And wash with deionized water for 20 seconds, repeat twice, and dry at 60°C to obtain conductive cotton fabric;

The ST-2258C multifunctional digital four-probe tester was used to test the square resistance of the conductive cotton fabric. The measured square resistance of the conductive cotton fabric was 0.23±0.02Ω/sq.

The conductive cotton fabrics prepared in Examples 8 to 11 were put into 2g/L soap solution, and 10 steel balls were put into each, and the conductive cotton fabrics were tested in a Wash Tec-P type wash color fastness testing machine at 45°C. Taking 15 minutes as a washing cycle, wash 2 times, 4 times, 8 times, and 10 times respectively, and use the ST-2258C multifunctional digital four-probe tester to test the resistance of each conductive cotton fabric. The test results are shown in Figure 4. It can be seen from Figure 4 that the conductive cotton fabric prepared by the method of the present invention has good washing resistance and stability.

Example 12

(1) Cleaning of cotton fabrics:

(2) Cotton fabric pretreatment:

(3) Conductive finishing:

The silver nanowires synthesized in Example 5 were configured into a silver nanowire aqueous solution with a mass concentration of 8g/L, and ultrasonically dispersed at room temperature for 4 minutes at a frequency of 50KHz; the cotton fabric treated in step (2) was impregnated into the silver nanowires In the solution, keep it in a oscillating water bath at 80°C for 20 minutes, take out the pad and remove the solution, and then dry it in an oven at 60°C. Repeat the dipping-padding-drying process three times; finally, immerse the obtained fabric in the potassium chloride aqueous solution for 60 seconds. And wash with deionized water for 10 seconds, repeat twice, and dry at 60°C to obtain conductive cotton fabric;

Among them, the rolling residue rate when rolling off the solution is 100%; the mass fraction of potassium chloride aqueous solution is 20%;

The ST-2258C multifunctional digital four-probe tester was used to test the square resistance of the conductive cotton fabric. The measured square resistance of the conductive cotton fabric was 0.80±0.04Ω/sq.

Example 13

(1) Cleaning of cotton fabrics:

(2) Cotton fabric pretreatment:

(3) Conductive finishing:

The silver nanowires synthesized in Example 6 were configured into a silver nanowire aqueous solution with a mass concentration of 10g/L, and ultrasonic dispersed at room temperature for 4 minutes at a frequency of 40KHz; the cotton fabric treated in step (2) was impregnated into the silver nanowires In the solution, keep it in a oscillating water bath at 80°C for 25 minutes, take out the pad and remove the solution, and then dry it in an oven at 60°C. Repeat the dipping-pad-drying process twice; finally, immerse the fabric obtained in the lithium chloride aqueous solution for 45 seconds. And wash with deionized water for 15 seconds, repeat twice, and dry at 60°C to obtain conductive cotton fabric;

Among them, the rolling residue rate when rolling off the solution is 120%; the mass fraction of lithium chloride aqueous solution is 10%;

The ST-2258C multifunctional digital four-probe tester was used to test the square resistance of the conductive cotton fabric. The measured square resistance of the conductive cotton fabric was 0.58±0.02Ω/sq.

Example 14

(1) Cleaning of cotton fabrics:

(2) Cotton fabric pretreatment:

(3) Conductive finishing:

The silver nanowires synthesized in Example 7 were configured into a silver nanowire aqueous solution with a mass concentration of 12g/L, and ultrasonically dispersed at room temperature for 5 minutes at a frequency of 60KHz; the cotton fabric treated in step (2) was impregnated into the silver nanowires In the solution, keep it in a oscillating water bath at 80°C for 25 minutes, take out the pad and remove the solution, and then dry it in an oven at 60°C. Repeat the dipping-pad-drying process twice; finally, immerse the fabric obtained in the sodium chloride aqueous solution for 30 seconds. And wash with deionized water for 20 seconds, repeat twice, and dry at 60°C to obtain conductive cotton fabric;

Among them, the rolling residue rate when rolling off the solution is 120%; the mass fraction of sodium chloride aqueous solution is 15%;

The ST-2258C multifunctional digital four-probe tester was used to test the square resistance of the conductive cotton fabric. The measured square resistance of the conductive cotton fabric was 0.33±0.02Ω/sq.

Claims

A method for preparing silver nanowires at room temperature based on small molecule phenolic acid is characterized in that: small molecule phenolic acid is used as a reducing agent, polyvinylpyrrolidone is used as a template agent, and the silver source is reduced at room temperature to prepare silver nanowires.
The method for preparing silver nanowires at room temperature based on small molecule phenolic acid according to claim 1, characterized in that the small molecule phenolic acid is caffeic acid, ferulic acid or chlorogenic acid.
The method for preparing silver nanowires at room temperature based on small molecule phenolic acid according to claim 1, wherein the molecular weight of polyvinylpyrrolidone is 20,000 to 1,300,000 daltons.
The method for preparing silver nanowires at room temperature based on small molecule phenolic acid according to claim 1, wherein the silver source is silver nitrate, silver bromide or silver sulfate.
The method for preparing silver nanowires at room temperature based on small molecule phenolic acid according to claim 1, characterized in that the silver nanowires are deposited on the surface of cotton fabric through a dipping-padding-drying method to prepare conductive cotton fabric, The sheet resistance of the conductive cotton fabric is 0.23-0.54Ω/sq.
The method for preparing silver nanowires at room temperature based on small molecule phenolic acid according to any one of claims 1 to 5, characterized in that the specific preparation steps are as follows:

(1) Prepare respectively a silver source solution with a concentration of 0.5~3mol/L, a small molecule phenolic acid aqueous solution with a concentration of 2~3g/L, and a polyvinylpyrrolidone solution with a concentration of 0.01~0.05g/L;

(2) Add the silver source solution to the polyvinylpyrrolidone solution, stir and mix evenly to obtain a mixed solution;

(3) Add a small molecule phenolic acid aqueous solution to the mixed solution obtained in step (2), stir and react at room temperature for 5 to 10 minutes, then raise the temperature to 28 to 30°C and let it stand for 3 to 4 hours;

(4) Centrifuge the solution after the reaction in step (3), remove the lower precipitate and clean it, repeat the centrifugation and cleaning steps 2 to 4 times to obtain silver nanowires.
The method for preparing silver nanowires at room temperature based on small molecule phenolic acid according to claim 6, characterized in that in step (2), the volume ratio of the silver source solution and the polyvinylpyrrolidone solution is 1:40 to 80;

In step (3), the volume ratio of the small molecule phenolic acid aqueous solution to the mixed solution is 7:41 to 81.
The method for preparing silver nanowires at room temperature based on small molecule phenolic acid according to claim 6, characterized in that the stirring speed in step (2) is 500~600r/min, and the mixing time is 15~20min;

The stirring speed in step (3) is 100~300r/min.
The method for preparing silver nanowires at room temperature based on small molecule phenolic acid according to claim 6, characterized in that in step (3), the small molecule phenolic acid aqueous solution is added dropwise, and the dropwise speed is 2.8 to 20 mL. /min.
The method for preparing silver nanowires at room temperature based on small molecule phenolic acid according to claim 6, characterized in that the cleaning in step (4) means: first cleaning with ethanol, and then cleaning with deionized water.