Antibacterial real silk and preparation method thereof

Abstract

The application provides antibacterial real silk and a preparation method thereof, and belongs to the technical field of textile weaving. The preparation method of the antibacterial real silk comprises the following steps: after the real silk is cleaned, the real silk is immersed in a silver nitrate composite solution, silver ions are adsorbed to the real silk, a reducing agent is used to reduce the nano-silver in situ, and fixing treatment is performed, so that the nano-silver is fixed to the surface and internal pores of the real silk fiber, the nano-silver-real silk is obtained, and efficient and durable antibacterial performance is realized. Experimental results show that the antibacterial rate of the antibacterial real silk is greater than or equal to 99%, and is still greater than 96% after 50 times of washing, and the softness and air permeability of the real silk are not affected, and the antibacterial real silk is suitable for multiple fields such as medical treatment, clothing and home.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of textile weaving, in particular to an antibacterial real silk and a preparation method thereof. BACKGROUND

[0002] Real silk is made of natural silk protein fiber, has excellent skin-friendliness, air permeability, moisture absorption and gloss, and is widely used in high-end clothing, home supplies and medical textile fields. However, its protein structure is easy to become a breeding carrier for bacteria and mold in a humid environment, resulting in the following problems: easy to produce odor and mold spots after long-term use, and even cause skin allergy; microbial degradation accelerates fiber aging and shortens service life; it is difficult to meet the needs of medical, sports and other high hygiene standard fields.

[0003] At present, the antibacterial modification methods for real silk mainly include: chemical finishing agent method, using quaternary ammonium salt, halogenated phenol and other organic antibacterial agents, but there are problems of toxicity residue and poor washing resistance (invalid after washing for 5-10 times); coating method, by coating a polymer layer containing silver, copper and other metals, but it will significantly reduce the air permeability and softness of the fabric; natural extract method (such as chitosan, plant essential oil): the antibacterial effect is short-term and the inhibition ability to gram-negative bacteria is weak.

[0004] Nanometer silver (AgNPs) is considered as an ideal antibacterial agent due to its broad-spectrum antibacterial property, low toxicity and high stability. However, in the prior art, there are the following difficulties in loading nanometer silver on real silk: nanometer silver is easy to agglomerate, resulting in too high local concentration and affecting the hand feeling of the fabric; physical adsorption method is easy to fall off during washing, and the antibacterial performance decays quickly; strong reducing agent or high temperature treatment may damage the silk protein structure.

[0005] In view of the above defects, the present application proposes a new type of nanometer silver loading process, which realizes the uniform distribution and firm combination of nanometer silver on the surface and inside of real silk fiber through in-situ reduction combined with fixing technology, while maintaining the original performance of the fabric. SUMMARY

[0006] The purpose of the present application is to provide an antibacterial real silk and a preparation method thereof, which solves the problems of rapid performance decay and hand feeling deterioration in traditional antibacterial technology, and realizes the goals of efficient antibacterial and long-lasting washing resistance.

[0007] In order to achieve the above-mentioned purpose of the application, the present application provides the following technical solutions:

[0008] The application provides a preparation method of antibacterial real silk, comprising the following steps: cleaning real silk in a surfactant solution, drying, ultrasonic immersion in a composite solution, adding a reducing agent to perform a reduction reaction, obtaining nano-silver-real silk, performing fixation treatment in a fixing agent solution, and cleaning and drying to obtain the antibacterial real silk; the composite solution comprises a silver nitrate solution and a dispersant solution.

[0009] Preferably, the surfactant is one or more of Triton X-100, fatty alcohol polyoxyethylene ether (for example, fatty alcohol polyoxyethylene ether-7) and sodium dodecyl sulfate, and the concentration of the surfactant solution is 1-5 g / L.

[0010] Preferably, the concentration of silver nitrate in the composite solution is 0.3-0.6 mol / L.

[0011] Preferably, the dispersant is one or more of polyvinylpyrrolidone (for example, polyvinylpyrrolidone K30), sodium polyacrylate and alkyl polyglucoside, and the mass fraction of the dispersant in the composite solution is 1%-3%.

[0012] Preferably, the ultrasonic immersion has a material-liquid ratio of 1:20-30 g / mL, a temperature of 35-45 DEG C, a frequency of 30-40 kHz and a time of 20-30 min.

[0013] Preferably, the reducing agent is one or both of L-ascorbic acid and plant extract.

[0014] Preferably, the reduction reaction has a temperature of 40-50 DEG C, a rotating speed of 60-70 r / min and a time of 30-40 min.

[0015] Preferably, the fixing agent is one or both of sodium citrate and quaternary ammonium chitosan, and the mass percentage content of the fixing agent is 2%-5%.

[0016] Preferably, the fixation has a temperature of 30-40 DEG C and a time of 40-50 min.

[0017] The application further provides the antibacterial real silk prepared by the above preparation method.

[0018] Compared with the prior art, the application has the following beneficial effects:

[0019] The application provides a preparation method of antibacterial real silk, comprising the following steps: washing real silk, immersing in a silver nitrate composite solution, adsorbing silver ions into the real silk, reducing nanosilver in situ by a reducing agent, and performing fixation treatment to fix the nanosilver on the surface and internal pores of the real silk fiber, so as to obtain nanosilver-real silk and realize high-efficiency and long-lasting antibacterial performance. Experimental results show that the antibacterial rate of the antibacterial real silk is greater than or equal to 99%, and is still greater than 96% after 50 times of washing, and the softness and air permeability of the real silk are not affected, and the antibacterial real silk is suitable for medical, clothing and home fields. DETAILED DESCRIPTION

[0020] The application provides a preparation method of antibacterial real silk, comprising the following steps: washing real silk, immersing in a silver nitrate composite solution, adsorbing silver ions into the real silk, reducing nanosilver in situ by a reducing agent, and performing fixation treatment to fix the nanosilver on the surface and internal pores of the real silk fiber, so as to obtain nanosilver-real silk and realize high-efficiency and long-lasting antibacterial performance. Experimental results show that the antibacterial rate of the antibacterial real silk is greater than or equal to 99%, and is still greater than 96% after 50 times of washing, and the softness and air permeability of the real silk are not affected, and the antibacterial real silk is suitable for medical, clothing and home fields.

[0021] The surface active agent is preferably one or more of Triton X-100, fatty alcohol polyoxyethylene ether-7 and sodium dodecyl sulfate, the fatty alcohol polyoxyethylene ether-7 is purchased from Texas Chengqi Chemical Co., Ltd., and the article number is cq-aeo7. The concentration of the surface active agent solution is preferably 1-5 g / L, and more preferably 3 g / L; the mass ratio in the washing process is preferably 1:20-30, and more preferably 1:25, the washing preferably adopts ultrasonic assisted washing, the temperature of the washing is preferably 40-50 DEG C, and more preferably 45 DEG C, the ultrasonic frequency is preferably 20-30 kHz, and more preferably 25 kHz, and the time is preferably 20-30 min, and more preferably 25 min; the temperature of the drying is preferably 40-50 DEG C, and more preferably 45 DEG C, and the water content in the real silk is less than 5%. In the preparation of the antibacterial real silk, the pretreatment washing is a more critical step, the washing method of the application can avoid the denaturation of the protein in the real silk caused by high temperature, remove the impurities, grease and residual silk glue on the surface of the fiber, and also maintain the integrity of the silk protein structure, and the drying step after washing can open the pores on the surface of the fiber, facilitating the subsequent adsorption of silver ions.

[0022] The concentration of silver nitrate in the composite solution is preferably 0.3-0.6 mol / L, more preferably 0.4 mol / L; the dispersant is preferably one or more of polyvinylpyrrolidone K30, sodium polyacrylate and alkyl polyglucoside, the polyvinylpyrrolidone K30 is purchased from Shandong Zhongyi Chemical Technology Co., Ltd., with a product number of 3561, the sodium polyacrylate is purchased from Guangdong Qianheng Biological Technology Co., Ltd., with a product number of 180626, and the alkyl polyglucoside is purchased from Shanghai Zhu Shihua Chemical Co., Ltd., with a model number of Agnique PG 8107; the mass fraction of the dispersant in the composite solution is preferably 1%-3%, more preferably 2%; the liquid-to-solid ratio of the ultrasonic immersion is preferably 1:20-30 g / mL, more preferably 1:25 g / mL; the temperature is preferably 35-45 DEG C, more preferably 40 DEG C; the frequency is preferably 30-40 kHz, more preferably 35 kHz; and the time is preferably 20-30 min, more preferably 25 min. The dispersant in the composite solution of the application can make silver ions uniformly dispersed in the solution, so that they are uniformly adsorbed on the silk, thereby avoiding aggregation of silver nanoparticles in the subsequent preparation of silver nanoparticles, which can cause the local concentration of silver nanoparticles to be too high and affect the hand feeling of the fabric. In this step, the functional groups contained in the silk fibroin of the silk can form coordinate bonds with silver ions (such as amino groups (-NH2), carboxyl groups (-COOH), mercapto groups (-SH) and hydroxyl groups (-OH)), so that the silver ions are more closely combined with the silk.

[0023] In the application, the reducing agent is preferably one or both of L-ascorbic acid and plant extract. The selected reducing agent in the application has a mild reaction condition relative to sodium borohydride, avoids affecting the fiber structure of the silk fabric due to a violent reaction, causes the silk protein in the silk fabric to be denatured, and makes the prepared silver nanoparticles not aggregate, have a uniform particle size and strong antibacterial capacity.

[0024] The plant extract in the application is preferably obtained by fermentation and enzymolysis of Alipinia oxphylla and Buddleja fallax. The preparation method of the plant extract preferably comprises the following steps: freeze-drying Alipinia oxphylla and Buddleja fallax respectively, mixing and crushing to obtain plant powder, adding 8-10 times the mass of deionized water, ultrasonic treatment, inoculating a composite microbial inoculant for anaerobic fermentation, sterilizing and filtering to obtain a fermentation liquor, adding a composite enzyme for enzymolysis, deactivating the enzyme, filtering, and spray drying to obtain the plant extract.

[0025] The selected Alipinia oxphylla and Buddleja fallax have a fragrance, and after the steps of fermentation and enzymolysis, the silk fabric has a unique fragrance.

[0026] The ultrasonic treatment temperature is preferably 50-60 DEG C, more preferably 55 DEG C, the frequency is preferably 70-80 kHz, more preferably 75 kHz, and the time is preferably 20-30 min, more preferably 25 min.

[0027] The composite microbial agent is composed of Lactobacillus johnsonii and Lactobacillus rhamnosus, preferably according to a weight ratio of 1-3:2-5, more preferably 2:3. The Lactobacillus johnsonii is produced by Xi'an Binghe Biotechnology Co., Ltd., with a product number of BH-YSRGJ and a CFU of 100 billion per gram; and the Lactobacillus rhamnosus is produced by Xi'an Binghe Biotechnology Co., Ltd., with a product number of BH-SLTRGJ and a CFU of 100 billion per gram. The fermentation temperature is 35-40 DEG C, more preferably 37 DEG C, the pH value is preferably 6.5-7.0, more preferably 6.8, the inoculation amount is 1%-2% of the total weight of the Radula neesiana and Buddleja officinalis, more preferably 1.5%, and the time is preferably 48-72 h, more preferably 60 h. The Lactobacillus johnsonii and the Lactobacillus rhamnosus have a significant synergistic effect, decompose complex polysaccharides and proteins in the raw materials, release more reducing substances (such as phenols and flavonoids), significantly enhance the reducing capacity of the raw materials, and thus improve the antioxidant activity.

[0028] The composite enzyme is composed of natto kinase and papain according to a weight ratio of 1:2-5, the natto kinase is purchased from Xi'an Ruixi Biotechnology Co., Ltd., with a product number of rx-4952 and a fu of 20000 per gram, and the papain is purchased from Longchuan (Nanjing) Biotechnology Co., Ltd., with a product number of mgm01 and a u of 200000 per gram. The enzymolysis temperature is 40-50 DEG C, more preferably 45 DEG C, the pH value is preferably 6-7, more preferably 6.5, the enzyme addition amount is preferably 2%-5%, more preferably 4%, and the time is 60-90 min, more preferably 70 min. The natto kinase and the papain have a synergistic effect, can produce diversified peptides, and significantly improve the reducing capacity of the fermentation liquor.

[0029] The fermentation step produces a variety of metabolites with antioxidant activity on the basis of the antioxidant activity of the substrate, optimizes the structure of the antioxidant substances of the substrate, produces diversified peptides through enzymolysis to improve the reducing capacity, and has a synergistic effect between fermentation and enzymolysis, which not only improves the reducing property of the Radula neesiana and the Buddleja officinalis, but also makes the silk have a unique fragrance.

[0030] The temperature of the reduction reaction is preferably 40-50 DEG C, more preferably 45 DEG C, the rotation speed is preferably 60-70 r / min, more preferably 65 r / min, and the time is preferably 30-40 min, more preferably 35 min. In this step, the silver ions adsorbed in the silk fabric are reduced to nano-silver particles by in-situ reduction deposition, and the nano-silver particles have stronger antibacterial activity. The nano-silver particles are firmly combined with the silk fibroin through physical adsorption and chemical bonding (such as coordination bond and hydrogen bond) after reduction, and the washing resistance is enhanced. The nano-silver particles prepared by the method of the application can be uniformly distributed in the silk fabric, and the ultraviolet resistance and antistatic performance of the silk fabric can be improved, while the softness and air permeability of the silk fabric are maintained.

[0031] The fixing agent is preferably one or both of sodium citrate and quaternary ammonium chitosan, and the mass percentage of the fixing agent is preferably 2-5%, more preferably 3%. The fixing temperature is preferably 30-40 DEG C, more preferably 35 DEG C, and the time is preferably 40-50 min, more preferably 45 min. The sodium citrate has reducing property, and the citrate forms Ag-O coordination bond with the surface of the nano-silver particles, preventing the oxidation and shedding of the nano-silver particles. On the other hand, the citrate is combined with the amino group of the silk fibroin to form a bridging structure of "fiber-citric acid-nano-silver", so that the antibacterial silk fabric still has excellent antibacterial performance after multiple washing. The amino group and quaternary ammonium group in the quaternary ammonium chitosan can form a stable complex with the nano-silver particles through electrostatic interaction or coordination bond, preventing the aggregation and precipitation of the nano-silver particles, thereby improving the adhesion stability and dispersibility of the nano-silver on the silk fabric, slowly releasing the silver ions, prolonging the antibacterial time, achieving high-efficiency antibacterial effect, and playing the role of lubricant after being fixed on the silk fabric, reducing the friction between fibers, making the silk fabric more soft and smooth. The fixing step can enhance the combination firmness of the nano-silver and the silk fabric, improve the antibacterial performance, and make the internal structure of the silk fabric more loose, so that the silk fabric exhibits better softness and flexibility in macroscopic view.

[0032] The technical scheme of in-situ reduction combined with fixing in the application can uniformly disperse the silver on the surface and inside of the silk fabric, firmly combine the silver with the silk fabric, maintain the original performance of the fabric, and achieve the effects of high-efficiency antibacterial and long-lasting washing resistance.

[0033] The application further provides the antibacterial silk fabric prepared by the preparation method.

[0034] In the application, all the raw material components are commercially available products well known to those skilled in the art, unless otherwise specified.

[0035] The technical solutions in the present application will be described clearly and completely below in connection with the embodiments in the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the protection scope of the present application.

[0036] In the following examples, all the conventional methods are used unless otherwise specified.

[0037] In the following examples, all the materials and reagents used are commercially available unless otherwise specified.

[0038] Example 1

[0039] Preparation of antibacterial silk

[0040] (1) Pretreatment

[0041] The silk is immersed in 25 times mass of surfactant solution (the surfactant is Triton X-100, the concentration is 3 g / L) and treated by ultrasonic at 45℃ and 25 kHz for 25 min. After the water droplet is removed, the silk is dried at 45℃ until the water content is 3%. The surface and internal pores of the silk are opened.

[0042] (2) Silver ion immersion

[0043] The dried silk is immersed in the composite solution by ultrasonic at 40℃ and 35 kHz for 25 min.

[0044] The composite solution is composed of silver nitrate solution and dispersant solution. The concentration of silver nitrate is 0.4 mol / L. The dispersant is composed of polyvinylpyrrolidone K30 and sodium polyacrylate according to the mass ratio of 1:1. The mass fraction of the dispersant in the composite solution is 2%. The mass-volume ratio of the silk to the composite solution is 1:25 g / mL.

[0045] (3) In-situ reduction

[0046] After the immersion in step (2), the plant extract is added (the addition amount is 3% of the mass of the composite solution). The nano-silver-silk is obtained after the reduction at 45℃ and 65 r / min for 35 min. The silk is taken out and washed with distilled water for 3 times to remove the excess silver ions.

[0047] The preparation method of the plant extract is as follows: the Morinda officinalis and Buddleja officinalis are freeze-dried, mixed according to a mass ratio of 1:1, crushed through a 200-mesh screen, 9 times the mass of deionized water is added, ultrasonic treatment is carried out at 55 DEG C and 75 kHz for 25 min, then a compound microbial inoculum (consisting of Lactobacillus johnsonii and Lactobacillus rhamnosus according to a mass ratio of 2:3, inoculation amount being 1.5% of the total weight of the Morinda officinalis and Buddleja officinalis) is inoculated, anaerobic fermentation is carried out at 37 DEG C and pH 6.8 for 60 h, sterilization and filtration are carried out, a fermentation liquor is obtained, a compound enzyme (consisting of natto kinase and papain according to a weight ratio of 1:3, addition amount being 1.5% of the total weight of the Morinda officinalis and Buddleja officinalis) is added, enzymolysis is carried out at 45 DEG C and pH 6.5 for 70 min, enzyme inactivation is carried out, a 1-kDa ultrafiltration membrane is used for filtration, the filtrate less than 1 kDa is collected, and spray drying is carried out at 55 DEG C, with a water content of 3%, to obtain the plant extract;

[0048] (4) Fixing treatment

[0049] The rinsed nanosilver-silk fabric is fixed in an aqueous fixing agent solution (amount being 25 times the mass of the silk fabric) at 35 DEG C for 45 min, taken out, rinsed with distilled water for 3 times, and dried at 45 DEG C until the water content is 3%, to obtain the antibacterial silk fabric.

[0050] The fixing agent consists of sodium citrate and quaternary ammonium chitosan according to a mass ratio of 1:5, and the concentration of the aqueous fixing agent solution is 3%.

[0051] Example 2

[0052] Preparation of antibacterial silk fabric

[0053] (1) Pretreatment

[0054] The silk fabric is immersed in 25 times the mass of a surfactant solution (the surfactant is fatty alcohol polyoxyethylene ether-7, concentration being 1 g / L) and ultrasonically treated at 40 DEG C and 20 kHz for 30 min, the silk fabric is taken out until no water drops, and dried at 40 DEG C until the water content is 4%, to open the surface and internal pores of the silk fabric.

[0055] (2) Silver ion impregnation

[0056] The dried silk fabric is ultrasonically impregnated in a composite solution at 35 DEG C and 30 kHz for 30 min.

[0057] The composite solution consists of a silver nitrate solution and a dispersant solution, the concentration of the silver nitrate is 0.3 mol / L, the dispersant is alkyl polyglucoside, the mass fraction of the dispersant in the composite solution is 1%, and the mass-volume ratio of the silk fabric to the composite solution is 1:20 g / mL.

[0058] (3) In-situ reduction

[0059] After the step (2) of immersion, plant extract (added amount is 1% of the mass of the composite solution) is added, and after reduction for 40 min at a temperature of 40 DEG C and a rotation speed of 60 r / min, a nano-silver real silk fabric is obtained, and the nano-silver real silk fabric is taken out and washed with distilled water for 3 times to remove the excess silver ions;

[0060] The plant extract is prepared as follows: the Morinda officinalis and the Buddleja officinalis are freeze-dried, mixed according to a mass ratio of 1:2, crushed through a 150-mesh sieve to obtain plant powder, 8 times of deionized water is added, ultrasonic treatment is carried out at 50 DEG C and 70 kHz for 30 min, a composite microbial inoculum (consisting of Lactobacillus johnsonii and Lactobacillus rhamnosus according to a mass ratio of 1:2, and the inoculation amount is 1% of the total weight of the Morinda officinalis and the Buddleja officinalis) is inoculated, anaerobic fermentation is carried out at 35 DEG C and pH 6.5 for 72 h, sterilization and filtration are carried out to obtain a fermentation liquor, a composite enzyme (consisting of natto kinase and papain according to a weight ratio of 1:2, and the added amount is 1% of the total weight of the Morinda officinalis and the Buddleja officinalis) is added, and enzymolysis is carried out at 40 DEG C and pH 6 for 90 min, the enzyme is inactivated, a 1-kDa ultrafiltration membrane is used for filtration, the filtrate with a molecular weight less than 1 kDa is collected, and spray drying is carried out at 50 DEG C to obtain the plant extract with a water content of 4%;

[0061] (4) fixing treatment

[0062] The washed nano-silver real silk fabric is placed in a fixing agent aqueous solution (the amount of the fixing agent is 20 times of the mass of the real silk fabric) for fixing treatment at 30 DEG C for 50 min, taken out, washed with distilled water for 3 times, and dried at 40 DEG C to a water content of 4% to obtain an antibacterial real silk fabric;

[0063] The fixing agent consists of sodium citrate and quaternary ammonium chitosan according to a mass ratio of 1:3, and the concentration of the fixing agent aqueous solution is 2%.

[0064] Example 3

[0065] Preparation of the antibacterial real silk fabric

[0066] (1) pretreatment

[0067] The real silk fabric is immersed in a surfactant solution (the surfactant is sodium dodecyl sulfate, and the concentration is 5 g / L) with a mass of 35 times, ultrasonic treatment is carried out at 50 DEG C and 30 kHz for 20 min, the real silk fabric is taken out until no water drops, and the real silk fabric is dried at 50 DEG C to a water content of 2% to open the surface and internal pores of the real silk fabric;

[0068] (2) silver ion immersion

[0069] The dried real silk fabric is immersed in a composite solution at 45 DEG C and 40 kHz for 20 min;

[0070] The composite solution is composed of silver nitrate solution and dispersant solution, the concentration of silver nitrate is 0.6 mol / L, the dispersant is polyvinylpyrrolidone K30, and the mass fraction of the dispersant in the composite solution is 1%; the mass-volume ratio of the silk to the composite solution is 1:30 g / mL;

[0071] (3) In-situ reduction

[0072] After the step (2) of immersion, L-ascorbic acid is added to a concentration of 1.2 mol / L, and the silver nanometer-silk is obtained after reduction at a temperature of 50°C and a rotation speed of 70 r / min for 30 min, and then the silver nanometer-silk is taken out and washed with distilled water for 3 times to remove the excess silver ions;

[0073] (4) Fixing treatment

[0074] The washed silver nanometer-silk is fixed in an aqueous solution of fixing agent (30 times of the mass of the silk) at a temperature of 40°C for 40 min, and then the silver nanometer-silk is taken out and washed with distilled water for 3 times, and dried at a temperature of 40°C until the water content is 5% to obtain the antibacterial silk;

[0075] The fixing agent is composed of sodium citrate and quaternary ammonium chitosan according to a mass ratio of 1:1, and the concentration of the aqueous solution of the fixing agent is 1%.

[0076] Example 4

[0077] Preparation of antibacterial silk

[0078] (1) Pretreatment

[0079] The silk is immersed in a surfactant solution (the surfactant is Triton X-100, and the concentration is 3 g / L) with a mass of 25 times, and then the silk is ultrasonically treated at a temperature of 45°C and a frequency of 25 kHz for 25 min, and then the silk is taken out until no water drops, and then the silk is dried at a temperature of 45°C until the water content is 3% to open the surface and internal pores of the silk;

[0080] (2) Silver ion immersion

[0081] The dried silk is immersed in a composite solution at a temperature of 40°C and a frequency of 35 kHz for 25 min;

[0082] The composite solution is composed of silver nitrate solution and dispersant solution, the concentration of silver nitrate is 0.4 mol / L, the dispersant is composed of polyvinylpyrrolidone K30 and sodium polyacrylate according to a mass ratio of 1:1, and the mass fraction of the dispersant in the composite solution is 2%; the mass-volume ratio of the silk to the composite solution is 1:25 g / mL;

[0083] (3) In-situ reduction

[0084] After the step (2) impregnation, L-ascorbic acid is added to a concentration of 0.8 mol / L, and after reduction for 35 min at a temperature of 45°C and a rotation speed of 65 r / min, nano-silver real silk is obtained, and the nano-silver real silk is taken out and washed with distilled water for 3 times to remove the excess silver ions;

[0085] (4) Fixing treatment

[0086] The washed nano-silver real silk is fixed in an aqueous solution of a fixing agent (25 times the mass of the real silk) at 35°C for 45 min, and the nano-silver real silk is taken out and washed with distilled water for 3 times and dried at a temperature of 45°C until the water content is 3% to obtain antibacterial real silk;

[0087] The fixing agent is composed of sodium citrate and quaternary ammonium chitosan at a mass ratio of 1:5, and the concentration of the aqueous solution of the fixing agent is 3%.

[0088] Example 5

[0089] (1) Pretreatment

[0090] The real silk is immersed in a surfactant solution (the surfactant is composed of Triton X-100 and fatty alcohol polyoxyethylene ether-7 at a mass ratio of 1:3, and the concentration is 3 g / L) with a mass of 25 times, ultrasonic treatment is performed at 45°C and 25 kHz for 25 min, the real silk is taken out until no water drops, and the real silk is dried at a temperature of 40°C until the water content is 4% to open the surface and internal pores of the real silk;

[0091] (2) Silver ion impregnation

[0092] The dried real silk is ultrasonically impregnated in a composite solution at 45°C and 30 kHz for 23 min;

[0093] The composite solution is composed of a silver nitrate solution and a dispersant solution, the concentration of the silver nitrate is 0.3 mol / L, the dispersant is composed of polyvinylpyrrolidone K30 and sodium polyacrylate at a mass ratio of 2:1, the mass fraction of the dispersant in the composite solution is 2%, and the mass-volume ratio of the real silk to the composite solution is 1:23 g / mL.

[0094] (3) In-situ reduction

[0095] After the step (2) impregnation, L-ascorbic acid is added to a concentration of 0.6 mol / L, and after reduction for 34 min at a temperature of 45°C and a rotation speed of 63 r / min, nano-silver real silk is obtained, and the nano-silver real silk is taken out and washed with distilled water for 3 times to remove the excess silver ions;

[0096] (4) Fixing treatment

[0097] The rinsed nanosilver-silk is fixed in a water solution of fixing agent (23 times of the mass of the silk) at 34°C for 42 min, taken out, rinsed with distilled water for 3 times, and dried at 45°C until the water content is 3% to obtain the antibacterial silk;

[0098] The fixing agent is composed of sodium citrate and quaternary ammonium chitosan according to a mass ratio of 1:4, and the concentration of the water solution of the fixing agent is 4%.

[0099] Comparative Example 1

[0100] The specific implementation is the same as that in Example 1, except that steps (2) and (3) are modified as follows:

[0101] (2) Preparation of nanosilver

[0102] 0.4 mol / L silver nitrate solution is added with polyvinylpyrrolidone K30 and sodium polyacrylate (the mass fraction of polyvinylpyrrolidone K30 and sodium polyacrylate in the silver nitrate solution is 1%), and plant extract (the addition amount is 3% of the mass of the composite solution), and the mixture is reduced at 45°C and a rotation speed of 65 r / min for 35 min to obtain a nanosilver colloidal solution.

[0103] The plant extract is the plant extract in step (3) of Example 1.

[0104] (3) Immersion loading

[0105] The silk dried in step (1) is loaded in the nanosilver colloidal solution in step (2) under ultrasonic conditions at 40°C and 35 kHz for 60 min; the mass-volume ratio of the silk to the nanosilver colloidal solution is 1:25 g / mL, and the mixture is taken out, rinsed with distilled water for 3 times, and the excess silver ions are removed.

[0106] Comparative Example 2

[0107] The specific implementation is the same as that in Example 1, except that the composite microbial agent in step (3) is composed of Lactobacillus paracasei and Lactobacillus plantarum according to a mass ratio of 2:3, Lactobacillus paracasei is purchased from Shandong Pinggao Pharmaceutical Co., Ltd. with a product number of PG-LPF109 and a CFU of 100 billion / g, Lactobacillus plantarum is purchased from Shanxi Yilin Biological Technology Co., Ltd. with a product number of YLZWRGJ and a CFU of 100 billion / g; and the fermentation conditions remain unchanged.

[0108] Comparative Example 3

[0109] The specific implementation is the same as that in Example 1, except that the fermentation and enzymolysis steps in step (3) are exchanged.

[0110] Comparative Example 4

[0111] The specific implementation is the same as that of Example 1, except that the fixing agent is only sodium citrate.

[0112] Comparative Example 5

[0113] The specific implementation is the same as that of Example 1, except that the fixing agent is only quaternized chitosan.

[0114] Comparative Example 6

[0115] The specific implementation is the same as that of Example 1, except that no sex fixing treatment is performed.

[0116] Test Example 1

[0117] Antibacterial performance test

[0118] According to the evaluation of the antibacterial performance of textiles GB / T 20944.3-2008, the antibacterial performance of Examples 1-5 and Comparative Examples 1-6 before and after 50 times of washing of the antibacterial real silk is detected, and the specific results are shown in Table 1.

[0119] The strains for detecting the antibacterial performance are Staphylococcus aureus (ATCC 6538), Escherichia coli (ATCC 11229), and Candida albicans (ATCC 10231).

[0120] Table 1: Antibacterial rate (%) of antibacterial real silk before and after washing

[0121]

[0122]

[0123] From the data in Table 2, it can be seen that washing can reduce the antibacterial performance of the antibacterial real silk. From the comparison of the antibacterial rates of Example 1 and Comparative Example 1, it can be seen that the method of first adsorbing silver ions on the real silk and then performing a reduction reaction has stronger stability and antibacterial performance than directly loading nano-silver on the real silk. From the comparison of the data of Example 1 and Comparative Examples 2-3, it can be seen that different microorganisms and the order of preparing the plant extract have an effect on the antibacterial performance of the real silk. From the comparison of the data of Example 1 and Comparative Examples 4-6, it can be seen that there is a synergistic effect between the fixing agents sodium citrate and quaternized chitosan, which has a fixing effect on the nano-silver and still has excellent antibacterial efficacy after washing.

[0124] Test Example 2

[0125] Sensory of antibacterial real silk

[0126] 30 trained professionals selected to conduct sensory evaluation of the antibacterial real silk of examples 1-5 and comparative examples 1-6. The antibacterial real silk was evaluated by hand touch method for softness, smoothness and fullness, the best grade was defined as 5 (close to real silk hand feeling), and the lowest grade was 1. The results of sensory evaluation are shown in Table 2.

[0127] Table 2 Sensory evaluation of antibacterial real silk

[0128] Group Sensory grade Example 1 5.0 Example 2 4.8 Example 3 4.7 Example 4 4.9 Example 5 4.7 Comparative Example 1 4.6 Comparative Example 2 4.4 Comparative Example 3 4.5 Comparative Example 4 4.1 Comparative Example 5 4.0 Comparative Example 6 3.4

[0129] From the data in Table 2, it can be seen that the antibacterial real silk of examples 1-5 has excellent hand feeling, close to real silk hand feeling. The antibacterial real silk of comparative examples 1-3 has little difference from the hand feeling of examples 1-5. The data comparison of example 1 and comparative examples 4-6 shows that there is a synergistic effect between sodium citrate and quaternized chitosan, which can significantly improve the hand feeling of antibacterial real silk, and make the antibacterial real silk keep the original silk hand feeling.

[0130] The above only describes the preferred embodiments of the present application, it should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A method for preparing an antibacterial real silk, characterized in that, The method comprises the following steps: cleaning and drying real silk in a surfactant solution, ultrasonic immersion in a composite solution, adding a reducing agent to perform a reduction reaction, obtaining nano-silver-real silk, and performing fixation treatment in a fixing agent solution, and cleaning and drying to obtain the antibacterial real silk; the composite solution comprises a silver nitrate solution and a dispersant solution; The surfactant is one or more of Triton X-100, fatty alcohol polyoxyethylene ether and sodium dodecyl sulfate; The dispersant is one or more of polyvinylpyrrolidone, sodium polyacrylate and alkyl polyglucoside; the mass fraction of the dispersant in the composite solution is 1%-3%; The reducing agent is a plant extract; The preparation method of the plant extract comprises the following steps: freeze-drying of Alstonia scholaris and Buddleja fallax respectively, mixing and crushing to obtain plant powder, adding 8-10 times the mass of deionized water, ultrasonic treatment, inoculating a composite microbial inoculant for anaerobic fermentation, sterilization and filtration to obtain a fermentation liquor, adding a composite enzyme for enzymolysis, enzyme inactivation, filtration and spray drying to obtain the plant extract; The composite microbial inoculant is composed of Lactobacillus johnsonii and Lactobacillus rhamnosus at a weight ratio of 1-3:2-5; The composite enzyme is composed of natto kinase and papain at a weight ratio of 1:2-5; the enzymolysis temperature is 40-50 DEG C, the pH value is 6-7, the enzyme addition amount is 2%-5%, and the time is 60-90 min; The reduction reaction temperature is 40-50 DEG C, the rotation speed is 60-70 r / min, and the time is 30-40 min; The fixing agent is sodium citrate and quaternary ammonium chitosan, and the mass percentage content of the fixing agent is 2%-5%. The concentration of the surfactant solution is 1-5 g / L.

2. The production method according to claim 1, characterized by, The concentration of silver nitrate in the composite solution is 0.3-0.6 mol / L.

3. The preparation method according to claim 1, characterized in that, The material-liquid ratio of ultrasonic immersion is 1:20-30 g / mL, the temperature is 35-45 DEG C, the frequency is 30-40 kHz, and the time is 20-30 min.

4. The method of claim 1, wherein, The fixation temperature is 30-40 DEG C, and the time is 40-50 min.

5. The preparation method according to claim 1, characterized in that, ​

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