Method for preparing long-acting antibacterial / bacteriostatic fiber with assistance of ionic liquid and application of long-acting antibacterial / bacteriostatic fiber

Abstract

The invention relates to a method for preparing long-acting antibacterial / bacteriostatic fibers with the assistance of ionic liquid and application of the long-acting antibacterial / bacteriostatic fibers, and aims to solve the problems that nanoparticles on the surfaces of current bacteriostatic fibers loaded with metal nanoparticles are easy to peel off, and highly metal nanoparticles are easy to peel off. The preparation method comprises the following steps: 1, adding sodium citrate dehydrate and sodium borate into deionized water to obtain a reducing solution; 2, immersing the plant fibers into a reducing solution; 3, adding 1-ethyl-3-methylimidazole acetate, ethylene glycol and silver nitrate into deionized water, and uniformly stirring to obtain an ionic liquid mixed solution; 4, filling the ionic liquid mixed solution into a container, immersing the impregnated plant fibers into the ionic liquid mixed solution, and carrying out ionic liquid auxiliary reaction at the temperature of 45-60 DEG C; and 5, ultrasonic cleaning. After the plant fibers are dissociated by the ionic liquid and reconstructed by the hydrogen bonds, loose structures among fiber bundles are gradually densified, the fibers with compact structures are obtained in the process, and the long-acting durability of the cotton fibers is ensured.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of antibacterial and bacteriostatic material preparation, and particularly relates to a method for preparing long-acting bacteriostatic fiber assisted by ionic liquid and application. BACKGROUND

[0002] Fiber is the most common material in daily life and has been widely used for making clothes, medical supplies, packaging, etc. With the improvement of technology and living quality, fiber products have not only been limited to the functions of keeping warm and decoration, and people have put forward new requirements for the antibacterial and bacteriostatic properties of fiber. The fiber with antibacterial / bacteriostatic properties is made into medical supplies for postoperative wound care of patients, which can greatly reduce the risk of postoperative infection of patients and is of great significance to improve the physical resistance and rapid recovery of patients. In addition, the antibacterial / bacteriostatic fiber is used to make fiber products widely used in hospitals or health institutions, which can also effectively improve the sanitary environment in public places and play an important role in reducing cross-infection of the crowd in a crowded environment.

[0003] At present, the preparation of antibacterial / bacteriostatic fiber has been widely reported, and the main technical routes include: immersing organic bacteriostatic polymers in fiber, compounding natural organic antibacterial materials with fiber, and loading metal nanoparticles on fiber. Among the three methods, the organic bacteriostatic polymers immersed in the fiber have moderate bacteriostatic effect, but the bacteriostatic performance of the polymer is often sensitive to the environment, is easy to fail, and can cause pollution to the environment and cause different degrees of rejection. The compounded natural organic antibacterial materials have good biocompatibility, but they also have the problems of poor stability, easy failure and low bacteriostatic capacity. Compared with the above two methods, the method of loading metal nanoparticles on the surface of the fiber has the optimal bacteriostatic characteristics, good biocompatibility and excellent environmental adaptability, and is the optimal method for preparing antibacterial / bacteriostatic fiber. At present, this method also has problems to be solved, i.e. the metal nanoparticles are easy to fall off from the surface of the fiber, and the relative position of the adjacent fiber bundle is also changed after being stressed, which further aggravates the peeling of the metal nanoparticles. Therefore, there is an urgent need to develop a method for strengthening the adhesion of metal nanoparticles on the surface of the fiber and improving the stability of the fiber structure. SUMMARY

[0004] The purpose of the present application is to solve the problems of the current antibacterial / bacteriostatic fiber loaded with metal nanoparticles, i.e. the metal nanoparticles are easy to peel off from the surface of the fiber, and the movement of the fiber bundle aggravates the peeling of the metal nanoparticles, and to provide a method for preparing long-acting antibacterial / bacteriostatic fiber assisted by ionic liquid and application.

[0005] The method for preparing long-acting antibacterial / bacteriostatic fiber assisted by ionic liquid of the present application is realized according to the following steps:

[0006] Step one, sodium citrate dihydrate and sodium borate are added to deionized water, mixed by a magnetic stirrer to obtain a reducing solution;

[0007] Step two, the plant fiber is immersed in the reducing solution in step one, and immersed at room temperature, and magnetic stirring is continuously carried out during the immersion treatment to obtain the plant fiber after immersion treatment;

[0008] Step three, 1-ethyl-3-methyl imidazole acetate (EMIAc), ethylene glycol and silver nitrate are added to deionized water, and uniformly stirred by a magnetic stirrer to obtain an ionic liquid mixture;

[0009] Step four, the ionic liquid mixture is loaded into a container, the plant fiber after immersion treatment is immersed in the ionic liquid mixture, the container is sealed with aluminum foil, and then placed in a vacuum drying oven, the vacuum degree is adjusted to be lower than 300 Pa, and the ionic liquid assisted reaction is carried out at a temperature of 45-60 DEG C, and after cooling to room temperature, the plant fiber after reaction is obtained;

[0010] Step five, the plant fiber after reaction in step four is ultrasonically cleaned with deionized water and anhydrous ethanol in sequence, and after natural airing, the long-acting antibacterial / inhibitory fiber is obtained;

[0011] In step one, the concentration of sodium citrate dihydrate in the reducing solution is 10-35 g / L, and the concentration of sodium borate is 5-15 g / L; in step three, the concentration of 1-ethyl-3-methyl imidazole acetate in the ionic liquid mixture is 50-80 g / L, the concentration of ethylene glycol is 10-20 mL / L, and the concentration of silver nitrate is 25-40 g / L.

[0012] The application of the long-acting antibacterial / inhibitory fiber is to weave the long-acting antibacterial / inhibitory fiber into medical care fabrics.

[0013] The medical care fabric includes medical gauze, masks, special work clothes and the like.

[0014] The application first mixes a proper amount of sodium citrate dihydrate, sodium borate and deionized water to prepare a reducing solution, then immerses the fiber in the reducing solution, immerses it in an ionic liquid mixed solution composed of a proper amount of 1-ethyl-3-methyl imidazole acetate (EMIAc), ethylene glycol, silver nitrate and deionized water after a specific time of immersion, and carries out a specific temperature (45-60 DEG C) and a specific long-time reaction. Under the action of the ionic liquid, the loose structure of the fiber bundle is gradually densified after dissociation and hydrogen bond reconstruction between the fiber bundles; at the same time, the nano Ag particles reduced on the surface of the fiber bundle are also firmly embedded in the fiber matrix in the process of densification of the fiber bundle. Finally, the antibacterial / inhibitory fiber with stable structure and strong adhesion of nano silver particles is obtained.

[0015] The application of the method for preparing long-acting antibacterial / inhibitory fiber assisted by ionic liquid mainly comprises the following beneficial effects:

[0016] 1. After the plant (cotton) fiber is dissociated and hydrogen-bonded restructured by EMIAc ionic liquid, the loose structure between the fiber bundles is gradually densified, the structure-densified fiber is obtained, the fiber bundle dislocation under stress is avoided, and the long-acting durability of the cotton fiber is ensured.

[0017] 2. After the plant fiber is pre-impregnated with the reducing solution, the in-situ generation of nano-silver in the gap structure on the surface and inside of the fiber bundle in the mixed solution of ionic liquid and silver nitrate can be ensured, and the efficient preparation of nano-Ag particles is realized.

[0018] 3. The generation of nano-Ag and the dissociation / hydrogen-bonded restructuring process of the fiber bundle are carried out synchronously. On the one hand, the structure of the dissociated fiber bundle becomes fluffy, providing more reaction sites for the reduction and precipitation of nano-Ag, which can significantly increase the Ag content attached to the fiber. On the other hand, during the subsequent hydrogen-bonded restructuring process of the fiber bundle, the generated nano-Ag will be firmly embedded in the gradually densified fiber matrix, realizing the strong combination of nano-Ag and fiber. In addition, the fiber structure is dense, and the fiber bundle does not dislocate under stress, further avoiding the problem of nano-Ag peeling caused by the relative friction between the fiber bundles.

[0019] 4. The reducing solution and the ionic liquid mixture used in the method can be reused, which is low in cost, simple in operation and convenient for industrial promotion. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The scanning electron microscope photos of the densified fiber obtained in Example 1 and the original fiber are compared, Figure 1 a is the scanning electron microscope picture of the original fiber, Figure 1 b is the scanning electron microscope picture of the densified fiber obtained in Example 1, Figure 1 c is the cross-sectional scanning electron microscope picture of the densified fiber obtained in Example 1;

[0021] Figure 2 The scanning electron microscope photos of the long-acting antibacterial / inhibitory fiber obtained in Example 1 are shown in the following figure,

[0022] Figure 3 The stability test results of the long-acting antibacterial / inhibitory fiber obtained in Example 1 are shown in the following figure, Figure 3 a is the scanning electron microscope picture of the fiber before washing, Figure 3 b is the scanning electron microscope picture of the fiber after 50 times of washing;

[0023] Figure 4 The results of the bacteriostatic performance of the long-acting antibacterial / inhibitory fiber obtained in Example 1 by the qualitative test of the inhibition zone method are shown in the following figure,Figure 4 a is E. coli culture medium, Figure 4 b is S. aureus culture medium, the upper is original cotton fiber, and the lower is long-acting antibacterial / inhibitory fiber group;

[0024] Figure 5 Results of quantitative testing of the antibacterial performance of the long-acting antibacterial / inhibitory fiber obtained in Example 1 by plate colony counting method, Figure 5 a and 5b are E. coli culture medium of original cotton fiber and long-acting antibacterial / inhibitory fiber respectively, Figure 5 c and 5d are S. aureus culture medium of original cotton fiber and long-acting antibacterial / inhibitory fiber. DETAILED DESCRIPTION

[0025] Specific embodiment one: the method for preparing long-acting antibacterial / inhibitory fiber assisted by ionic liquid in the embodiment is implemented according to the following steps:

[0026] Step one: sodium citrate dihydrate and sodium borate are added to deionized water, and after mixing by a magnetic stirrer, a reducing solution is obtained;

[0027] Step two: plant fiber is immersed in the reducing solution in step one, and is immersed and treated at room temperature, and magnetic stirring is continuously carried out during the immersion and treatment process, to obtain plant fiber after immersion and treatment;

[0028] Step three: 1-ethyl-3-methyl imidazole acetate (EMIAc), ethylene glycol and silver nitrate are added to deionized water, and are uniformly stirred by a magnetic stirrer to obtain an ionic liquid mixture;

[0029] Step four: the ionic liquid mixture is loaded into a container, the plant fiber after immersion and treatment is immersed in the ionic liquid mixture, the container is sealed with aluminum foil, and then is placed in a vacuum drying oven, the vacuum degree is adjusted to be lower than 300 Pa, and then the ionic liquid assisted reaction is carried out at a temperature of 45-60℃, and after cooling to room temperature, plant fiber after reaction is obtained;

[0030] Step five: deionized water and anhydrous ethanol are used in sequence to ultrasonically clean the plant fiber after reaction in step four, and after natural air drying, long-acting antibacterial / inhibitory fiber is obtained;

[0031] In step one, the concentration of sodium citrate dihydrate in the reducing solution is 10-35 g / L, and the concentration of sodium borate is 5-15 g / L; in step three, the concentration of 1-ethyl-3-methyl imidazole acetate in the ionic liquid mixture is 50-80 g / L, the concentration of ethylene glycol is 10-20 mL / L, and the concentration of silver nitrate is 25-40 g / L.

[0032] The plant fiber is immersed into an ionic liquid composed of 1-ethyl-3-methylimidazole acetate (EMIAc), ethylene glycol and silver nitrate, and under specific reaction conditions, i.e. a reaction temperature of 45-60℃ and a time of 16-22h, nano-silver particles are generated in situ on the surface of the plant fiber, and finally a bacteriostatic fiber loaded with silver nano-particles is generated. It is found in the development process that when the reaction temperature is higher than 70℃, the plant fiber is obviously corroded and presents a dark yellowish brown color, and the reason is that the AgNO3 solution causes damage to the cotton fiber at high temperature. Therefore, the ionic liquid assisted reaction is carried out at a lower temperature of 45-60℃ in the present application, and the nano-silver particles have a smaller particle size and a more uniform distribution, which ensures the bacteriostatic performance; at the same time of reducing the reaction temperature, the reaction time is extended to 16-22h, which not only ensures that the dissociation and reconstruction process of the fiber is fully completed, but also makes the nano-silver particle matrix well combined and not easy to fall off.

[0033] Specific embodiment two: different from the specific embodiment one, the concentration of sodium citrate dihydrate in the reducing solution in step one is 10-20g / L, and the concentration of sodium borate is 6-10g / L.

[0034] Specific embodiment three: different from the specific embodiment one or two, the immersion treatment time in step two is 5-10h.

[0035] Specific embodiment four: different from any one of the specific embodiments one to three, the plant fiber in step two is cotton fiber, flax fiber or silk fiber.

[0036] Specific embodiment five: different from any one of the specific embodiments one to four, the concentration of 1-ethyl-3-methylimidazole acetate in the ionic liquid mixture in step three is 50-70g / L, the concentration of ethylene glycol is 12-18mL / L, and the concentration of silver nitrate is 30-35g / L.

[0037] Specific embodiment six: different from the specific embodiment five, the concentration of 1-ethyl-3-methylimidazole acetate in the ionic liquid mixture in step three is 50g / L, the concentration of ethylene glycol is 15mL / L, and the concentration of silver nitrate is 30g / L.

[0038] Specific embodiment seven: different from any one of the specific embodiments one to six, the ionic liquid assisted reaction time in step four is 16-22h.

[0039] The specific embodiment needs to control the long-time ionic liquid assisted reaction.

[0040] Eighth Embodiment: The difference between this embodiment and any one of the first to seventh embodiments is that the ionic liquid assisted reaction in step four is performed at a temperature of 50°C for 18-20h.

[0041] Ninth Embodiment: The difference between this embodiment and any one of the first to eighth embodiments is that deionized water and anhydrous ethanol are used to ultrasonically clean the plant fiber after the reaction in step four for 10-20min, respectively.

[0042] Example 1: The method for preparing long-acting antibacterial / inhibitory fiber assisted by ionic liquid in this example is implemented according to the following steps:

[0043] Step one, sodium citrate dihydrate and sodium borate are added to deionized water, and a reducing solution is obtained after mixing by a magnetic stirrer;

[0044] Step two, cotton fiber is immersed in the reducing solution in step one, and is immersed and treated at room temperature for 5h, and magnetic stirring is continuously performed during the immersion and treatment process, to obtain the immersed and treated plant fiber;

[0045] Step three, 1-ethyl-3-methylimidazole acetate (EMIAc), ethylene glycol and silver nitrate are added to deionized water, and the mixture is uniformly stirred by a magnetic stirrer to obtain an ionic liquid mixture;

[0046] Step four, the ionic liquid mixture is loaded into a container, the immersed and treated plant fiber is immersed in the ionic liquid mixture, the container is sealed with aluminum foil, and then is placed in a vacuum drying box, the vacuum degree is adjusted to be lower than 300Pa, and an ionic liquid assisted reaction is performed at a temperature of 50°C for 18h, and after cooling to room temperature, the reacted plant fiber is obtained;

[0047] Step five, deionized water and anhydrous ethanol are used to ultrasonically clean the plant fiber after the reaction in step four for 10min, respectively, and the long-acting antibacterial / inhibitory fiber is obtained after natural air drying;

[0048] In step one, the concentration of sodium citrate dihydrate in the reducing solution is 15g / L, and the concentration of sodium borate is 8g / L; in step three, the concentration of 1-ethyl-3-methylimidazole acetate in the ionic liquid mixture is 50g / L, the concentration of ethylene glycol is 15mL / L, and the concentration of silver nitrate is 30g / L.

[0049] In this example, after the treatment of the ionic liquid mixture at 50°C for 18h, the comparison chart of scanning electron microscope photos of the densified fiber obtained and the original fiber shows that the structure of the original fiber is loose, the densified fiber is obtained after the treatment of the ionic liquid, the fiber diameter is reduced from 700μm to 500μm, and the gap in the fiber is almost disappeared. The scanning electron microscope photo of the long-acting antibacterial / inhibitory fiber loaded with nano Ag particles is as follows: Figure 2As shown in the SEM images, it can be seen that the nano-Ag particles are formed on the surface of the fiber substrate and firmly combined with the fiber substrate.

[0050] Fiber washing stability analysis: the fibers obtained in Example 1 were washed for 50 times, and then the morphology of the nano-silver particles was observed under a scanning electron microscope. The comparison results of the morphology are shown in Figure 3 From the SEM images, it can be seen that the surface of the cotton fibers changes from flat and compact to loose and rough after being washed for 50 times. The change in the appearance of the cotton fibers is probably caused by the repeated rubbing during the washing process. The distribution of the nano-silver on the cotton fibers does not change significantly before and after being washed for 50 times, and the size and morphology of the nano-silver particles also do not change significantly.

[0051] Fiber antibacterial performance result analysis: the antibacterial performance of the NFW silver-loaded fibers was qualitatively tested by using the inhibition zone method, and the antibacterial activity of the NFW silver-loaded fibers was quantitatively tested by using the plate colony counting method.

[0052] The silver-loaded fibers obtained in Example 1 and the untreated original cotton fibers were subjected to the inhibition zone test, and the test results are shown in Figure 4 The silver-loaded cotton fibers formed an inhibition zone with a diameter of 15.6 mm on the E. coli culture medium and an inhibition zone with a diameter of 17.2 mm on the S. aureus culture medium, while the original cotton fibers did not form an inhibition zone. As can be seen from the figure, the fibers have an obvious inhibitory effect on the growth of E. coli and S. aureus. The plate colony counting test and the antibacterial rate test were performed on the silver-loaded fibers and the untreated original cotton fibers, and the results are shown in Figure 5 The number of bacteria on the culture medium prepared by using the long-acting antibacterial / inhibitory fiber (silver-loaded fiber) is far less than that on the culture medium prepared by using the original cotton fiber. It is calculated that the antibacterial rates of the silver-loaded fibers on E. coli and S. aureus are 96.1% and 97.8%, respectively. The experiment proves that the NFW silver-loaded fibers prepared by using the initial wetting impregnation method have excellent antibacterial effect on E. coli and S. aureus.

[0053] Example 2: The difference between this example and Example 1 is that the concentration of sodium citrate dihydrate in the reducing solution in step one is 20 g / L, and the concentration of sodium borate is 10 g / L; the concentration of 1-ethyl-3-methylimidazole acetate in the ionic liquid mixture in step three is 55 g / L, the concentration of ethylene glycol is 12 mL / L, and the concentration of silver nitrate is 32 g / L.

[0054] Example 3: The difference between this example and Example 1 is that the concentration of sodium citrate dihydrate in the reducing solution in Step 1 is 25 g / L, and the concentration of sodium borate is 12 g / L; the concentration of 1-ethyl-3-methylimidazolium acetate in the ionic liquid mixture in Step 3 is 65 g / L, the concentration of ethylene glycol is 15 mL / L, and the concentration of silver nitrate is 35 g / L.

[0055] Example 4: The difference between this example and Example 1 is that the concentration of sodium citrate dihydrate in the reducing solution in Step 1 is 35 g / L, and the concentration of sodium borate is 15 g / L; the concentration of 1-ethyl-3-methylimidazolium acetate in the ionic liquid mixture in Step 3 is 80 g / L, the concentration of ethylene glycol is 20 mL / L, and the concentration of silver nitrate is 40 g / L.

Claims

1. A method for preparing long-lasting antibacterial / antibacterial fibers with the aid of ionic liquids, characterized in that The method for preparing long-lasting antibacterial / antibacterial fiber with the assistance of ionic liquid is achieved by the following steps: Step 1: adding sodium citrate dihydrate and sodium borate to deionized water, and mixing them with a magnetic stirrer to obtain a reducing solution; Step 2: Immersing the plant fiber in the reducing solution of step 1, and performing an immersion treatment at room temperature, while continuously performing magnetic stirring during the immersion treatment, to obtain an immersion-treated plant fiber; Step 3: Add 1-ethyl-3-methylimidazolium acetate, ethylene glycol and silver nitrate to deionized water, and stir magnetically to obtain an ionic liquid mixture; Step 4: The ionic liquid mixture is placed in a container, the plant fiber after the immersion treatment is immersed in the ionic liquid mixture, the container is sealed with aluminum foil, and then placed in a vacuum drying oven. After adjusting the vacuum degree to less than 300 Pa, the ionic liquid-assisted reaction is carried out at a temperature of 45-60° C., and after cooling to room temperature, the reacted plant fiber is obtained; Step 5: ultrasonically cleaning the plant fiber after the reaction in step 4 with deionized water and anhydrous ethanol in sequence, and naturally drying it to obtain a long-lasting antibacterial / antibacterial fiber; The concentration of sodium citrate dihydrate in the reducing solution in step 1 is 10-35 g / L, and the concentration of sodium borate is 5-15 g / L; the concentration of 1-ethyl-3-methylimidazolium acetate in the ionic liquid mixture in step 3 is 50-80 g / L, the concentration of ethylene glycol is 10-20 mL / L, and the concentration of silver nitrate is 25-40 g / L.

2. The method for preparing long-lasting antibacterial / antibacterial fiber assisted by ionic liquid according to claim 1, characterized in that In step 1, the concentration of sodium citrate dihydrate in the reducing solution is 10-20 g / L, and the concentration of sodium borate is 6-10 g / L.

3. The method for preparing long-lasting antibacterial / antibacterial fiber assisted by ionic liquid according to claim 1, characterized in that The immersion treatment time in step 2 is 5 to 10 hours.

4. The method for preparing long-lasting antibacterial / antibacterial fiber assisted by ionic liquid according to claim 1, characterized in that The plant fiber described in step 2 is cotton fiber, flax fiber or silk fiber.

5. The method for preparing long-lasting antibacterial / antibacterial fiber assisted by ionic liquid according to claim 1, characterized in that In step 3, the concentration of 1-ethyl-3-methylimidazolium acetate in the ionic liquid mixture is 50-70 g / L, the concentration of ethylene glycol is 12-18 mL / L, and the concentration of silver nitrate is 30-35 g / L.

6. The method for preparing long-lasting antibacterial / antibacterial fiber assisted by ionic liquid according to claim 5, characterized in that In step 3, the concentration of 1-ethyl-3-methylimidazolium acetate in the ionic liquid mixture is 50 g / L, the concentration of ethylene glycol is 15 mL / L, and the concentration of silver nitrate is 30 g / L.

7. The method for preparing long-lasting antibacterial / antibacterial fiber assisted by ionic liquid according to claim 1, characterized in that The ionic liquid-assisted reaction time in step 4 is 16 to 22 hours.

8. The method for preparing long-lasting antibacterial / antibacterial fiber assisted by ionic liquid according to claim 1, characterized in that In step 4, the ionic liquid-assisted reaction is carried out at a temperature of 50° C. for 18 to 20 hours.

9. The method for preparing long-lasting antibacterial / antibacterial fiber assisted by ionic liquid according to claim 1, characterized in that In step five, the plant fibers after the reaction in step four are ultrasonically cleaned with deionized water and anhydrous ethanol for 10 to 20 minutes respectively.

10. The use of the ionic liquid prepared as claimed in claim 1 to assist in the preparation of long-lasting antibacterial / antibacterial fibers, characterized in that The application of the long-lasting antibacterial / bacteriostatic fiber is to weave the long-lasting antibacterial / bacteriostatic fiber into medical fabrics.

Images