Nano-zinc oxide dispersion liquid for polyester fibers as well as preparation method and application of nano-zinc oxide dispersion liquid

Abstract

The invention discloses a nano-zinc oxide dispersion liquid for polyester fibers and a preparation method and application thereof, and the preparation method comprises the following steps: (1) dissolving a zinc salt in ethylene glycol to obtain a zinc salt solution; and (2) dropwise adding an ethylene glycol solution of inorganic alkali into the zinc salt solution, stirring for reaction, and then performing ultrasonic dispersion to obtain the nano zinc oxide dispersion liquid. According to the invention, ethylene glycol, which is one of polyester monomers, is taken as a reaction medium, nano-zinc oxide colloid is directly synthesized in ethylene glycol, and the prepared zinc oxide colloid has good stability and can be added before esterification or polycondensation in a polyester synthesis process, so that the dispersity of nano-zinc oxide in a resin matrix is greatly improved, and agglutinated particles influencing spinning performance do not appear; the equipment is simple and suitable for industrial production.

Description

Technical Field

[0001] This invention relates to the field of antibacterial materials technology, and in particular to a nano zinc oxide dispersion for polyester fibers, its preparation method, and its application. Background Technology

[0002] Polyethylene terephthalate (PET) has been widely used in clothing, medical textiles, and industrial textiles due to its excellent mechanical properties and good processing characteristics. However, the unique physicochemical properties of polyester fibers (such as hydrophobicity and high surface energy) endow them with an affinity for microorganisms, easily leading to bacterial accumulation and growth. This phenomenon exacerbates the carrier effect of fiber materials in pathogen retention and diffusion, thus increasing the risk of cross-contamination of microorganisms. The lack of antibacterial properties limits its application in the medical and health fields. Therefore, developing polyester materials with antibacterial functions has significant practical implications and promising application prospects.

[0003] Zinc oxide has attracted widespread attention in the field of antibacterial materials due to its light color, broad-spectrum antibacterial properties, and low cost, and it also possesses excellent photocatalytic antibacterial capabilities. In existing technologies, zinc oxide dispersions are generally added during the synthesis of polyester fibers to impart antibacterial properties. For example, patent CN116355280B discloses a nano-zinc oxide dispersion for in-situ polymerization of polyester and its preparation method. This method involves surface-treating nano-zinc oxide with a compound modifier to prepare a stable ethylene glycol dispersion, which can be added online during the pulping or esterification stage of polyester synthesis, significantly improving the dispersibility of the nanoparticles and enhancing polyester performance.

[0004] However, in the application of nano-zinc oxide antibacterial agents in polyester fibers, multiple processes are required for surface modification. Although this improves dispersibility, the modifier, as a substance detrimental to fiber performance, is introduced into the fiber system, adversely affecting the fiber's mechanical properties. This added modifier not only makes filament breakage and fineness fluctuations more likely during melt spinning, but also restricts the industrial production efficiency and performance consistency of antibacterial fibers. Summary of the Invention

[0005] This invention aims to overcome the aforementioned problems of existing zinc oxide antibacterial agents for polyester fibers, and provides a nano zinc oxide dispersion for polyester fibers, its preparation method, and its application. Using ethylene glycol, one of the polyester monomers, as the reaction medium, nano zinc oxide colloids are directly synthesized in ethylene glycol. The prepared zinc oxide colloids exhibit good stability and can be added before esterification or polycondensation during polyester synthesis, significantly improving the dispersibility of nano zinc oxide in the resin matrix and preventing the formation of aggregated particles that affect spinning performance. The equipment is simple and suitable for industrial production.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing a nano-zinc oxide dispersion for polyester fibers, comprising the following steps: (1) Dissolve zinc salt in ethylene glycol to obtain zinc salt solution; (2) Add an inorganic alkali solution of ethylene glycol to the zinc salt solution, stir and react, and then disperse by ultrasonication to obtain a nano zinc oxide dispersion.

[0007] This invention directly synthesizes nano-zinc oxide in ethylene glycol, one of the monomers used in polyester synthesis. The resulting nano-zinc oxide dispersion is then used in polyester synthesis, where the ethylene glycol can participate in esterification or volatilize during polycondensation. The nano-zinc oxide dispersion obtained by this invention, after centrifugation, washing, and drying, exhibits highly dispersed nano-zinc oxide without forming agglomerates. This invention can significantly improve the dispersibility of nano-zinc oxide in a resin matrix without the addition of external modifiers, preventing the formation of agglomerated particles that affect spinning performance. The equipment is simple and suitable for industrial production.

[0008] Preferably, in step (2), silver nitrate aqueous solution is added dropwise to the zinc salt solution first, and after stirring evenly, an inorganic base ethylene glycol solution is added dropwise; or an inorganic base ethylene glycol solution is added dropwise, stirred to react, and then silver nitrate aqueous solution is added dropwise and stirred to react.

[0009] Introducing a small amount of silver into nano-zinc oxide to construct a nano-silver / zinc oxide heterostructure can effectively reduce the photogenerated carrier recombination rate, broaden the visible light response range, and reduce the nano-zinc oxide grain size, thereby significantly improving the antibacterial efficacy of antibacterial resins and fibers. Silver nanoparticles promote the directional migration of photogenerated electrons to the island-like silver metal in the Schottky junction through surface plasmon resonance, inhibiting electron-hole recombination and thus enhancing the generation efficiency of reactive oxygen species (ROS). Simultaneously, the slow-release effect of silver ions can disrupt the integrity of microbial cell membranes and interfere with enzyme activity, forming a "photocatalysis-metal ion" dual-mode synergistic antibacterial mechanism. This synergistic effect can not only efficiently kill Gram-positive bacteria (such as Staphylococcus aureus) and Gram-negative bacteria (such as Escherichia coli), but also disrupt bacterial biofilms.

[0010] Preferably, the concentration of the silver nitrate aqueous solution is 0.00045~0.06 mol / L; the mass ratio of silver ions in the added silver nitrate aqueous solution to the mass of the generated nano-zinc oxide is 1:20~1:300. After adding 3%-5% silver (relative to zinc oxide) by mass, the grain size of the nano-zinc oxide is smaller than that without silver loading, and the grain sizes of silver and zinc oxide are comparable.

[0011] Preferably, the zinc salt mentioned in step (1) is one or more of zinc acetate, zinc sulfate, zinc chloride, and zinc nitrate, and the zinc salt concentration in the zinc salt solution is 0.25~2 mol / L.

[0012] Preferably, the inorganic base in the ethylene glycol solution of the inorganic base in step (2) is sodium hydroxide and / or potassium hydroxide, and the concentration of the inorganic base is 0.5~4 mol / L.

[0013] Preferably, the stirring reaction temperature in step (2) is 60~125℃ and the stirring reaction time is 2~3h.

[0014] Secondly, the present invention provides a nano zinc oxide dispersion for polyester fibers prepared by the above method.

[0015] Preferably, the particle size of nano zinc oxide is less than 20 nm.

[0016] The third invention provides an application of the above-mentioned nano zinc oxide dispersion for polyester fibers in polyester synthesis, which is added during the esterification or polycondensation stage.

[0017] Preferably, the amount of the nano zinc oxide dispersion added to the polyester fiber is 0.2~5wt%.

[0018] Therefore, the present invention has the following beneficial effects: (1) The present invention uses ethylene glycol as the reaction medium, without introducing any external substances that are detrimental to the performance of polyester, and the product can be used directly without additional surface modification; (2) The synthesis method used in this invention is simple and mild, suitable for industrial production. The reaction is carried out at room temperature and pressure of 60~120℃, without the need for high temperature and high pressure or complex equipment. (3) In this invention, silver nanoparticles are modified on the surface of zinc oxide. The nano-silver is an element with a crystal size comparable to that of nano-zinc oxide. After silver loading, the crystal size of zinc oxide is smaller. The synthesized nanoparticles have good dispersibility and do not require post-modification. They are also applicable to other nanocomposite systems. The silver / zinc oxide heterojunction polyester fiber constructed in this invention not only achieves dual synergy of ion release and photocatalysis under dark light conditions in terms of antibacterial mechanism and significantly reduces the amount of antibacterial agent used, but also provides a new technical path for applications in wearable protection, environmental remediation and medical textiles. Attached Figure Description

[0019] Figure 1 Transmission electron microscopy (TEM) images of the zinc oxide-loaded silver nanoparticles prepared in Examples 1-5; wherein: a-Example 1, b-Example 2, c-Example 3, d-Example 4, e-Example 5, f-HRTEM images of the zinc oxide-loaded silver nanoparticles in Example 4.

[0020] Figure 2 This is a transmission electron microscope image of the zinc oxide nanoparticles prepared in Example 6.

[0021] Figure 3The image shows the UV-Vis absorption spectrum of the silver / nano zinc oxide-ethylene glycol dispersion prepared in Example 5.

[0022] Figure 4 The image shows the UV-Vis absorption spectrum of the nano-zinc oxide-ethylene glycol dispersion prepared in Example 6.

[0023] Figure 5 The figure shows the dispersion stability curve of the nano zinc oxide-ethylene glycol dispersion prepared in Example 5.

[0024] Figure 6 The image shows scanning electron microscope (SEM) images of the surface and cross-section of the antibacterial polyester fiber prepared using Example 2.

[0025] Figure 7 The stress-strain curve is that of the antibacterial polyester fiber prepared using Example 1.

[0026] Figure 8 The image shows plate count photographs of the antibacterial polyester fiber prepared using Example 2, which is used in the antibacterial test.

[0027] Figure 9 These are plate count photographs of the antibacterial test results of the antibacterial polyester fiber prepared using Example 1. Detailed Implementation

[0028] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0029] In this invention, unless otherwise specified, all equipment and raw materials are available from the market or commonly used in the industry. Unless otherwise specified, the methods in the following embodiments are conventional methods in the art.

[0030] General Implementation Examples: A method for preparing a nano-zinc oxide dispersion for polyester fibers includes the following steps: (1) Dissolve zinc salt in ethylene glycol to obtain zinc salt solution; (2) Add an inorganic alkali solution of ethylene glycol to the zinc salt solution, stir and react, and then disperse by ultrasonication to obtain a nano zinc oxide dispersion.

[0031] In one specific implementation, in step (2), silver nitrate aqueous solution is first added dropwise to zinc salt solution, stirred evenly, and then ethylene glycol solution of inorganic base is added dropwise; or ethylene glycol solution of inorganic base is added dropwise, stirred to react, and then silver nitrate aqueous solution is added dropwise and stirred to react.

[0032] In one specific embodiment, the concentration of the silver nitrate aqueous solution is 0.00045~0.06 mol / L; the mass ratio of silver ions in the added silver nitrate aqueous solution to the mass of generated nano zinc oxide is 1:20~1:300.

[0033] In one specific implementation, the zinc salt mentioned in step (1) is one or more of zinc acetate, zinc sulfate, zinc chloride, and zinc nitrate, and the zinc salt concentration in the zinc salt solution is 0.25~2 mol / L.

[0034] In one specific implementation, the inorganic base in the ethylene glycol solution of the inorganic base in step (2) is sodium hydroxide and / or potassium hydroxide, and the concentration of the inorganic base is 0.5~4 mol / L.

[0035] In one specific implementation, the stirring reaction temperature in step (2) is 60~125℃ and the stirring reaction time is 2~3h.

[0036] In one specific embodiment, the particle size of the nano zinc oxide in the obtained nano zinc oxide dispersion is less than 20 nm.

[0037] Example 1: A method for preparing a nano-zinc oxide dispersion for polyester fibers includes the following steps: (1) Weigh 9.17g of zinc nitrate and dissolve it in 50mL of ethylene glycol, and add 5mL of deionized water to aid dissolution to obtain a zinc nitrate solution; (2) Weigh 4.0g of sodium hydroxide and dissolve it in 50mL of ethylene glycol to obtain a sodium hydroxide solution; (3) Weigh 0.02g of silver nitrate and dissolve it in 5mL of deionized water to obtain a silver nitrate solution; (4) After adding silver nitrate solution to zinc acetate solution and stirring for 30 min, sodium hydroxide solution was slowly added to zinc acetate solution at a rate of 1.0 mL / s, and the mixture was stirred at 600 rpm at 60 °C for 2.0 h. After the reaction was completed, the mixture was placed in an ultrasonic bath and ultrasonically dispersed for 30 min to obtain silver / nano zinc oxide-ethylene glycol dispersion, wherein the mass ratio of silver was 0.3% (relative to zinc oxide).

[0038] Example 2: A method for preparing a nano-zinc oxide dispersion for polyester fibers includes the following steps: (1) Weigh 9.17g of zinc nitrate and dissolve it in 50mL of ethylene glycol, and add 5mL of deionized water to aid dissolution to obtain a zinc nitrate solution; (2) Weigh 4.0g of sodium hydroxide and dissolve it in 50mL of ethylene glycol to obtain a sodium hydroxide solution; (3) Weigh 0.03g of silver nitrate and dissolve it in 5mL of deionized water to obtain a silver nitrate solution; (4) After adding silver nitrate solution to zinc acetate solution and stirring for 30 min, sodium hydroxide solution is slowly added to zinc acetate solution at a rate of 1.0 mL / s and reacted at 60℃ with a stirring speed of 600 rpm for 2.0 h. After the reaction is completed, it is placed in an ultrasonic tank and ultrasonically dispersed for 30 min to obtain silver / nano zinc oxide-ethylene glycol dispersion, wherein the mass ratio of silver is 0.5% (relative to zinc oxide).

[0039] Example 3: A method for preparing a nano-zinc oxide dispersion for polyester fibers includes the following steps: (1) Weigh 9.17g of zinc nitrate and dissolve it in 50mL of ethylene glycol, and add 5mL of deionized water to aid dissolution to obtain a zinc nitrate solution; (2) Weigh 4.0g of sodium hydroxide and dissolve it in 50mL of ethylene glycol to obtain a sodium hydroxide solution; (3) Weigh 0.06g of silver nitrate and dissolve it in 5mL of deionized water to obtain a silver nitrate solution; (4) After adding silver nitrate solution to zinc acetate solution and stirring for 30 min, sodium hydroxide solution is slowly added to zinc acetate solution at a rate of 1.0 mL / s, and the mixture is stirred at 600 rpm at 60 °C for 2.0 h. After the reaction is completed, the mixture is placed in an ultrasonic bath and ultrasonically dispersed for 30 min to obtain silver / nano zinc oxide-ethylene glycol dispersion, wherein the mass ratio of silver is 1% (relative to zinc oxide).

[0040] Example 4: A method for preparing a nano-zinc oxide dispersion for polyester fibers includes the following steps: (1) Weigh 9.17g of zinc nitrate and dissolve it in 50mL of ethylene glycol, and add 5mL of deionized water to aid dissolution to obtain a zinc nitrate solution; (2) Weigh 4.0g of sodium hydroxide and dissolve it in 50mL of ethylene glycol to obtain a sodium hydroxide solution; (3) Weigh 0.19g of silver nitrate and dissolve it in 5mL of deionized water to obtain a silver nitrate solution; (4) After adding silver nitrate solution to zinc acetate solution and stirring for 30 min, sodium hydroxide solution is slowly added to zinc acetate solution at a rate of 1.0 mL / s and reacted at 60℃ with a stirring speed of 600 rpm for 2.0 h. After the reaction is completed, it is placed in an ultrasonic tank and ultrasonically dispersed for 30 min to obtain silver / nano zinc oxide-ethylene glycol dispersion, wherein the mass ratio of silver is 3% (relative to zinc oxide).

[0041] Example 5: A method for preparing a nano-zinc oxide dispersion for polyester fibers includes the following steps: (1) Weigh 2.12g of zinc nitrate and dissolve it in 25mL of ethylene glycol, and add 2.5mL of deionized water to aid dissolution to obtain a zinc nitrate solution; (2) Weigh 1.0g of sodium hydroxide and dissolve it in 25mL of ethylene glycol to obtain a sodium hydroxide solution; (3) Weigh 0.07g of silver nitrate and dissolve it in 5mL of deionized water to obtain a silver nitrate solution; (4) Sodium hydroxide solution was slowly added dropwise to zinc nitrate solution at a rate of 1.2 mL / s and reacted at 60℃ with a stirring speed of 800 rpm for 2.0 h. After the reaction was completed, silver nitrate solution was added dropwise to the solution after the reaction and stirred for 30 min. Then, it was placed in an ultrasonic bath and ultrasonically dispersed for 30 min to obtain silver / nano zinc oxide-ethylene glycol dispersion, wherein the mass ratio of silver was 5% (relative to zinc oxide).

[0042] Example 6: A method for preparing a nano-zinc oxide dispersion for polyester fibers includes the following steps: (1) Weigh 2.29g of zinc acetate and dissolve it in 50mL of ethylene glycol, and add 5mL of deionized water to aid dissolution to obtain a zinc acetate solution; (2) Weigh 2.0g of sodium hydroxide and dissolve it in 50mL of ethylene glycol to obtain a sodium hydroxide solution; (3) Sodium hydroxide solution was slowly added dropwise to zinc acetate solution at a rate of 1.0 mL / s and stirred at 600 rpm for 2.0 h at 60 °C. After the reaction was completed, the solution was placed in an ultrasonic bath and ultrasonically dispersed for 30 min to obtain nano zinc oxide-ethylene glycol dispersion.

[0043] The nano-zinc oxide particles prepared in the above embodiments were subjected to TEM testing, and the results are as follows: Figure 1 and Figure 2 As shown. From Figure 1 As can be seen, the zinc oxide-loaded silver nanoparticles prepared in Examples 1-5 exhibit a spherical distribution. Silver ions preferentially adsorb on the surface of the zinc oxide nanoparticles, react with alkali to form silver hydroxide, and are then reduced by ethylene glycol to form silver nanocrystals. Furthermore, the introduction of silver may increase the interfacial kinetic potential of the nanoparticles, enhancing the electrostatic repulsion between particles and making the particles more dispersed in the system. Ethylene glycol chemisorption increases steric hindrance and also increases its dispersibility in ethylene glycol and polyester chips and fibers. In Examples 4 and 5, when the silver loading is in the range of 3-5 wt% (… Figure 1 d、 Figure 1 e), Examples 1-3 with lower average particle size and silver loading ( Figure 1 a, Figure 1 b、 Figure 1 c) Smaller and better dispersed. From Figure 2As can be seen from the results, relatively regular, highly dispersed granular zinc oxide nanoparticles were synthesized in Example 6.

[0044] The UV-Vis absorption spectra of the nano-zinc oxide particles prepared in the above embodiments were tested, and the results are as follows: Figure 3 and Figure 4 As shown. From Figure 3 As can be seen from the data, the zinc oxide-supported silver nanoparticles prepared in Example 5, in addition to the intrinsic absorption edge of zinc oxide, exhibit an absorption peak in the visible light region near 430 nm. This peak originates from the localized surface plasmon resonance (LSPR) effect of the metallic silver particles. Figure 4 As can be seen, the zinc oxide nanoparticles prepared in Example 6 exhibit strong absorption in the ultraviolet region, with an absorption edge of 351 nm, which is smaller than the absorption edge of bulk zinc oxide (368 nm, Eg=3.37 eV). The nano-zinc oxide exhibits good dispersibility, does not form large particles with strong visible light scattering, and has very weak Mie scattering of visible light, further confirming its colloidal properties and high dispersibility.

[0045] Figure 5 This is the dispersion stability curve of the zinc oxide nanoparticles obtained in Example 5 in ethylene glycol. It can be seen that the instability index of the zinc oxide dispersion synthesized in Example 5 is only 0.1, indicating its excellent stability and flowability in the medium. This shows that under these synthesis conditions, the nano-silver / zinc oxide exhibits a stable colloidal dispersion.

[0046] Application Example 1: The silver / nano zinc oxide-ethylene glycol dispersion prepared in Example 5 above was used in the synthesis of polyester fibers. The method is as follows: (1) Esterification stage: Purified terephthalic acid, ethylene glycol and silver / nano zinc oxide-ethylene glycol dispersion (0.7wt%) prepared in Example 1 are added sequentially to the reactor in a molar ratio of 1:1.25 and stirred. During stirring, 200 ppm of antimony catalyst is added to ensure that the materials are fully and evenly mixed. Nitrogen gas is introduced into the reactor to replace the air and raise the temperature of the reaction system to 230~245℃ and the pressure to 0.3 MPa. Purified terephthalic acid and ethylene glycol begin to undergo esterification reaction to produce diethyl terephthalate and water. When the water volume in the water separator no longer increases significantly, it is generally 95% of the theoretical value. At this point, the esterification reaction can be judged to be over. (2) Polycondensation stage: The product obtained in the esterification stage is further reacted to generate high molecular weight polyester; the temperature inside the reactor is raised to 260℃, and a vacuum is slowly drawn. First, a low vacuum system is used to gradually reduce the pressure inside the reactor to 100 Pa; after 50 min, the high vacuum system is switched to further reduce the pressure inside the reactor to 50 Pa, and the temperature inside the reactor is controlled at 270~280℃; the high vacuum environment can promote the polycondensation reaction to proceed in the forward direction, so that small molecule by-products such as ethylene glycol are continuously discharged from the reaction system, thereby increasing the molecular weight of polyester; when the power of the stirrer is stable at a certain value, the reaction ends; after discharge, cooling, pelletizing and drying, antibacterial polyester chips can be obtained; (3) Antibacterial modified polyester fiber was prepared by melt spinning-stretching one-step method: antibacterial polyester chips were first pre-crystallized in a 120℃ forced-air drying oven for 4 h and vacuum dried at 170℃ for 6 h. Subsequently, the antibacterial polyester chips were melted at 295℃, filtered, and fed into the spinning assembly by a metering pump; the fibers were cooled and stretched into nascent fibers, oiled, drawn, and collected into fibers by a high-speed winding device.

[0047] Application Example 2: The nano-zinc oxide-ethylene glycol dispersion prepared in Example 6 above was used in the synthesis of polyester fibers, as follows: (1) Esterification stage: Purified terephthalic acid, ethylene glycol and nano zinc oxide-ethylene glycol dispersion (0.5 wt%) prepared in Example 3 were added to the reactor in a molar ratio of 1:1.25 and stirred. During the stirring process, 200 ppm of antimony catalyst was added to ensure that the materials were fully mixed. Nitrogen gas was introduced into the reactor to replace the air and raise the temperature of the reaction system to 230~245℃ and the pressure to 0.3 MPa. Purified terephthalic acid and ethylene glycol began to undergo esterification reaction to produce diethyl terephthalate and water. When the water volume in the water separator no longer increased significantly, it was generally 95% of the theoretical value. At this time, it can be judged that the esterification reaction was over. (2) Polycondensation stage: The product obtained in the esterification stage is further reacted to generate high molecular weight polyester; the temperature inside the reactor is raised to 260℃, and a vacuum is slowly drawn. First, a low vacuum system is used to gradually reduce the pressure inside the reactor to 100 Pa; after 50 min, the high vacuum system is switched to further reduce the pressure inside the reactor to 50 Pa, and the temperature inside the reactor is controlled at 270~280℃; the high vacuum environment can promote the polycondensation reaction to proceed in the forward direction, so that small molecule by-products such as ethylene glycol are continuously discharged from the reaction system, thereby increasing the molecular weight of polyester; when the power of the stirrer is stable at a certain value, the reaction ends; after discharge, cooling, pelletizing and drying, antibacterial polyester chips can be obtained; (3) Antibacterial modified polyester fiber was prepared by melt spinning-stretching one-step method: antibacterial polyester chips were first pre-crystallized in a 120℃ forced-air drying oven for 4 h and vacuum dried at 170℃ for 6 h. Subsequently, the antibacterial polyester chips were melted at 295℃, filtered, and fed into the spinning assembly by a metering pump; the fibers were cooled and stretched into nascent fibers, oiled, drawn, and collected into fibers by a high-speed winding device.

[0048] Figure 6 These are scanning electron microscope (SEM) images of the surface and cross-section of the antibacterial polyester fiber obtained in Application Example 2. Observations show that the fiber surface is relatively smooth, without obvious particle agglomeration or pore depressions. The nano-zinc oxide is evenly distributed on the fiber surface, achieving a monodisperse state within the polyester matrix. This uniform dispersion characteristic fully verifies the good spinnability of the polyester chips at this content.

[0049] Figure 7 This is the stress-strain curve of the antibacterial polyester fiber obtained in Application Example 1. It can be seen that, due to the relatively small amount of nano-silver / zinc oxide added, the inorganic particles can be relatively uniformly dispersed in the fiber system, causing less damage to the original intermolecular forces and structure of the fiber, thus giving the fiber higher strength than the fiber matrix.

[0050] Figure 8 The image shows plate count photographs of the antibacterial polyester fiber obtained in Application Example 2. It can be seen that the antibacterial fiber with 0.6 wt% nano-zinc oxide showed an inhibition rate of 93.6% against Escherichia coli and 96.3% against Staphylococcus aureus, both significantly higher than the national standard, indicating that the introduction of zinc oxide effectively improved the antibacterial properties of the polyester.

[0051] Figure 9 These are plate count photographs of the antibacterial polyester fibers obtained in Application Example 1. It can be seen that when nano-silver / zinc oxide is introduced, the fibers exhibit excellent antibacterial activity, with inhibition rates of 99.9% against both Escherichia coli and Staphylococcus aureus. Their antibacterial effect is significantly better than that of fibers modified with zinc oxide alone, forming a synergistic antibacterial mechanism.

[0052] It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A method for preparing a nano-zinc oxide dispersion for polyester fibers, characterized in that, Includes the following steps: (1) Dissolve zinc salt in ethylene glycol to obtain zinc salt solution; (2) Add an inorganic alkali solution of ethylene glycol to the zinc salt solution, stir and react, and then disperse by ultrasonication to obtain a nano zinc oxide dispersion.

2. The method for preparing nano-zinc oxide dispersion for polyester fibers according to claim 1, characterized in that, In step (2), first add silver nitrate aqueous solution to zinc salt solution, stir evenly, and then add ethylene glycol solution of inorganic base; or add ethylene glycol solution of inorganic base, stir to react, and then add silver nitrate aqueous solution to stir to react.

3. The method for preparing nano-zinc oxide dispersion for polyester fibers according to claim 2, characterized in that, The concentration of the silver nitrate aqueous solution is 0.00045~0.06 mol / L; the mass ratio of silver ions in the added silver nitrate aqueous solution to the mass of generated nano zinc oxide is 1:20~1:

300.

4. The method for preparing nano-zinc oxide dispersion for polyester fibers according to claim 1 or 2, characterized in that, The zinc salt mentioned in step (1) is one or more of zinc acetate, zinc sulfate, zinc chloride, and zinc nitrate, and the zinc salt concentration in the zinc salt solution is 0.25~2 mol / L.

5. The method for preparing nano-zinc oxide dispersion for polyester fibers according to claim 1 or 2, characterized in that, The inorganic base in the ethylene glycol solution of the inorganic base in step (2) is sodium hydroxide and / or potassium hydroxide, and the concentration of the inorganic base is 0.5~4 mol / L.

6. The method for preparing nano-zinc oxide dispersion for polyester fibers according to claim 1 or 2, characterized in that, The stirring reaction temperature in step (2) is 60~125℃, and the stirring reaction time is 2~3h.

7. A nano zinc oxide dispersion for polyester fibers, characterized in that, It is prepared using the preparation method described in any one of claims 1 to 6.

8. The nano zinc oxide dispersion for polyester fibers according to claim 7, characterized in that, The particle size of nano zinc oxide is less than 20 nm.

9. The application of the nano-zinc oxide dispersion for polyester fibers as described in claim 7 or 8 in polyester synthesis, characterized in that, Add during the esterification or polycondensation stage.

10. The application of the nano-zinc oxide dispersion for polyester fibers according to claim 9 in polyester synthesis, characterized in that, The amount of the nano zinc oxide dispersion added to the polyester fiber is 0.2~5wt%.

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