Preparation method of high-performance uvioresistant water-repellent polyester fiber

Abstract

This invention discloses a method for preparing high-performance UV-resistant and water-repellent polyester fiber, comprising the following steps: S1, preparing core-shell composite modified particles; S2, preparing a modification finishing solution; S3, impregnating the polyester fiber with the modification finishing solution to obtain high-performance UV-resistant and water-repellent polyester fiber. The polyester fiber provided by this invention possesses both excellent UV resistance and water repellency. In this invention, titanium dioxide and carbon dots are used as the main components of the UV-resistant agent. By constructing core-shell composite modified particles with a special structural system, excellent UV resistance can be provided, and the adverse effects of the photocatalytic effect of titanium dioxide can be overcome. Simultaneously, carbon dots can improve the water repellency of the polyester fiber and further reduce the negative effects of the photocatalytic effect of titanium dioxide, thus enabling carbon dots to play multiple improving roles.

Description

Technical Field

[0001] This invention relates to the field of polyester materials, and in particular to a method for preparing high-performance UV-resistant and water-repellent polyester fibers. Background Technology

[0002] Polyester, also known as polyester fiber, is a synthetic fiber obtained by spinning polyester, which is formed by the condensation polymerization of organic diacids and diols. It is also commonly referred to as PET fiber. Polyester fiber possesses excellent modulus, strength, elasticity, and shape retention, making it one of the most widely used and consumed synthetic fibers. Functional modification of polyester fiber, such as improving its water-repellent properties, is crucial for expanding its application areas. When used in outdoor applications, high water-repellent performance is required. A common method is to modify polyester fiber with a fluorinated finishing solution to form a hydrophobic film on the fiber surface, as illustrated by a low-loss water-repellent and UV-resistant polyester fabric preparation process disclosed in patent CN117166236A. However, the hydrophobicity achieved through this method heavily depends on the stability of the hydrophobic film. As the film ages and degrades under the influence of ultraviolet light, heat, and oxygen during use, its water-repellent properties will significantly decrease.

[0003] On the other hand, polyester fibers have insufficient UV resistance. When used in outdoor environments, they gradually age under UV radiation, exhibiting yellowing, loss of elasticity, and decreased mechanical properties. Adding UV stabilizers is an effective way to improve the UV resistance of polyester fibers. Titanium dioxide has good UV absorption properties and is a widely used inorganic UV stabilizer in polyester fibers. For example, patent CN118441397B discloses a UV-resistant breathable polyester fiber fabric and its preparation method, and CN114806096B discloses a UV-resistant masterbatch for polyester fibers, its preparation method, and UV-resistant polyester fibers and fabrics. However, titanium dioxide as a UV stabilizer has the following drawbacks: its photocatalytic activity causes it to produce active oxides that degrade polyester fibers under light, ultimately reducing the weather resistance of the polyester fibers.

[0004] Carbon quantum dots, also known as carbon dots or carbon nanodots, are a class of zero-dimensional carbon nanomaterials with significant fluorescence properties. Due to their excellent optical properties, good water solubility, low toxicity, and environmental friendliness, they are continuously being developed and applied in various fields. Patent CN121065846A, "Anti-UV High Flame Retardant Polyester Fiber and Its Preparation Method," successfully applied carbon dots as UV absorbers in the functional modification of polyester fibers, but it did not explore the possibility of using carbon dots to improve the water-repellent properties of polyester fibers.

[0005] Therefore, it is now necessary to improve existing technologies to provide more reliable solutions. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method for preparing high-performance UV-resistant and water-repellent polyester fibers, addressing the shortcomings of the prior art.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: In its first aspect, the present invention provides a method for preparing high-performance UV-resistant and water-repellent polyester fibers, comprising the following steps:

[0008] S1. Preparation of core-shell composite modified particles:

[0009] S1-1. Preparation of core particles: Cerium salt and aluminum salt are added to TiCl4 solution, the pH is adjusted to alkaline and the reaction is stirred. The solid product obtained is separated, dried and calcined to obtain Al-Ce co-doped titanium dioxide nanoparticles, namely the core particles.

[0010] S1-2. Core-shell intermediate particles are prepared by coating the surface of core particles with silicon dioxide.

[0011] S1-3. Grafting carbon dots onto the surface of core-shell intermediate particles to prepare core-shell composite modified particles:

[0012] Core-shell intermediate particles and vinyltrimethoxysilane were dispersed in ethanol to obtain a dispersion mixture; citric acid and acetylcysteine ​​were added to deionized water, and the resulting solution was added to the dispersion mixture. The resulting precursor mixture was transferred to a reaction vessel, heated to react, and the product was washed and dried to obtain core-shell composite modified particles.

[0013] S2. Preparation of modified finishing solution:

[0014] S2-1. Add the core-shell composite modified particles and emulsifier to deionized water and disperse them by ultrasonication to obtain a particle emulsion.

[0015] S2-2. Methyl acrylate, butyl acrylate, octadecyl methacrylate, dodecafluoroheptyl methacrylate and an initiator are added dropwise to the particle emulsion. The mixture is heated under a nitrogen atmosphere and cooled after the reaction is complete to obtain the modified finishing solution.

[0016] S3. Polyester fibers are impregnated with a modified finishing solution to obtain high-performance UV-resistant and water-repellent polyester fibers.

[0017] Preferably, step S1-1 specifically includes:

[0018] TiCl4 was dissolved in hydrochloric acid to prepare a TiCl4 solution. The TiCl4 solution, Ce(NO3)3 aqueous solution, and Al(NO3)3 aqueous solution were mixed evenly. Sodium hydroxide solution was added dropwise to the resulting mixture to adjust the pH to 9-11. The mixture was stirred and reacted, filtered, and the solid product was washed, dried, calcined, and ground to obtain Al-Ce co-doped titanium dioxide nanoparticles, i.e., the core particles.

[0019] Preferably, in step S1-1, the concentration of TiCl4 solution is 0.5-3 mol / L, the concentration of Ce(NO3)3 aqueous solution is 0.1-0.5 mol / L, the concentration of Al(NO3)3 aqueous solution is 0.2-2 mol / L, and the volume ratio of TiCl4 solution, Ce(NO3)3 aqueous solution, and Al(NO3)3 aqueous solution is 1:(0.05-0.15):(0.1-0.4).

[0020] Preferably, in step S1-1, the calcination time is 20-90 min and the calcination temperature is 700-1100℃.

[0021] Preferably, step S1-2 specifically includes:

[0022] The kernel particles were added to the hydrochloric acid solution, stirred, filtered, and washed with deionized water. All the pretreated kernel particles were added to deionized water, and sodium hexametaphosphate was added. The mixture was ultrasonically dispersed and the pH was adjusted to 9-11 to obtain a kernel particle mixture.

[0023] Na2SiO3 solution and sulfuric acid solution were added dropwise to the core-shell particle mixture. After the addition was complete, the mixture was aged, centrifuged, and the resulting solid product was washed and dried to obtain core-shell intermediate particles.

[0024] Preferably, the heating reaction temperature in steps S1-3 is 120-160℃ and the reaction time is 24-48h.

[0025] Preferably, steps S1-3 are as follows:

[0026] Add 1-4g of core-shell intermediate particles and 0.74-2.96g of vinyltrimethoxysilane to 125-500mL of ethanol, and ultrasonically disperse for 0.5-2h to obtain a dispersion mixture;

[0027] Add 2-8g of citric acid and 0.82-3.26g of acetylcysteine ​​to 50-200mL of deionized water and stir for 5-20min. Add the resulting solution to the dispersion mixture while stirring and sonicate for 15-60min. Transfer the resulting precursor mixture to a reaction vessel and react at 120-160℃ for 24-48h. Filter the mixture and wash the solid product with deionized water and ethanol in sequence. Dry it under vacuum at 70-100℃ to constant weight to obtain core-shell composite modified particles.

[0028] Preferably, the emulsifier in step S2-1 is a mixture of Tween-20 and CTAB, with a mass ratio of Tween-20 to CTAB of 1:(0.75-3).

[0029] Preferably, the preparation method of the high-performance UV-resistant water-repellent polyester fiber includes the following steps:

[0030] S1. Preparation of core-shell composite modified particles:

[0031] S1-1, Preparation of core particles:

[0032] TiCl4 was dissolved in 0.25-1 mol / L hydrochloric acid to prepare a TiCl4 solution with a concentration of 0.5-3 mol / L;

[0033] TiCl4 solution, 0.1-0.5 mol / L Ce(NO3)3 aqueous solution, and 0.2-2 mol / L Al(NO3)3 aqueous solution were mixed evenly at a volume ratio of 1:(0.05-0.15):(0.1-0.4). 0.5-2 mol / L sodium hydroxide solution was added dropwise to the resulting mixture to adjust the pH to 9-11. The mixture was stirred for 0.5-2 h, filtered, and the solid product was washed with deionized water, dried at 80-100℃ for 2-8 h, and finally calcined in a muffle furnace at 700-1100℃ for 20-90 min. The mixture was then ground to obtain Al-Ce co-doped titanium dioxide nanoparticles, i.e., the core particles.

[0034] S1-2. Core-shell intermediate particles are prepared by coating the surface of core particles with silica:

[0035] Add 5-20g of kernel particles to 100-400mL of hydrochloric acid solution with a concentration of 0.1-0.3mol / L, stir for 15-60min, filter, wash with deionized water, add all the pretreated kernel particles to 150-600mL of deionized water, add 25-100mg of sodium hexametaphosphate, sonicate for 30-90min, adjust the pH to 9-11 with 0.5-2mol / L sodium hydroxide solution to obtain the kernel particle mixture;

[0036] Simultaneously and uniformly add 15-60 mL of 0.1-0.4 mol / L Na2SiO3 solution and 15-60 mL of 0.25-1 wt% sulfuric acid solution to the core-shell particle mixture, keeping the dropping rate of the Na2SiO3 solution and sulfuric acid solution the same, and complete the dropping in 45-180 min. Then age for 75-300 min, centrifuge, wash the obtained solid product with deionized water, and dry to obtain core-shell intermediate particles.

[0037] S1-3. Grafting carbon dots onto the surface of core-shell intermediate particles to prepare core-shell composite modified particles:

[0038] Add 1-4g of core-shell intermediate particles and 0.74-2.96g of vinyltrimethoxysilane to 125-500mL of ethanol, and ultrasonically disperse for 0.5-2h to obtain a dispersion mixture;

[0039] Add 2-8g citric acid and 0.82-3.26g acetylcysteine ​​to 50-200mL of deionized water and stir for 5-20min. Add the resulting solution to the dispersion mixture while stirring and sonicate for 15-60min. Transfer the resulting precursor mixture to a reaction vessel and react at 120-160℃ for 24-48h. Filter the mixture and wash the solid product with deionized water and ethanol in sequence. Dry it under vacuum at 70-100℃ to constant weight to obtain core-shell composite modified particles.

[0040] S2. Preparation of modified finishing solution:

[0041] S2-1. Add 1.5-6g of core-shell composite modified particles, 0.25-1g of Tween-20, and 0.3-1.5g of CTAB to 60-240mL of deionized water and ultrasonically disperse for 15-60min to obtain a particle emulsion.

[0042] S2-2. Add 3-12g of methyl acrylate, 4-16g of butyl acrylate, 1.25-5g of octadecyl methacrylate, and 5-20g of dodecafluoroheptyl methacrylate to the particle emulsion dropwise. Stir under nitrogen atmosphere for 30-90 minutes, maintain nitrogen atmosphere, heat to 65-75℃, add 5-20mL of potassium persulfate aqueous solution with a concentration of 0.01-0.05g / mL dropwise, complete the addition in 0.5-2 hours, keep warm for 1-4 hours, raise the temperature to 80-85℃, add 2.5-10mL of potassium persulfate aqueous solution with a concentration of 0.01-0.05g / mL dropwise, keep warm for 1-3 hours, cool to room temperature, and obtain the modified finishing solution.

[0043] S3. Immerse the polyester fiber in the modified finishing solution at a bath ratio of 1:(25-50) for 5-20 minutes at 40-60℃. Remove the fiber and dry it at 60-70℃ for 20-40 minutes to complete one immersion treatment. Repeat the immersion treatment 2-3 times, and then dry it at 80-100℃ for 2-8 minutes and at 140-170℃ for 1-4 minutes to obtain high-performance water-repellent polyester fiber.

[0044] Preferably, the preparation method of the high-performance UV-resistant water-repellent polyester fiber includes the following steps:

[0045] S1. Preparation of core-shell composite modified particles:

[0046] S1-1, Preparation of core particles:

[0047] TiCl4 was dissolved in 0.5 mol / L hydrochloric acid to prepare a TiCl4 solution with a concentration of 1 mol / L.

[0048] TiCl4 solution, 0.2 mol / L Ce(NO3)3 aqueous solution, and 1 mol / L Al(NO3)3 aqueous solution were mixed evenly at a volume ratio of 1:0.075:0.2. 1 mol / L sodium hydroxide solution was added dropwise to the resulting mixture to adjust the pH to 10. The mixture was stirred for 1 h, filtered, and the solid product was washed with deionized water, dried at 90 °C for 4 h, and finally calcined in a muffle furnace at 1000 °C for 30 min. After grinding, Al-Ce co-doped titanium dioxide nanoparticles, i.e., the core particles, were obtained.

[0049] S1-2. Core-shell intermediate particles are prepared by coating the surface of core particles with silica:

[0050] Add 10g of kernel particles to 200mL of 0.2mol / L hydrochloric acid solution, stir for 30min, filter, wash with deionized water, add all the pretreated kernel particles to 300mL of deionized water, add 50mg of sodium hexametaphosphate, sonicate for 45min, adjust the pH to 10 with 1mol / L sodium hydroxide solution to obtain kernel particle mixture.

[0051] 30 mL of 0.2 mol / L Na₂SiO₃ solution and 30 mL of 0.5 wt% sulfuric acid solution were simultaneously and uniformly added dropwise to the core-shell particle mixture. The addition was completed in 90 min, and the mixture was then aged for 150 min. After centrifugation, the resulting solid product was washed with deionized water and dried under vacuum at 100 °C to constant weight to obtain core-shell intermediate particles.

[0052] S1-3. Grafting carbon dots onto the surface of core-shell intermediate particles to prepare core-shell composite modified particles:

[0053] 2g of core-shell intermediate particles and 1.48g of vinyltrimethoxysilane were added to 250mL of ethanol and ultrasonically dispersed for 1h to obtain a dispersion mixture.

[0054] Add 4g of citric acid and 1.63g of acetylcysteine ​​to 100mL of deionized water and stir for 10min. Add the resulting solution to the dispersion mixture while stirring and sonicate for 30min. Transfer the resulting precursor mixture to a polytetrafluoroethylene-lined reactor and react at 150℃ for 30h. Filter the mixture and wash the solid product with deionized water and ethanol in sequence. Dry it under vacuum at 90℃ to constant weight to obtain core-shell composite modified particles.

[0055] S2. Preparation of modified finishing solution:

[0056] S2-1. Add 3g of core-shell composite modified particles, 0.5g of Tween-20, and 0.75g of CTAB to 120mL of deionized water and sonicate for 30min to obtain a particle emulsion.

[0057] S2-2. Add 6g of methyl acrylate, 8g of butyl acrylate, 2.5g of octadecyl methacrylate, and 10g of dodecafluoroheptyl methacrylate to the particle emulsion. Stir under nitrogen atmosphere for 45min. While maintaining the nitrogen atmosphere, heat to 70℃ and add 10mL of 0.02g / mL potassium persulfate aqueous solution dropwise. The addition is completed in 1h. Keep warm for 2h. Raise the temperature to 82℃ and add 5mL of 0.02g / mL potassium persulfate aqueous solution dropwise. Keep warm for 1.5h and cool to room temperature to obtain the modified finishing solution.

[0058] S3. Immerse the polyester fiber in the modified finishing solution at a bath ratio of 1:40, soak at 50°C for 15 minutes, remove and dry at 40°C for 30 minutes to complete one impregnation treatment; repeat the impregnation treatment twice, then dry at 90°C for 5 minutes and at 160°C for 2 minutes to obtain high-performance water-repellent polyester fiber.

[0059] In a second aspect, the present invention provides a high-performance UV-resistant water-repellent polyester fiber, which is prepared by the method described above.

[0060] The beneficial effects of this invention are:

[0061] The polyester fiber provided by this invention has both excellent UV resistance and water repellency. In this invention, titanium dioxide and carbon dots are used as the main components of the UV resisting agent. By constructing core-shell composite modified particles with a special structural system, excellent UV resistance can be provided, and the adverse effects of the photocatalytic effect of titanium dioxide can be overcome. At the same time, the water repellency of polyester fiber can be improved by carbon dots, and the negative effects of the photocatalytic effect of titanium dioxide can be further reduced. Thus, carbon dots play multiple improving roles.

[0062] In this invention, a modified finishing liquid is prepared by in-situ copolymerization of core-shell composite modified particles and acrylate monomers (including fluorinated acrylates). This liquid is then used to impregnate and modify polyester fibers, resulting in a high-performance polyester fiber with significantly improved UV resistance and water repellency. The core-shell composite modified particles, by constructing a core-shell structure system with surface-grafted carbon dots, significantly enhance water repellency by forming a rough surface structure at nanoscale. Furthermore, the enhanced UV absorption due to the multiple reflections of the core-shell structure and the auxiliary UV absorption provided by the carbon dots also significantly improve the UV resistance of the polyester fiber. Moreover, the synergistic effect between the core-shell composite modified particles and the acrylate monomers further improves the water repellency and UV resistance of the polyester fiber. Attached Figure Description

[0063] Figure 1 The results are from the contact angle test in the performance testing of polyester fibers;

[0064] Figure 2 The results of ultraviolet light absorption performance testing in the performance testing of polyester fibers;

[0065] Figure 3 The results of the UV aging resistance test in the performance testing of polyester fibers;

[0066] Figure 4 XRD patterns of the core particles prepared in Example 1;

[0067] Figure 5 The ultraviolet-visible absorption spectra of the core-shell composite modified particles in Example 1, Comparative Example 4, Comparative Example 5, and Comparative Example 6 are shown.

[0068] Figure 6 These are the results of the antioxidant performance test. Detailed Implementation

[0069] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description.

[0070] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0071] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are commercially available. For examples where specific conditions are not specified, conventional conditions or conditions recommended by the manufacturer are followed. For reagents or instruments whose manufacturers are not specified, they are all commercially available products.

[0072] This invention provides a high-performance UV-resistant and water-repellent polyester fiber, the preparation method of which includes the following steps:

[0073] S1. Preparation of core-shell composite modified particles:

[0074] S1-1, Preparation of core particles:

[0075] TiCl4 was dissolved in 0.25-1 mol / L hydrochloric acid to prepare a TiCl4 solution with a concentration of 0.5-3 mol / L;

[0076] TiCl4 solution, 0.1-0.5 mol / L Ce(NO3)3 aqueous solution, and 0.2-2 mol / L Al(NO3)3 aqueous solution were mixed evenly at a volume ratio of 1:(0.05-0.15):(0.1-0.4). 0.5-2 mol / L sodium hydroxide solution was added dropwise to the resulting mixture to adjust the pH to 9-11. The mixture was stirred for 0.5-2 h, filtered, and the solid product was washed with deionized water, dried at 80-100℃ for 2-8 h, and finally calcined in a muffle furnace at 700-1100℃ for 20-90 min. The mixture was then ground to obtain Al-Ce co-doped titanium dioxide nanoparticles, i.e., core particles.

[0077] S1-2. Core-shell intermediate particles are prepared by coating the surface of core particles with silica:

[0078] Add 5-20g of kernel particles to 100-400mL of hydrochloric acid solution with a concentration of 0.1-0.3mol / L, stir for 15-60min, filter, wash with deionized water, add all the pretreated kernel particles to 150-600mL of deionized water, add 25-100mg of sodium hexametaphosphate, sonicate for 30-90min, adjust the pH to 9-11 with 0.5-2mol / L sodium hydroxide solution to obtain the kernel particle mixture;

[0079] Simultaneously and uniformly add 15-60 mL of 0.1-0.4 mol / L Na2SiO3 solution and 15-60 mL of 0.25-1 wt% sulfuric acid solution to the core-shell particle mixture, keeping the dropping rate of the Na2SiO3 solution and sulfuric acid solution the same, and complete the dropping in 45-180 min. Then age for 75-300 min, centrifuge, wash the obtained solid product with deionized water, and dry to obtain core-shell intermediate particles.

[0080] S1-3. Grafting carbon dots onto the surface of core-shell intermediate particles to prepare core-shell composite modified particles:

[0081] Add 1-4g of core-shell intermediate particles and 0.74-2.96g of vinyltrimethoxysilane to 125-500mL of ethanol, and ultrasonically disperse for 0.5-2h to obtain a dispersion mixture;

[0082] Add 2-8g citric acid and 0.82-3.26g acetylcysteine ​​to 50-200mL of deionized water and stir for 5-20min. Add the resulting solution to the dispersion mixture while stirring and sonicate for 15-60min. Transfer the resulting precursor mixture to a reaction vessel and react at 120-160℃ for 24-48h. Filter the mixture and wash the solid product with deionized water and ethanol in sequence. Dry it under vacuum at 70-100℃ to constant weight to obtain core-shell composite modified particles.

[0083] S2. Preparation of modified finishing solution:

[0084] S2-1. Add 1.5-6g of core-shell composite modified particles, 0.25-1g of Tween-20, and 0.3-1.5g of CTAB (hexadecyltrimethylammonium bromide) to 60-240mL of deionized water and ultrasonically disperse for 15-60min to obtain a particle emulsion.

[0085] S2-2. Add 3-12g of methyl acrylate, 4-16g of butyl acrylate, 1.25-5g of octadecyl methacrylate, and 5-20g of dodecafluoroheptyl methacrylate to the particle emulsion dropwise. Stir under nitrogen atmosphere for 30-90 minutes, maintain nitrogen atmosphere, heat to 65-75℃, add 5-20mL of potassium persulfate aqueous solution with a concentration of 0.01-0.05g / mL dropwise, complete the addition in 0.5-2 hours, keep warm for 1-4 hours, raise the temperature to 80-85℃, add 2.5-10mL of potassium persulfate aqueous solution with a concentration of 0.01-0.05g / mL dropwise, keep warm for 1-3 hours, cool to room temperature, and obtain the modified finishing solution.

[0086] S3. Immerse the polyester fiber in the modified finishing solution at a bath ratio of 1:(25-50) for 5-20 minutes at 40-60℃. Remove the fiber and dry it at 60-70℃ for 20-40 minutes to complete one immersion treatment. Repeat the immersion treatment 2-3 times, and then dry it at 80-100℃ for 2-8 minutes and at 140-170℃ for 1-4 minutes to obtain high-performance water-repellent polyester fiber.

[0087] In this invention, a modified finishing liquid is prepared by in-situ copolymerization of core-shell composite modified particles and acrylate monomers (including fluorinated acrylates). This liquid is then used to impregnate and modify polyester fibers, resulting in a high-performance polyester fiber with significantly improved UV resistance and water repellency. Specifically, the core-shell composite modified particles construct a core-shell structure system with surface-grafted carbon dots. On one hand, this significantly enhances water repellency by forming a rough surface structure at the nanoscale. On the other hand, the enhanced UV absorption through the multiple reflections of the core-shell structure and the auxiliary UV absorption provided by the carbon dots also significantly improve the UV resistance of the polyester fiber. Furthermore, the synergistic effect between the core-shell composite modified particles and the acrylate monomers further improves the water repellency and UV resistance of the polyester fiber. The main mechanisms of this invention are described in detail below.

[0088] I. Preparation process

[0089] 1. Preparation of core-shell composite modified particles:

[0090] First, TiCl4 was used as the titanium source, and Ce(NO3)3 and Al(NO3)3 were used as the cerium source and aluminum source, respectively. Al2O3-CeO2 co-doped titanium dioxide nanoparticles, i.e. core particles, were prepared by conventional sol-gel method.

[0091] Then, the core-shell intermediate particles were prepared by coating the surface of the core particles with silicon dioxide using the traditional liquid phase deposition method. The main process of preparing coated SiO2 by liquid phase deposition is as follows: Na2SiO3 hydrolyzes to produce active silicic acid molecules, which can react with the hydroxyl groups on the surface of TiO2 particles to form a silicon film. Subsequently, Si(OH)4 generated by the gradual hydrolysis of silicate ions polymerizes on the surface of TiO2 particles to form a film. During the subsequent aging process, free silicic acid and silicate ions continue to be adsorbed onto the particle surface, which increases the film thickness and gradually forms a dense nano-silica film (Qin Cao, Wang Tingjie, Jin Yong. Preparation of nano-SiO2 film on the surface of TiO2 particles by liquid phase deposition method [J]. Acta Physico-Chimica Sinica, 2002, 18(10):884-889.DOI:10.3866 / PKU.WHXB20021004.). In this invention, since Al2O3 is doped into the titanium dioxide nanoparticles, the core particles are pre-treated with dilute hydrochloric acid during the preparation process, which enables the formation of a certain amount of Al on the particle surface. 3+ With the help of AI 3+ The electrostatic adsorption and coordination with silicic acid and silicate ions can promote the adsorption of silicic acid and silicate ions on the surface of core particles, thereby improving the efficiency of nano-SiO2 coating film formation.

[0092] Next, carbon dots are grafted onto the surface of the core-shell intermediate particles through a one-pot solvothermal reaction, ultimately preparing core-shell composite modified particles. In this process, vinyltrimethoxysilane in the raw materials can introduce double bonds and doped Si elements into the carbon dots. Furthermore, during preparation, vinyltrimethoxysilane can adsorb onto the surface of the core-shell intermediate particles, promoting the uniform dispersion of the particles and the binding of other raw materials to them. This facilitates the successful grafting and uniform distribution of carbon dots on the surface of the core-shell intermediate particles.

[0093] 2. Preparation of modified finishing solution: The pre-prepared core-shell composite modified particles are mixed with acrylate monomers. Potassium persulfate is used as an initiator and polymerization is carried out under heating. The double bonds in the carbon dots grafted on the surface of the core-shell composite modified particles can participate in the polymerization reaction, so that the core-shell composite modified particles and the polymer can be connected by chemical bonds. This can improve the compatibility between the core-shell composite modified particles and the polymer, as well as the dispersion uniformity of the core-shell composite modified particles in the finishing solution. At the same time, it can also improve the bonding strength and stability of the modified film layer formed by the finishing solution on the surface of polyester fibers.

[0094] II. Mechanism of Action

[0095] Titanium dioxide possesses excellent ultraviolet absorption and scattering properties, making it a widely used inorganic UV stabilizer in polyester fibers. However, its photocatalytic activity causes it to produce reactive oxides under light irradiation, which degrade polyester fibers and ultimately reduce their weather resistance. This invention addresses this by coating titanium dioxide with nano-SiO2 to form core-shell intermediate particles, effectively blocking the photocatalytic activity of titanium dioxide and reducing its negative impact on the weather resistance of polyester fibers. Furthermore, by constructing a core-shell structure with nano-SiO2 as the outer shell and Al-Ce co-doped titanium dioxide nanoparticles as the core, during ultraviolet irradiation, some ultraviolet light is blocked by the nano-SiO2 shell, while some of the ultraviolet light passing through the shell is absorbed by the titanium dioxide core, and some is scattered by the core, resulting in multiple reflections between the shell and core, thereby enhancing the absorption of this portion of ultraviolet light.

[0096] The crystal form and particle size of titanium dioxide affect its ultraviolet absorption performance. Titanium dioxide mainly consists of anatase and rutile phases. The mixture of anatase and rutile phases has better ultraviolet absorption performance than a single crystal form, and the ultraviolet absorption performance of the anatase phase is stronger than that of the rutile phase. The crystal form of titanium dioxide is affected by the calcination temperature. Generally, when the temperature exceeds 700-800℃, the anatase phase will rapidly transform into the rutile phase. Within a certain range, the smaller the particle size of titanium dioxide, the higher the ultraviolet absorption performance (Wang Zhiyi, Cui Zuolin. Effect of Al2O3 heterocomposite on crystal form transformation and grain growth of TiO2 nanocrystals [J]. Journal of Inorganic Materials, 2006, 21(1):7.DOI:10.3321 / j.issn:1000-324X.2006.01.008.). In this invention, by doping nano-titanium dioxide with alumina, the stability of titanium dioxide can be improved, significantly suppressing the phase transformation process from anatase to rutile and effectively limiting grain growth, thereby enhancing its ultraviolet absorption capacity. Furthermore, a high anatase phase content can be maintained even at relatively high calcination temperatures (e.g., 700-1100℃), thus improving the stability of the anatase phase in titanium dioxide and increasing preparation efficiency through higher calcination temperature heat treatment. Further, alumina doping can also improve the mechanical strength of the core particles.

[0097] In this invention, further doping of nano-titanium dioxide with cerium oxide can achieve the following effects: (1) The band gap of cerium oxide is slightly smaller than that of TiO2, enabling it to absorb UVB (280-315nm) bands and UVA (320-400nm) bands, which are more widely covered than TiO2, thereby improving its ultraviolet absorption capacity; (2) The oxygen vacancies (Ce) on the surface of cerium oxide 3+ It can capture and neutralize free radicals through Ce 3+ / Ce 4+ The redox cycle can continuously quench the free radicals generated by the photocatalysis of TiO2, reducing the oxidation damage of the material. This effect, combined with the physical sealing effect of the shell formed by the nano SiO2 coating on TiO2, can greatly reduce the negative impact of the photocatalysis of TiO2 on polyester fibers.

[0098] In this invention, carbon dots are further grafted onto the surface of core-shell intermediate particles. These carbon dots use citric acid and acetylcysteine ​​as carbon sources and introduce Si dopant through vinyltrimethoxysilane. Firstly, these carbon dots possess a broad spectral absorption range and excellent absorption capacity for ultraviolet light, thereby further improving UV resistance. Simultaneously, these carbon dots inherit the reducing properties of acetylcysteine, giving them a certain free radical scavenging ability, which can further suppress the negative effects of titanium dioxide photocatalytic activity and improve the post-processing performance of polyester fibers. The Si doping in the carbon dots can regulate their electronic structure and band gap, optimizing their ultraviolet light absorption capacity (the introduction of silicon atoms alters the electron distribution of the carbon nucleus, forming new energy levels or adjusting the original band gap, causing a red or blue shift in the absorption edge and enhancing the absorption intensity in the ultraviolet region; furthermore, silicon doping can introduce new defect states or functional groups on or inside the carbon dots, which can serve as new electron transition channels, broadening the absorption spectrum and improving the ultraviolet light capture efficiency).

[0099] After the modified finishing liquid of this invention treats polyester fibers, the core-shell composite modified particles can construct a nanoscale uneven structure on the surface of the polyester fibers, thereby significantly improving the water-repellent properties of the polyester fibers. The even smaller nanoscale carbon dots grafted onto the surface of the core particles and uniformly distributed within these core-shell composite modified particles can increase the roughness of the uneven structure, thereby further enhancing the water-repellent properties of the polyester fibers. Thus, it can be seen that in this invention, by constructing a special nanostructure system through the cooperation of carbon dots and core particles, the carbon dots can exert multiple enhancing effects, including improved ultraviolet absorption, enhanced water repellency, and improved weather resistance.

[0100] In the modified finishing liquid of the present invention, the doping of dodecafluoroheptyl methacrylate causes a fluorine-containing organic film to form on the surface of the polyester fiber after treatment with the modified finishing liquid. The introduction of fluorine-containing functional groups greatly reduces the surface energy. Combined with the core-shell composite modified particles, the water repellency of the polyester fiber is significantly improved.

[0101] The above is the general concept of the present invention. Based on this, detailed embodiments and comparative examples are provided below to further illustrate the present invention.

[0102] The polyester fibers used in this invention are conventional commercially available products or ordinary polyester fibers prepared by conventional processes. The polyester fibers in the following examples and comparative examples were prepared using the following methods:

[0103] Polyester chips were vacuum dried at 120°C for 10 hours, and then melt-extruded in a twin-screw extruder at 250°C. The resulting melt was then spun (spinning temperature 260°C, spinning speed 600 m / min, draw ratio 2.5 times, stretching rate 550 m / min) to obtain polyester fibers.

[0104] The polyester chips were sourced from Far Eastern Textiles (Shanghai) Co., Ltd., model CB-602, with a relative viscosity of 0.8 dl / g and an acid value of 35 mg KOH / g.

[0105] The sources of some of the raw materials in the following examples and comparative examples are as follows:

[0106] Vinyltrimethoxysilane, Shanghai Tongyuan Chemical Co., Ltd.;

[0107] Dodecafluoroheptyl methacrylate, brand: Senfida, Shanghai Huafutai Chemical Co., Ltd.;

[0108] Methyl acrylate, Shanghai Kundu Industrial Co., Ltd.;

[0109] Butyl acrylate, Shanghai Yongzheng Chemical Co., Ltd.;

[0110] Octadecyl methacrylate, Shanghai Yongzheng Chemical Co., Ltd. Example

[0111] A high-performance UV-resistant and water-repellent polyester fiber is prepared by the following steps:

[0112] S1. Preparation of core-shell composite modified particles:

[0113] S1-1, Preparation of core particles:

[0114] TiCl4 was dissolved in 0.5 mol / L hydrochloric acid to prepare a TiCl4 solution with a concentration of 1 mol / L.

[0115] TiCl4 solution, 0.2 mol / L Ce(NO3)3 aqueous solution, and 1 mol / L Al(NO3)3 aqueous solution were mixed evenly at a volume ratio of 1:0.075:0.2. 1 mol / L sodium hydroxide solution was added dropwise to the resulting mixture to adjust the pH to 10. The mixture was stirred for 1 h, filtered, and the solid product was washed with deionized water, dried at 90 °C for 4 h, and finally calcined in a muffle furnace at 1000 °C for 30 min. After grinding, Al-Ce co-doped titanium dioxide nanoparticles, i.e., core particles, were obtained.

[0116] S1-2. Core-shell intermediate particles are prepared by coating the surface of core particles with silica:

[0117] Add 10g of kernel particles to 200mL of 0.2mol / L hydrochloric acid solution, stir for 30min, filter, wash with deionized water, add all the pretreated kernel particles to 300mL of deionized water, add 50mg of sodium hexametaphosphate, sonicate for 45min, adjust the pH to 10 with 1mol / L sodium hydroxide solution to obtain kernel particle mixture.

[0118] 30 mL of 0.2 mol / L Na₂SiO₃ solution and 30 mL of 0.5 wt% sulfuric acid solution were simultaneously and uniformly added dropwise to the core-shell particle mixture. The addition was completed in 90 min, and the mixture was then aged for 150 min. After centrifugation, the resulting solid product was washed with deionized water and dried under vacuum at 100 °C to constant weight to obtain core-shell intermediate particles.

[0119] S1-3. Grafting carbon dots onto the surface of core-shell intermediate particles to prepare core-shell composite modified particles:

[0120] 2g of core-shell intermediate particles and 1.48g of vinyltrimethoxysilane were added to 250mL of ethanol and ultrasonically dispersed for 1h to obtain a dispersion mixture.

[0121] Add 4g of citric acid and 1.63g of acetylcysteine ​​to 100mL of deionized water and stir for 10min. Add the resulting solution to the dispersion mixture while stirring and sonicate for 30min. Transfer the resulting precursor mixture to a polytetrafluoroethylene-lined reactor and react at 150℃ for 30h. Filter the mixture and wash the solid product with deionized water and ethanol in sequence. Dry it under vacuum at 90℃ to constant weight to obtain core-shell composite modified particles.

[0122] S2. Preparation of modified finishing solution:

[0123] S2-1. Add 3g of core-shell composite modified particles, 0.5g of Tween-20, and 0.75g of CTAB to 120mL of deionized water and sonicate for 30min to obtain a particle emulsion.

[0124] S2-2. Add 6g of methyl acrylate, 8g of butyl acrylate, 2.5g of octadecyl methacrylate, and 10g of dodecafluoroheptyl methacrylate to the particle emulsion. Stir under nitrogen atmosphere for 45min. While maintaining the nitrogen atmosphere, heat to 70℃ and add 10mL of 0.02g / mL potassium persulfate aqueous solution dropwise. The addition is completed in 1h. Keep warm for 2h. Raise the temperature to 82℃ and add 5mL of 0.02g / mL potassium persulfate aqueous solution dropwise. Keep warm for 1.5h and cool to room temperature to obtain the modified finishing solution.

[0125] S3. Immerse the polyester fiber in the modified finishing solution at a bath ratio of 1:40, soak at 50°C for 15 minutes, remove and dry at 40°C for 30 minutes to complete one impregnation treatment; repeat the impregnation treatment twice, then dry at 90°C for 5 minutes and at 160°C for 2 minutes to obtain high-performance water-repellent polyester fiber. Example

[0126] The only difference between this example and Example 1 is that the amount of core-shell intermediate particles added in step S1-3 of this example is changed to 2.25g. Example

[0127] The only difference between this example and Example 1 is that in step S1-1 of this example, the volume ratio of TiCl4 solution, 0.2 mol / L Ce(NO3)3 aqueous solution, and 1 mol / L Al(NO3)3 aqueous solution is 1:0.06:0.15. Example

[0128] A high-performance UV-resistant and water-repellent polyester fiber is prepared by the following steps:

[0129] S1. Preparation of core-shell composite modified particles:

[0130] S1-1, Preparation of core particles:

[0131] TiCl4 was dissolved in 0.5 mol / L hydrochloric acid to prepare a TiCl4 solution with a concentration of 1 mol / L.

[0132] TiCl4 solution, 0.2 mol / L Ce(NO3)3 aqueous solution, and 1 mol / L Al(NO3)3 aqueous solution were mixed evenly at a volume ratio of 1:0.075:0.2. 1 mol / L sodium hydroxide solution was added dropwise to the resulting mixture to adjust the pH to 10. The mixture was stirred for 1 h, filtered, and the solid product was washed with deionized water, dried at 80 °C for 6 h, and finally calcined in a muffle furnace at 1000 °C for 30 min. After grinding, Al-Ce co-doped titanium dioxide nanoparticles, i.e., core particles, were obtained.

[0133] S1-2. Core-shell intermediate particles are prepared by coating the surface of core particles with silica:

[0134] Add 10g of kernel particles to 200mL of 0.2mol / L hydrochloric acid solution, stir for 30min, filter, wash with deionized water, add all the pretreated kernel particles to 300mL of deionized water, add 45mg of sodium hexametaphosphate, sonicate for 45min, adjust the pH to 10 with 1mol / L sodium hydroxide solution to obtain kernel particle mixture.

[0135] 30 mL of 0.2 mol / L Na₂SiO₃ solution and 30 mL of 0.5 wt% sulfuric acid solution were simultaneously and uniformly added dropwise to the core-shell particle mixture. The addition was completed in 100 min while maintaining the same dropping rate for both the Na₂SiO₃ and sulfuric acid solutions. The mixture was then aged for 120 min, centrifuged, and the resulting solid product was washed with deionized water and dried under vacuum at 100 °C to constant weight to obtain core-shell intermediate particles.

[0136] S1-3. Grafting carbon dots onto the surface of core-shell intermediate particles to prepare core-shell composite modified particles:

[0137] 2g of core-shell intermediate particles and 1.48g of vinyltrimethoxysilane were added to 250mL of ethanol and ultrasonically dispersed for 1h to obtain a dispersion mixture.

[0138] Add 4g of citric acid and 1.63g of acetylcysteine ​​to 100mL of deionized water and stir for 10min. Add the resulting solution to the dispersion mixture while stirring and sonicate for 30min. Transfer the resulting precursor mixture to a polytetrafluoroethylene-lined reactor and react at 150℃ for 30h. Filter the mixture and wash the solid product with deionized water and ethanol in sequence. Dry it under vacuum at 90℃ to constant weight to obtain core-shell composite modified particles.

[0139] S2. Preparation of modified finishing solution:

[0140] S2-1. Add 3g of core-shell composite modified particles, 0.65g of Tween-20, and 0.5g of CTAB to 120mL of deionized water and sonicate for 30min to obtain a particle emulsion.

[0141] S2-2. Add 6g of methyl acrylate, 8g of butyl acrylate, 2.5g of octadecyl methacrylate, and 10g of dodecafluoroheptyl methacrylate to the particle emulsion. Stir under nitrogen atmosphere for 45min. While maintaining the nitrogen atmosphere, heat to 70℃ and add 10mL of 0.02g / mL potassium persulfate aqueous solution dropwise. The addition is completed in 1h. Keep warm for 2h. Raise the temperature to 82℃ and add 5mL of 0.02g / mL potassium persulfate aqueous solution dropwise. Keep warm for 1.5h and cool to room temperature to obtain the modified finishing solution.

[0142] S3. Immerse the polyester fiber in the modified finishing solution at a bath ratio of 1:40, immerse at 55°C for 12 minutes, remove and dry at 40°C for 30 minutes to complete one immersion treatment; repeat the immersion treatment twice, then dry at 90°C for 5 minutes and at 150°C for 3 minutes to obtain high-performance water-repellent polyester fiber.

[0143] The only difference between this example and Example 1 is that the polyester fiber is not treated with a modified finishing solution.

[0144] The only difference between this example and Example 1 is that the modified finishing solution in this example is prepared through the following steps:

[0145] 6g of methyl acrylate, 8g of butyl acrylate, 2.5g of octadecyl methacrylate, 0.5g of Tween-20, and 0.75g of CTAB were added to 120mL of deionized water and ultrasonically dispersed for 30min. Then, 10g of dodecafluoroheptyl methacrylate was added, and the mixture was stirred under nitrogen atmosphere for 45min. While maintaining the nitrogen atmosphere, the mixture was heated to 70℃, and 10mL of a 0.02g / mL potassium persulfate aqueous solution was added dropwise over 1h. The mixture was kept at this temperature for 2h, then heated to 82℃, and 5mL of a 0.02g / mL potassium persulfate aqueous solution was added dropwise. The mixture was kept at this temperature for 1.5h and then cooled to room temperature to obtain the modified finishing solution.

[0146] The only difference between this example and Example 1 is that dodecafluoroheptyl methacrylate is not added in step S2-2 of this example, and the amounts of methyl acrylate, butyl acrylate, and octadecyl methacrylate added are changed to 10g, 12g, and 4.5g respectively.

[0147] The only difference between this example and Example 1 is that Ce(NO3)3 aqueous solution is not added in step S1-1 of this example.

[0148] The only difference between this example and Example 1 is that Al(NO3)3 aqueous solution is not added in step S1-1 of this example.

[0149] The only difference between this example and Example 1 is that this example uses the core-shell intermediate particles prepared in Example 1 as core-shell composite modified particles.

[0150] The only difference between this example and Example 1 is that vinyltrimethoxysilane is not added in steps S1-3 of this example.

[0151] I. Polyester Fiber Performance Testing

[0152] 1. Contact angle

[0153] The contact angles of the examples and comparative examples were measured using a contact angle tester. The test results are shown in Table 1 below. Figure 1 :

[0154] Table 1

[0155]

[0156] The test results show that Examples 1-4 have excellent water-repellent properties. Comparative Example 1 did not undergo modification treatment of the polyester fiber and therefore lacks hydrophobicity. Comparative Example 2 did not add core-shell composite modified particles to its modification solution, resulting in a significant decrease in contact angle. Comparative Example 3 did not add dodecafluoroheptyl methacrylate to its modification solution, leading to a decrease in water repellency. The contact angle of Comparative Example 4 did not change significantly. The contact angle of Comparative Example 5 decreased slightly, which was attributed to the absence of alumina doping in the core particles, thus losing its grain refinement and stability-enhancing effects, adversely affecting the size and structural stability of the constructed nanoscale uneven structure. In Comparative Example 6, carbon dots were not grafted onto the surface of the core-shell intermediate particles, lacking the surface roughness enhancement effect of carbon dots on the constructed uneven structure, resulting in a decrease in water repellency. In Comparative Example 7, the absence of vinyltrimethoxysilane doping during carbon dot grafting affected the grafting effect of carbon dots, leading to a decrease in water repellency.

[0157] 2. Ultraviolet light absorption performance

[0158] The ultraviolet transmittance of polyester fibers prepared according to the test examples and comparative examples in accordance with standard GB / T18830-2009 is shown in Table 2 below. Figure 2 As shown:

[0159] Table 2

[0160]

[0161] The test results show that Examples 1-4 have excellent UV resistance; Comparative Example 1 has poor UV absorption capacity because the polyester fiber was not treated with the modification solution; Comparative Example 2 also has poor UV absorption capacity because the core-shell composite modified particles were not added to the modification solution; the UV absorption capacity of Comparative Example 3 did not change much; the results of Comparative Examples 4 and 5 show that the cerium oxide and aluminum oxide doped in the core particles significantly help to improve UV absorption capacity; in Comparative Example 6, carbon dots were not grafted onto the surface of the core-shell intermediate particles, and the UV absorption provided by the carbon dots was missing, resulting in a significant decrease in both UVA and UVB transmittance; the reason for the decrease in UV absorption capacity of Comparative Example 7 is that vinyltrimethoxysilane was not doped during the carbon dot grafting process, which affected the grafting effect of the carbon dots, and at the same time, the improvement effect of Si doping on the UV absorption performance of the carbon dots was missing.

[0162] 3. UV aging resistance

[0163] The polyester fibers of the examples and comparative examples were subjected to accelerated aging under ultraviolet irradiation (UV light source wavelength 320nm, power 50W, distance between the light source and the sample 60cm, irradiation time 240h), and then the contact angle was tested; the test results are shown in Table 3 below. Figure 3 As shown:

[0164] Table 3

[0165]

[0166] The test results show that Examples 1-4 have excellent UV aging resistance, with a small decrease in contact angle after UV aging; Comparative Example 1, which did not undergo modification treatment of the polyester fiber, has poor UV aging resistance; Comparative Example 2, which did not add core-shell composite modified particles to its modification solution, has a significantly decreased contact angle after UV aging; Comparative Examples 3, 5, and 7 show no significant decrease; Comparative Example 4 shows a certain degree of decrease in contact angle, indicating that the cerium oxide doping in the core particles significantly helps to improve UV aging resistance; Comparative Example 6 shows a significant decrease in contact angle after UV aging, which is attributed to the grafted carbon dots being able to remove free radicals generated by UV irradiation through their reducing ability.

[0167] II. To further study and verify the mechanism of action of the core-shell composite modified particles of the present invention, the following performance tests were conducted on the core-shell composite modified particles and their precursors (core particles and core-shell intermediate particles):

[0168] 1. Figure 4 The XRD pattern of the core particles shows that titanium dioxide is a mixture of anatase (TiO2-A) and rutile (TiO2-R) phases, with anatase being the dominant phase. The presence of characteristic peaks for CeO2 and Al2O3 indicates successful doping of CeO2 and Al2O3.

[0169] 2. Reference Figure 5 The UV-Vis absorption spectra of the core-shell composite modified particles in Examples 1, 4, 5, and 6 are shown. It can be seen that Example 1 has a superior UV absorption capacity, and its results match the UV absorption performance test results above.

[0170] 3. Antioxidant performance test

[0171] The core-shell intermediate particles and core-shell composite modified particles prepared in Example 1 were dispersed in ethanol to prepare dispersions with a concentration of 0.5 mg / mL, which were designated as test samples, denoted as 1# and 2# respectively. The antioxidant properties of the dispersions were tested using a DPPH free radical scavenging ability assay kit (Shanghai Shangbao Biotechnology Co., Ltd., catalog number BA1871). Measurement principle: DPPH free radicals have unpaired electrons, and their alcoholic solution is purple with strong absorption at 515 nm. When an antioxidant is present, DPPH free radicals are scavenged, the solution color lightens, and the absorbance at 515 nm decreases. Within a certain range, the change in absorbance is directly proportional to the degree of free radical scavenging: the lower the absorbance at 515 nm, the stronger the antioxidant properties.

[0172] Test results are as follows Figure 6 As shown in the test results, the core-shell composite modified particles prepared in Example 1 have better antioxidant properties, while the antioxidant properties of the core-shell intermediate particles are significantly worse than those of the core-shell composite modified particles. This indicates that the antioxidant function of the core-shell composite modified particles is mainly provided by the grafted carbon dots.

[0173] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details.

Claims

1. A method for preparing high-performance UV-resistant and water-repellent polyester fiber, characterized in that, Includes the following steps: S1. Preparation of core-shell composite modified particles: S1-1. Preparation of core particles: Cerium salt and aluminum salt are added to TiCl4 solution, the pH is adjusted to alkaline and the reaction is stirred. The solid product obtained is separated, dried and calcined to obtain Al-Ce co-doped titanium dioxide nanoparticles, namely the core particles. S1-2. Core-shell intermediate particles are prepared by coating the surface of core particles with silicon dioxide. S1-3. Grafting carbon dots onto the surface of core-shell intermediate particles to prepare core-shell composite modified particles: Core-shell intermediate particles and vinyltrimethoxysilane were dispersed in ethanol to obtain a dispersion mixture; citric acid and acetylcysteine ​​were added to deionized water, and the resulting solution was added to the dispersion mixture. The resulting precursor mixture was transferred to a reaction vessel, heated to react, and the product was washed and dried to obtain core-shell composite modified particles. S2. Preparation of modified finishing solution: S2-1. Add the core-shell composite modified particles and emulsifier to deionized water and disperse by ultrasonication to obtain a particle emulsion. S2-2. Methyl acrylate, butyl acrylate, octadecyl methacrylate, dodecafluoroheptyl methacrylate and an initiator are added dropwise to the particle emulsion. The mixture is heated under a nitrogen atmosphere and cooled after the reaction is complete to obtain the modified finishing solution. S3. Polyester fibers are impregnated with a modified finishing solution to obtain high-performance UV-resistant and water-repellent polyester fibers.

2. The method for preparing high-performance UV-resistant water-repellent polyester fiber according to claim 1, characterized in that, Step S1-1 is as follows: TiCl4 was dissolved in hydrochloric acid to prepare a TiCl4 solution. The TiCl4 solution, Ce(NO3)3 aqueous solution, and Al(NO3)3 aqueous solution were mixed evenly. Sodium hydroxide solution was added dropwise to the resulting mixture to adjust the pH to 9-11. The mixture was stirred and reacted, filtered, and the solid product was washed, dried, calcined, and ground to obtain Al-Ce co-doped titanium dioxide nanoparticles, i.e., the core particles.

3. The method for preparing high-performance UV-resistant water-repellent polyester fiber according to claim 2, characterized in that, In step S1-1, the concentration of TiCl4 solution is 0.5-3 mol / L, the concentration of Ce(NO3)3 aqueous solution is 0.1-0.5 mol / L, the concentration of Al(NO3)3 aqueous solution is 0.2-2 mol / L, and the volume ratio of TiCl4 solution, Ce(NO3)3 aqueous solution, and Al(NO3)3 aqueous solution is 1: (0.05-0.15): (0.1-0.4).

4. The method for preparing high-performance UV-resistant water-repellent polyester fiber according to claim 2, characterized in that, In step S1-1, the calcination time is 20-90 min and the calcination temperature is 700-1100℃.

5. The method for preparing high-performance UV-resistant water-repellent polyester fiber according to claim 1, characterized in that, Step S1-2 is as follows: The kernel particles were added to the hydrochloric acid solution, stirred, filtered, and washed with deionized water. All the pretreated kernel particles were added to deionized water, and sodium hexametaphosphate was added. The mixture was ultrasonically dispersed and the pH was adjusted to 9-11 to obtain a kernel particle mixture. Na2SiO3 solution and sulfuric acid solution were added dropwise to the core-shell particle mixture. After the addition was complete, the mixture was aged, centrifuged, and the resulting solid product was washed and dried to obtain core-shell intermediate particles.

6. The method for preparing high-performance UV-resistant water-repellent polyester fiber according to claim 1, characterized in that, In steps S1-3, the heating temperature is 120-160℃ and the reaction time is 24-48h.

7. The method for preparing high-performance UV-resistant water-repellent polyester fiber according to claim 6, characterized in that, Steps S1-3 are as follows: Add 1-4g of core-shell intermediate particles and 0.74-2.96g of vinyltrimethoxysilane to 125-500mL of ethanol, and ultrasonically disperse for 0.5-2h to obtain a dispersion mixture; Add 2-8g of citric acid and 0.82-3.26g of acetylcysteine ​​to 50-200mL of deionized water and stir for 5-20min. Add the resulting solution to the dispersion mixture while stirring and sonicate for 15-60min. Transfer the resulting precursor mixture to a reaction vessel and react at 120-160℃ for 24-48h. Filter the mixture and wash the solid product with deionized water and ethanol in sequence. Dry it under vacuum at 70-100℃ to constant weight to obtain core-shell composite modified particles.

8. The method for preparing high-performance UV-resistant water-repellent polyester fiber according to claim 1, characterized in that, The emulsifier in step S2-1 is a mixture of Tween-20 and CTAB, with a mass ratio of Tween-20 to CTAB of 1:(0.75-3).

9. The method for preparing high-performance UV-resistant water-repellent polyester fiber according to claim 1, characterized in that, Includes the following steps: S1. Preparation of core-shell composite modified particles: S1-1, Preparation of core particles: TiCl4 was dissolved in 0.25-1 mol / L hydrochloric acid to prepare a TiCl4 solution with a concentration of 0.5-3 mol / L; TiCl4 solution, 0.1-0.5 mol / L Ce(NO3)3 aqueous solution, and 0.2-2 mol / L Al(NO3)3 aqueous solution were mixed evenly at a volume ratio of 1:(0.05-0.15):(0.1-0.4). 0.5-2 mol / L sodium hydroxide solution was added dropwise to the resulting mixture to adjust the pH to 9-11. The mixture was stirred for 0.5-2 h, filtered, and the solid product was washed with deionized water, dried at 80-100℃ for 2-8 h, and finally calcined in a muffle furnace at 700-1100℃ for 20-90 min. The mixture was then ground to obtain Al-Ce co-doped titanium dioxide nanoparticles, i.e., the core particles. S1-2. Core-shell intermediate particles are prepared by coating the surface of core particles with silica: Add 5-20g of kernel particles to 100-400mL of hydrochloric acid solution with a concentration of 0.1-0.3mol / L, stir for 15-60min, filter, wash with deionized water, add all the pretreated kernel particles to 150-600mL of deionized water, add 25-100mg of sodium hexametaphosphate, sonicate for 30-90min, adjust the pH to 9-11 with 0.5-2mol / L sodium hydroxide solution to obtain the kernel particle mixture; Simultaneously and uniformly add 15-60 mL of 0.1-0.4 mol / L Na2SiO3 solution and 15-60 mL of 0.25-1 wt% sulfuric acid solution to the core-shell particle mixture, keeping the dropping rate of the Na2SiO3 solution and sulfuric acid solution the same, and complete the dropping in 45-180 min. Then age for 75-300 min, centrifuge, wash the obtained solid product with deionized water, and dry to obtain core-shell intermediate particles. S1-3. Grafting carbon dots onto the surface of core-shell intermediate particles to prepare core-shell composite modified particles: Add 1-4g of core-shell intermediate particles and 0.74-2.96g of vinyltrimethoxysilane to 125-500mL of ethanol, and ultrasonically disperse for 0.5-2h to obtain a dispersion mixture; Add 2-8g citric acid and 0.82-3.26g acetylcysteine ​​to 50-200mL of deionized water and stir for 5-20min. Add the resulting solution to the dispersion mixture while stirring and sonicate for 15-60min. Transfer the resulting precursor mixture to a reaction vessel and react at 120-160℃ for 24-48h. Filter the mixture and wash the solid product with deionized water and ethanol in sequence. Dry it under vacuum at 70-100℃ to constant weight to obtain core-shell composite modified particles. S2. Preparation of modified finishing solution: S2-1. Add 1.5-6g of core-shell composite modified particles, 0.25-1g of Tween-20, and 0.3-1.5g of CTAB to 60-240mL of deionized water and ultrasonically disperse for 15-60min to obtain a particle emulsion. S2-2. Add 3-12g of methyl acrylate, 4-16g of butyl acrylate, 1.25-5g of octadecyl methacrylate, and 5-20g of dodecafluoroheptyl methacrylate to the particle emulsion dropwise. Stir under nitrogen atmosphere for 30-90 minutes, maintain nitrogen atmosphere, heat to 65-75℃, add 5-20mL of potassium persulfate aqueous solution with a concentration of 0.01-0.05g / mL dropwise, complete the addition in 0.5-2 hours, keep warm for 1-4 hours, raise the temperature to 80-85℃, add 2.5-10mL of potassium persulfate aqueous solution with a concentration of 0.01-0.05g / mL dropwise, keep warm for 1-3 hours, cool to room temperature, and obtain the modified finishing solution. S3. Immerse the polyester fiber in the modified finishing solution at a bath ratio of 1:(25-50) for 5-20 minutes at 40-60℃. Remove the fiber and dry it at 60-70℃ for 20-40 minutes to complete one immersion treatment. Repeat the immersion treatment 2-3 times, and then dry it at 80-100℃ for 2-8 minutes and at 140-170℃ for 1-4 minutes to obtain high-performance water-repellent polyester fiber.

10. A high-performance UV-resistant and water-repellent polyester fiber, characterized in that, It is prepared by the method described in any one of claims 1-9.

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