A nano-titanium dioxide for matting polyester fibers and its preparation method

Abstract

This invention relates to a modified titanium dioxide for matting polyester fibers and its preparation method. The modified titanium dioxide comprises a mesoporous titanium dioxide core and a cysteine ​​graft layer grafted into the pores of the mesoporous titanium dioxide. The mesoporous titanium dioxide core is prepared by evaporation-induced self-assembly using an alkenyl sulfonate surfactant as a liquid crystal template and tetraethyl or tetrabutyl titanate as the titanium source. Due to the self-polymerization reaction of the alkenyl sulfonate, the resulting polyalkenyl sulfonic acid compound reduces the crystallinity of the mesoporous titanium dioxide, thereby significantly reducing its photocatalytic activity. The mesoporous titanium dioxide is mixed with cysteine ​​and heated to graft cysteine ​​into its pores. The presence of cysteine ​​results in the modified titanium dioxide exhibiting both good matting properties and suppressed photocatalytic activity, preventing fiber structure damage from prolonged ultraviolet irradiation when applied to polyester fibers.

Description

Technical Field

[0001] This invention relates to the field of matting agents for polyester fibers, and more particularly to a nano-titanium dioxide for matting polyester fibers and its preparation method. Background Technology

[0002] Polyester fabric is a widely used synthetic fiber clothing material in daily life. It has excellent mechanical properties, high strength, and elastic recovery. However, due to the orderly arrangement of its molecules, ordinary polyester fibers reflect light strongly, resulting in a strong silk-like feel, bright luster, and a shimmering appearance, which can be dazzling. To solve this problem, functional inorganic powders, such as anatase titanium dioxide, are usually added to synthetic fibers as a matting agent for polyester fibers.

[0003] Titanium dioxide is currently a popular chemical fiber additive with good overall performance in terms of light-blocking power and whiteness. However, inexpensive anatase titanium dioxide has photocatalytic activity, which can degrade polyester molecules and lead to aging problems in polyester fibers. Therefore, it needs to be modified to obtain a more stable product with better dispersibility. Furthermore, numerous studies have confirmed that the extinction effect of titanium dioxide is optimal when the particle size is around half the wavelength of visible light (i.e., the particle size distribution is around half the visible light wavelength range), at which point scattering and diffraction properties are basically balanced. However, currently produced industrial anatase titanium dioxide has a relatively large particle size, which cannot achieve the optimal extinction effect. On the other hand, when ultrafine titanium dioxide powder is used directly, it is prone to agglomeration and even clogging of the spinneret orifices, resulting in uneven distribution in polyester fibers and poor spinnability.

[0004] To overcome the aforementioned characteristics of titanium dioxide, existing technologies typically involve ultrafine grinding of anatase titanium dioxide followed by surface coating and other post-treatments. Specific methods include coating with inorganic particles or organic polymers, i.e., coating the surface of titanium dioxide with one or more dense layers of oxide-based inorganic particles (such as silicon dioxide, aluminum oxide, etc.) to prevent contact between titanium dioxide and fibers. Other methods involve forming an organic coating layer on the surface of titanium dioxide to block light. For example, CN109881278A discloses a method for preparing and applying titanium dioxide for matting viscose fibers. This method involves dispersing pigment-grade anatase titanium dioxide into an aqueous slurry, grinding, diluting, and classifying to remove large particles; then coating the surface of the titanium dioxide particles with hydrated silicon dioxide, hydrated zirconium oxide, and hydrated bismuth oxide; finally, initiating free radical polymerization to coat the modified titanium dioxide particles with a polymer layer, obtaining titanium dioxide for matting viscose fibers. This method uses multi-layer coating to completely cover the internal titanium oxide, which is almost equivalent to losing the function of titanium oxide itself and only serving as a particle core.

[0005] CN103333527A discloses a method for manufacturing a surface matting agent for nylon fibers, in which an amorphous silicon or titanium layer is coated onto the surface of titanium dioxide using silicides and titanium alkoxides during the inorganic coating process. CN107541097A discloses a method for preparing inorganic and organic coated titanium dioxide, specifically disclosing the preparation of aluminum-coated titanium dioxide using NaAlO2 solution, followed by organic coating treatment of the aluminum-coated titanium dioxide using methyl hydrogen silicone oil and hexamethyldisilazane. CN112457691A discloses a matting agent with low photocatalytic activity, its preparation method, and its application, wherein the matting agent comprises a titanium dioxide core and a hindered amine layer grafted onto the titanium dioxide core. CN112457691A relates to a method for preparing a matting agent for nylon fibers, comprising the following steps: preparing anatase titanium dioxide ultrafine powder; preparing aluminum-coated titanium dioxide slurry; and surface grafting modification using a coupling agent method.

[0006] However, the aforementioned existing technologies have the following drawbacks: 1. To form a dense layer, multiple coating operations are often employed, using high concentrations of metal salts. This not only results in excessively large particle sizes but also easily leads to the formation of a large amount of alumina and silica particle impurities in the solution, generating substantial amounts of metal salt wastewater that is difficult to recycle and has high treatment costs; 2. The organic molecule modification in existing technologies often involves direct physical adsorption onto the surface of titanium dioxide particles, resulting in weak bonding forces and easy molecule desorption from the surface, failing to improve the compatibility between titanium dioxide and chemical fibers; 3. Multiple coating operations prevent titanium dioxide particles from fully utilizing their properties and severely reduce their extinction ability. Although grinding is performed after coating to reduce particle size, this damages the formed coating layer, leading to instability in the technical effect.

[0007] Therefore, in response to existing chemical fiber matting agents, it is necessary to provide a titanium dioxide with low photocatalytic activity and stable dispersion. Summary of the Invention

[0008] In order to overcome the shortcomings of the prior art, the present invention innovatively provides a matting agent for polyester chemical fibers and its preparation method.

[0009] In a first aspect, the present invention provides a modified titanium dioxide for matting polyester fibers, comprising a mesoporous titanium dioxide core and a polycysteine ​​layer grafted into the pores of the mesoporous titanium dioxide.

[0010] In some embodiments of the present invention, the method for preparing mesoporous titanium dioxide includes the following steps: S1: In a water bath at 40-50°C, α-alkenyl sulfonate and deionized water are stirred evenly to form a liquid crystal, and a mixture of tetraethyl titanate or tetrabutyl titanate and an alcohol solvent is added dropwise to it. After the addition is completed, a mixture of alcohol solvent and deionized water is added dropwise to carry out a hydrolysis reaction.

[0011] S2: Add an initiator to the mixture obtained in S2 and initiate the polymerization reaction under closed conditions of 50-80℃ and 1-3MPa for 3-5 hours;

[0012] S3: Take the mixed system after the reaction in S2 is completed, adjust the pH of the system to acidic, and distill it at 90-100℃ until a gel is formed. After extraction, drying and grinding, the mesoporous titanium dioxide is obtained.

[0013] In some embodiments of the present invention, in S1, the α-alkenyl sulfonate comprises 65-73 wt% alkenyl sulfonate, 21-24 wt% hydroxysulfonate and 3-14 wt% disulfonate, wherein the alkenyl sulfonate has the structure of Formula I, the hydroxysulfonate has the structure of Formula II and the disulfonate has the structure of Formula III.

[0014]

[0015] Wherein, R1, R2, and R3 are C10-15 alkyl groups, M is a monovalent metal, and x, y, and z are each an independent integer from 1 to 3.

[0016] α-Alkenyl sulfonates, as surfactants, can effectively reduce surface tension. In this invention, the inventors use them as templates for evaporative self-assembly to prepare nano-titanium dioxide. Due to the presence of straight-chain alkyl groups in the α-alkenyl sulfonate, the resulting nano-titanium dioxide exhibits a large number of ordered, narrow mesoporous pores. The double bonds in the α-alkenyl sulfonate are used to initiate its self-polymerization. The disordered structure of the resulting polymer effectively reduces the crystallinity of the prepared mesoporous titanium dioxide, thereby increasing the defects on the titanium dioxide crystal surface and reducing its photocatalytic activity.

[0017] In some embodiments of the present invention, in S1, the ratio of α-alkenyl sulfonate to tetraethyl titanate or tetrabutyl titanate is 4.5-5.5g: 25-40ml.

[0018] Experimental comparisons revealed that the amounts of α-alkenyl sulfonate and tetraethyl or tetrabutyl titanate need to be appropriate. Excessive use of α-alkenyl sulfonate will cause the formed polymer to interfere with the hydrolysis of tetraethyl or tetrabutyl titanate in the system, resulting in nano-titanium dioxide containing more impurities and failing to exhibit good extinction properties. Conversely, insufficient use of α-alkenyl sulfonate will not ideally adjust the pore structure of nano-titanium dioxide and will not significantly reduce its crystallinity. Therefore, the optimal ratio of α-alkenyl sulfonate to tetraethyl or tetrabutyl titanate is 4.5-5.5 g : 25-40 ml.

[0019] In some embodiments of the present invention, in step S1, the alcohol solvent is at least one of anhydrous ethanol, n-butanol, and isobutanol.

[0020] In some embodiments of the present invention, the amount of alcohol solvent mixed with tetraethyl titanate or tetrabutyl titanate is 2-2.5 times the volume of tetraethyl titanate or tetrabutyl titanate. Since the hydrolysis rate of tetraethyl titanate or tetrabutyl titanate also affects the structure and properties of the final obtained nano-titanium dioxide, in the present invention, preferably, the dropping rate of tetraethyl titanate or tetrabutyl titanate with the alcohol solvent is 2-3 s / drop.

[0021] In some embodiments of the present invention, in step S1, the volume ratio of the alcohol solvent to the deionized water is 50-55:1. Preferably, the dropping rate of the mixture should also be controlled at 1-2 s / drop.

[0022] In some embodiments of the present invention, the initiator used in S2 is at least one of azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, ammonium persulfate, and potassium persulfate, and is selected according to the reaction conditions.

[0023] Secondly, the preparation method of the modified titanium dioxide includes the following steps: dispersing the above-obtained mesoporous titanium dioxide in a buffer solution containing cysteine, stirring at 60-80℃ for 0.5-1h, cooling, filtering, washing and drying to obtain the modified titanium dioxide.

[0024] In some embodiments of the present invention, the dispersion concentration of the mesoporous titanium dioxide in the buffer solution is 10-15 mg / ml, and the solubility concentration of cysteine ​​is 0.8-1.5 mg / ml.

[0025] Because sulfonic acid groups are introduced during the preparation of the mesoporous titanium dioxide, cysteine ​​is grafted into the pores of the mesoporous titanium dioxide through the reaction of sulfonic acid groups with amino and carboxyl groups, or the dehydration reaction of thiol groups with hydroxyl groups on the surface of the mesoporous titanium dioxide. Furthermore, since cysteine ​​can undergo self-polymerization in the presence of titanium ions, polycysteine ​​may also be present in the final modified titanium dioxide. The attachment of polycysteine ​​in the pores of the mesoporous titanium dioxide can, on the one hand, suppress the photocatalytic performance of the modified titanium dioxide, and on the other hand, improve the dispersion compatibility of the modified titanium dioxide in polyester fiber materials to a certain extent.

[0026] However, the amount of cysteine ​​used should be appropriate; otherwise, it will not be able to effectively suppress the photocatalytic performance of the modified titanium dioxide, or the attraction between it and the fiber molecules will be too great, leading to fiber molecule aggregation, uneven system, and unfavorable for subsequent spinning.

[0027] In some embodiments of the present invention, the buffer solution is one of disodium hydrogen phosphate / citric acid buffer, citric acid / sodium hydroxide / hydrochloric acid buffer, or citric acid / sodium citrate buffer, with a pH of 4.0-6.5.

[0028] Beneficial effects: Compared with the prior art, this invention innovatively utilizes α-alkenyl sulfonate as an evaporation-induced self-assembly liquid crystal template for preparing nano-titanium dioxide. By initiating the double bond polymerization of α-alkenyl sulfonate, a mesoporous titanium dioxide with high specific surface area and low crystallinity is prepared. The photocatalytic activity of this mesoporous titanium dioxide is significantly reduced compared with that of ordinary nano-titanium dioxide. In addition, the surface of the mesoporous titanium dioxide not only has hydroxyl groups but also sulfonic acid groups. Therefore, through the reaction of sulfonic acid groups with cysteine ​​and the self-polymerization of cysteine, polycysteine ​​is introduced into the pore surface of the mesoporous titanium dioxide. This can not only effectively inhibit the photocatalytic activity of the modified titanium dioxide but also improve its dispersion compatibility in the fiber system, which is beneficial to the smooth progress of the subsequent spinning process. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to examples. It should be noted that the following embodiments and comparative examples are examples of the present invention and are only used to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from the spirit or scope of the invention.

[0030] Example 1

[0031] A modified titanium dioxide for matting polyester fibers is prepared as follows:

[0032] S1: In a 40℃ water bath, 4.5g of α-alkenyl sulfonate containing 65wt% sodium alkenyl sulfonate of formula I-1, 21wt% sodium hydroxysulfonate of formula II-1 and 14wt% sodium disulfonate of formula III-1 is stirred with deionized water to form a liquid crystal. A mixture of 25ml tetraethyl titanate and 50ml anhydrous ethanol is added dropwise at a rate of 2 drops / s. After the addition is complete, a mixture of 100ml anhydrous ethanol and 2ml deionized water is added dropwise at a rate of 1 drop / s to carry out the hydrolysis reaction.

[0033]

[0034]

[0035] S2: Add 1 wt% of azobisisobutyronitrile to the mixture obtained in S2, and initiate the polymerization reaction under closed conditions of 50℃ and 1MPa for 3 hours.

[0036] S3: Take the mixed system after the reaction in S2 is completed, adjust the pH of the system to acidic with 1 mol / L hydrochloric acid solution, and distill at 90℃ until a gel is formed. After extraction, drying and grinding, the mesoporous titanium dioxide is obtained.

[0037] 1000 mg of the mesoporous titanium dioxide obtained above was uniformly dispersed in 100 ml of disodium hydrogen phosphate / citric acid buffer solution with pH = 4.0 containing 80 mg of cysteine. After stirring at 60 °C for 1 h, the mixture was cooled and filtered. After washing with anhydrous ethanol and deionized water, the modified titanium dioxide was obtained.

[0038] Example 2

[0039] A modified titanium dioxide for matting polyester fibers is prepared as follows:

[0040] S1: In a 50℃ water bath, 5.0g of α-alkenyl sulfonate containing 70wt% sodium alkenyl sulfonate of formula I-2, 22wt% sodium hydroxysulfonate of formula II-2 and 8wt% sodium disulfonate of formula III-2 is stirred with deionized water to form a liquid crystal. A mixture of 30ml tetraethyl titanate and 70ml anhydrous ethanol is added dropwise at a rate of 3 drops / s. After the addition is complete, a mixture of 110ml anhydrous ethanol and 2ml deionized water is added dropwise at a rate of 2 drops / s to carry out the hydrolysis reaction.

[0041]

[0042]

[0043] S2: Add 1 wt% of azobisisobutyronitrile to the mixture obtained in S2, and initiate the polymerization reaction under closed conditions of 70℃ and 1.5MPa for 4 hours.

[0044] S3: Take the mixed system after the reaction in S2 is completed, adjust the pH of the system to acidic with 1 mol / L hydrochloric acid solution, and distill at 90℃ until a gel is formed. After extraction, drying and grinding, the mesoporous titanium dioxide is obtained.

[0045] 1500 mg of the mesoporous titanium dioxide obtained above was uniformly dispersed in 100 ml of pH 5.5 citric acid / sodium citrate buffer solution containing 100 mg of cysteine. After stirring at 70 °C for 1 h, the mixture was cooled and filtered. After washing with anhydrous ethanol and deionized water, the modified titanium dioxide was obtained.

[0046] Example 3

[0047] A modified titanium dioxide for matting polyester fibers is prepared as follows:

[0048] S1: In a 50℃ water bath, 5.5g of α-alkenyl sulfonate containing 73wt% sodium alkenyl sulfonate of formula I-3, 24wt% sodium hydroxysulfonate of formula II-3 and 3wt% sodium disulfonate of formula III-3 is stirred with deionized water to form a liquid crystal. A mixture of 40ml tetraethyl titanate and 80ml anhydrous ethanol is added dropwise at a rate of 2 drops / s. After the addition is complete, a mixture of 150ml anhydrous ethanol and 3ml deionized water is added dropwise at a rate of 1 drop / s to carry out the hydrolysis reaction.

[0049]

[0050]

[0051] S2: Add 1 wt% of azobisisobutyronitrile to the mixture obtained in S2, and initiate the polymerization reaction under closed conditions of 80℃ and 3MPa for 5 hours.

[0052] S3: Take the mixed system after the reaction in S2 is completed, adjust the pH of the system to acidic with 1 mol / L hydrochloric acid solution, and distill at 100℃ until a gel is formed. After extraction, drying and grinding, the mesoporous titanium dioxide is obtained.

[0053] 1500 mg of the mesoporous titanium dioxide obtained above was uniformly dispersed in 100 ml of pH 6.5 citric acid / sodium citrate buffer solution containing 150 mg of cysteine. After stirring at 80 °C for 1 h, the mixture was cooled and filtered. After washing with anhydrous ethanol and deionized water, the modified titanium dioxide was obtained.

[0054] Example 4

[0055] The preparation process is the same as in Example 3, except that the amount of α-olefin sulfonate used is 6g.

[0056] Example 5

[0057] The preparation process is the same as in Example 3, except that the amount of α-olefin sulfonate used is 4g.

[0058] Example 6

[0059] The preparation process is the same as in Example 3, except that the mass of cysteine ​​used is 200 mg.

[0060] Example 7

[0061] The preparation process is the same as in Example 3, except that the mass of cysteine ​​used is 70 mg.

[0062] Comparative Example 1

[0063] The preparation process is also shown in Example 3, except that the mesoporous titanium dioxide is not subjected to cysteine ​​grafting treatment.

[0064] Comparative Example 2

[0065] A titanium dioxide for matting polyester fibers is prepared as follows:

[0066] S1: In a 50℃ water bath, 5.5g of α-alkenyl sulfonate containing 73wt% sodium alkenyl sulfonate of formula I-3, 24wt% sodium hydroxysulfonate of formula II-3 and 3wt% sodium disulfonate of formula III-3 is stirred with deionized water to form a liquid crystal. A mixture of 40ml tetraethyl titanate and 80ml anhydrous ethanol is added dropwise at a rate of 2 drops / s. After the addition is complete, a mixture of 150ml anhydrous ethanol and 3ml deionized water is added dropwise at a rate of 1 drop / s to carry out the hydrolysis reaction.

[0067]

[0068] S2: Take the mixed system after the reaction in S1 is completed, adjust the pH of the system to acidic with 1 mol / L hydrochloric acid solution, and distill at 100℃ until a gel is formed. After extraction, drying and grinding, the titanium dioxide is obtained.

[0069] The titanium dioxide obtained above was subjected to the following performance tests:

[0070] Photocatalytic activity: Acid Red B (product of TISA (Shanghai) Chemical Industry Development Co., Ltd.) was dissolved in water to prepare nine 100ml dye solutions with a concentration of 20mg / L. Under continuous stirring at 150rpm, 0.5g of titanium dioxide from Examples 1-7 and Comparative Examples 1-2 were added to the dye solutions respectively. The nine dye solutions were continuously irradiated with a 200W mercury lamp for 1 hour to test the degradation rate of Acid Red B. The absorbance of the dye solutions was measured using a UV spectrophotometer (UV-2102C, manufactured by Unico (Shanghai) Instruments Co., Ltd.), and the concentration was converted according to the standard curve. The degradation rate R (%) was calculated using the following formula:

[0071]

[0072] Among them, C 初始 and C 最终 These refer to the initial dye concentration in the solution and the dye concentration during degradation, respectively.

[0073] Dispersion stability: Titanium dioxide from Examples 1-7 and Comparative Examples 1-2 was added to monomers of terephthalic acid and ethylene glycol and heated to polymerize, preparing a polyester melt with a matting agent content of 1.5 wt%. After water cooling, it was prepared into chips. After water extraction and drying, the filtration performance of each chip was tested using a BL-6176-B type laboratory single-screw extruder (Dongguan Baolun Precision Testing Instruments Co., Ltd.). Since large particles can clog the filter channels and cause pressure to rise, the filter pressure change can be used to characterize the dispersion stability of the titanium dioxide in molten polyester.

[0074] Extinction property: The gloss of the above slices was tested using 60° incident light.

[0075] The performance test results are shown in Table 1:

[0076] Table 1 Performance test results of Examples 1-7 and Comparative Examples 1-2

[0077]

[0078] Comparative Example 1 used untreated titanium dioxide as a matting agent, while in Comparative Example 2, the titanium dioxide was prepared using only alkenyl sulfonate as a template without initiating polymerization. As shown in Table 1, compared to Comparative Examples 1-2, the titanium dioxide from Examples 1-7 exhibited significantly lower dye degradation rates, lower filter pressure rise differences in the resulting polyester chips within the single-screw extruder, and lower gloss. This demonstrates that introducing polyalkenyl sulfonate and polycysteine ​​into titanium dioxide can effectively reduce its photocatalytic activity, improve its dispersion stability in molten polymers, and provide better matting properties. The reasons are as follows: the presence of polyolefin sulfonate can affect the crystallinity of mesoporous titanium dioxide. The decrease in crystallinity leads to an increase in surface defects of mesoporous titanium dioxide crystals, and the photocatalytic activity will decrease accordingly. The presence of cysteine ​​or polycysteine ​​can capture the holes generated by titanium dioxide and cut off the path of fiber attack, thereby inhibiting the photocatalytic activity of titanium dioxide. Moreover, the cysteine ​​structure can improve the compatibility between titanium dioxide and polymer matrix, thereby preventing the agglomeration of titanium dioxide.

[0079] The difference between Examples 4-5 and Example 3 lies in the amount of α-olefin sulfonate used. As a result, the extinction properties and photocatalytic activity of the obtained titanium dioxide are negatively affected. The difference between Examples 6-7 and Example 3 lies in the amount of cysteine ​​used. As can be seen from the results, too much or too little cysteine ​​is not conducive to the dispersibility of the obtained titanium dioxide.

[0080] In summary, the modified titanium dioxide for matting polyester fibers provided by this invention has low photocatalytic activity, ideal dispersion stability and matting properties, and has good application prospects in the field of fiber matting agents.

Claims

1. A modified titanium white powder for polyester fiber matt, characterized by, The mesoporous titanium dioxide comprises a mesoporous titanium dioxide core and a poly-cysteine layer grafted in the pores of the mesoporous titanium dioxide. The preparation method of the mesoporous titanium dioxide comprises the following steps: S1: uniformly stirring α-alkenyl sulfonate and deionized water in a 40-50°C water bath to form a liquid crystal, and then adding a mixture of tetraethyl titanate or tetrabutyl titanate and an alcohol solvent dropwise, and then adding a mixture of the alcohol solvent and deionized water dropwise, and performing a hydrolysis reaction; S2: adding an initiator to the mixture obtained in S2, and initiating a polymerization reaction under a sealed condition of 50-80°C and 1-3MPa for 3-5h; S3: taking the mixed system after the reaction in S2, adjusting the pH of the system to be acidic, and distilling at 90-100°C until a gel is formed, and then extracting, drying and grinding to obtain the mesoporous titanium dioxide; In S1, the α-alkenyl sulfonate comprises 65-73wt% of alkenyl sulfonate, 21-24wt% of hydroxyl sulfonate and 3-14wt% of disulfonate, wherein the structure of the alkenyl sulfonate is as shown in formula I, the structure of the hydroxyl sulfonate is as shown in formula II, and the structure of the disulfonate is as shown in formula III. In S1, the α-alkenyl sulfonate and the tetraethyl titanate or tetrabutyl titanate are used in a ratio of 4.5-5.5g:25-40ml.

2. The modified titanium dioxide for polyester fiber matt according to claim 1, characterized in that, In S1, the alcohol solvent is at least one of anhydrous ethanol, n-butanol and isobutanol.

3. The modified titanium dioxide for polyester fiber matt according to claim 1, characterized in that, The amount of the alcohol solvent mixed with the tetraethyl titanate or tetrabutyl titanate is 2-2.5 times the volume of the tetraethyl titanate or tetrabutyl titanate.

4. The modified titanium dioxide for polyester fiber delustering according to claim 3, characterized in that, In S1, the volume ratio of the alcohol solvent to deionized water is 50-55:

1.

5. The modified titanium dioxide for polyester fiber matt according to claim 1, characterized in that, The method comprises the following steps: dispersing the mesoporous titanium dioxide obtained above in a buffer solution in which cysteine is dissolved, stirring at 60-80°C for 0.5-1h, and then cooling, filtering, washing and drying to obtain the modified titanium dioxide.

6. The method for preparing modified titanium dioxide for polyester fiber matt according to any one of claims 1-5, characterized in that, The dispersion concentration of the mesoporous titanium dioxide in the buffer solution is 10-15mg / ml, and the dissolution concentration of the cysteine is 0.8-1.5mg / ml.

7. The method for preparing modified titanium dioxide for polyester fiber matt according to claim 6, characterized in that, The buffer solution is one of disodium hydrogen phosphate / citric acid buffer solution, citric acid / sodium hydroxide / hydrochloric acid buffer solution and citric acid / sodium citrate buffer solution, and the pH is 4.0-6.

5.

8. The method for preparing modified titanium dioxide for polyester fiber delustering according to claim 6, characterized in that, ​

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