Preparation method of TiO2 / polyester composite aerogel photocatalytic material

Abstract

The invention aims to provide a preparation method of a TiO2 / polyester composite aerogel photocatalytic material, and belongs to the technical field of photocatalytic degradation, the preparation method comprises the following steps: firstly, crushing and grinding polyester fibers to obtain polyester particles, then carrying out amination treatment on the polyester particles by using allylamine, and introducing amino active groups into molecular chains of the polyester particles; meanwhile, a silane coupling agent KH550 is used for carrying out surface modification on nano TiO2, and particle aggregation is inhibited; finally, glycerol triglycidyl ether is introduced as a cross-linking agent, an epoxy group of glycerol triglycidyl ether, the fiber particles and amino groups on the surface of the modified titanium dioxide are subjected to a ring-opening reaction, and a three-dimensional cross-linked network is formed. A network structure among the polyester particles provides a carrier for nano titanium dioxide, titanium dioxide agglomeration is inhibited through a space confinement effect, meanwhile, the stability of the composite material in a complex water quality environment is improved, and efficient loading and uniform dispersion of titanium dioxide are realized. The obtained photocatalytic composite aerogel has excellent photocatalytic degradation performance on dye pollutants in wastewater.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of photocatalytic degradation, and particularly relates to a preparation method of TiO2 / polyester composite aerogel photocatalytic material. BACKGROUND

[0002] With the rapid development of industrialization, industrial wastewater increases year by year, and the organic pollutants in the wastewater are difficult to degrade, which has a serious threat to the ecological environment and human health. Under this situation, it has become a research hotspot in the field of environmental governance to develop a multifunctional composite material which has good adsorption to organic pollutants (such as dyes) and excellent photocatalytic degradation performance. Titanium dioxide (TiO2) has excellent photocatalytic activity and chemical stability, and is widely used in this field. However, in nature, titanium dioxide usually exists in the form of powder, and when treating polluted wastewater, it is easy to agglomerate and is not easy to recover, which can easily cause secondary pollution. These characteristics make the actual application effect not as desired. In order to solve this problem, it is necessary to load it on a suitable material to improve its dispersibility and operability. SUMMARY

[0003] In view of the above problems, the application provides a preparation method of TiO2 / polyester composite aerogel photocatalytic material. The TiO2 / polyester aerogel composite material is prepared by amine modification of polyester fiber microparticles and cross-linking of the amine-modified polyester microparticles with titanium dioxide modified by a coupling agent.

[0004] To achieve the above object, the application adopts the following technical scheme: A preparation method of TiO2 / polyester composite aerogel photocatalytic material, comprising the following steps: S1, grinding polyester fabric to obtain polyester microparticles; S2, amine treatment of the polyester microparticles with allylamine, and then filtering and drying for standby to obtain modified polyester powder; S3, putting silane coupling agent KH550 and nano-TiO2 into water, stirring, then adding the modified polyester powder, and ultrasonic dispersing to obtain a mixed solution; S4, adding glycerol triglycidyl ether to the mixed solution, stirring at 60℃ for 10min, and placing at 60℃ for more than 2h to gel, and then freeze-drying to obtain the TiO2 / polyester aerogel composite photocatalytic material.

[0005] Further, the grinding process of the polyester fabric in S1 is as follows: the polyester fabric is cut into blocks of 10x10mm, and then ground for 5min using a grinding machine; the ground polyester fabric is further ground using a nanometer ball mill, and then sieved through a 100-mesh sieve for standby.

[0006] Further, the amount ratio of the polyester microparticles to the allylamine in S2 is 4 g:10 mL, the mass concentration of the allylamine is 10-30%, the temperature of the amination treatment is 110-130 DEG C, and the treatment time is 5-15 min.

[0007] Further, the mass concentration of the allylamine in S2 is 20%, the temperature of the amination treatment is 130 DEG C, and the treatment time is 5 min.

[0008] Further, the amount ratio of the silane coupling agent KH550, nano-TiO2, water and modified polyester powder in S3 is 2 mL:0.04 g:40 mL:2 g, the stirring time is 10 min, and the ultrasonic dispersion time is 20 min.

[0009] Further, the amount of the glycerol triglycidyl ether in S4 is 0.5-2 mL.

[0010] Further, the amount of the glycerol triglycidyl ether in S4 is 2 mL.

[0011] The beneficial effects of the present application are as follows: The present application prepares a TiO2 / polyester aerogel composite material by a method of amine modification of polyester fiber microparticles and then crosslinking with coupling agent modified titanium dioxide. First, polyester fibers are ground to obtain polyester microparticles, then allylamine is used to amine treat the polyester microparticles to introduce amino (-NH2) active groups into the molecular chains, so as to enhance the hydrophilicity and realize uniform dispersion in water; meanwhile, the surface of nano-TiO2 is modified by silane coupling agent KH550 to inhibit particle agglomeration; finally, glycerol triglycidyl ether (GTE) is introduced as a crosslinking agent, the epoxy groups of which react with the amino groups on the surface of the fiber microparticles and modified titanium dioxide to form a three-dimensional crosslinked network. The network structure between the polyester microparticles provides a carrier for nano-titanium dioxide, inhibits titanium dioxide agglomeration through space confinement effect, at the same time improves the stability of the composite material in complex water environment, realizes efficient loading and uniform dispersion of titanium dioxide. The obtained photocatalytic composite aerogel has excellent photocatalytic degradation performance on dye pollutants in wastewater. This method uses waste polyester fabrics as raw materials to prepare high-performance photocatalytic functional materials, which is an effective method for high-value recycling of waste resources. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 SEM image of the composite aerogel photocatalytic material prepared in Example 1 of the present application; Figure 2 SEM image of the composite aerogel photocatalytic material prepared in Example 1 of the present application; Figure 3EDS spectrum of the composite aerogel photocatalytic material prepared for the embodiment 1 of the present application; Figure 4 Infrared spectrum of the composite aerogel photocatalytic material prepared for the embodiment 1 of the present application; Figure 5 Graph of the degradation rate of methylene blue by different amounts of TiO2 / polyester composite aerogel photocatalytic materials; Figure 6 Graph of the degradation rate of methylene blue by the composite aerogel photocatalytic material under different numbers of cycles. DETAILED DESCRIPTION

[0013] In order to make the purpose, technical scheme and advantages of the present application more clear and explicit, the specific embodiments of the present application are described in detail, but not limited to this. The raw materials used in the embodiments are ordinary commercially available products unless otherwise specified; the methods used are common methods in the art unless otherwise specified.

[0014] A preparation method of a TiO2 / polyester composite aerogel photocatalytic material, comprising the following steps: S1, grinding the polyester fabric to obtain polyester microparticles; S2, amine treatment of the polyester microparticles using allylamine, then filtering and drying for standby, to obtain modified polyester powder; S3, putting silane coupling agent KH550 and nano-TiO2 into water, stirring, then adding the modified polyester powder, ultrasonic dispersion, to obtain a mixed solution; S4, adding glycerol triglycidyl ether to the above mixed solution, stirring at 60℃ for 10min, and placing at 60℃ for more than 2h to gel, then freeze-drying, to obtain a TiO2 / polyester aerogel composite photocatalytic material.

[0015] Embodiment 1 Pre-treatment of polyester fabric: cutting the polyester fabric into 10x10mm blocks, then using a pulverizer for pulverization treatment for 5min; further grinding the pulverized polyester fibers using a nanometer ball mill, then passing through a 100-mesh sieve for standby; Taking 4g polyester fiber powder, surface amine modification at 130℃ with 20% mass concentration of allylamine, stirring for 5min, then filtering and drying for standby.

[0016] Taking 0.04g TiO2 and 2mL silane coupling agent KH550 solution, putting into 40ml water, stirring for 10min; then adding 2g modified polyester powder, ultrasonic dispersion for 20min.

[0017] In the above solution, add glycerol triglycidyl ether 2 ml, stirring at 60 ℃ for 10 min, and gel at 60 ℃ for 2 h or more, then freeze-drying to obtain TiO2 / polyester aerogel composite photocatalytic material.

[0018] From the SEM image of Figure 1 , it can be seen that the composite material is a loose block material. From the cross-sectional image of Figure 2 , it can be seen that there are many honeycomb pore structures in the composite material, which is very beneficial to the adsorption of pollutants in the wastewater treatment process. The microstructure is a three-dimensional hole with large pores and thin walls. From the EDS spectrum of Figure 3 , it can be seen that the content of N element increased after amination in the composite material, and the titanium element in titanium dioxide, indicating that the composite aerogel is composed of aminated polyester and titanium dioxide.

[0019] From Figure 4 , it can be seen that the symmetric vibration peak of methylene group appears at 2816 cm -1 , the N-H bending vibration peaks of primary and secondary amines observed at 1631 cm -1 , 1549 cm -1 and 1293 cm -1 , indicating that the polyester is treated by amination reagent to form amine derivatives. The out-of-plane bending vibration and stretching vibration peaks of C-H on benzene ring are shown at 1468 cm -1 and 1410 cm -1 , a strong C-O-C stretching vibration peak from the crosslinking reagent glycerol glycidyl ether at 1089 cm -1 , indicating that the amination product is successfully crosslinked. At the same time in the sample, the relatively strong stretching vibration peaks of titanium dioxide appear at 500-770 cm -1 , indicating that titanium dioxide and polyester are successfully crosslinked to form a composite structure.

[0020] Example 2 The composite aerogel materials were prepared by different processes, and the degradation rate of methylene blue was shown in Table 1.

[0021] Table 1 Degradation rate of methylene blue by composite photocatalytic aerogel prepared under different process conditions As can be seen from Table 1, the degradation rate of all samples reached more than 85%, i.e. the samples had good photocatalytic degradation ability.

[0022] Example 3 Different amounts of TiO2 / polyester composite material were used to degrade methylene blue, and the degradation rate curve was shown in Figure 5 Figure 5 ​It is known that ultraviolet lamps also have a certain degradation rate on methylene blue solution, but the irradiation time is very long and the degradation rate is very low. When the amount of TiO2 / polyester composite material is 0.5g, the degradation rate reaches more than 90% after 30min of photocatalytic degradation, indicating that the composite photocatalytic aerogel has a good degradation rate for methylene blue.

[0023] Example 4 The degradation rate curves of methylene blue by the composite aerogel photocatalyst material under different cycles are shown below. Figure 6 As shown, by Figure 6 It can be seen that the degradation rate of methylene blue gradually decreases with increasing usage. However, after five cycles, the degradation rate is still above 60%, indicating that the composite aerogel photocatalytic material has good cycle stability and a long service life.

[0024] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. The above embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for preparing a TiO2 / polyester composite aerogel photocatalytic material, characterized by comprising the following steps: It comprises the following steps: ​ S1, the polyester fabric is ground by crushing to obtain polyester microparticles; S2, the polyester microparticles are treated by amination using allylamine, then filtered and dried for standby, to obtain modified polyester powder; S3, silane coupling agent KH550 and nano-TiO2 are put into water, stirred, then the modified polyester powder is added, ultrasonic dispersed, to obtain a mixed solution; S4, to the mixed solution, add glycerol triglycidyl ether, stir at 60℃ for 10min, and place at 60℃ for more than 2h to make it gelatinize, then freeze-dried, to obtain TiO2 / polyester aerogel composite photocatalytic material.

2. The preparation method of the TiO2 / polyester composite aerogel photocatalytic material according to claim 1, characterized in that: The crushing process of the polyester fabric in S1 is as follows: the polyester fabric is cut into 10*10mm blocks, then crushed by a crusher for 5min; the crushed polyester fabric is further ground by a nanometer ball mill, then passed through a 100 mesh sieve for standby.

3. The preparation method of the TiO2 / polyester composite aerogel photocatalytic material according to claim 1, characterized in that: The dosage ratio of the polyester microparticles to allylamine in S2 is 4g:10mL, the mass concentration of the allylamine is 10-30%, the amination treatment temperature is 110-130℃, and the treatment time is 5-15min.

4. The preparation method of the TiO2 / polyester composite aerogel photocatalytic material according to claim 3, characterized in that: The mass concentration of the allylamine in S2 is 20%, the amination treatment temperature is 130℃, and the treatment time is 5min.

5. The preparation method of the TiO2 / polyester composite aerogel photocatalytic material according to claim 1, characterized in that: The dosage ratio of the silane coupling agent KH550, nano-TiO2, water, and modified polyester powder in S3 is 2mL:0.04g:40mL:2g; the stirring time is 10min, and the ultrasonic dispersion time is 20min.

6. The preparation method of the TiO2 / polyester composite aerogel photocatalytic material according to claim 1, characterized in that: The dosage of the glycerol triglycidyl ether in S4 is 0.5-2mL.

7. The method according to claim 6, wherein the method comprises the following steps: 1) preparing a TiO2 / polyester composite sol; 2) preparing a TiO2 / polyester composite aerogel by a supercritical drying method; 3) preparing a TiO2 / polyester composite aerogel photocatalytic material by a calcination method. The dosage of the glycerol triglycidyl ether in S4 is 2mL.

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