二氧化钛复合纳米静电纺纤维膜的制备及其光催化降解甲苯性能研究

发布时间：2018-04-12 15:47

本文选题：光催化 + 静电纺丝　；参考：《上海师范大学》2017年硕士论文

【摘要】：挥发性有机污染气体(VOCs)是室内污染物的主要成分,它主要包括苯、甲苯、苯乙烯和甲醛等,长期暴露其中,可对人体产生急性或慢性毒性,室内环境污染问题已引起了人们的普遍关注。光催化技术可以将污染物降解为无毒无害的二氧化碳和水,因此成为处理挥发性有机气体研究最多的技术。光催化剂TiO_2是使用最为频繁的光催化剂,但目前制备出的TiO_2大都为纳米颗粒形态,在使用时易团聚造成光催化性能的降低,使用后难以回收,实际使用潜能较低。因此,如果能将TiO_2做成兼具有较大比表面积并且二维连续形态的纳米纤维材料或将其复合于纳米纤维中,使其呈现膜状结构,那么它将具有较高的实际使用价值。静电纺丝是目前唯一可以制备纳米尺寸的连续长纤维的技术,具有设备简单、操作灵活方便、成本低廉、适用材料范围广泛等优点,因此,近些年静电纺丝技术被越来越多地应用于TiO_2纳米纤维材料的制备。本论文主要的研究内容如下所述:(1)静电纺丝/静电喷雾方法制备TiO_2及其性能对比研究(纺丝条件探究)纺丝液中高聚物的浓度是电纺能否成丝的关键,在本实验中通过控制纺丝液中PVP(MW=58000)的浓度制备出不同的TiO_2前驱体电纺溶液,PVP含量低的在高压下只能产生喷雾颗粒,当PVP浓度达到一定值时才能电纺成丝。将电喷雾和电纺丝后得到的产物经高温焙烧后即可得到颗粒状和短棒状的TiO_2,并对其形貌、物相结构和光催化降解甲苯性能进行了对比。(2)TiO_2/聚酰亚胺(PI)复合纳米纤维的制备及性能研究通过同步静电纺PAA和PVP/TiO_2前驱体纺丝液然后高温焙烧的方法得到膜状的TiO_2/PI复合纳米纤维,PI纤维与TiO_2纤维交错分布,TiO_2纤维赋予材料光催化性能,PI纤维为材料提供结构加固的作用并提高了纤维膜的机械性能。探究了材料的形貌、结构、机械性能和光催化性能与复合比例的关系。(3)TiO_2/PAN复合纳米纤维膜的制备及性能探究通过同步静电纺PAN和静电喷雾TiO_2颗粒的方法制备了TiO_2/PAN复合纤维膜,在复合纤维膜中TiO_2颗粒均匀地附着于纤维的表面,探究了复合纤维膜的形貌、结构、光催化降解甲苯气体和空气过滤粉尘的性能与复合比例的关系。实验结果表明本论文利用静电纺丝技术制备出的两种含有TiO_2的复合纳米纤维膜,在有效净化空气的同时实现自身的回收利用,为提高TiO_2的实际使用价值提供了可能的解决方案。
[Abstract]:Volatile organic pollutants (VOCs) are the main components of indoor pollutants. They mainly include benzene, toluene, styrene and formaldehyde.The problem of indoor environmental pollution has aroused widespread concern.Photocatalytic technology can degrade pollutants into non-toxic and harmless carbon dioxide and water, so it has become the most widely studied technology for the treatment of volatile organic gases.Photocatalyst TiO_2 is the most frequently used photocatalyst, but at present, most of the prepared TiO_2 is nano-particle morphology, easy to agglomerate in the use of the degradation of photocatalytic performance, difficult to recover after use, the actual use of low potential.Therefore, if TiO_2 can be made into nanofiber materials with large specific surface area and two-dimensional continuous morphology, or composite into nanofibers to present membrane structure, then it will have higher practical value.Electrostatic spinning is the only technology that can produce nanoscale continuous long fibers. It has the advantages of simple equipment, flexible operation, low cost, wide range of materials and so on.In recent years, electrostatic spinning technology has been used more and more in the preparation of TiO_2 nanofibers.The main contents of this thesis are as follows: (1) preparation of TiO_2 by electrostatic spinning / electrostatic spray method and comparative study of its properties (study of spinning conditions) the concentration of polymer in spinning solution is the key to the formation of silk by electrospinning.In this experiment, by controlling the concentration of PVP / MWN 58000 in spinning solution, different TiO_2 precursor electrospinning solution (PVP) with low content can only produce spray particles at high pressure. When the concentration of PVP reaches a certain value, it can be electrospun into silk.After calcination of the products obtained by electrospray and electrospinning, the granular and short rod tio _ 2s can be obtained and their morphology can be obtained.Phase structure and photocatalytic degradation of toluene the preparation and properties of TIO _ 2 / polyimide _ Pi composite nanofibers prepared by simultaneous electrospinning of PAA and PVP/TiO_2 precursors and then calcined at high temperature to obtain membrane TiO_2/PIThe composite nanofiber Pi fiber and TiO_2 fiber interlaced the TiO2 fiber to give the material photocatalytic properties and Pi fiber to provide structural strengthening effect and improve the mechanical properties of the fiber membrane.The relationship between the morphology, structure, mechanical properties, photocatalytic properties and the ratio of composite materials. The preparation and properties of nano-fiber films composed of TiO-2 / pan nanofibers were studied. TiO_2/PAN composite fiber membranes were prepared by synchronous electrospinning of PAN and electrostatic sprayed TiO_2 particles.TiO_2 particles were uniformly attached to the surface of the composite fiber membrane. The relationship between the morphology, structure, photocatalytic degradation of toluene gas and air filtration dust and the composite ratio was investigated.The experimental results show that two kinds of composite nanofiber membranes containing TiO_2 prepared by electrostatic spinning technology can effectively purify the air and realize their own recycling, which provides a possible solution for improving the practical use value of TiO_2.
【学位授予单位】：上海师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X701

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