本文選題：溶膠-凝膠法 + 靜電紡絲　； 參考：《華南理工大學(xué)》2010年碩士論文

【摘要】： 二氧化鈦因其在光照下化學(xué)性質(zhì)穩(wěn)定,對生物無毒性,無二次污染,且能有效地降解各種有機污染物,已然成為環(huán)境污染治理技術(shù)的研究熱點。常規(guī)懸浮相光催化體系存在著分散性差、顆粒易團聚、回收困難等問題,極大地限制了其在廢水處理中的實際應(yīng)用。因此,對二氧化鈦光催化劑的負載固定化成為光催化劑今后發(fā)展的趨勢。本文利用一步溶膠凝膠法結(jié)合靜電紡絲技術(shù)制備出二氧化鈦自支撐纖維氈,兼具催化劑活性組分與基體組分雙重身份,不僅具有高的光催化活性,還容易回收,具有一定的應(yīng)用前景。 本論文以鈦酸丁酯與乙酸為反應(yīng)原料,采用一步溶膠-凝膠法,通過原位酯化反應(yīng)緩慢釋放水,實現(xiàn)鈦源的均勻水解,生成含鈦的線性大分子,獲得具有一定可紡性的溶膠體系,通過摻雜不同量的正硅酸乙酯,制備含硅二氧化鈦纖維溶膠體系。利用錐板流變儀系統(tǒng)研究溶膠體系的粘度變化,靜電紡絲成型設(shè)備研究溶膠體系可紡性并制備二氧化鈦及其硅摻雜微/納米纖維氈,并利用掃描電子顯微鏡研究所得纖維的形貌,結(jié)果發(fā)現(xiàn):在鈦酸丁酯與乙酸質(zhì)量之比為1:2.5,反應(yīng)溫度為50℃時,溶劑體系可紡性最佳的反應(yīng)時間為84h左右。摻雜硅對二氧化鈦前驅(qū)體纖維直徑有細化作用,且摻雜量越大細化作用越明顯。固定硅摻雜量為5 mol %,當(dāng)供液速率從2.33mL/h增大至原來的兩倍、四倍甚至八倍時,硅摻雜纖維比未摻雜纖維直徑減小3%至30%不等。 探討了硅摻雜對二氧化鈦纖維晶型與晶粒尺寸的影響。由TG-DSC分析可得在摻硅二氧化鈦前驅(qū)體纖維熱處理過程中,前驅(qū)體纖維的有機組分的脫除變得緩和,二氧化鈦的結(jié)晶行為在更高溫度下才發(fā)生。根據(jù)TG-DSC結(jié)果在質(zhì)量與熱量變化較快的溫度段設(shè)置較慢的升溫速率,在質(zhì)量與熱量變化不明顯的階段設(shè)置較快的升溫速率。樣品經(jīng)煅燒后,采用XRD研究不同加熱溫度、不同摻硅量的二氧化鈦的晶型與晶粒尺寸,發(fā)現(xiàn)摻雜硅使二氧化鈦從銳鈦礦到金紅石礦的晶型轉(zhuǎn)變溫度從800℃提高到900℃,晶粒的生長也受到抑制。用氮氣吸附法對摻硅二氧化鈦纖維的比表面積與孔結(jié)構(gòu)進行了表征,摻硅量為5%的樣品比表面積較大,介孔結(jié)構(gòu)較發(fā)達。 以亞甲基藍為目標(biāo)降解物,系統(tǒng)研究熱處理溫度與摻硅量對二氧化鈦光催化活性的影響,結(jié)果發(fā)現(xiàn),不摻硅的樣品在熱處理溫度為700℃時表現(xiàn)出最高的光催化活性,而摻硅的樣品則在600℃活性最高。摻雜硅后二氧化鈦樣品的光催化活性均得到提高,其中摻硅量為5%時光催化活性最佳,摻硅量進一步增加活性反而降低。
[Abstract]:Because of its stable chemical properties under light, no toxicity to biology, no secondary pollution, and effective degradation of various organic pollutants, titanium dioxide has become a research hotspot in environmental pollution control technology. The conventional suspended phase photocatalytic system has some problems such as poor dispersion, easy agglomeration of particles and difficult recovery, which greatly limits its practical application in wastewater treatment. Therefore, the immobilization of titanium dioxide photocatalyst has become the trend of photocatalyst development in the future. In this paper, TIO _ 2 self-supporting fiber felt was prepared by one-step sol-gel method combined with electrostatic spinning technology. It has the dual identity of active component of catalyst and matrix component, which not only has high photocatalytic activity, but also can be easily recovered. It has a certain application prospect. In this paper, using butyl titanate and acetic acid as raw materials, a one-step sol-gel method was used to slowly release water through in-situ esterification reaction to realize homogeneous hydrolysis of titanium source and to form titanium linear macromolecules. The sol system with certain spinnability was prepared by doping different amounts of ethyl orthosilicate to prepare the silica fiber sol system. The viscosity change of sol system was studied by cone plate rheometer, the spinnability of sol system was studied by electrostatic spinning equipment, and titanium dioxide and silicon doped micro / nano fiber felt were prepared. The morphology of the fibers was studied by scanning electron microscope. The results showed that the optimum reaction time for the spinnability of the solvent system was about 84 h when the mass ratio of butyl titanate to acetic acid was 1: 2.5 and the reaction temperature was 50 鈩，

本文編號：1918228