具有光催化性能的温敏复合凝胶聚(N-异丙基丙烯酰胺)/纳米TiO_2的制备及表征

Preparation and Characterization of Thermosensitive Photocatalyst: Poly(N-isopropylacrylamide)/Nano-TiO_2 Hydrogel

采用掺杂法制备具有光催化性能的聚(N-异丙基丙烯酰胺)/纳米TiO2温敏复合凝胶,利用凝胶的温敏性改善纳米TiO2的可回收性。研究TiO2负载率对复合凝胶的微观形貌、化学结构、吸水溶胀性及光催化性能的影响。结果表明:该复合凝胶具有均匀的微观多孔结构,纳米TiO2负载于复合凝胶孔结构内壁,未参与N-异丙基丙烯酰胺的聚合反应,对复合凝胶的化学结构和温敏性没有影响,各负载率复合凝胶的体积突变温度均为33℃,但复合凝胶的吸水溶胀性和光催化性能会随TiO2负载率的变化而变化。光催化实验证明:该复合凝胶的光催化性能随TiO2负载率的提高而增强;负载率50%的复合凝胶,在15W紫外灯作用下,4 h内对100 mg/L活性蓝X-BR的降解率达90%以上。最后对紫外光照射后的复合凝胶样品进行红外分析和热重分析,证明经反复紫外光照射后的复合凝胶不会发生明显降解,凝胶高分子化学结构没有显著变化。

In this paper,poly（N-isopropylacrylamide）/Nano-TiO2 hydrogel,a kind of thermosensitive photocatalyst,is prepared in doping method.The influence of the nano-TiO2 to the microstructure,chemical constitution,swelling ratio and the photocatalysis of the hydrogel is studied.The result indicates that the hydrogel has well-proportioned vesicular structure where the nano-TiO2 loads.And the nano-TiO2 didn＇t react with N-isopropylacrylamide,so the chemical constitution and thermosensitive properties of poly（N-isopropylacrylamide） hydrogel are not influenced,and the LCST is 33℃.However,the swelling ratio and photocatalysis properties of the hydrogel change with nano-TiO2 loading ratio.The experimentation indicates that the photocatalysis of the hydrogel will be improved as the nano-TiO2 loading ratio enhances.For example,100mg/L reactive dye X-BR will be degraded as a degree as 90 percent by the hydrogel whose nano-TiO2 loading ratio is 50% under 30W UV lamp in 4h.Furthermore,FTIR and TGA are operated to evaluate the hydrogel which is radiated by UV lamp.It proves that the hydrogel possesses so good chemical stability that it can not be degraded by nano-TiO2,so that the hydrogel can be used many times,and the problem about the recycle of the nano-TiO2 is improved.