【作者】 何晓囡；

【导师】 徐瑞芬；

【作者基本信息】 北京化工大学 ， 应用化学， 2005， 硕士

【摘要】 通过对多种改性剂的筛选,得出对纳米TiO₂表面亲油改性效果最佳的为超分散剂C。采用超分散剂C对纳米TiO₂粉体进行表面改性,可将超分散剂C分子成功地包覆于TiO₂表面,对TiO₂表面进行非极性修饰,使其表面由极性亲水性变为非极性亲油性。由沉降性实验观测到超分散剂改性后的纳米二氧化钛粒子可以在非极性溶液中稳定悬浮960h以上;透射电镜（TEM）观测到改性后的二氧化钛粒子在非极性溶剂中呈纳米级分散状态,团聚体的粒径基本控制在100nm以内;通过润湿性测试及红外分析观察到颗粒表面由亲水性变为疏水性,纳米TiO₂颗粒表面增加了-CH₂-和C=O-O基团键的振动峰,因而可以判断纳米TiO₂表面状态发生了改变,使TiO₂与非极性材料具有较好亲和相容性。并且得出超分散剂的最佳用量为6%;最佳改性时间为1h;最佳改性温度为75℃;最佳分散溶剂为溶剂甲。 采用聚合物的原位聚合法改性纳米TiO₂,制备出纳米TiO₂/硅丙复合乳液。由透射电子显微镜观察到纳米TiO₂/硅丙复合乳液胶膜中纳米颗粒呈较好的分散状态,达到了纳米尺寸。通过分光光度分析方法,测得该膜在200～400nm紫外光光波范围吸收强度大于2.O,在可见光光波范围有明显的光吸收。杀菌实验测试结果为:该乳液对枯草杆菌黑色变种芽孢、大肠杆菌和金黄色葡萄球菌的杀灭率达到98%以上;更多还原

【Abstract】 Hyper-dispersant C is the best modifier by selecting from many kinds of different modifiers. After nano-TiO2 is modified by hyper-dispersant C, non-polar decorate surface of TiO2 through adsorb hyper-dispersant molecule to surface of TiO2, so surface of TiO2 changed from polarity and hydrophilic to non-polar and hydrophobic. The result shows that the modified TiO2 can steady suspend more than 960h in non-polarity solvent, the TEM shows the modified TiO2 particles are nanometer and whose average size is almost less than lOOnm. Wetting test and the FT-IR show TiO2 particles have been changed from hydrophilic to hydrophobic, and vibration peaks for - CH2- and C=O-O appear in infrared spectrum of modified TiO2, which show surface states of TiO2 have been changed, and TiO2 can excellent consist with non-polar material. The experiment foundthat the best dosage of hyper-dispersant C is 6%, the best modified time is lh, the best modified temperature is 75 ℃ and the best disperse solvent is Jia.Nano-TiO2 is modified by in-situ polymerization, and at the same time nano-TiO2/silicon-acrylic composite emulsion is prepared. The result of TEM shows that nano-TiO2 particles in silicon-acrylic emulsion were better dispersed and its measure is nanometric. The spectrophotometric determination showed that nano-TiO2/silicon-acrylic composite emulsion, whose ultraviolet absorption is over 2.0 in 200~400nm, and whose light absorption is obvious in visible region. Sterilization test showed: the killing rate of Bacillus subtilis var. niger, Staphylococcus aureus and Escherichia coli are over 98%, and hepatitis B antigen (HbsAg) can be changed from positive to negative after 8h. So we can conclude that nano-TiO2/silicon-acrylic composite emulsion film has obvious photocatalysis and transforms energy of light into chemical energy with antibacterial and antivirotic.更多还原