Preparation of Transparent, Super-Hydrophilic and Photocatalytic Thin Film under Visible-Light via Sol-Gel/Plasma-Modification Processes

• Main Authors: Yu-Hsuan Wu, 吳宇璇
• Other Authors: Cheng-Hsien Tsai
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/gcqjg2

碩士 === 國立高雄應用科技大學 === 化學工程與材料工程系博碩士班 === 103 === Rearview mirrors allow drivers to see the rearview while operating the vehicle. However, due to attachments with air pollution on the surface of mirror, the visibility is reduced; the safety of operators and passengers will be an issue. But, if the rearview mirror has a function of self-cleaning under visible light the concern about people’s safety will be solved. Therefore, in this study high transmittance and super-hydrophilic nature of titanium dioxide - silicon dioxide film is made. And the ratio of sol-gel rw (H2O / TTIP), rc (AcAc / TTIP) is changed. By dip coating method (50mm / s), high transmittance of titania - silica films is produced. By high-temperature annealing furnace, photo catalyst of anatase type is obtained. By changes of the power of microwave plasma and the period of modification, nitrogen in TiO2-SiO2 film is instantly changed to have the effect of photo degrading in the range of visible light. The results showed that nitrogen in TiO2-SiO2 thin films quickly modified by via microwave plasma processes is super-hydrophile (Contact Angle <5∘) and had anti-fogging effect after the contact with visible light irradiation for 20 min. The transparency of modified film is about (90.9%) similar to the transmittance of clean glass. Then, we compared the ability of photo-degradation of methylene blue of unmodified and modified TiO2-SiO2 films under the visible light. According to the final result, modified TiO2-SiO2 films has the ability of photo-degradation. Especially, with the Microwave plasma power of 900W, and 1 min. modified time, the performance of photo-degradation of film is best (97.7%). By XPS analysis thin films changed by plasma had N-TiO2, TiN and TiNXOY bonds; it represented that thin TiO2-SiO2 films can be nitrogen-doped quickly with microwave plasma under atmospheric pressure. With SEM, it showed that the film surface was smooth and particle size is about 25-35 nm. But, with longer period of plasma modification, the power of microwave plasma was increased, particle size became smaller and thickness became thinner. By AFM analysis, root mean square roughness of the film is about 0.16 ~ 0.40 nm. With the method of pencil hardness (8H) and adhesion rating test (5B), the result showed that the film had great mechanical properties.