奈米二氧化鈦光觸媒對陶瓷坯體中之高分子黏結劑PVB光裂解探討

Investigation of PVB binder photo-degradation by nano-Titanium photo-catalyst in green ceramic body

童明德(Ming-Te Tung)

指導教授 ： 廖朝光

元智大學/工程學院/化學工程與材料科學學系/碩士(2005年)

摘要

本研究探討高分子黏結劑聚乙烯醇縮丁醛（poly(vinyl butyral), PVB）和奈米二氧化鈦複合薄膜經光催化分解之固相光催化反應。藉由TGA測得PVB經光催化分解之反應速率，再由傅立葉散射－反射紅外光譜技術（Diffuse Reflectance Infrared Fourier Transform Spectroscopy, in situ DRIFTS）及Gas-Cell分析其反應機構，最後由SEM及AFM分析PVB/TiO2複合薄膜的表面結構變化。
　　實驗結果成功的分解掉高分子黏結劑PVB，並提出PVB經光催化分解之反應動力分析，且由反應物及產物之FTIR光譜圖，推測出固相光催化分解PVB之反應機構。且發現當組成中TiO2的重量比例增加時、樣品之紫外光照射距離離燈管越近時、塗佈成較薄的薄膜時、使用玻璃基材和在反應時通入水氣，皆能提高PVB被光催化分解的反應速率，而預先加熱處理溫度不同時，PVB被光催化分解的反應途徑皆有所不同。

關鍵字

聚乙烯醇縮丁醛 ； 固相光催化 ； 二氧化鈦 ； 光觸媒

並列摘要

Solid-phase photocatalytic degradation of PVB (poly(vinyl butyral)) with nano-TiO2 as photocatalyst was investigated in the room temperature under ultraviolet light irradiation. Kinetic parameters of the composite sample were estimated by thermogravimetry (TG) measurements. Solid-phase photocatalytic reaction mechanism of PVB/TiO2 sample is conducted by diffuse reflectance Fourier transform spectroscopy (DRIFTS). The morphologies of irradiated PVB/TiO2 samples were carried out by using scanning electron microscope (SEM) and atomic forces microscope (AFM) analysis.
Results revealed that photo-degradation of PVB binder are removable. The kinetic analysis of the PVB photo-degradation was carried out. The PVB photo-degradation experiments exhibit that higher composition of TiO2, near distance of UV lighting; thinner coating films and the use of glass substrate can accelerate the degradation rate. In addition, the PVB photo-degradation rate can be increased when wet air condition was applied. Furthermore, the degradation mechanism was proposed from the analytical results.

並列關鍵字

solid-phase ； photocatalytic degradation ； PVB ； TiO2