PVA／TMPS／TiO2奈米複合材料之合成及其物性研究

Synthesis and Properties of PVA/TMPS/TiO2 Nanocomposites

本研究成功的利用溶膠—凝膠法合成出PVA／TMPS／TiO2奈米複合材料，而合成出之材料有良好之耐熱性、高透光性、遮蔽紫外光能力和光降解能力。首先先利用pH＝2.0之酸性水溶液將TMPS矽氧烷偶合劑水解成矽醇（silanol）中間物，使無機TiO2粉末經有機改質化反應，使之能成功地共價鍵結在有機基材上，接著將TMPS／TiO2複合物上的-OH活性官能基與有機PVA基材上之-OH活性官能基，進行縮合脫水反應合成出PVA／TMPS／TiO2奈米複合材料。利用IR光譜儀的實驗結果，來確定反應的最佳的條件及組成配方比例，接著利用TGA量測材料之熱性質、UV-Vis光譜儀來檢測其透光性質及對染料之光催化降解能力、利用FE-SEM來觀察其表面之形態學、以及利用硬度計來測試薄膜之硬度、利用表面電阻儀來測量薄膜之表面電阻。實驗結果顯示，本研究所合成之複合材料其透明度可以達到90％以上，耐熱性質Td點提升到276.14°C，較純PVA的256.54°C提升約20°C，薄膜硬度從3H提升至6H，表面電阻由2.15x1010 Ω／cm2降為2.13x109 Ω／cm2，由FE-SEM觀察其形態學，確認無機TiO2粉末均勻的分布在有機PVA基材中，且無機微粒平均粒徑約在40nm左右，符合奈米複合材料的範圍。最後將此奈米複合薄膜進行光催化降解染料的測試，成功的降解亞甲基藍及甲基紅。

This research is to synthesize PVA/TMPS/TiO2 nanocomposites with good heat resistance, UV-shielding, high transparency and photocatalytic degradation by sol-gel methods. At the first, the TMPS was performed to the silanol intermediate by hydrolysis in acid solution of pH=2. In order to couple with the organic matrixes the inorganic TiO2 powder was modified by silanol. The active -OH functional groups of TMPS/TiO2 and organic PVA matrixes will progress condensation with each other to synthesize PVA/ TMPS/TiO2 nanocomposites. The chemical bonding formation and the best weight contents of reaction components were identified by FT-IR spectra. The thermal resistance, optical transmittance and the ability of photocatalytic degradation, morphology of surface, surface resistance, and hardness of these nanocomposites were measured by TGA, UV-Visible, FE-SEM, super megohmeter and hardness tester respectively. Experimental results showed that these hybrid films had over 90% transmittance and the best Td value of 276.14°C was 20°C higher than the Td value of 256.54°C for PVA. The hardness of these hybrid films was improved from 3H to 6H. The surface resistance of these hybrid films were decreased from 2.15x1010 Ω/cm to 2.13x109 Ω/cm2 . The morphology of hybrid films were estimated by FE-SEM. The results of FE-SEM showed that the inorganic TiO2 powder were well distributed throughout the PVA matrixes and the average particles size of these nanocomposites were about 40nm. Finally, the tests of photocatalytic degradation of methylene blue and methyl red with these hybrid films was successful.