镶嵌钨硅酸的新型有机-无机纳米复合薄膜的制备及光致变色性能研究  

Synthesis and Photochroism of a Novel Organic-inorganic Nanocomposite Film Entrapping Tungstosilicate Acid

作　　者：黄焱[1] 潘庆谊[1] 程知萱[1] 张雯[1] 夏崴[1] 

机构地区：[1]上海大学理学院化学系,上海200436

出　　处：《高等学校化学学报》2005年第2期204-208,共5页Chemical Journal of Chinese Universities

基　　金：上海市纳米专项基金 (批准号 :0 45 2 nm0 73 )资助

摘　　要：将超分子自组装技术与 Sol-gel过程相结合 ,制备了镶嵌 Keggin结构钨硅酸的 MAAM/VTEOS/TEOS纳米复合薄膜 ,并采用 IR,XRD和 TG-DSC等方法对薄膜进行了结构表征 .在复合薄膜光照变蓝后 ,通过 UV-Vis和 ESR光谱对薄膜的光致变色性能及其机理进行了研究 .结果表明 ,钨硅酸在复合网络中仍保持 Keggin结构 ,与有机 -无机复合基体中的— NH2 通过氢键发生强烈的相互作用 ,经紫外光照后发生电荷转移 ,[Si W1 2 O4 0 ]4 -被还原为 [Si W1 2 O4 0 ]5- ,同时产生氨基自由基 .褪色过程则与氧气存在与否有关 ,实验结果表明 ,该薄膜具有良好的光致变色性能 ,对光有较快的响应恢复速度和良好的可逆重复性 .A novel photochromic organic-inorganic nanocomposite film was prepared through entrapping Keggin structure H_4SiW_ 12O_ 40 into MAAM/VTEOS/TEOS matrix by combining supramolecular self-assembly technology with sol-gel process. The composite film was characterized by IR, XRD and TG-DSC, and its photochromic behavior and mechanism were also studied and discussed. The transparent film changed from colorless to dark-blue under UV irradiation and was measured by UV-Vis and ESR spectra. The results indicate that [SiW_ 12O_ 40] 4- anions maintain Keggin structure in the composite film and interacted strongly with _NH_2 group of the matrix via hydrogen bond. After irradiation under UV light, a hydrogen atom is transferred to a [SiW_ 12O_ 40] 4- anion, and a free radical is formed at the same time. The bleaching process is closely related to the presence of O_2, and the experiments show that the composite film has excellent photochromic properties, with a short response and bleaching time and good reversibility.

关 键 词：有机-无机复合 自组装 溶胶-凝胶法 光致变色 钨硅酸 

分 类 号：O635[理学—高分子化学]