杂多酸-钛凝胶-聚乙烯基吡咯烷酮复合材料的制备与性能

Preparation and structure on heteropoly acids-TiO_2 colloid-polyvinylpyrrolidone composites

以原位复合溶胶-凝胶新型制备方法,利用不同相对分子质量乙烯基吡咯烷酮预聚物产生的位阻效应阻碍钛凝胶团聚,将具有Keggin结构的磷钨酸和磷钼酸分别嵌入钛凝胶中制备杂多酸-钛凝胶-聚乙烯基吡咯烷酮复合材料。利用傅里叶红外分析仪、X线衍射仪和紫外-可见分光光度计对所制备材料的结构和性能进行分析,结果表明:复合材料中保留着部分Keggin结构,其大部分已经消失,形成新的晶体结构;在紫外光的照射下,复合材料由淡黄色变为蓝色,经过20min光照后仍未饱和,之后,将材料置于无光的环境中,其很快变回淡黄色。

Composites of Keggin structured H3WP12O40 or H3PMo12O40, TiO2 colloid, Polyvinylpyrrolidone（PVP） were prepared by in-situ sol-gel method, and PVP with different relative molecular mass were used to prevent the crystallization of TiO2 colloid by its space steric effect. The structure and property of the materials were studied via IR, XRD and ultraviolet-visible （UV-vis） spectrophotometer. The results show that part of the Keggin structure is still retained in the composites though most of that have disappeared, and new crystal structure is formed. In addition, the color of the composites changes from light yellow to blue, and doesn’t reach saturation degree after ultraviolet irradiation for 20 min. Meanwhile, when it is moved to the dark environment, the composites return to light yellow soon.