Photochromic behavior and mechanism of thin films in H3PW12O40/polyacrylamide system

被引:22
作者
Feng, W
Zhang, TR
Wei, L
Lu, R
Bai, YB
Li, TJ
Zhao, YY [1 ]
Yao, JN
机构
[1] Jilin Univ, Dept Chem, Changchun 130023, Peoples R China
[2] Chinese Acad Sci, Inst Chem, Ctr Mol Sci, Beijing 100080, Peoples R China
基金
中国国家自然科学基金;
关键词
H3PW12O40; polyacrylamide; photochromism; photoreduction;
D O I
10.1016/S0167-577X(01)00583-3
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
A new photochromic film was prepared based on the Keggin type H3PW12O40 (PW12) with polyacrylamide (PAM) matrix. The microstructure, photochromic behavior and mechanism were investigated with FT-Infrared spectroscopy (FT-IR), atomic force microscopy (AFM), transmission electron microscopy (TEM), ultraviolet-visible absorption spectroscopy (UV-VIS), and electron resonance spectroscopy (ESR). FT-IR results showed that the Keggin geometry of PW12 was still preserved inside the matrix, and a charge-transfer bridge was built between PW12 and PAM via hydrogen bond. AFM images indicated that the surface topography of the polymer matrix changed after adding PW12. In the hybrid films, the PW12 particles had regular microstucture in nanoscale shown in TEM image. Under UV irradiation, the film was reduced photochemically to yield a blue species. With the increase of irradiation time, the photoreduction proceeded from one-electron to two-electron blue stage. The characteristic signals of W (V) and radical in ESR spectra indicated that the photoreduced process was in accordance with the radical mechanism. (C), 2002 Elsevier Science B.V. All rights reserved.
引用
收藏
页码:309 / 313
页数:5
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