Photochromic polyoxotungstoeuropate K12[EuP5W30O110]/polyvinylpyrrolidone nanocomposite films
2003; Elsevier BV; Volume: 172; Issue: 2 Linguagem: Inglês
10.1016/s0022-4596(03)00036-7
ISSN1095-726X
AutoresTierui Zhang, Ran Lu, Xin Li Liu, Ying Zhao, Tie Jin Li, Jian Yao,
Tópico(s)Transition Metal Oxide Nanomaterials
ResumoA novel photochromic nanocomposite film containing polyoxotungstoeuropate K12[EuP5W30O110] entrapped in polyvinylpyrrolidone has been prepared through a spin-on coating technique. Thus-obtained amorphous nanocomposite film was characterized by IR spectra, UV–vis absorption spectra, XRD, SEM, TG-DTA, and ESR. Results show that polyoxotungstoeuropate interacts with polyvinylpyrrolidone strongly and disperses homogeneously in the matrix. The composite film exhibits good photochromic properties. When irradiated with UV light, the transparent film changes from colorless to blue. Then, bleaching occurs when the film is in contact with ambient air or O2 in the dark. The photochromism of the composite film is due to charge transfer by reduction of polyoxotungstoeuropate and oxidation of polyvinylpyrrolidone.
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