Yanhua PANG
,
Wei FENG
,
Jie CHEN
,
Yan LIU
,
Weimin CAI
材料科学技术（英文）
A series of inorganic-organic thin films based on uniformly dispersed nanoparticles of polyoxometalates (POM) entrapped in polyacrylamide (PAM) matrix were prepared by ultrasonic method with different irradiation time. The microstructure, photochromic behavior and mechanism of the films were studied by transmission electron microscopy (TEM), ultraviolet-visible spectra (UV-VIS) and Fourier transform-infrared spectroscopy (FT-IR). The microstructure and photochromic properties of the hybrid thin films could be controlled by ultrasound. TEM image revealed that the average size of phosphotungstic acid (PWA) nanoparticles decreased from 20 to 10 nm with the ultrasound irradiation time from 30 to 60 min. After irradiated with ultraviolet light, the transparent films changed from colorless to blue and showed reversible photochromism. The hybrid film, with ultrasound irradiation for 60 min had higher photochromic efficiency and faster bleaching reaction than the one with ultrasound irradiation for 30 min. FT-IR spectra showed that the Keggin geometry of heteropolyoxometalate was still preserved inside the composites, and the interactions between polyanions and polymer matrix increased as the ultrasound time prolonged. It is suggested that the mechanism of the different photochromic properties for the inorganic-organic thin films is the variation of the microstructure and interfacial interactions induced by ultrasound.
关键词:
sonochemical
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null
,
null
,
null
Chuanli QIN
,
Dongyan TANG
,
Jun CAI
,
Jusheng.ZHANG
,
Weimin CAI
,
Xiaodong SUN
材料科学技术（英文）
Polyurethane/(vinyl ester resin) interpenetrating polymer network (PU/VER IPN) materials with broad temperature ranges and excellent damping properties from low temperature to room temperature were prepared. The influence of comonomers and component ratios on the compatibility and damping properties of IPN materials was studied by DMA which indicates that such properties are improved by introducing acrylic esters instead of polystyrene (PSt) into VER comonomer system. The detected results of microstructure by AFM show that the phase ranges of the dual-phase continuous IPN materials obtained are both in nanometer scale. The results of mechanical properties show that IPN materials show the regulation from elastic deformation to brittle deformation with the increase of VER
proportion.
关键词:
Interpenetrating polymer network
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null
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null
,
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