T. Kyprianidouleodidou et al., POLYMER SHEETS WITH A THIN NANOCOMPOSITE LAYER ACTING AS A UV FILTER, Polymers for advanced technologies, 8(8), 1997, pp. 505-512
A surface layer (thickness 1-10 mu m) containing colloidal TiO2 or ZnO
particles was prepared in EVA (a copolymer of ethylene and vinyl acet
ate). The inorganic particles were formed in situ by hydrolysis of inc
orporated titanium tetrachloride or diethyl zinc. The resulting materi
als were analyzed with UV spectroscopy, electron microscopy, X-ray dif
fraction, thermogravimetric analysis and atomic emission spectroscopy.
The average diameter of the embedded TiO2 particles was 70 nm; these
particles absorb UV radiation but also induce opacity in the polymer s
heets in the visible wavelengths range. The ZnO particles were smaller
(average diameter 15 nm); with a surface layer of embedded ZnO, trans
parent polymer sheets can be obtained that absorb UV radiation. (C) 19
97 by John Wiley & Sons, Ltd.