Preparation and characterization of tungsten／silica／urea-formaldehyde resin multiful-component composite materials
LI Guo-liang, FENG Pan-pan, LI La-ai, LIU Rong-rong, ZHANG Ying*
(Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education;College of Chemistry and Materials Science, Shaanxi Normal University, Xi′an 710062, Shaanxi, China)
Abstract:
The SiO2 layer coated on the tungsten powders (W/SiO2) by the sol-gel technique was firstly carried out. After modification of (3-aminopropyl)-triethoxysilane (APTES) onto the W／SiO2 particle surface, W／SiO2／UF multi-component composites with core-shell structures were fabricated via polycondensation between formaldehyde and urea under acidic condition. The morphologies, the structures and the composition of composite materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectrometer (FT-IR) techniques. The conductivity of the prepared composite materials significantly decreased from 1.7×10－3 S/m to 1.2×10-8 S/m, after coating of urea-formaldehyde resin layer on the surface of W/SiO2. It was showed that the prepared W／SiO2／UF multi-component composites are of the quite full and dense coating layer, and the conductivity is nearly close to the insulating materials.
KeyWords:
core-shell materials; tungsten powder; silica; urea-formaldehyde resin
