Ceramics-Silikáty 46 (2) 49-51 (2002)

CORROSION OF SiO₂ AND TiO₂ SOL-GEL LAYERS IN WATER AND DILUTED HCl

A. Gryčová, G. Kejmarová, J. Matoušek

In the preparation of sol-gel layers based on SiO₂ and TiO₂, use was made of alkoxides (tetraethoxysilane and tetrabutoxytitanium), which were hydrolysed with distilled water under the catalytic effect of HCl. The layers were applied on glass by the dip coating method. Following the drying of applied layers and their final heat treatment, their resistance to the effects of distilled water (pH = 6.1) and to aqueous solution of HCl (pH= 2.2) was studied by determining the content of sodium ions and silica in the leachates. The data obtained were compared with the values corresponding to untreated glass surface. It was found that the sol-gel surface layers reduce significantly the content of sodium ions and silica in leachates produced by the effect of the aggressive solutions. The anticorrosive protective effect in acid media depends on the composition of the coating. The best protection was provided by the silica layer, while the layers based on titanium dioxide were less effective.
 

Keywords: Glass corrosion, Sol-gel, Glass surface layers