Study on formation process of chromate-varnish double coating for corrosion protection on brass silic

Abstract

Alumina were synthesized by using the sol-gel. In order to study the gel aging effect, Samples were aged for 1. 5, 15 and 30 days. The products obtained were characterized with X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) with pyridine adsorption, nitrogen physisorption, TG-DTA and by their catalytic activity for cyclohexene isomerization. The specific surface area of the sample aged for 30 days was 346 m²/g and it present. The highest catalytic activity for cyclohexene isomerization whereas the lowest activity obtained with the sample aged for 1 day. The intrinsic activity correlated linearly with the Lewis acid site density.