CONDUCTIVE COATING BY SOL-GEL

Abstract

Purpose: The objective is to coat insulating substrates to transform in conductors, using the method sol-gel and the technique dip-coating . Methods: The conventional sol-gel methodology was used, the precursor solution for the coating is composed of H 2 O, isopropyl alcohol, tetraethylorthosilicate and surfactant CTAB. The reagents were agitated for 30 min, the coatings were performed through by process dip-coating. In each plate was performed only 1 deposition and after went in an oven at 100o C for 120 seconds. The rate of deposition speed from 50 to 200 mm/min, and the immersion time was 120 to 600 seconds. With a solution of silver nitrate of concentration 2.10 -1 mol.L -1 , were realized 5 depositions, at the speed of 100 mm/min, with 120 seconds immersion, on all 5 plates by process dip-coating , subsequently the plates were submitted to an ultraviolet light by 600 seconds to realize the reduction of silver. For the electrical conductivity test, was used a voltage source of 10V, applied to the circuit three resistors 450 Ω in parallel, and the plates in series with the resistors. The presence of metallic silver in coatings was confirmed through electronic spectra. Results: The spectra in the region of UV-Vis presented bands in the region of 400 nm, confirming the presence of metallic silver in the order of 20 nm. Conclusion: Despite containing silver in the films, was not enough to conducts electric current, the films of CTAB presented bubbles on the surface of the glass, so a study concerning the solution deposition process should be performed so the film has aspect homogeneous.