Mechanisms Involved in the Deposition of Coatings from Aqueous Colloidal Suspensions of Silica in an Electric Field

Although several processes have been developed to obtain ceramic coatings, many of them are complex, and expensive equipment is required. As an alternative process, in this work, electrodeposition was used to deposit silica on stainless steel substrates. The properties of commercial silica were changed by adding some chemical compounds. Potassium hydroxide was added to promote, in a controllable way, the formation of a silicate network to obtain good adherence on metallic substrates. The addition of reagents caused controlled destabilization on suspension and promoted the formation of clusters. The application of an electric field to obtain coatings allowed the orientation of charged particles and, hence, the properties of the deposited material to be modified. Electrokinetic parameters, electrical response, and GDS profiles were measured to determine the influence of electric field on the coatings.