The action of molasses on properties of coatings obtained with electrodeposition from a SiO2 aqueous suspension

The effect of molasses added to a suspension on the properties of coatings obtained with electrodeposition is investigated. It is found that the combined action of molasses and an electric field makes it possible to obtain a homogeneous coating with the Si/O mass ratio constant in depth; there is no way to attain this constancy when employing an electric field only. In the absorption spectrum of coatings obtained in the presence of an electric field, a wide band is observed at 450 nm; in the process, the coating is kept transparent to the red spectral region radiation: this is responsible for its distinguishing brown coloring. The examination performed with different procedures allows one to infer that the presence of an electric field within the suspension induces the orientation of suspended particles, resulting in a greater packing density of particles forming the coating. The effect of molasses on the depth distribution of chemical elements in the coating is studied with glow discharge spectroscopy (GDS) and atomic force microscopy (AFM). In accordance with the investigations performed with these methods, the dominant chemical elements are evenly distributed in the coating obtained in the presence of an electric field. If molasses is present in the process of electrodeposition, the action of the field grows in orienting the particles, resulting in a more perfect coating structure and in upgrading of its quality.