Studies of the influence of acetate groups from polyvinyl alcohol on adsorption and electrochemical properties of the TiO2-polymer solution interface

An influence of polyvinyl alcohol molecular weight and acetate groups, pres ent in the macromolecule, on adsorption and electrochemical properties of t he TiO2-polymer solution interface was studied. Calculated thickness of ads orption layers of PVA, on the surface of the oxide, allowed assume that ace tate groups may have meaningful influence on the polymer chain conformation at the interface. Structure of macromolecules at titania-polymer solution interface was compared with that of bulk of solution. Obtained data allow d etermine the changes of the size and shape of polymer coils in the system. The results of experiments let us conclude main factors, responsible for ob served zeta potential and surface charge changes of TiO2. It was proved tha t change of the ion structure of Stern layer, depends on molecular weight a nd number of acetate groups (degree of hydrolysis) of PVA macromolecule. Po ssible mechanism of zeta potential changes was proposed as a function of pH of the solution and molecular weight of the polymer.