Modification of submicron barium titanate particles via sol-gel synthesis of interface layers of SiO2 for fabrication of polymer-inorganic composites with improved dielectric properties

Modification of the surface of submicron BaTiO₃ particles by SiO₂ layer using sol-gel method has led to significant (>50%) increase in the dielectric permittivity and decrease in the dielectric losses of the composites prepared via introduction of BaTiO₃ into a matrix of poly(vinyl alcohol) cyanoethyl ester. The effect has been due to the formation of basic hydroxy groups (Brønsted centers) at the filler surface; these groups can interact with weakly acidic hydroxyl groups of poly(vinyl alcohol) cyanoethyl ester, thus improving the compatibility of the polymer matrix and the filler.