ZnO nanoparticle-containing emulsions for transparent, hydrophobic UV-absorbent films.

A simple method for the preparation of thin, zinc oxide nanoparticle-containing films showing high UV absorption, high transmittance in the visible range (>88%), and water repellence with contact angles of 120 degrees is presented. The films are coated from an emulsion containing the hydrophobic polymer and the nanoparticles. This emulsion was prepared by mixing commercial o/w emulsions used for hydrophobic coatings on textiles with ZnO nanoparticle-containing o/w emulsions. The latter were designed so that the mixed coating formulation could be prepared without breaking. Preparation and properties of the o/w emulsions as well as the final films are elaborated. The performance of hydrophobic and hydrophilic ZnO nanoparticles during preparation and in the final film is evaluated.