Superhydrophobic Alumina Surfaces Based on Polymer‐Stabilized Oxide Layers

Abstract

Abstract Aluminum sheets were furnished with a water‐repellent composite layer consisting of microroughened alumina, chitosan (CHS), and poly[octadecene‐ alt ‐(maleic anhydride)] (POMA). CHS was electrochemically deposited or spin‐coated. In a subsequent reaction step, POMA was covalently bonded onto the immobilized CHS layer. The produced composite layers showed superhydrophobic properties, which are indicated by the water contact angles >150° and negligible hysteresis. Cross‐linking reactions of the CHS layer were able to enhance the layer stability. The superhydrophobic surface properties were also maintained after abrasion of the protruding polymer‐coated alumina peaks. This is due to a CHS/POMA reservoir incorporated in the microroughened alumina surface region. magnified image