Morphology and hydrophobicity of a polyurethane film molded on a porous anodic alumina template

Surface characteristics are so paramount that they invariably require surface modification to improve biocompatibility as biomaterials. We describe a method for modulating the morphology and corresponding hydrophobicity of a polyurethane (PU) using PU solution and a suitable porous anodic alumina (PAA) template. The film is characterized by optical microscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), and water contact angle measurements. The water contact angle on a molded PU film surface is approximately 152°, much bigger than that of 85° on a free surface formed in air. Super-hydrophobicity is due to the enhanced roughness, which is modulated by a well-designed PAA template surface morphology.