Controllable wettability of paraffin-anodic aluminum oxide composite surface with a roughness tunable by thermal expansion

Abstract

The roughness of a composite surface, one of factors determining the contact angle (CA), is controlled by the difference in the thermal expansion of constituents of the composite. The CA on a composite surface can be calculated by using an equation derived from Cassie and Wenzel relations. A composite of paraffin and anodic aluminum oxide was fabricated to verify this equation. The CA on this surface changed from 63 to 113A degrees as the temperature increased from 1 to 40A degrees C.