Effect of pre-anodizing, electrocoating processes and fatty acid chain length on morphology, roughness and durability of ZnO-coated superhydrophobic surfaces

Abstract

Anodizing process was applied for the first time in this study for pre-modification of the 1050 aluminum surface before the zinc electrodeposition to obtain superhydrophobic surface by modifying with palmitic, lauric and stearic acid for the comparison. The effect of the pre-anodizing process, the electrodeposition time and the acid chain length on the super-hydrophobicity and durability was investigated in detail to explain the relationships between the roughness, morphology and acid chain length. Anodized, electrocoated and modified surfaces were characterized by FTIR, XRD, SEM and topography analysis. The highest contact angles were 154 degrees, 157 degrees and 160 degrees for electrodeposition process modified with lauric, palmitic and stearic acid, respectively. Sandpaper abrasion, UV, pH and temperature tests showed that molecular length, pre-anodizing and coating time strongly related the durability and super-hydrophobicity of the coated surfaces. As a result, anodizing time has a great impact on the durability and contact angle compared to non-anodized plates thanks to the creating macro-roughness.