A novel and cost-effective method for fabrication of a durable superhydrophobic aluminum surface with self-cleaning properties.

Afzali, Neda; Taghvaei, Ehsan; Moosavi, Ali

A hierarchical superhydrophobic surface is prepared via a 2-step boiling water immersion process and anodization of the treated aluminum substrate in a novel hydrophobic electrolyte of aluminum nitrate and stearic acid mixture at room temperature. The immersion time in boiling water had a significant influence on the morphology and durability of the sample. A pseudoboehmite coating is created on the aluminum surface during the boiling process, as revealed by the Field Emission Scanning Electron Microscopy (FE-SEM) and Fourier Transform Infrared Spectrophotometer (FTIR) results. The Energy-Dispersive X-ray Spectroscopy analysis (EDS) confirmed the formation of hydrophobic coating surface after anodization. Also, the FE-SEM images and the Atomic Force Microscopy (AFM) investigation proved the hierarchical nano-and microstructure stem from boiling and anodizing procedures, respectively. The successively boiled and anodized surface exhibited contact angle of about 155Ëš, sliding and hysteresis contact angles of < 5Ëš and 2 Ëš, respectively. It also demonstrated a self-cleaning property and remarkable durability.