Controllable superwettability of Cu mesh by one-step immersion in fatty acids with different carbon chain lengths

Abstract The preparation of superhydrophobic metal surfaces by one-step immersion in fatty acid solutions is simple and convenient, but the effect of the fatty acid type has not been investigated. In this work, Cu meshes were soaked in ethanol solutions of fatty acids with different carbon chain lengths to obtain surfaces with different wettabilities, which varied from superhydrophilicity to superhydrophobicity. The results showed that the contact angle of the surfaces gradually increased from 2.7° for the sample prepared with formic acid to 151.8° for the sample prepared with myristic acid. The maximum apparent surface energy and solubility parameter were 82.33 mN/m and 65.79 J1/2/cm3/2 for the C1-Cu surface, and the lowest were only 6.3 mN/m and 19.91 J1/2/cm3/2, respectively, for C14-Cu. A simulation confirmed that as the carbon chain length of the fatty acid increased, the solubility parameter decreased, and the hydrophobicity increased. One-step immersion enables facile, inexpensive one-step preparation of membrane surfaces with controllable superhydrophobicity for large-scale industrial applications.