Fabrication of superhydrophobic surfaces on zinc substrates

Stable superhydrophobic surfaces were fabricated on the zinc substrates through simple silver replacement deposition process with the modification of octadecyl mercaptan. The effects of reaction conditions on the surface morphology and wettability of the prepared surfaces were carefully studied. The results show that the fabrication of a best superhydrophobic surface depends largely on the moderate reactant concentration. When the concentration of AgNO3 solution was 2 mmol/L, the zinc substrate was covered by a dendritic outline structure. Aggregated silver nanoparticles were formed on the substrate in accordance with some certain laws, exhibiting great surface roughness. The typical hierarchical micro-nanostructures, flower-like structures and porous structures also could be found from the SEM images. The maximal water contact angle (CA) value of about 161 ± 2°, and the minimal sliding angle (SA) of about 2° were obtained under the same reaction condition.

Research highlights▶ The effects of reaction conditions on the surface morphology and hydrophobicity of prepared surfaces were carefully studied. ▶ The best stable superhydrophobic surface depends largely on the reactant concentration. ▶ The best superhydrophobic surface with the optimal surface structure (hierarchical micro-nanostructures, flower-like porous structures, great surface roughness) and the maximal CA value (161.43°) was prepared. ▶ Using octadecyl mercaptan as the modified material instead of common fluoride can reduce the toxicity and protect the environment.