Superhydrophobic surface of ZnO-coated cotton fabrics: Synthesis and wettability modification.

Hydrophilic cotton fabric (WCA = 68°) was successfully converted to superhydrophobic (WCA > 150°) by coating the surface with ZnO nanoparticles (NPs) using the hydrothermal method without additional reagent. We noted that the ZnO particle size, as well as the sample surface density, increased with the higher precursor concentrations, forming hierarchical morphology. Interestingly, the coexistence of the excitonic state (∼ 4 eV) and the defect state (2 - 3.2 eV) was observed, which has the potential for developing a water-repellent and anti-bacterial surface. The role of morphology on absorption and wettability properties is then studied comprehensively. Our results can be used as a strategy for designing water-repellent and anti-bacterial coatings for medical and textile applications. [ABSTRACT FROM AUTHOR]