LAUSR

Abstract Micro/nano hierarchical ZnO superhydrophobic surfaces were fabricated on iron plates via chemical bath deposition (CBD) method. The fabricated surfaces were modified with stearic acid (STA). Taguchi L27 experimental design was used to study and optimize the effective factors such as type of the zinc salt, type of the basic agent, deposition time, chemical modification time, type of the additive such as hexadecyltrimethylammonium bromide (CTAB), hexamethylenetetramine (HMTA) and Triton X100, concentration of additive, reaction temperature, volume ratio of ethanol to water in the reaction medium and the zinc salt/alkaline agent molar ratio. Morphology features, phase analysis and chemical composition were evaluated by means of SEM, XRD and FTIR. Results showed that the chemical modification time and type of the zinc salt were the most effective factors to achieve superhydrophobic property. CTAB, HMTA and Triton X100 respectively created nano-petals, nano-rods and flower-like structures. The stabilities of the resulted surfaces in acidic, alkaline and saline solutions were studied. The ZnO surfaces exhibited excellent chemical stability in the alkaline environment. A superhydrophobic ZnO thin film with WCA of 165.1° ± 0.5° and contact angle hysteresis of about 1.4° was obtained under optimum condition. The thickness of nano plates obtained was ∼50 nm.