Preparation of ZnO/polystyrene superhydrophobic composite coating and its performance

ZnO particles were modified by dodecafluoro- heptyl-propyl-trimethoxysilane for making their surface from hydrophilic to hydrophobic, and then blended with polystyrene (a low-surface-energy thermoplastic resin) and baked at 160 °C for 25 min to prepare a modified-ZnO/ polystyrene superhydrophobic composite coating on the surface of steel sheet. The surface structure and hydrophobicity of the coating was studied by infrared spectroscopy, scanning electron microscopy, and contact angle analyzer. The results showed that─CH3 and ─CF2 ─ groups are introduced on the surfaces of ZnO particles after modification, leading to a micro-and nano-meter double rough structure. The composite coating obtained at mass ratio of modified ZnO to polystyrene 7:3 has a static contact angle of 156° and a rolling angle of 8° against water, and features the follows performances: 2nd-grade adhesion tosteel substrate, B-H hardness, impact strength 50 kg·cm, and water absorption rate of 7.3%. The modified ZnO/ polystyrene superhydrophobic composite coating has good application prospect.