YU Wanfei ¹, HOU Xue ², WAN Weimin ¹, ZHANG Yanping ¹, GAO Peng ¹, YU Hui ³, LI Jianbao ¹
(1. State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570100, Hainan, China; 2. CAS Key Laboratory of Experimental Study under Deep-sea Extreme Conditions, Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, Hainan, China; 3. School of Biological and Environmental Engineering, Jingdezhen University, Jingdezhen 333032, Jiangxi, China)

Abstract: Hydrophobic silica gel was prepared using methyl trimethoxy-silane (MTMS) as the precursor, while cetyltrimethyl ammonium bromide (CATB) was used to control the degree of polymerization. Then, surface of wood was sprayed by atomizing spray on one side and hydrophobic SiO₂ coating was then obtained after drying at 80 ℃. Surface morphology, chemical composition, surface wettability and wear resistance of the coating were characterized by using field emission scanning electron microscope (SEM), Fourier infrared (FT-IR) spectroscopy, contact angle meter and automatic surface area and porosity analyzer. As compared with those made with the mixed spraying method, the coating prepared by using the sol-gel spraying method has higher wear resistance. When the content of CATB was 15 mmol·L⁻¹, the wear resistance of the coating was optimized. When the content of CATB was 20 mmol·L⁻¹, the hydrophobicity of the coating was the highest, with water contact angle of 148.76±0.94°. The hydrophobicity of the coating was attributed to the presence of CH₃ derived from MTMS, while the enhanced wear resistance was ascribed to the accumulation of the hydrophobic silica gel on surface of the substrate. The hydrophobic silica prepared with MTMS has promising stability and strong acid and alkaline resistance. Based on the 3D uniform porous tubular structure of wood and unilateral atomization spraying technology, double-sided asymmetric wettability film was constructed, which has a wide application prospect in the field of oil/water mixture separation.
Key words: sol-gel method; atomizing spraying method; hydrophobic SiO₂ coating; hydrophobic SiO₂ coating; wear resistance; stability