溶胶-凝胶法制备超疏水PMHS—SiO_2涂膜

Preparation of Superhydrophobic PMHS-SiO_2 Coatings by Sol-Gel Method

通过溶胶-凝胶法制备了二氧化硅(SiO_2)溶胶,并以含氢硅油(PMHS)为改性剂,对SiO_2粒子表面进行疏水化处理,然后在玻璃基片上提拉成膜和加热凝胶化,制备出超疏水PMHS-SiO_2涂膜。通过接触角测定、红外光谱、透射电镜、扫描电镜、湿热老化等手段对涂膜的制备条件、结构与性能进行了研究。结果表明,在PMHS/SiO_2质量比为1:1、改性时间为4 h、涂膜热处理温度170℃、热处理时间3 h的条件下,可制得具有优良超疏水性的PMHS-SiO_2涂膜,其水接触角可达163°,滚动角可低至3°-5°,且具有优异的耐湿热老化性能。对改性前后的SiO_2溶胶和PMHS-SiO_2涂膜的结构形态研究发现,PMHS与SiO_2表面产生了化学结合,形成了PMHS-SiO_2杂化交联材料;涂膜表面被疏水性PMHS包覆,同时较均匀地分布着许多粒径为50-400 nm的微米-纳米双重粗糙度的微凸体,这是产生优异的超疏水性能的主要原因。

The PMHS-SiO_2 superhydrophobic coatings were prepared by sol-gel process.The preparation conditions,structure and properties of the coatings were investigated by contact angle measurement, Fourier transfer infrared spectroscopy（FTIR）,Transmission electron microscope（TEM）,Scanning electron microscope（SEM） and hygrothermal ageing.The results show that the contact angle of the coating reaches 163°and rolling angle is 3°-5°when the PMHS/SiO_2 mass ratio is 1：1,modified time is 4 h,and heat-treated conditions are 170℃for 3 h.The coatings also have good hygrothermal ageing resistance. The crosslinked PMHS-SiO_2 hybrid materials was obtained due to the chemical combination between PMHS and SiO_2 surfaces.The excellent superhydrophobic property of the coatings is due to dual effects of forming an appropriate surface roughness with micrometer-nanometer composite particles and the low surface energy of PMHS.