基于全氟硅烷/烷基SiO2协同效应的PTFE中空纤维膜表面超疏水改性研究

Super-hydrophobic Modification Investigation for PTFE Hollow Fiber Membrane Surface Based on the Synergy of Perfluorinated Silane and Alkylated SiO2

在聚四氟乙烯(PTFE)微孔膜表面构建超疏水结构,有利于突破其在膜蒸馏、膜吸收等疏水膜应用过程中膜润湿的技术瓶颈。以正硅酸乙酯(TEOS)和甲基三乙氧基硅烷(MTES)为前驱体,水解-缩合制备疏水性烷基Si O2纳米粒子,通过浸涂的方式将烷基Si O2纳米粒子沉积组装到PTFE中空纤维膜表面;进一步应用全氟癸基三乙氧基硅烷对烷基Si O2纳米粒子进行低表面能修饰,构建膜表面超疏水结构,制备具有超疏水性能的PTFE中空纤维膜。考察了烷基Si O2纳米粒子制备时间、前驱体MTES和TEOS的体积比R、不同质量分数的全氟癸基三乙氧基硅烷溶液对PTFE中空纤维膜表面疏水性能和微孔结构的影响。结果表明,当烷基Si O2纳米粒子制备时长为48 h,前驱体体积比R为4时,膜表面静态水接触角(WCA)出现最大值;当使用3%的全氟癸基三乙氧基硅烷溶液为表面修饰剂时,膜表面接触角最大可达154°,疏水效果达到最佳。

Constructing superhydrophobic structures on the surface of teflon(PTFE) micro porous membranes was beneficial to break through the technical bottleneck of membrane wetting in the application of hydrophobic membranes,such as,membrane distillation and membrane absorption.The hydrophobic alkyl silicon dioxide(SiO2) nanoparticles were prepared by hydrolysis-condensation using ethyl orthosilicate(TEOS) and methyl triethoxysilane(MTES) as precursors.The alkyl SiO2 nanoparticles were deposited and assembled to the surface of the PTFE hollow fiber membrane by dip-coating.The low surface energy modification of alkyl SiO2 nanoparticles was further applied by perfluorodecyl triethoxysilane to construct superhydrophobic structure on the membrane surface to prepare the PTFE hollow fiber membrane with properties.The effects of the preparation time of alkyl SiO2 nanoparticles,the volume ratio of precursor MTES and TEOS(R),the concentration of perfluorodecyl triethoxysilane solution on the surface hydrophobicity and micropore structure of PTFE hollow fiber membrane were investigated.The results show when the preparation time of alkyl SiO2 nanoparticles is 48 h,the precursor ratio R is 4,the maximum value of static water contact angle(WCA) on the surface of the membrane could be obtained.When 3%of perfluorodecyl triethoxysilane is used as surface modifier,the maximum contact angle of the membrane surface could reach 1540 and the hydrophobic effect is the best.