炭膜表面疏水改性及老化性能研究  

Surface hydrophobic modification and aging performance of carbon membrane

作　　者：周晓东[1] 李琳[1] 王同华[1] 

机构地区：[1]大连理工大学化工学院精细化工国家重点实验室炭材料研究室膜科学与技术研究开发中心,大连116024

出　　处：《膜科学与技术》2014年第4期12-19,共8页Membrane Science and Technology

基　　金：国家自然科学基金资助项目(20836006;20976021;21176036;21276035);国家"863"项目(2009AA03Z215;2012AA03A611)

摘　　要：采用溶胶凝胶法,以正硅酸乙酯(TEOS)和甲基三乙氧基硅烷(MTES)为混合硅源,合成疏水硅溶胶,将其浸渍涂覆在卷式炭膜上,经干燥、热处理制备了具有高疏水性能的疏水炭膜.考察了硅溶胶制备工艺和膜热处理工艺对所制备炭膜疏水性能的影响.采用水接触角测试仪、TG、FTIR、AFM、SEM和TEM等测试手段,对疏水炭膜的表面结构和疏水性能进行了表征.结果表明,通过硅溶胶表面改性,在炭膜表面引入了甲基化的二氧化硅的表面结构,提高了其疏水性能.硅溶胶的制备工艺对所制备疏水炭膜的表面化学结构、形貌及粗糙度有较大的影响.其中硅溶胶合成反应温度对提高膜表面疏水性能的影响最为显著;膜表面甲基基团含量对改善炭膜表面的疏水性能起到决定性作用.通过控制硅溶胶合成和膜的热处理工艺可以有效地调控疏水炭膜的表面疏水性能;在最佳条件下制备的疏水炭膜,其表面粗糙度为34.263nm;水接触角达到138°左右,表现出良好的疏水性能.气体渗透性能测试表明,炭膜疏水改性对炭膜的气体渗透性能影响较小,但明显地提高了炭膜的抗老化性能.The hydrophobic carbon membranes were prepared by coating the methylated silica sol,which was prepared by sol-gel method using the tetraethoxysilane （TEOS） and methyltriethoxysilane （MTES） as silica sources,on the carbon membrane and calcinating at 400～600 ℃ in the N2 atmosphere.The effects of silica sol preparation and membrane calcination condition on the hydrophobicity of carbon membranes were investigated.The surface structure and morphology of the hydrophobic carbon membrane were characterized by TG,FTIR,AFM,SEM and TEM.The results show that the hydrophobicity of carbon membranes is greatly improved by introducing the methylated silica structure onto the carbon membrane via silica sol.The preparation conditions such as silica sol and reaction temperature have great influence on the surface chemical structure,morphology and roughness of hydrophobic carbon membrane.The contents of methyl group on the membrane surface play a decisive role in the improvement of hydrophobic properties of carbon membranes.The hydrophobicity of carbon membranes can effectively tuned by controlling the preparation condition of silica sol and membrane calcination condition.The hydrophobic carbon membrane prepared under the optimum conditions exhibits an excellent hydrophobicity,which the surface roughness is 34.263 nm and water contact angle is 138°.Aging experiment results show that the hydrophobic modification of carbon membrane surface obviously improves the aging-resistant property of carbon membranes,but does not reduce the O2 permeation flux of carbon membrane too much.

关 键 词：溶胶凝胶 疏水炭膜 正硅酸乙酯(TEOS) 甲基三乙氧基硅烷(MTES) 气体分离 

分 类 号：TQ051.893[化学工程] TQ127.11