HNTs填充PDMS膜的制备及其分离ABE-水体系的研究  

Preparation of HNTs filled PDMS membranes for the separation of ABE from aqueous solution

作　　者：路姣姣 毛恒 王涛 蔡玮玮 赵之平 LU Jiaojiao;MAO Heng;WANG Tao;CAI Weiwei;ZHAO Zhiping(School of and chemistry and Chemical Engineering,Beijing Institute of Technology,Beijing 102488,China)

机构地区：[1]北京理工大学化学与化工学院,北京102488

出　　处：《膜科学与技术》2020年第1期53-63,共11页Membrane Science and Technology

基　　金：国家自然科学基金(21736001和21576024)。

摘　　要：埃洛石纳米管(Halloysite nanotube,HNTs)是一种天然的管状材料,鉴于其独特的一维内腔管道,且管道两端为开孔结构,在膜分离领域具有应用前景.本文首次通过物理共混法,将HNTs填充到聚二甲基硅氧烷(PDMS)中制备混合基质膜(MMMs),用于渗透汽化分离水溶液中丙酮-丁醇-乙醇(ABE)组分,并对膜化学组成及其微结构进行系统表征,重点考察了HNTs填充量、料液温度及操作时间对膜渗透汽化性能的影响.研究表明:HNTs可均匀分散在PDMS基质中,与PDMS之间具有良好的相容性.该纳米管的引入,使得膜的水接触角从110°提高到131°,而其表面自由能显著降低,增强了HNTs/PDMS膜对ABE组分的选择性.同时,HNTs具有开孔的一维内腔(直径为15~25 nm),可在膜内构筑低能垒的快速扩散通道,以实现ABE组分在膜内高效传递.当分离ABE溶液及操作温度为55℃时,所制膜总渗透通量达到1368 g/(m^2·h),且其丁醇分离因子为38.2.值得注意的是,在从水溶液中回收ABE组分连续操作100 h过程中,所制膜具有良好的分离性和稳定性.Halloysite nanotubes(HNTs),as one of the naturally tubular materials,have great potential in the field of membrane separations,due to the unique one-dimensional lumen tube with open-pore endings.In this study,a series of mixed matrix membranes(MMMs)were prepared by incorporating HNTs into polydimethylsiloxane(PDMS)matrix through physical blending for pervaporation separation of acetone-butanol-ethanol(ABE)from aqueous solution.Chemical composition and microstructures of the membranes were characterized in detail.The effects of HNTs loading,feed temperature,and testing time on the pervaporation performance of the resultant membrane were investigated.The results revealed that the HNTs had good compatibility with PDMS matrix,and the HNTs were uniformly dispersed in PDMS matrix.The addition of HNTs increased the water contact angle of the membrane from 110o to 131o,while the surface free energy was reduced significantly.As a result,the selectivity of the membrane about ABE from aqueous solution was enhanced.Meanwhile,the high permeability of the resultant membrane was achieved arising from the one-dimensional open-pore lumen(diameter,15~25 nm)of HNTs,which constructed a fast diffusion channel with low transfer resistance for penetrants.The total permeation flux of the resultant membrane reached about 1368 g/(m^2·h)in separation model ABE solution at 55℃,and the separation factor of n-butanol was 38.2.Notably,the resultant membrane had good long-term stability and selectivity during the 100 h continuous operation for ABE recovery from aqueous solution.

关 键 词：渗透汽化 埃洛石纳米管 聚二甲基硅氧烷 混合基质膜 ABE回收 

分 类 号：O634.41[理学—高分子化学]