近年来，采用渗透汽化 (PV) 技术分离水中挥发性有机物 (VOCs) 的研究受到高度的关注。目前，研究较多的是以聚二甲基硅氧烷 (PDMS) 为分离层，以聚丙烯腈 (PAN) 膜为支撑层的PDMS/PAN复合膜。本文通过对PAN膜进行表面化学接枝改性和表面涂覆改性，试图提高复合膜对醇/水溶液的渗透汽化性能，研究的内容包括如下两个方面：(1) 表面化学接枝先用水合肼 (HH) 对PAN膜进行氨基化改性，得到PAN-NH膜，然后用γ-甘油醚基丙基三甲氧基硅烷 (GPTMS) 对PAN-NH膜进行硅烷化改性，得到PAN-GPTMS膜。以PDMS为分离层，以PAN-GPTMS膜为支撑层，制得PDMS/PAN-GPTMS复合膜。系统地研究了两步改性对PAN膜的亲水性、吸水率和纯水通量的影响，表征了PAN膜的理化性质和孔隙结构的变化，并考察了其对复合膜性能的影响。与传统的PDMS/PAN复合膜相比，采用Si、N元素原子比为0.133的PAN-GPTMS膜为支撑层制备的PDMS/PAN-GPTMS复合膜，其渗透通量基本不变，分离因子增加5.43%。(2) 表面涂覆分别将四甲基二乙烯基二硅氧烷 (DVTMS) 和2,4,6,8-四甲基-2,4,6,8-四乙烯基环四硅氧烷 (TMTV) 与交联剂PDMS的B (B) 组分共混后形成DB和TB铸膜液，涂覆于PAN膜的表面经预交联，制备出两种聚硅氧烷 (POS) 过渡层DB和TB；再涂覆PDMS，获得PDMS/DB/PAN和PDMS/TB/PAN渗透汽化复合膜。系统地研究了POS的组分质量比和固含量对PAN膜的理化性质和孔隙结构的影响，同时考察了其对复合膜性能的影响。与具有相同分离层厚度的空白PDMS/PAN 复合膜比较，三层复合膜的分离因子分别提高了8.50 %和10.20 %，渗透通量提高了29.50 %和11.30 %。

Pervaporation (PV) has been considered as a promising membrane technique for the separation of volatile organic compounds (VOCs) from aqueous solution in recent year. The PDMS/PAN composite membrane consists a polydimethylsiloxane (PDMS) separation layer and a polyacrylonitrile (PAN) support layer, which has been investigated for the separation of VOCs from aqueous solution by means of pervaporation. In this study, the PAN membrane as the support layer of PDMS/PAN composite membrane has been modified using a surface chemical grafting method and a surface coating method to increase the pervaporation performance of the composite membrane for alcohol-water solution. The work with regard to the following two respects has been partially addressed.(1) Surface chemical graftingThe PAN-NH membrane was synthesized with hydrazine hydrate (HH) using amination reaction on the surface of PAN membrane. Then the PAN-GPTMS membrane was synthesized with γ-glycidyloxypropyltrimethoxysilane (GPTMS) using silanization reaction on the surface of PAN-NH membrane. The PDMS/PAN-GPTMS composite membrane was prepared by method of coating PDMS layer on the PAN-GPTMS membrane as support layer. The hydrophilic property, water absorption content and pure water flux of modified or unmodified PAN membranes were investigated after two reactions. And they were characterized by various methods to respect the morphology, chemical structure and permeation properties and the affect on the pervaporation performance of PDMS/PAN composite membrane. When the Si/N ratio of atom of PAN-GPTMS membrane was 0.133, the separation factor of PDMS/PAN-GPTMS composite membrane increased by 5.43 % than unmodified PDMS/PAN composite membrane, but the permeation fluxes of the two composite membrane were the same value.(2) Surface coating With surface coating meathods, two kind of polyorganosiloxane (POS, respectively DB and TB) were prepared and coated on the surface of PAN membrane to form DB or TB translation layer. The DB or TB was prepared from the copolycondensation of 1,3-divinyltetramethyldisiloxane (DVTMS) or tetravinyltetramethylcyclotetrasiloxane (TMTV) with polydimethylsiloxane component B (B) . Then the tri-layer composite membrane PDMS/DB (TB) /PAN was prepared by methods of coating PDMS layer on the DB or TB translation layer. The effects of mass ratio and mass content of POS in casting solution on pervaporation performance were investigated. The modified and unmodified PAN membranes were characterized by various methods to respect the morphology, chemical structure and permeation properties of PAN membrane and the effect on the pervaporation performance of PDMS/PAN composite membrane. Under the optimal conditions, the separation factors were increased by 8.50 % and by 10.20 %, the permeation fluxes also increased by 29.50 % and by 11.30 % respectively, compared with the same thickness PDMS/PAN composite membrane.