采用聚合左旋多巴涂覆及MPEG-NH_2接枝对PVDF膜亲水改性的研究  

Hydrophillicsurface modification of PVDF membrane by Poly(L-DOPA) coating and MPEG-NH_2 grafting

作　　者：汪帅[1] 李方[1] 李勇[1] 潘婷[1] 杨波[1] 田晴[1] 

机构地区：[1]东华大学环境科学与工程学院,国家环境保护工业污染防治工程技术中心,上海201620

出　　处：《膜科学与技术》2015年第1期42-48,共7页Membrane Science and Technology

摘　　要：通过涂覆3-羟基-L-酪氨酸(左旋多巴,L-DOPA)和再接枝氨基聚乙二醇单甲醚(Methoxypolyethylene glycol amine,MPEG-NH2)的方式对疏水聚偏氟乙烯(PVDF)膜进行表面亲水改性.在Tris缓冲溶液中,左旋多巴通过氧化反应形成聚合物,粘附在膜表面形成涂覆层,再通过氨基与聚合左旋多巴的共价结合将MPEG-NH2刷状聚合物接枝到PVDF膜表面.实验通过水接触角、傅里叶红外光谱、扫描电子显微镜等测试手段,分析和对比膜改性前后的特征和表面形貌,同时考察原膜、涂覆改性膜和接枝改性膜对乳化油的分离效率和抗污染能力.实验结果表明,左旋多巴涂覆和后续MPEG-NH2接枝改性虽然减小了PVDF膜孔径和纯水通量,但能明显提高膜表面的亲水性和过滤效率,并在乳化液分离实验中提高膜的抗污染性能和膜清洗通量恢复率.The hydrophobic Polyvinylidene Fluoride（PVDF） membranes were modified by coating 3-（3,4- Dihydroxyphenyl）-L-alanine（L-DOPA） and grafting methoxypolyethylene glycol amine（MPEG-NH2）. In a Tris solution, the polymers of L-DOPA were formed by the oxidation reduction of the monomers, which then adhere on the membrane surface to form a coating layer. Further, the MPEG-NH2 with brush structure was grafted on the coating layer with covalent bonds. To analysis the characteristics and morphologyof nascent membrane and modified membranes, the measurements, such as contact angle, fouriertransform infrared spectrometer（ATR-FTIR）,scanning electoralmicroscopy（SEM） were employed. The antifouling ability and separation efficiency of these membranes were also investigated with oil/water emulsion filtration tests. It was found that although the pore size and the water flux reduced after the modification of L-DOPA coating and MPEG-NH2 grafting. The hydrophilicity and rejection efficiency of the modified membranes enhanced significantly comparing to the nascent membrane. In the emulsion filtration tests, the antifouling and flux recovery after cleaning were improved after the membrane modification.

关 键 词：左旋多巴 PVDF超滤膜 亲水性 MPEG-NH2 表面改性 

分 类 号：TQ316.6[化学工程—高聚物工业] TQ051.893