等离子体引发表面两性离子化制备抗污染性PVDF膜

摘要

为了提高聚偏氟乙烯(PVDF)膜的抗污染性能,采用等离子体技术将甲基丙烯酸二甲胺乙酯(DMAEMA)接枝到PVDF膜表面,使其与3-溴丙酸(3-BPA)发生季铵化反应,得到两性离子化改性膜(PVDF-g-PCBMA).利用傅利叶红外光谱仪(FTIR-ATR)、扫描电子显微镜(SEM)、接触角测定仪分析改性前后PVDF膜表面化学官能团、结构形态以及亲疏水性的变化.通过动态过滤实验来考察原膜、改性膜对牛血清蛋白(BSA)和海藻酸钠(SA)的抗污染性能.结果表明,相比于原PVDF膜,PVDF-g-PCBMA膜的接触角从88.3°降至39.0°,亲水性得到了较大的提高;另外,其在BSA和SA溶液的过滤实验中通量衰减率降低、清洗后的清水通量恢复率升高,体现了两性离子化改性膜良好的抗污染性能.%In order to improve the antifouling performance of polyvinylidene fluoride (PVDF) membrane,dimethylamine ethyl methacrylate (DMAEMA) was first grafted onto the surface of PVDF membrane by plasma technology,and then reacted with 3-bromopropionic acid (3-BPA) by quatemization reaction.,and finally the zwitterionic modified membrane(PVDF-g-PCBMA) was obtained.The chemical functional groups,structural morphology and hydrophilicity/hydrophobicity of PVDF membrane were analyzed by Fourier transform infrared spectroscopy (FTIR-ATR),scanning electron microscopy (SEM) and contact angle analyzer.The antifouling properties of the original membrane and the modified membrane against bovine serum albumin (BSA) and sodium alginate (SA) were investigated by dynamic filtration experiment.The result shows that the contact angle of PVDF-g-PCBMA membrane decreases from 88.27° to 39° comparing to the original membrane,and the hydrophilicity of PVDF-g-PCBMA membrane is improved greatly.The flux reduction rate of BSA and SA decreases,and the water flux recovery rate increases after cleaning,reflecting the good antifouling performance of the zwitterionic modified membrane.