多孔膜基材对等离子体接枝膜微观结构的影响

采用等离子体诱导接枝聚合法,在有机聚偏氟乙烯(PVDF)膜、尼龙(N6)膜和无机多孔阳极氧化铝(PAA)膜上接枝甲基丙烯酸(MAA),系统地研究了多孔膜基材及接枝工艺条件对接枝开关膜微观结构的影响。结果发现,对于PVDF基材膜,单体溶液脱气次数越多接枝率越大。对于不同类别的多孔膜基材,采用相同工艺条件接枝时,N6膜的接枝率高于PVDF膜,PAA膜接枝率最低。在接枝率相近的时候,接枝层在PVDF膜整个断面孔内和表面均存在,而N6膜则主要集中在表层。在PAA膜上接枝时发现,等离子体照射功率的强弱对基材膜的影响很大,当功率超过50W时,PAA膜表层就会被刻蚀而导致膜的质量减轻。

Effects of Porous Substrates and Technical Conditions on Microstructures of Plasma-Induced Grafted Membranes

A series of environmental responsive gating membranes were prepared by grafting methacrylic acid(MAA) onto two organic substrates,including porous polyvinylidene fluoride(PVDF) membranes and nylon(N6) membranes,and onto inorganic substrate porous anodic aluminum(PAA) membranes,with plasma-induced graft polymerization.Effects of porous membrane substrates and grafted technical conditions on microstructures of grafted gating membranes have been systematically studied.Times of repeated freezing and thawing for degassing,porous membrane substrates and plasma-discharge power(PDP) have significant effects on the grafting in this study.For PVDF membranes,the more times of repeated freezing and thawing for degassing lasted,the higher grafting yields of PVDF membranes could be achieved.With substrates varying,different grafting yields were obtained under the same technical conditions.The grafting yield of N6 membrane was higher than PVDF membrane,and PAA membrane was the lowest one.Because of their differences in microstructures,when the grafting yield of PVDF membranes was closed to that of N6 membranes,the grafted layer existed both in the pores and on the surface of PVDF membranes,while it only existed in the surface layer of N6 membranes.PDP has significant effect on PAA membranes due to the corrosion by plasma.The PAA substrate lost weight when PDP was larger than 50W.