摘要
采用湿法相转化法制备了聚偏氟乙烯(PVDF)/聚乙烯醇(PVA)共混膜,研究了PVDF/PVA共混体系的相容性,并讨论了PVDF/PVA共混比、固含量、添加剂浓度、凝固条件与后处理对膜结构及性能的影响。结果表明,PVDF/PVA为不相容体系,在成膜过程中产生界面微孔;随PVA含量增加,PVDF/PVA共混膜水通量先增大后减小,在PVDF/PVA为8/2时呈较大值,截留率变化趋势则相反;PVA的存在明显改善了PVDF/PVA共混膜的亲水性,表现为随其含量增加共混膜接触角明显减小;随固含量增加,膜厚度增加,孔隙率降低,水通量减小,截留率升高;添加剂PEG600浓度为6%时,孔隙率高,水通量大,但截留率低;凝固浴种类直接影响膜结构及性能;热处理可完善膜结构从而获得性能更优的膜。选择适当的铸膜条件可制成较好的膜产品,而且共混膜通量明显大于各组分通量的加权,表明共混是一种改善PVDF膜性能的有效方法。
The membrane was prepared from PVDF/ PVA blend polymer by L-S phase inversion method. The compatibility of PVDF/PVA and the effects of PVDF/PS blend ratio, polymer concentration,additive, coagulation＇bath and after treatment on blend membranes performance were studied. The results showed that： （1） PVDF/PVA were incompatible blends, new interface microvoid structure was produced as a result of phase separation in PVDF/PVA; （2） With PVA content increased,the water flux of PVDF/PVA blend membrane increased due probably to the new interface microvoid which reached the maximum when PVDF/PVA was structure,and decreased with PVA content increased again, 8/2 （wt/wt）. The trends of rejection ratio and alcohol flux are contrary. PVA could improve the hydrophilicity of PVDF/PVA blend membranes,which could be illuminated by the decrease of contact angle; （3） The membrane thickness and rejection ratio increased whereas porosity and water flux decreased with polymer concentration increased;（4） The blend membranes performance was the best when PEG600 concentration ratio was 6%; （5） The composition of coagulation bath were much effective for porous structure and blend membranes performance~ （6） The blend membranes performance could be improved due to the compact porous structure by heat treatment. Top-quality PVDF/PVA blend membrane could be obtained through selecting proper preparation condition, blending was an efficient method to improve the PVDF membrane performance.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2007年第12期1975-1980,共6页
Journal of Functional Materials
基金
国家重点基础研究发展计划(973计划)资助项目(2006CB708602)
教育部高等学校博士学科点专项科研基金资助项目(20040058002)
