荷负电改性聚偏氟乙烯超滤膜对染料的吸附和截留研究

Study on Adsorption and Interception of Dye by Negatively Charged Modified Polyvinylidene Fluoride Ultrafiltration Membrane

通过臭氧预处理偶氮二异丁腈引发接枝丙烯酸到聚偏氟乙烯(PVDF)主链上,得到改性产物聚偏氟乙烯接枝丙烯酸(PVDF-g-PAA)。采用浸没沉淀相转化法制备系列荷负电超滤膜(PA膜),通过傅里叶全反射红外光谱(ATR-FTIR)、扫描电子显微镜(SEM)分析膜的组成和结构,并对阳离子染料亚甲基蓝(MB)和阴离子染料刚果红(CR)进行吸附和截留研究,考察了荷负电膜对染料吸附和截留的影响因素。结果表明,相比未改性的纯PVDF膜(P膜),PA膜的孔径、孔隙率、纯水通量、亲水性能均有不同程度的提高;PA膜对MB吸附量达到10.06mg/g,对CR基本没有吸附;PA膜对MB在前50min内可实现对其截留,而CR的截留率可以保持在96%左右,并且能起到浓缩作用。

The Polyvinylidene fluoride（PVDF）was pretreated with ozone,then the modified product Polyvinylidene fluoride grafted acrylic acid（PVDF-g-PAA）was obtained by grafting acrylic acid onto the PVDF main chain with AIBN as initiator.The series of negatively charged ultrafiltration membrane（PA membrane）was prepared by immersion precipitation phase inversion.The composition and structure of the membrane was characterized by Fourier transform infrared spectroscopy（ATR-FTIR）and scanning electron microscope（SEM）.The adsorption and retention performance of charged membrane for cationic dye methylene blue（MB）and anionic dye Congo red（CR）and the influence of absorption and retention were investigated.It was showed that the pore size,porosity,pure water flux and hydrophilicity of PA membrane were higher than unmodified pure PVDF membrane（P membrane）.The adsorption capacity of PA membrane for MB reached 10.06 mg/g,however,CR was nearly not adsorpted.The MB can be intercepted by PA membrane in the initial 50 min,but the retention rate of PA membrane for CR was around 96% for a long time and could be concentrated.