新型荷正电纳滤膜的制备与表征

Preparation and Characterization of the Novel Positively Charged Nanofiltration Membrane

以聚砜超滤膜为基膜、聚乙烯亚胺和均苯三甲酰氯为单体,采用界面聚合方法制备荷正电复合纳滤膜。采用均匀设计实验优化制膜条件,用SPSS软件处理实验数据得到模型方程。模拟计算结果表明,膜对PEG400的截留率随界面聚合反应时间、热处理时间的增长而增大;聚乙烯亚胺浓度和表面活性剂浓度之间的交互作用比较明显。实验结果表明,随着操作压力的增加,膜的纯水通量以及膜对NaCl和PEG400的截留率均相应增大。在NaCl/PEG400/水混合体系中,随着NaCl或PEG400浓度的增大,膜的渗透通量稍有减小,膜对NaCl-PEG400的分离因子有所降低。在0.4MPa、25℃,NaCl和PEG400浓度分别为0.01mol?L?1和500mg?L?1条件下,膜对NaCl-PEG400的分离因子大于10。

A novel positively charged nanofiltration membrane（NF） was prepared by interracial polymerization. The polysulfone （PSF） support membrane was orderly immersed in an aqueous solution of polyethylenimine （PEI） and a hexane solution of trimesoyl choride （TMC）, then the coated substrate was heat-cured in an air-circulating oven. The uniform design was applied to optimize the preparing conditions for fabrication of the charged NF membrane and the experimental data were processed by SPSS software, upon which the model equation was established. The model calculation shows that the retention of PEG400 will increase with increasing the polymeric reaction time or the heat-cured time. The interaction between the concentrations of PEI and of surfactant is quite evident. When the concentration of PEI is lower, the effect of the surfactant is positive; but when the concentration of PEI is higher, the effect of the surfactant becomes negative. The experimental results of membrane separation for NaCl/PEG400/H20 mixture show that the separation factor will decrease with increasing concentration of NaCI or PEG400 in the mixture. At 0.4MPa and 25 ℃, when the concentrations of NaCl and PEG400 are 0.01mol·L^-1 and 500mg·L^-1, respectively, the membrane separation factor for NaCl- PEG400 mixture system is larger than 10.