以聚丙烯腈（PAN）超滤膜为基膜，通过羧甲基纤维素钠(CMCNa)阴离子聚电解质和聚二甲基二烯丙基氯化铵(PDDA)阳离子聚电解质层层静电自组装(LbL)制备得到复合纳滤膜。考察了阴离子聚电解质溶液浓度、组装层数对膜表面荷电性、形貌和亲水性等的影响；同时研究了操作条件不同时该纳滤膜对罗丹明B染料分离性能变化。结果表明，CMCNa阴离子聚电解质浓度增大时，膜表面荷负电性和亲水性增强；当PDDA浓度为5.0g/L，CMCNa的浓度为2.0g/L，且组装4.0个派对层时，复合膜表面ζ电位约为-70mV，其接触角约为30°；制备的(5PDDA/2CMCNa)5.0-PAN复合纳滤膜，在25℃ 和0.60MPa的操作条件下，对0.4×10-3g/L的罗丹明B截留率达到90%，通量为42 L·m-2·h-1·MPa-1。

In this work, (PDDA/CMCNa)n-PAN composite NF membrane has been fabricated by layer-by-layer electrostatic self-assembly technology on PAN ultrafiltration membrane substrate, using negatively charged carboxymethyl cellulose sodium as anionic polyelectrolyte and PDDA as cationic polyelectrolyte. The variation of surface morphologies, ζ potential values and contact wetting angle with each deposited layer as well as the nanofiltration performance on dyeing solution of rhodamine B were investigated. The results indicated that the membrane surface showed more negatively charged and hydrophilic with increase of CMCNa anionic polyelectrolyte concentration. The ζ potential and the contact wetting angle of the membrane with 4.0 bi-layers was -70mV and 30°, respectively, when 5.0g/L of PDDA and 2.0g/L of CMCNa was self-assembled. The rejection of 0.4×10-3g/L of rhodamine B was more than 90% with flux of 42 L·m-2·h-1·MPa-1 at 25℃ and 0.60MPa pressure.

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