【摘要】 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质量浓度为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0.60 MPa的操作条件下,对0.4×10-3 g/L的罗丹明B截留率达到90%,通量为42L/(m2·h·MPa).更多还原

【Abstract】 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,ζpotential 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.Theζpotential and the contact wetting angle of the membrane with 4.0bi-layers was-70 mV 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 42L/(m2·h·MPa)at 25 ℃ and 0.60 MPa pressure.更多还原