高渗透选择性纳滤膜的制备及其分盐性能  

Fabrication and salt fractionation performance of nanofiltration membrane with high perm-selectivity

作　　者：丁华烘 郑彤 葛宇航 刘梅红 俞三传[2] DING Huahong;ZHENG Tong;GE Yuhang;LIU Meihong;YU Sanchuan(Hangzhou Creflux Membrane Technology Co.,Ltd.Hangzhou 311121,China;School of Science,Zhejiang Sci-Tech University,Hangzhou 310018,China)

机构地区：[1]杭州求是膜技术有限公司,杭州311121 [2]浙江理工大学理学院,杭州310018

出　　处：《膜科学与技术》2022年第2期103-109,共7页Membrane Science and Technology

基　　金：浙江省重点研发计划项目(2021C03172,2020C03080);国家自然科学基金项目(21978275)。

摘　　要：以鞣酸(TA)作为第二水相反应材料,通过TA分子与初生态聚酰胺(PA)复合膜表面残余酰氯的酯化反应,调节分离层的物理化学性质和微观结构,研究二次界面反应对复合纳滤膜性能的影响,制备高渗透选择性纳滤膜.结果表明:TA分子通过酯化反应实现在初生态聚酰胺分离层表面的致密沉积;与PA分离层相比,PA-TA分离层具有更小的孔径、更窄的孔径分布和更强的表面电负性;在最优制备条件下,含PA-TA分离层的复合膜的切割分子量为210 g/mol、纯水渗透率为120 L/(m^(2)·h·MPa);在0.5 MPa下,对0.5 g/L单一溶质水溶液硫酸钠截留率高达99.3%、氯化钠截留率为60.2%;在3.0 MPa、40℃下,PA-TA复合膜过滤含200 g/L NaCl和10.0 g/L Na_(2)SO_(4)的水溶液,在浓缩倍率5倍下,对硫酸钠平均截留率大于98.5%,平均水通量达120 L/(m^(2)·h);而对氯化钠几乎无截留;对氯化钠和硫酸钠混合盐溶液的分盐性能优于NF270.In this study, the physico-chemical and performance properties of nascent polyamide(PA) thin-film composite membrane were tuned via secondary interfacial reaction with tannic acid(TA) as the reactive material. Composite membrane with high perm-selectivity was fabricated through investigating the effects of secondary interfacial reaction on membrane property and separation performance. The results indicated that TA molecules deposited densely onto the surface of the PA-based nascent TFC membrane through esterification reaction between their phenolic hydroxyl groups and the residual acyl chloride groups. Compared with the PA layer, the PA-TA layer showed decreased mean pore size, narrowed pore size distribution and intensified surface negative charge. The desired PA-TA membrane possessed a low molecular mass-cut off of around 210 g/mol, pure water permeability of 120 L/(m^(2)·h·MPa), Na;SO;rejection of 99.3% and NaCl rejection of 60.2% to 0.5 g/L aqueous solution under 0.5 MPa. The PA-TA membrane also exhibited an average Na;SO;rejection above 98.5%, water flux of about 120 L/(m^(2)·h·MPa), and almost no NaCl rejection to concentrated brine of 200 g/L NaCl and 10.0 g/L Na;SO;under 3.0 MPa, 40.0 ℃ and a concentrating factor of 5. The separation performance of PA-TA membrane to concentrated brine was better than that of commercial membrane NF270.

关 键 词：纳滤膜 界面聚合 渗透选择性 浓盐水 

分 类 号：TQ028.8[化学工程]