新型耐溶剂纳滤膜的性能表征

Characterization of the new solvent-resistance nanofiltration membrane

考察了纳滤膜在8种常用有机溶剂中的稳定性,通过表面观察、扫描电镜和原子力显微镜分析膜结构的变化情况和膜溶胀程度大小,同时考察了纳滤膜在不同溶剂中的通量和截留性能。稳定性实验结果表明,该纳滤膜在烷烃、醇类、酮类、酯类、苯类等多种溶剂中有良好的稳定性,但二甲基甲酰胺类溶剂对该膜有明显破坏作用;此外,在膜结构没有明显变化的情况下,有机溶剂的存在会使膜的表面粗糙度增加明显。膜分离性能试验结果表明,膜通量受溶剂种类的影响很大,其膜通量变化规律为:水>甲醇>乙醇>丙酮>乙酸乙酯>正己烷;膜对一、二价离子有不同选择性,对分子量大于400的有机物普遍具有良好的截留性能。

The stability of nanofiltration membrane in eight common kinds of organic solvents were studied. By the analysis of surface observation, scanning electron microseopy（SEM） and Atomic force microscopy（AFM） the changes of membrane structure and the degree of membrane swelling were observed. In addition, the experimental study observed the flux and retention performance of the nanofiltration membrane in different solvents. The results of stability test showed that the membrane had good stability in alkanes, alcohols, ketones, esters, benzenes and other solvents, in addition, in the circum- stance the membrane structure had no significant change in the naked eye, the existence of organic solvent would significant- ly increase the roughness of the membrane surface. The results of membrane separation performance test showed that the membrane flux was greatly influenced by the type of solvent, the membrane flux variation： water^methanol^ethanol^ace- tone, ethyl acetate^n-hexane. It had different selectivity in monovalent and divalent ions , and had good retention proper- ties for organic compounds which the Molecular weight was greater than 400.