Preparation of positively charged nanofiltration membrane from 2-hydroxypropyltrimethyl ammonium chloride chitosan by 1,4-butanediyl diglycidyl ether cross-linking

摘要

A novel positively charged composite nanofiltration (NF) membrane was prepared using 2-hydroxypropyltrimethyl ammonium chloride chitosan as active layer, polyacrylonitrile ultrafiltration membrane as substrate layer, and 1,4-butanediol diglycidyl ether as cross-linking reagent. The observation from scanning electron microscope revealed its composite structure. At room temperature and cross-flow rate of 40 L h~(-1), the permeability for pure water was 14.3 L h~(-1) m~(-2) MPa~(-1). With an increase in operating pressure, the flux increased linearly. The rejection to different salt solutions was decreasing in the order of CaCl_2, MgCl_2, MgSO_4, NaCl, and Na_2SO_4, revealing the rejection characteristic of positively charge NF membrane. And it had good ion perm-selectivity.