Preparation and properties of metal-PVA composite hydrophilic ultrafiltration membranes

Abstract

Metal-polyvinyl alcohol (PVA) composite ultrafiltration membranes were prepared by coating a certain concentration of PVA solution on metallic fiber sintered membranes. The effects of preparation conditions, such as the coating solution concentration, sequence and times of coating, and heat-treatment on the properties of the composite membranes were studied. The results show that the hole diameter of the composite membrane decreases with the increases of the concentration of PVA, the hole diameter of composite membrane is different when the sequence of coating is different. When the higher concentration of PVA solution is used to coat the metallic membrane for the first time and the other smaller one for the second time, the hole diameter of the composite membrane is relatively small, compared with that of the composite membrane made by the smaller concentration of PVA solution for the first time and the other higher one for the second time. The holes of the composite membrane contract and the stability of the membrane is improved by heat treatment. When metal-PVA composite hydrophilic membranes are used to treat the oil/water emulsion with the concentration of 1000 mg·L⁻¹, the retention is from 80% to 90%, and the permeate flux is from 15 L·m⁻²·h⁻¹ to 40 L·m⁻²·h⁻¹ at pressure of 0.2 to 0.3 MPa.

Keywords

polyvinyl alcohol / composite membrane / hydrophilicity / ultrafiltration / modification