Preparation and performance of novel thermal stable composite nanofiltration membrane

Abstract

The novel thermal stable composite nanofiltration membranes were prepared through the interfacial polymerization of piperazine and trimesoyl chloride on the poly (phthalazinone ether) ultrafiltration substrate. The effects of polymerization and testing conditions on membrane performance were studied. The surface morphologies of the substrate and the composite membranes were observed by means of scanning electron microscopy (SEM) and atomic force microscopy (AFM). The separation properties of membranes for dyes and salts were tested. The composite membranes show good thermal stability. The rejection for Na₂SO₄ was kept over 96%, while the flux reached 400 L·m^-2·h^-1 when it was tested at 1.0 MPa and 80°C. When tested at 1.0 MPa and 60°C, the rejection of the composite membrane for dyes was kept at high level, and the flux reached 180–210 Lm^-2·h^-1, while the rejection for NaCl was lower than 20%.

Keywords

ultrafiltration membrane / interfacial polymerization / composite membrane / nanofiltration membrane / thermal stability