A thin-film composite polyarylester membrane prepared from orcinol and trimesoyl chloride for organic solvent nanofiltration

It is necessary to recover dimethyl sulfoxide (DMSO) from pharmaceutical organic wastewater. In recent years, organic solvent nanofiltration (OSN), as an important means of recovering organic solvents, is being studied and paid attention constantly. Here, we prepared a solvent-resistant composite nanofiltration membrane with stable performance for the recovery of DMSO solvent using orcinol (OL), a natural alkyl resorcinol compound to synthetize a thin-film composite polyarylester membrane with trimesoyl chloride (TMC) by interfacial polymerization (IP) on the polyetherimide (PEI) substrate crosslinked by ethylenediamine (EDA). The results of chemical characterization such as X-ray photoelectron spectroscopy (XPS) and attenuated total reflection fluorescence transform infrared spectroscopy (ATR-FTIR) show that interfacial polymerization occurs between TMC and orcinol on the surface of PEI and forms polyarylester top-layer. The rejection of crystal violet (CV, 407.99 g/mol) in DMSO takes place by 91%, and the maximum permeance is about 3.1 L.m−2.h−1.bar−1. To further improve selectivity of membrane, microwave heating was adopted as a strengthening method of interfacial polymerization. The results illustrate that the microwave heating can significantly increase the rejection of OL-TMC membrane. The optimized membrane shows stable solvent resistance in DMSO with a rejection of 98% for CV and the permeance of 1.8 L.m−2.h−1.bar−1 and a rejection of 81% for clindamycin phosphate (CLP) with the permeance of 1.9 L.m−2.h−1.bar−1. This study not only opens up an interesting research field for more natural polyphenols as solvent-resistant nanofiltration membrane materials, but also indicates that microwave-assisted heating can be used as an important means during IP process to strengthen the properties of OSN membranes.