Interfacial polymerization: A facile technique for developing solvent resistant nanofiltration (SRNF) membrane

Interfacial polymerization (IP) is recently evolved method to fabricate solvent resistant nanofiltration (SRNF) membrane. Herein the preparation of SRNF is presented which involves the polymerization of piperazine (PIP) and trimesoyl chloride (TMC) on the surface of inert support i.e. Celgard 2400. The extent of interfacial polymerization (IP) on Celgard 2400 membrane was examined afterwards by different analytical techniques including atomic force microscopy (AFM), scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FTIR). Their outcome revealed obvious surface modification of Celgard 2400 with thin and homogenous polyamide layer. Furthermore, the sugar (dextrose, sucrose and raffinose) solutions were passed from SRNF membranes to calculate the molecular weight cutoff (MWCO). Based on sugar rejection, the value of MWCO of SRNF membranes come in the range of nanofiltration (> 300 Da). An economical, chemical resistant, homemade NF Cell was fabricated to conduct permeation study through these membranes. Effect of various reaction conditions i.e. monomer concentrations, curing temperature and reaction time on the synthesis of SRNF membranes was optimized. Bromothymol blue (BTB) was selected dye in ethanol to permeate across SRNF membranes. The rise in monomer concentrations augments the rejection of BTB thereby declining ethanol flux, owing to more even surface coverage of Celgard 2400 membrane. Moreover, the reaction time and curing temperature affect the BTB rejection and ethanol flux in the same way. The pore size in SRNF membranes was estimated theoretically by Hagen-Poiseuille as ~0.59 nm. In conclusion, PIP-TMC monomeric system synthesized stable, homogenous and effective SRNF membranes with distinct rejection and flux values.