Vacuum-Assisted Interfacial Polymerization Technique for Enhanced Pervaporation Separation Performance of Thin-Film...

In this work, thin-film composite polyamide membranes were fabricated using triethylenetetramine (TETA) and trimesoyl chloride (TMC) following the vacuum-assisted interfacial polymerization (VAIP) method for the pervaporation (PV) dehydration of aqueous isopropanol (IPA) solution. The physical and chemical properties as well as separation performance of the TFC_VAIP membranes were compared with the membrane prepared using the traditional interfacial polymerization (TIP) technique (TFC_TIP). Characterization results showed that the TFC_VAIP membrane had a higher crosslinking degree, higher surface roughness, and denser structure than the TFC_TIP membrane. As a result, the TFC_VAIP membrane exhibited a higher separation performance in 70 wt.% aqueous IPA solution at 25 °C with permeation flux of 1504 ± 169 g∙m^-2∙h^-1, water concentration in permeate of 99.26 ± 0.53 wt%, and separation factor of 314 (five times higher than TFC_TIP). Moreover, the optimization of IP parameters, such as variation of TETA and TMC concentrations as well as polymerization time for the TFC_VAIP membrane, was carried out. The optimum condition in fabricating the TFC_VAIP membrane was 0.05 wt.% TETA, 0.1 wt% TMC, and 60 s polymerization time.