The Permeability-Selectivity of Polyamide-Based Membranes: Role of Ambient Temperature in the Interfacial Polymerization

The thin-film composite (TFC) membrane is the state-of-art membrane for the nanofiltration process. The polyamide active layer of the TFC membrane formed through interfacial polymerization and temperature control during the fabrication process plays an important role in membrane permeability-selectivity. However, the commonly used ambient temperature in membrane production workshops has not been studied systematically. Here, under an ambient temperature range from 10 to 25 °C, we fabricated polyamide layers on a free interface between the aqueous phase and organic phase and on the traditional PES support interface, respectively. We observed polyamide morphologies using the infrared thermal imager for the free interface and SEM for the support interface, respectively. We found that a minor change in ambient temperature could switch the polyamide from a ridge-like to bubble-like morphology. Moreover, with increasing the temperature of the fabrication process from 10 to 25 °C, the pure water permeance exhibited a decline of 38.94%, and the monodivalent selectivity presented a 12.04-fold increase. These findings highlight that the daily ambient temperature of membrane-based enterprises should be fully considered and reasonably used to decrease the production costs in both initial site selection and membrane production stability. Additionally, the permeability-selectivity of the TFC membrane could be tailored through temperature control in a membrane production workshop.