There’s a critical need for reliable and equitable access to safe drinking water, and it is a major and growing challenge worldwide. Safe and readily available water is important for public health, whether it is used for drinking, domestic use, food production, or recreational purposes. One method that has been of particular interest to purify water is using Ultra Filtration (UF) membranes with a pore size range of 1-100 nm. UF commercial membranes have found utility in the decontamination of drinking water, wastewater treatment, and membrane bioreactors. Unfortunately, UF membranes are limited by the stochastic pore sizes and undesirable surface chemistry which results in inadequate separations and prone to fouling. Alternatively, recent research shows that a more successful method to purify water is to utilize Block Copolymer (BCP) membranes, which have similar pore sizes and hence sharp filtration cut-offs. However, most of the work in BCP membranes has focused on using cylindrical pores. In this work, we have developed novel slit-based membranes using lamellar block copolymers. The lamellar BCPs are vertically oriented in sone step film casting process by tuning the solvent evaporation rates with additives. The vertically oriented BCPs are converted to slit membranes using a wet etching process. The pore sizes of these slit-based membranes are measured using surface characterization and filtration cut-off experiments. We demonstrate the enhanced separation of 1-D nanomaterials as compared to the 0-D nanomaterials using these slit-based membranes, which is facilitated by the shape similarity of 1-D nanomaterials with the nano-slits. Such membranes possess the potential for shape-selective filtration of biomaterials such as proteins, viruses, and pharmaceutical drugs and open avenues for shape-selective filtration across a spectrum of applications.

Shape-selective filtration using lamellar block copolymer membranes

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.