Ultrafiltration membranes are considered the 'state-of-the-art' material for water treatment, because they effectively remove particulates and waterborne pathogens from drinking water. Unfortunately, over time, membranes become fouled and require cleaning, which increases water treatment process downtime. Improving membrane lifetime is vital to decreasing the cost and energy required to produce clean water. In nature, the Nepenthes Pitcher Plant uses a thin, immobilized liquid layer to create an ultra-slippery surface which causes insects to slide into its cup. Inspired by the pitcher plant, this research project will develop a new approach to membrane design that reduces the adhesion of foulants and thereby enables the membrane's long-term operation. By properly selecting a stable 'gating liquid' that provides a thin protective layer on the membrane, reversible pore gates are created that quickly open and shut to enable liquid transport while reducing the ability of foulants to attach. Furthermore, when pressure is released, the gating liquid refills the pores, dislodging contaminants trapped within the pores and enabling flux recovery. In addition to improving the functionality of membranes for water purification, understanding the materials-biology interface will help inform the design of new membranes for a broad range of separations, including food processing, blood filtration, and protein purification. A key component of this research is providing an experiential platform to give women and underrepresented groups the confidence and tools to become successful engineers.
This research project will engineer high-flux liquid-gated membranes that resist biofouling without the use of biocides or physical cleaning. The approach employs fabricating liquid-gated membranes using non-toxic perfluoropolyether liquids with various viscosities systematically paired with fluorinated polyethersulfone ultrafiltration membranes to establish a continuous, stable liquid gate. Data acquired from pure water flux experiments as a function of transmembrane pressures will establish the membrane's performance and in-line liquid-gate regeneration capabilities. This experimental data will be benchmarked against both theoretical and chip-based models. The biofouling resistance properties of liquid-gated membranes will be established using organic and biological foulants. This research project provides a critical translation between the structure and properties of liquid-gated membranes and the use of a bioinspired materials approach to reduce the attachment of microbes to membranes while enabling a facile mechanism for flux recovery. This research project will result in numerous new research experiences for women and underrepresented groups both at the undergraduate and graduate level at the University of Massachusetts and the University of Maine. Collaboratively, this team will develop, pilot, and broadly disseminate an educational module called, 'Bioinspired Clean Water Solutions' to middle and high school students. This project is jointly funded by the Molecular Separations program and the Established Program to Stimulate Competitive Research (EPSCoR).
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
