AMHERST, Mass. – Jessica Schiffman, a chemical engineer at the University of Massachusetts Amherst, has received a three-year, $340,541 grant from the National Science Foundation to design new water purification membranes that reduce fouling using a thin liquid coating inspired by the Pitcher Plant.
Ultrafiltration membranes are considered the state-of-the-art material for water treatment because they effectively remove particulates and waterborne pathogens from drinking water, Schiffman says. Over time, however, membranes become fouled and require cleaning, which increases water treatment process downtime. Improving membrane lifetime decreases the cost and energy required to produce clean water.
Schiffman, an associate professor of chemical engineering and the Professor James M. Douglas Career Development Faculty Fellow, is collaborating with Caitlin Howell, assistant professor of chemical and biomedical engineering at the University of Maine. Howell has received an additional $304,350 NSF grant to work on this project.
They are designing high-flux, liquid-gated membranes that resist biofouling without the use of chemicals or physical cleaning using a biological characteristic of the pitcher plant. “In nature,” the researchers say, “the Nepenthes pitcher plant uses a thin, immobilized, liquid layer to create an ultra-slippery surface which causes insects to slide into its cup.” They say they were inspired by the pitcher plant to 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, Schiffman and Howell can create reversible pore gates 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,” Schiffman says, “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.”
This research project will result in numerous new research experiences for women and underrepresented groups both at the undergraduate and graduate level at UMass Amherst and Maine.
Schiffman heads an interdisciplinary research group that designs and applies green materials science toward new solutions to grand challenges in human health. “Our research is interdisciplinary in nature,” Schiffman says, “drawing influences from chemical engineering, materials science and microbiology.”