(7fy) Bio-Mimetic Membranes for Energy Efficient Clean Water Processes

Research Interests: water-energy nexus, bio-mimetic materials, bio-inspired materials, membrane separations, water and wastewater treatment systems, surface functionalization

Over one billion people lack access to clean drinking water and membranes provide an energy efficient platform to purify impaired waters and fill that need. Unfortunately, treatment of impaired waters exposes membranes to biological and abiotic species, which leads to fouling and loss of membrane productivity over time. Since reduction in flux due to fouling is one of the largest costs associated with membrane processes in water treatment, new membrane modification methods that limit fouling would have significant economic and societal impacts.

In one project, a dual-mode membrane coating was developed that is capable of limiting and reversing membrane biofouling by switching reversibly between anti-fouling and anti-microbial states of biofouling control. This strategy differs fundamentally from most other surface modification strategies that rely solely on using chemical coatings designed only to weaken foulant adhesion and, thus, limit their accumulation or adding biocides. In the second project, a method to nano-pattern the surface of thin film composite membranes was developed to combine with chemical coatings to yield membrane surfaces that are more effective at fouling control than either method alone. Nature provides many examples where structured features can prevent accumulation of ‘foulant’ materials on the surface (i.e., shark skin, lotus leaves, etc.). We were the first to show that polyamide thin film composite membranes can be directly patterned.

Proposed future research will apply my expertise in membrane modification to mimicking bio-inspired materials to solve challenging separations problems and to improve the energy efficiency of membrane processes. One research project would be to mimic shark skin patterns by fabricating microfiltration membranes by phase inversion to reduce fouling in membrane distillation processes. Membrane distillation has a lot of promise in desalination, and water and wastewater treatment, however fouling on the membrane surface and in the membrane pores is still a major issue. A second project would be to modify membrane surfaces by mimicking a chemistry similar to what mussels use to exclude salt to stay attached to rocks to improve the salt rejection of nanofiltration membranes. Nanofiltration membranes offer the benefit of some salt rejection and higher fluxes than reverse osmosis membranes. However, if the salt rejection is increased while maintaining the flux, the energy efficiency would increase for desalination. A challenge of this research will be implementing nature’s models into a membrane system. The results of this research will have implications in the field of membrane science, water treatment, and wastewater reuse.

Teaching Interests:

For 2 years, I have taught Membrane Separations for Clean Water and Energy through the Creative Inquiry program at Clemson University. I taught 12 students the basics of different types of membranes and guided them on designing and building two different membrane separation units to be used for unit operations lab and outreach events. The students presented two posters over the course of this class, including winning 2^nd place in People’s Choice at the Focus on Creative Inquiry event at Clemson in 2016. In conjunction with my NSF GRFP, I have participated in numerous outreach events through Clemson to engage K-12 students in science through filtration and separation activities. As a fundamentally trained chemical engineer with a focus on membrane separations, I am excited to teach courses related to reaction engineering, mass and energy balances, transport, polymers, and membrane separations.