Membrane filtration is energy efficient, simple, scalable, and a key technology for generating clean, safe water and for preventing water pollution. Most commercially available membranes are composed of a handful of polymers, and are limited in the types of separations they can perform. This project aims to build an integrated research and education plan centered on developing novel membranes with new capabilities by designing polymers that self-assemble to form nanostructures. Specifically, this research will focus on controlling the pore size of a novel family of membranes with high flux, exceptional fouling resistance, and sharp size-based selectivity, prepared by coating zwitterion-containing amphiphilic copolymers on porous supports. This research will lead to the development of improved membranes for separations underserved by existing technologies such as peptide separations and textile wastewater treatment. It will create a link between polymer structure and membrane performance that will enable the rational design of membrane materials for specific applications. The research will be fully integrated with a system of educational activities through the involvement of students at multiple stages in developing and performing outreach activities on polymer science and separations. The team will work closely with Tufts Center for Engineering Education and Outreach (CEEO) to develop new outreach activities for K-12 students. The activity ideas will be initiated as term projects in the PI's courses for undergraduate and graduate students. They will be tested in summer workshops for girls in Malden, MA and also implemented in local schools through the Tufts Student Teacher Outreach Mentorship Program (STOMP), and disseminated through the STOMP Network.
This project aims to build an integrated research and education plan centered on designing polymeric materials that self-assemble into functional nanostructures that lead to the desired membrane functionality (e.g. selectivity, fouling resistance), and on discovering fundamental relationships that correlate polymer chemistry and architecture, self-assembled nanostructure, and function in membrane applications. The specific research objective of this project is to understand how the chemical structure and molecular architecture of copolymers with hydrophobic and zwitterionic groups, and their processing methods, affect (1) their self-assembled nanostructure and (2) their performance as membrane materials in selective separations. The team aims to control the pore size of these membranes by varying the polymer architecture and processing, and to develop fundamental structure-property-function relationships that serve as design rules for polymeric membrane materials with tunable, precise and monodispersed pore size. For this purpose, the team will synthesize amphiphilic copolymers that combine hydrophobic and zwitterionic monomers in random, comb and star-block architectures. How these materials self-assemble will be studied by transmission electron microscopy (TEM) and X-ray scattering. Membranes will be made by coating porous supports with these polymers, and the pore size will be determined by filtration experiments. The pore size, permeability and fouling resistance of membranes will be correlated with the self-assembled morphology. The results will be used to compile design rules or a toolkit for the rational design of membrane materials targeted at specific separations that derive their permeability, selectivity and fouling resistance from their self-assembled structure. The research will be fully integrated with several educational, outreach and mentorship activities, such as the development of outreach activities for K-12 students that introduce concepts in polymer science, self-assembly and separations, incorporation of proposed research into undergraduate lab courses and classes, and involvement of undergraduate students in research.
