Teaching a New Dog Old Tricks: Phase Inversion in Polyelectrolytes

While the design and synthesis of water filters has been the focus of a significant amount of research, there is still a need for easily processable and versatile materials for membrane fabrication. One such available materials system is based on polyelectrolyte complexes. In these complexes, polyanions and polycations form electrostatic rather than covalent bonds that are stable in most solvents. Current polyelectrolyte processing techniques such as layer by layer deposition are not scalable for industrial applications. In this work, a rapid quenching method induces a bi-phase separation within these complexes forming a desired porous structure much faster than current techniques. Additionally, simple changes in the processing chemistry allow for these membranes to be used in a wide suite of applications. Cross-sectional SEM was used to understand the driving factors behind pore formation. Furthermore, solvent stability measurements were taken using the quartz crystal microbalance. Finally, performance characteristics in a range of filtration were assessed.