(711f) Synthesis of Biomimetic Polybenzimidazole Nanofiltration Membranes

The search for new technologies for water treatment is an increasingly important research topic. Depending on the application, water is desired in varying degrees of purity. For some applications, such as desalination, a very high degree of purification is desired. This project relies on the idea of combining the ultra-efficient functioning of biological molecules with the productivity of synthetic membranes. A successful formulation should lead to the production of water purification membranes with high selectivity along with high water flux. Aquaporin, a highly selective water channel protein, has received worldwide attention because of its potential to form biomimetic membranes with high flux and rejection for water reuse and desalination. The high water permeability and selectivity of aquaporins makes aquaporin-based biomimetic membranes potentially attractive for water purification and “green-energy” production.  In nature, aquaporins move water across membranes from areas of low dissolved solids to an area of higher dissolved solids by osmosis. However, if pressure is applied to the side of the membrane containing higher concentrations of dissolved material, pure water can flow through the aquaporins back into the low concentration side of the system. In this sense, pressure can be used to induce reverse osmosis across a membrane embedded with aquaporins and effectively purify water.

The overarching objective of this project is to form a biomimetic membrane made of unaltered aquaporin dispersed in a membrane selective layer and capable of operation under high hydraulic pressure. A challenge of the current study is to design and prepare an assembly that allows artificial biomimetic membranes with embedded aquaporin proteins to sustain hydraulic water pressure gradients without losing their integrity and performance. To this end, aquaporins will be dispersed in hydrophilized polybenzimidizole (PBI) membranes that are chemically and mechanically strong so that the resulting biomimetic membrane will be able to withstand high hydraulic pressures. Membranes with pores or channels specifically engineered to maximize water transport or ion selectivity would offer the potential for dramatically more efficient operation compared to conventional polymer membranes.