(679f) Polybenzimidizole Nanofiltration Membranes with Biomimetic Surfaces

Title:

Polybenzimidizole Nanofiltration Membranes with Biomimetic Surfaces.

Abstract:

Aquaporin is a bidirectional water channel protein present in cells, and it regulates the flow of water in and out of the cells while preventing the transport of ions, protons and hydroxyl ions. Biomimetic membranes attempt to artificially replicate this natural process of highly selective and efficient transport of different molecules across a semi-permeable membrane. Therefore, aquaporins have received worldwide attention because of their potential to form biomimetic membranes with high flux and selectivity for water reuse and desalination. However, challenges involved in the incorporation of aquaporin proteins in membranes limit their applicability. One of them is to attach aquaporins to the membranes without chemically altering or damaging the aquaporins during the binding to the membrane. The second challenge is to design and prepare an assembly that allows biomimetic membranes with aquaporins to sustain hydraulic water pressure gradients without losing their integrity and performance. The overarching objective of this project is to form a biomimetic membrane made of unaltered aquaporins dispersed in a polymeric membrane selective layer and capable of operation under high hydraulic pressure. To this end, polybenzimidazole (PBI) membranes were surface modified with treated aquaporins in order to achieve higher water flux and selectivity. Membranes modified with aquaporins displayed lower flux declines and higher flux recovery values after backwash as compared to unmodified PBI membranes. Also, modified membranes showed improved rejection values for both protein and salt solutions of different concentrations.