Biomimetic Membrane for Desalination and Water Reuse

Abstract

Water is transported rapidly through most biological cell membranes. Peter Agre and his co-workers revealed the origin of this high water permeability in 1992 with the discovery of the first aquaporin protein. Inspired from biological membranes where aquaporins provide extraordinary water permeability and selectivity, the use of aquaporin to fabricate membranes for water purification has recently drawn worldwide attention. In this study, novel biomimetic membranes consisting of AquaporinZ (AqpZ) for desalination and water reuses are targeted. The work consists of four parts. In the first part, a fundamental work was carried out to demonstrate the AqpZ reconstitution into a lipid bilayer with the aid of the Langmuir-Blodgett technique. This is the first attempt to reconstitute hydrophobic transmembrane proteins using LB method and a three-step mechanism for protein incorporation in the Langmuir film was proposed. In the second part, a nanofiltration membrane was fabricated via immobilization of AqpZ incorporated liposomes onto a porous substrate. The stability of the proteoliposomes was enhanced by introducing a polymerized network within the lipid bilayer. In the third and fourth parts, an AqpZ embedded mixed-matrix membrane is introduced via a layer-by-layer approach. This readily approach is believed having better viability for large-scale production due to its relatively simple formation procedures.