Highly permeable aquaporin-embedded biomimetic membranes featuring a magnetic-aided approach

Abstract

Aquaporin (AQP) reconstituted biomimetic membranes can potentially be applied in water treatment applications due to the outstanding water permeability and selectivity of AQP. The AQP-embedded mixed matrix membrane was previously obtained using a multilayer polyelectrolyte adsorption method. However, the amount of proteoliposomes embedded in the membrane was lower than expected. In this work, we adopted a magnetic-aided approach to enhance the capacity of AQP-embedded membranes and to maximize the AQP potential for filtration applications. Magnetic nanoparticles were encapsulated inside the proteoliposomes and a magnet was used to accelerate the precipitation and adsorption of these magnetic liposomes onto the membrane matrix. Results from confocal laser scanning microscopy confirm the liposome coverage on the membrane surface was largely improved using this approach. The embedded AQPs facilitate the membrane capability for water transport in the forward osmosis process by enhancing the water flux up to 70%. However, minor defects may still exist in the membrane, which requires further improvements in the membrane structure to minimize the salt reverse flux.