Ultra-Thin Pore-Spanning Biomimetic Membrane Embedded with Aquaporin Z In Forward Osmosis

Aquaporin (Aqp), a highly selective water channel protein, has received worldwide attention because of its potential to form Aqp-based membranes with high flux and rejection for water reuse and desalination. However, proof-of-concept has never been demonstrated. Here, we molecularly architect a pore-spanning biomimetic membrane embedded with aquaporin Z (AqpZ) via a combination of surface modification followed by pressure-assisted vesicle adsorption and, finally, covalent conjugation-driven vesicle fusion onto a porous support. The biomimetic membrane consisting of a 1:100 molar ratio of AqpZ to poly(2-methyloxazoline)-b-poly(dimethylsiloxane)-b-poly(2-methyloxazoline), end functionalized with acrylate, (PMOXA₁₂-PDMS₅₄-PMOXA₁₂) exhibits a water flux as high as 142 L/m²/h with a sufficiently low salt reverse flux in forward osmosis (FO) operation using 2.0 M NaCl as the draw solution. The proposed AqpZ embedded pore-spanning membrane design not only shows superior performance in the FO process, but also may open a new horizon for next-generation membranes aimed at water purification and production.

Acknowledgement

This work was fi nancially supported by the Environment and Water Industry Programme Offi ce (EWI) (NUS grant number: R-279-000-293-272) under the Singapore National Research Foundation (NRF).