Fabrication of an aquaporin-based forward osmosis membrane through covalent bonding of a lipid bilayer to a microporous support

Abstract

AquaporinZ (AqpZ)-containing, planar, biomimetic membranes hold great application potential in water purification and seawater desalination, due to the excellent permeability and selectivity of AqpZ. However, there remain many challenges to production of robust and defect-free supported lipid bilayer (SLB) biomimetic membranes. By forming amide bonds between the lipid bilayer and microporous substrate, we fabricated an AqpZ-incorporated SLB forward osmosis (FO) membrane, with a large area of 36 cm 2 . With deionized water and 2 mol/L MgCl 2 draw solution, the AqpZ-incorporated biomimetic membrane exhibited a water flux of ~19.2 L·m −2 ·h −1 (LMH) and a reverse solute flux of ~3.2 g·m −2 ·h −1 (gMH). When positively charged phospholipid 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) was blended in the 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) bilayer, a higher flux (~23.1 LMH) could be reached accompanied with a constant reverse salt flux of 3.1 gMH, due to more AqpZ being embedded in the mixed bilayer. From nanofiltration (NF) test, the water permeability (A) could reach 6.31 LMH/bar with a relative low solute permeability (B) of 1.7 LMH for AqpZ-DOPE/DOTAP SLB membrane. When rinsed by a 0.24 mmol/L TritonX-100 (TX-100) surfactant solution, water flux and reverse salt flux of the biomimetic membrane with covalent bond only slightly increased, whereas the membrane without covalent bonds showed significant increase in both water flux and reverse salt flux after TX-100 treatment.This paper presented an effective method for preparation of biomimetic FO membrane with good separation performance as well as excellent stability and durability. Graphical Abstract IntroductionIn recent decades, forward osmosis (FO) has gradually emerged as one of the most promising water purification and desalination technologies in water supply, energy generation, and food processing. 1-4 Unlike pressure-driven membrane processes, like reverse osmosis (RO) and nanofiltration (NF), FO is a naturallyoccurring osmosis-driven membrane process that takes advantage of the osmotic pressure gradient to impel water across a semipermeable membrane, from the feed solution side with high chemical potential,

Performance evaluation of interfacial polymerisation-fabricated aquaporin-based biomimetic membranes in forward osmosis

“…The selective layers of previously reported ABMs were prepared by directly fusing or collapsing AQPs-incorporated liposomes onto porous substrates or membrane surfaces. [17][18][19] However, most of the membranes fabricated by this method exhibit relatively low NaCl retention, which renders them unusable for forward osmosis due to draw-solute loss and low feed-solute rejection. Maintaining the activity of AQPs in the external environment and reducing defect formation in the selective layer remain challenging tasks in the preparation of high-performance ABMs.…”

Glioblastoma cells labeled by robust Raman tags for enhancing imaging contrast

“…After the SA modification, the C = O bond at 1697 cm −1 is observed. The vibrations from C-O bond of the ester group and from SO 3 2group are observed after modification of the sulfo-NHS [31]. Finally, the dip at 1644 cm −1 from amide I and 1541 cm −1 from amide II are contributed by the antibodies.…”

Advances in forward osmosis membranes: Altering the sub-layer structure via recent fabrication and chemical modification approaches

“…Initially, a polycationethyleneimine (PEI) was deposited followed by a polyanion polystyrene Additionally, a novel strategy was developed to form stable aquaporin based biomimetic membranes with excellent FO performance [206]. This strategy is described in Fig.…”