High-Flux Solvent-Resistant Reverse Osmosis Membrane Enabled by D-glucamine Surface Modification

Organic solvent reverse osmosis (OSRO) is an emerging membrane technology for low-energy separation of organic mixtures, yet developing OSRO membranes with both high permeance and robust stability remains challenging. Herein, we present a surface modification strategy using a D-glucamine/ethanol solution to tailor the physicochemical properties of a crosslinked polyimide-supported polyamide OSRO membrane. D-glucamine, as an amino sugar alcohol compound contains a primary amino group and multiple hydroxyl groups, endowing it with specific chemical reactivity and potential for interface modification. The optimized OSRO membrane exhibited a significantly decreased water contact angle from 52.6° of the control membrane to 36.6°, indicating substantially enhanced surface hydrophilicity. The optimized membrane (TFC-D-0.2) achieves a high water permeance of 12.84 LMH/MPa with a NaCl rejection of 98.25% and demonstrates excellent operational stability and pressure resistance (2.5~4.0 MPa). The membrane also shows good tolerance to most organic solvents, maintaining >96.5% NaCl rejection after 30 days of immersion in all tested solvents except acetone. In concentrating ethyl cinnamate/ethanol mixtures over 50 h, the membrane delivers stable performance with an ethanol permeance of ~2.5 L m^-2 h^-1 MPa^-1 and a solute rejection of >88%. This work provides an effective surface modification strategy for developing high-performance OSRO membranes, holding promise for green separation processes in fine chemical industries.