Blended Membrane of Polyethylene-Glycol-Grafted-PIM-1 and Tröger's Base Polymer for the Separation of Pentose and Hexose

Graphical Self-supported osmotic membranes were prepared by blending PIM-1-mPEG, which was obtained by modifying PIM-1 with polyethylene glycol monomethyl ether (mPEG), and hydrophilic Tröger's base polymer (DMBP-TB). The membranes utilized microporous molecular sieves and the differences in solute-membrane interactions to achieve high pentose/hexose selectivity in aqueous solutions. Monosaccharides are vital building blocks in bioengineering applications; however, their extraction from intricate mixtures is challenging and uses substantial amounts of energy. Polymers of intrinsic microporosity (PIMs) offer an innovative avenue for separating monosaccharides. We modified PIM-1membranes to improve the glucose/xylose separation by incorporating polyethylene glycol monomethyl ether (mPEG). The optimal mPEG (molecular weight: 1000 Da; mass fraction: 2.5 %; solvent: methanol) delivered a xylose separation coefficient of 2.62. With the hybrid membrane of PIM-1-mPEG (50 w.t.%) and hydrophilic Tröger's base polymerer (DMBP-TB, 50 w.t.%), the separation factor for xylose/glucose in an aqueous solution was 2.51 for single-stage running and 11.32 after five-stage running. There are large fractions of micropores for PIM-1-mPEG, and there is difference on solute-membrane interactions for pentose/hexose, which are regarded to be the main driving force for the high pentose/hexose selectivity in methanol. The blending of PIM-1-mPEG and DMBP-TB, integrates the microporosity and hydrophilicity, finally endues the high pentose/hexose selectivity in aqueous solution. These microporous membranes are promising materials for efficiently separating monosaccharides and jnl> small organic molecules while minimizing energy consumption. We established a solid foundation for further exploring microporous membranes for various applications, notably in bioengineering.