Hydroxypropyl-β-cyclodextrin-incorporated Pebax composite membrane for improved permselectivity in organic solvent...

Area of Science:

• Materials Science
• Chemical Engineering
• Separation Science

Background:

• Cyclodextrins possess unique hollow cavity structures and are sustainable, non-toxic macrocyclic molecules.
• These properties make cyclodextrins suitable building blocks for organic solvent nanofiltration (OSN) membranes, enhancing permeability and selectivity.

Purpose of the Study:

• To fabricate and characterize crosslinked hydroxypropyl-β-cyclodextrin/poly(ether-block-amide) (CHP) membranes for OSN applications.
• To investigate the effect of HP-β-CD concentration and crosslinking time on membrane performance.

Main Methods:

• Hydroxypropyl-β-cyclodextrin (HP-β-CD) was incorporated into a poly(ether-block-amide) (Pebax) layer on a polysulfone support.
• The composite layer was crosslinked using toluene 2,4-diisocyanate to form CHP membranes.
• Membrane performance was evaluated by dye removal in methanol, with varying HP-β-CD concentrations (x) and crosslinking times (y).

Main Results:

• Adjusting HP-β-CD concentration and crosslinking time allowed manipulation of the microporous structure and surface morphology of CHP membranes.
• The optimal CHP$_{0.5-10}$ membrane achieved a high methanol permeance of 8.7 L m$^{-2}$ h$^{-1}$ bar$^{-1}$ and high dye rejection (>96%).
• The optimized membrane demonstrated excellent running stability, maintaining performance for at least 336 hours.

Conclusions:

• The developed CHP membranes exhibit promising performance for organic solvent nanofiltration, attributed to their tailored microporous structure and surface morphology.
• This study highlights the potential of cyclodextrins and other macrocyclic molecules in creating advanced membranes for efficient organic solvent reclamation and pollutant removal.