Healable, Recyclable, and Upcyclable Gel Membranes for Efficient Carbon Dioxide Separation.

Ionic liquids (ILs) are prized for their selective dissolution of carbon dioxide (CO2), leading to their widespread use in ionogel membranes for gas separation. Despite their advantages, creating sustainable ionogel membranes with high IL contents poses challenges due to limited mechanical strength, leakage risks, and poor recyclability. Herein, we leverage copolymerized and supramolecularly bound ILs to develop ionogel membranes with high mechanical strength, zero leakage, and excellent self-healing and recycling capabilities. These membranes exhibit superior ideal selectivity for gas separation compared to other reported ionogel membranes, achieving a CO2/nitrogen selectivity of 61.7 and a CO2/methane selectivity of 24.6, coupled with an acceptable CO2 permeability of 186.4 Barrer. Additionally, these gas separation ionogel membranes can be upcycled into ionic skins for sensing applications, further enhancing their utility. This research outlines a strategic approach to molecularly engineer ionogel membranes, offering a promising pathway for developing sustainable, high-performance materials for advanced gas separation technologies.

Controllable hydrogen-bonded poly(dimethylsiloxane) (PDMS) membranes for ultrafast alcohol recovery.

The lack of efficient separation membranes limits the development of bio-alcohol purification via a pervaporation process. In this work, novel controllable hydrogen-bonded poly(dimethylsiloxane) (PDMS) membranes are prepared from self-synthesized supramolecular elastomers for alcohol recovery. Different from the conventional covalently-bonded PDMS membranes, the hydrogen-bonding content and therefore the crosslinking degree in the as-synthesized PDMS membranes can be exactly regulated, by the suitable molecular design of the supramolecular elastomers. The effects of hydrogen-bonding content on the flexibility of the polymer chains and the separation performance of the resultant supramolecular membranes are investigated in detail. In comparison with the state-of-the-art polymeric membranes, the novel controllable hydrogen-bonded supramolecular PDMS membrane exhibits ultrahigh fluxes for ethanol (4.1 kg m-2 h-1) and n-butanol (7.7 kg m-2 h-1) recovery from 5 wt% alcohol aqueous solutions at 80 °C, with comparable separation factors. The designed supramolecular elastomer is therefore believed to provide valuable insights into the design of next-generation separation membrane materials for molecular separations.