Hydrocarbon separation relies on energy-intensive distillation. Membrane technology can offer an energy-efficient alternative but requires selective differentiation of crude oil molecules with rapid liquid transport. We synthesized multiblock oligomer amines, which comprised a central amine segment with two hydrophobic oligomer blocks, and used them to fabricate hydrophobic polyamide nanofilms by interfacial polymerization from self-assembled vesicles. These polyamide nanofilms provide transport of hydrophobic liquids more than 100 times faster than that of conventional hydrophilic counterparts. In the fractionation of light crude oil, manipulation of the film thickness down to ~10 nanometers achieves permeance one order of magnitude higher than that of current state-of-the-art hydrophobic membranes while retaining comparable size- and class-based separation. This high permeance can markedly reduce plant footprint, which expands the potential for using membranes made of ultrathin nanofilms in crude oil fractionation.

Azo-COP-2 is a nanoporous polymer with exceptional CO2/N2 separation performance. In this study, we further investigate the application of Azo-COP-2 as a low-energy CO2 adsorbent and porous filler in mixed matrix membranes (MMMs) for CO2/N2 separation. As an adsorbent, the UV-irradiated Azo-COP-2 showed lower CO2 uptake than in the non-irradiated state and Azo-COP-2 also exhibited highly efficient CO2 photoswitching between the two states. Combined with high CO2/N2 selectivity, this makes Azo-COP-2 an excellent candidate for low-energy CO2 capture and release. Azo-COP-2 is also shown to be a beneficial filler in MMMs. For polysulfone-based MMMs, the CO2 permeability and CO2/N2 selectivity could be increased up to 160% and 66.7%, respectively. The strategy shows the great potential of Azo-COP-2 not only for a lowenergy CO2 adsorbent but also to improve the performance of conventional polymeric membranes for CO2 post-combustion capture.

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