Solvent purification plays a remarkable role in the chemical and pharmaceutical industries. Energy-efficient membrane technology has shown great potential for this important separation process. This talk will present our recent progress in manipulating solvent transport pathways in membranes with sub-nanosized channels including two-dimensional-material membranes (2DMMs) and metal-organic framework (MOF) membranes. For 2DMMs, we focused on optimizing the assembly behaviour of 2D nanosheets, tuning the microstructure of interlayer channels, and controlling the physicochemical properties of the membrane surface. Assembly methods including vacuum filtration assembly and polymer-induced assembly have been proposed to construct ordered laminates for solvent transport. The size and chemical structure of interlayer channels were further tailored by strategies such as nanoparticle intercalation, cationic control, and chemical modification. Interestingly, the manipulation of surface properties of 2DMMs was proven to contribute to fast solvent transport through interlayer channels. For MOF membrane, recently we payed attention to the defects at atomic-scale in high-valence MOF membranes that disrupt MOF intrinsic apertures and scarify the molecular-sieving property. And we developed a high-probability theoretical coordination strategy to eliminate lattice defects, thus constructing the intrinsic angstrom-sized lattice apertures in MOF membranes (MOF-801, UiO-66, MOF-804 and so on) and achieving high-efficiency solvent separation. In addition, the issues concerning confined mass transport membranes toward practical solvent separation will be discussed with an emphasis on the substrate effect, molecular bridge strategy, and preliminary progress in large-scale fabrication. This talk will also discuss the remaining challenges and the new opportunities of membranes with sub-nanosized channels in solvent separation.

Reference:

1. Chen, L.; Shi, G.; Shen, J.; Peng, B.; Zhang, B.; Wang, Y.; Bian, F.; Wang, J.; Li, D.; Qian, Z.; Xu, G.; Liu, G.; Zeng, J.; Zhang, L.; Yang, Y.; Zhou, G.; Wu, M.; Jin, W.; Li, J.; Fang, H., Ion sieving in graphene oxide membranes via cationic control of interlayer spacing. Nature 2017, 550, 380.
2. Shen, J.; Liu, G.; Han, Y.; Jin, W., Artificial channels for confined mass transport at the sub-nanometre scale. Nat. Rev. Mater. 2021, 4, 294-312.
3. Liu, G.; Guo, Y.; Chen, C.; Lu, Y.; Chen, G.; Liu, G.; Han, Y.; Jin, W.; Xu, N., Eliminating of lattice defects in metal-organic framework molecular-sieving membrane. Nat. Mater. 2023, 22, 769–776.