Highly enantioseparation in membrane-supported one-dimensional metal-organic framework hollow nanotube array prepared via mussel-inspired chemistry

High-enantioselective chiral metal-organic framework (CMOF) nanochannel membranes are of critical impor-tance for chiral enantiomeric separations by taking advantage of their inherent high porosity and intrinsic chirality. However, traditional chiral membranes are still constrained by the permeability-selectivity trade-off, making it challenging to improve both simultaneously. This study described the structure of a new class of membrane-supported one-dimensional MOF hollow nanotube for transport and separation of chiral 1-phenyle-thanol (PE), utilizing a biomimetic polydopamine (PDA)-mediated counter-diffusion synthesis strategy. The inner cylindrical pore channel surface of polycarbonate track-etched membranes (PCTM) was modified by PDA chemistry to control the nucleation and interfacial growth of CMOF crystals, leading to the development of integrated chromatographic micro-column array membranes PCTM@PDA@Cu2C2D and PCTM@PDA@Cu2C2B with one-dimensional (1D) CMOF hollow nanochannels. Compared to PCTM@PDA@Cu2C2B, it was highlighted that the chiral membrane PCTM@PDA@Cu2C2D possessed the higher loading of Cu2C2D functional layer and more suitable steric chiral microenvironment, thus exhibited more outstanding permeability and selectivity for S -PE enantiomer with an enantiomeric excess value up to 90 % under an optimal guest concentration of 250 ppm at 30 degrees C for 1 h. The chiral membrane with 1D MOF hollow nanotubes, created by applying a gentle and simple method to introduce CMOF into the surface and pore channels of the substrate membrane, was expected to be utilized for the large-scale production of chiral separation membranes for industrial applications.