Chemically tailored microporous nanocomposite membranes with multi-channels for intensified solvent permeation

Membrane technology is of great significance to realize efficient and energy-saving molecular separation in the petrochemicals, pharmaceuticals, and food industries. However, current membrane materials are subject to an insurmountable trade-off between permeability and selectivity. Herein, we report on a microporous nanocomposite membrane with multiple sophisticated transport channels to intensify solvent permeation. To achieve this goal, we designed polymers of intrinsic microporosity (PIMs) with precise contorted rejection pores as the matrix and covalent organic frameworks (COFs) with uniform one-dimensional (1D) channels as porous nanomaterials. Notably, the selected PIMs and COFs have similar chemical components and structures, ensuring that the interfacial compatibility between them was perfectly addressed. The as-prepared PIMs/COFs nanocomposite membranes showed a significant boost in solvent permeance ( e.g. , 18.1 and 4.2 L m −2 h −1 bar −1 for acetonitrile and ethanol), while leading to high rejection (>90%) toward solute molecules larger than 450 Da. Therefore, this work paves a promising avenue for the development of advanced membranes to achieve efficient organic solvent nanofiltration. • Nanocomposite membranes with multiple permeation channels were prepared. • The design of chemical structures tackled the interfacial compatibility. • Both high permeability and selectivity were achieved at the same time.