Interfacial polymerization of self-standing ABC-stacking Covalent organic framework membranes for dye separation.

Covalent organic framework (COF)-based membranes are burgeoning candidates for separation technologies owing to their well-ordered channel structures. However, it is still a significant challenge to obtain high-quality COF membranes with a mild and convenient preparation strategy. In this paper, we adopted a simple liquid-liquid interfacial polymerization method to manufacture a self-standing COF membrane with decent crystallinity at room temperature. Aldehyde monomer and catalyst were dissolved in water as the bottom layer and the amine monomer was dissolved in ethyl acetate as the top layer, and new COF membranes were subsequently obtained by interfacial polymerization in the two-phase interface. The synthetic conditions including precursor and catalyst dosage were further optimized, and thus-synthesized PDA-TAPB-ABC membrane displayed a stable rejection to MB of 97.57% with a high water permeance of up to 101. 32 L m−2h−1bar−1. Its dyes separation performance was much better than their AA-stacking counterpart. Moreover, the prepared membrane endowed favorable chemical stability and long-term durability. [Display omitted] • A novel ABC-stacking clover-like COFs membrane with 1.5 nm pore size was synthesized. • Interfacial polymerization method was employed to prepare the PDA-TAPB-ABC membrane. • The ABC-stacking membranes exhibited better dyes separation performance than their AA-stacking counterpart. • The membranes possessed good long-term stability and excellent chemical stability. [ABSTRACT FROM AUTHOR]