Colloidal 2D Covalent Organic Framework-Tailored Nanofiltration Membranes for Precise Molecular Sieving

Abstract

Covalent organic frameworks (COFs) with tunable pore sizes and ordered structures are ideal materials for engineering nanofiltration (NF) membranes. However, most of the COFs prepared by solvothermal synthesis are unprocessable powders and fail to form well-structured membranes, which seriously hinders the development of COF NF membranes. Herein, colloidal 2D-COFs with processable membrane formation ability were synthesized by oil-in-water emulsion interfacial polymerization technology. COF NF membranes with tailored thickness and surface charge were fabricated via a layer-by-layer (LBL) assembly strategy. The prepared COF NF membrane achieved precise sieving of dye molecules with high permeance (85 L•m −2 •h −1 •bar −1 ). In this work, the strategy of prepared COF NF membranes based on colloid 2D-COF LBL assembly is proposed for the first time, which provides a new idea for the on-demand design and preparation of COF membranes for precise molecular sieving.

Advances in High-Performance Nanofiltration Membranes Facilitated by Two-Dimensional Materials

“…The resulting carbon is made of an extremely thin polyaromatic backbone and contains well-defined vertically aligned micropores (0.69 nm in diameter). In a similar work, Zhao et al [79] developed colloidal 2D COF membranes with tailored thicknesses and surface charges for precise molecular sieving by oil-in-water emulsion interfacial polymerization technology.…”

“…Two-dimensional ZTC was bottom thesized through carbon deposition on presynthesized IWV zeolite (Si/Al = 28) usi ylene as a carbon source and subsequent zeolite etching with a NaOH solution [ resulting carbon is made of an extremely thin polyaromatic backbone and contai defined vertically aligned micropores (0.69 nm in diameter). In a similar work, Zh [79] developed colloidal 2D COF membranes with tailored thicknesses and charges for precise molecular sieving by oil-in-water emulsion interfacial polyme technology.…”