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Updated: Nov 30, 2025
Electrophoretic Crystallization of Ultrathin High-performance Metal-organic Framework Membranes
Published on: August 16, 2018
Cross-linked Graphene Oxide Framework Membranes with Robust Nano-Channels for Enhanced Sieving Ability
Baoqiu Yuan1, Mingxin Wang1, Bo Wang1
1Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education, MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
Abstract:
It remains challenging for graphene oxide (GO) membranes to achieve highly efficient performance and sufficient stability for aqueous molecule/ion precise separations. Herein, a molecular-level rational structure design protocol was proposed to develop ceramic-based graphene oxide framework (GOF) membranes with significantly enhanced sieving performance and stability for efficient removal of salts and micropollutants. Via a molecular cross-linking strategy, interlayered nanochannels between GO nanosheets can be rationally designed, featuring precisely tailorable channel size, promising surface chemistries and remarkably robust stability suitable for aqueous separation. Due to a significantly decreased nanochannel size, cross-linking of TU (thiourea) molecule significantly improved monovalent salt rejection (95.6% for NaCl), outperforming existing state-of-the-art GO-based, commercial organic nanofiltration and emerging two-dimensional MoS2 membranes, while moderately decreasing water permeability. In comparison, the GOF membranes cross-linked with MPD (m-phenylenediamine) exhibited a simultaneous increase in permeability and rejection for both salts and micropollutants (21.0% and 53.3% enhancement for chloramphenicol (CAP) solution), breaking their conventional trade-off issue. Cross-linking mechanism indicates that more robust nanochannels were formed by stronger covalent bonds via dehydration condensation between amine (TU/MPD) and carboxyl groups (GO), and nucleophilic addition between amine (TU/MPD) and epoxy groups (GO). Molecule/ion separation mechanism involved size sieving (steric hindrance), electrostatic interaction, Donnan effect, and partial dehydration effect. This work provides a novel protocol for rationally designing size and surface chemistry of highly robust GO nanochannels at a subnanometer level to construct water-stable functional GOF membranes with enhanced sieving performance for water treatment applications.
