Covalent triazine frameworks membrane with highly ordered skeleton nanopores for robust and precise molecule/ion separation

• Published in: Journal of membrane science 2020-02, Vol.595, p.117525, Article 117525
• Main Authors: Li, Guiliang, Wang, Wen, Fang, Qile, Liu, Fu
• Format: Article
• Language: English
• Subjects: Covalent triazine frameworks; Excellent stability; Precise sieving; Two-dimensional membrane
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2019.117525

Two dimensional covalent triazine frameworks (2D-CTF) with controlled pore size and stable structure are a new class of 2D building blocks for constructing separation membrane materials. In this work, we synthesize few-layer 2D-CTF-1 nanosheets with high crystallinity and excellent solvent dispersion using a micro-interface method. The as-prepared 2D-CTF-1 membrane via filtration assembly of few-layer 2D-CTF-1 nanosheets exhibits superior permeability due to its ultralow solvent-interface interaction and the abundant in-plane pores, with a water permeance of 141.5 L m−2 h−1 at 1 bar. The skeleton-pores are proved to be the main transfer channels on 2D-CTF-1 membrane, which are stable and nondeformable by external pressure. Size screening based on the cut-off of skeleton-pore (1.39 nm) is also demonstrated, which enables 2D-CTF-1 membrane a huge application potential in precise molecule/ion sieving. Besides, a stable layered structure in aqueous environment renders 2D-CTF-1 membrane with outstanding separation performance in the long-term running, continuously keeping high permeability and selectively. Thus, this work shows a promising application of 2D-CTF-1 as building blocks for 2D membrane construction in the separation field. 2D-CTF-1 membrane with highly ordered skeleton nanopores (intrasheet pathways) as the main transfer channels exhibits robust and precise molecule/ion separation performance. [Display omitted] •Covalent triazine frameworks membranes were fabricated for precise separation.•The abundant skeleton-pores dominated the mass transfer of 2D-CTF-1 membrane.•Precise molecule sieving was achieved via the skeleton-pores at nano-scale.•2D-CTF-1 membrane showed stable layered structure and separation performance.