Designing Nanofluidic Channels of Boron Nitride Nanosheets/Aramid Nanofibers/Covalent Organic Frameworks Nanofiltration Membrane for Ultrafast Mass Transport

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2024-10, Vol.20 (40), p.e2402284-n/a
• Main Authors: Ning, Doudou, Lu, Zhaoqing, Hua, Li, Zhang, Xinyi, Li, Nan, Huang, Kaiyue, E, Songfeng
• Format: Article
• Language: English
• Subjects: 2D lamellar nanofiltration membrane; Adhesive strength; aramid nanofibers; Boron nitride; Brackish water; Channels; covalent organic frameworks; Durability; dye separation; Fluidics; Mass transport; Membranes; Nanofibers; Nanofiltration; nanofluidic channels; Nanofluids; Nanosheets; Seawater; Stability
• ISSN: 1613-6810; 1613-6829; 1613-6829
• DOI: 10.1002/smll.202402284

2D lamellar nanofiltration membrane is considered to be a promising approach for desalinating seawater/brackish water and recycling sewage. However, its practical feasibility is severely constrained by the lack of durability and stability. Herein, a ternary nanofiltration membrane via a mixed‐dimensional assembly of 2D boron nitride nanosheets (BNNS) is fabricated, 1D aramid nanofibers (ANF), and 2D covalent organic frameworks (COF). The abundant 2D and 1D nanofluid channels endow the BNNS/ANF/COF membrane with a high flux of 194 L·m‒2·h‒1. By the synergies of the size sieving and Donnan effect, the BNNS/ANF/COF membrane demonstrates high rejection (among 98%) for those dyes whose size exceeds 1.0 nm. Moreover, the BNNS/ANF/COF membrane also exhibits remarkable durability and mechanical stability, which are attributed to the strong adhesion and interactions between BNNS, ANF, and COF, as well as the superior mechanical robustness of ANF. This work provides a novel strategy to develop robust and durable 2D lamellar nanofiltration membranes with high permeance and selectivity simultaneously. The boron nitride nanosheets/aramid nanofibers/covalent organic frameworks (BNNS/ANF/COF) membranes with abundant 1D and 2D nanofluid channels are obtained by a mixed‐dimensional assembly. Owing to the synergies of the size sieving and Donnan effect, the BNNS/ANF/COF membrane demonstrates high rejection (among 98%) for those dyes whose size exceeds 1.0 nm. Moreover, it also exhibits remarkable durability, superior mechanical stability, and excellent anti‐swelling properties.