Fabrication of high-permeance dye separation porous membranes based on covalent triazine frameworks via interfacial crystallization

Confronting the escalating global issue of water pollution, membrane separation technology is regarded as one of the most effective methods for wastewater treatment due to its energy-saving potential, high separation efficiency, and environmental friendliness. Covalent organic frameworks (COFs) present unique advantages in the field of membrane separation technology owing to their high specific surface area and tunable pore size. In this study, a new type of triazine-based COF (BTA-TAPT-COF) membrane is synthesized by using 1,3,5-tris-(4-aminophenyl) triazine and 1,3,5-tricarbaldehyde via a room-temperature interfacial polymerization. The porous and crystalline thin membrane exhibits a continuous and dense surface morphology and multi-layer cross-section structure. The BTA-TAPT-COF membrane showed a relatively high rejection rate of 98 % for acidic fuchsin, 92 % for malachite green, and 91 % for Congo red, respectively. The permeance of BTA-TAPT-COF membrane to acetonitrile can be up to 816 L m −2 h −1 bar −1 , and the permeance to ethanol is 647 L m −2 h −1 bar −1 . In the continuous separation test, the rejection rate of the prepared BTA-TAPT-COF membrane can be recovered up to 90 %. These findings provide new strategies for the development of high-permeance triazine covalent organic framework membranes.