High-performance COFs composite nanofiltration membrane fabricated by organobase catalyst

Covalent Organic Frameworks (COFs) composite nanofiltration (NF) membrane has high permeation flux and rejection. However, the reaction rate of COFs is relatively slow. Adding acid catalyst is a common method to shorten reaction time. However, the dissatisfactory synthesis rate will lead to irregular structure of COFs materials. In this work, it is the first time to use organobase as a catalyst to prepare COFs composite membrane. The COFs structure will be optimized and the membrane performance can be enhanced. The prepared TpPa-PIP membrane compared with acid catalyzed TpPa-HAc membrane has better permeability, permeance of 89 L m−2·h−1·bar−1 and CR rejection of 99.54 %. This improvement is because of the TpPa-PIP intermediate made slower reaction speed that improves the overall regularity and crystallinity of COFs. Therefore, it is better method for broadening the application of organobase-catalyzed in preparing membranes.