Fig. 3: Mechanism of dual-activation interfacial polymerization.
From: Assembling covalent organic framework membranes with superior ion exchange capacity
a Fabrication of the TpBD-(SO3H)2 iCOFMs by non-activation IP: (i) schematic diagram and (ii) digital photo of the IP system after 72 h of reaction. b Fabrication of the TpBD-(SO3H)2 iCOFMs by single-activation IP (aldehyde monomer activation): (i) schematic diagram, (ii) digital photo of the IP system after 72 h of reaction, and (iii) SEM image of the TpBD-(SO3H)2 COF nanosheets in the water phase. c Fabrication of the TpBD-(SO3H)2 iCOFMs by single-activation IP (amine monomer activation): (i) schematic diagram, (ii–iv) digital photo, cross-section SEM image and PXRD pattern of the TpBD-(SO3H)2 iCOFMs. d Fabrication of the TpBD-(SO3H)2 iCOFMs by dual-activation IP: (i) schematic diagram, (ii–iv) digital photo, cross-section SEM image and PXRD pattern of the TpBD-(SO3H)2 iCOFMs. e Fukui functions for nucleophilic attack sites (f+) of aldehyde monomer. f Fukui functions for electrophilic attack sites (f-) of amine monomer.
