Ligand Substitution: An Effective Way for Tuning Structures of ZIF-7 Nanoparticles (NPs) and Improving Energy Recovery Performance of ZIF/PA TFN Membranes

Chaojie Bai; Yang Gao; Zuoqun Zhang; Longdou Tu; Dajian Cai; Zixuan Lv; Congjie Gao; Lixin Xue

doi:10.1021/acsami.2c22701

Ligand Substitution: An Effective Way for Tuning Structures of ZIF-7 Nanoparticles (NPs) and Improving Energy Recovery Performance of ZIF/PA TFN Membranes

ACS Appl Mater Interfaces. 2023 Mar 13. doi: 10.1021/acsami.2c22701. Online ahead of print.

Authors

Chaojie Bai¹, Yang Gao¹, Zuoqun Zhang¹, Longdou Tu¹, Dajian Cai¹, Zixuan Lv¹, Congjie Gao¹, Lixin Xue^{1

2}

Affiliations

¹ Center for Membrane Separation and Water Science & Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, China.
² College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang 325035, China.

PMID: 36913424
DOI: 10.1021/acsami.2c22701

Abstract

It is an important initiative to reduce the building energy consumption using energy recovering ventilation (ERV) systems. The application of ERV systems is hindered by the low CO₂ barrier performance of commercial total heat exchange membranes (THEMs) that lead to unsatisfactory indoor air refreshing rate, and there is an urgent need for THEMs that have improved CO₂ barrier properties and effective energy recovery efficiencies. Here, we report the formation of novel ZIF/PA TFN THEMs based on ZIF-7-X nanoparticles (NPs) with "core-shell" structures and tunable particle sizes, formed from benzimidazole (BIM) ligands and BIM substituted by -NH₂, -CH₃, -C₂H₅, and -C₃H₇ functional groups. The NPs were mixed with pyr omellitic triformyl chloride (TMC) in the organic phase during the interface polymerization process to form ZIF/PA TFN membranes. The total heat exchange performance of ZIF/PA TFN membranes could be effectively modified by the type and quantity of ZIF-7-X NPs added. The CO₂ barrier properties and water vapor permeability of ZIF/PA TFN membranes could be improved by the addition of optimal levels of ZIF-7-X NPs, showing low CO₂ permeance of 7.76 GPU, high H₂O permeance of 663.8 GPU, and excellent enthalpy exchange efficiency of 72.1%. This work provided an effective strategy for tuning not only the nanostructures of ZIF-7 fillers but also the CO₂ barrier properties of the formed ZIF/PA TFN membranes.

Keywords: CO2 barrier property; TFN membrane; ZIF-7-X; nanoparticle; total heat exchange; water vapor permeability.