Enhanced CO2 separation performance of mixed-matrix membranes through PIM-1 based surface engineering using non-solvent induced surface deposition

초록

Carbon dioxide (CO2), a major greenhouse gas, significantly contributes to global warming and negatively affects ecosystems. This necessitates the development of high-performance materials for CO2 removal. Mixed-matrix membranes (MMMs) incorporating metal-organic frameworks (MOFs) are effective for CO2 separation, but the poor interfacial compatibility between the polymer and filler often reduces membrane performance. In this study, the interfacial issue in MMMs was addressed by surface modification of ZIF-8 with polymers of intrinsic microporosity (PIM-1) using the non-solvent induced surface deposition method. The PIM-1 polymer on the ZIF-8 surface has a high surface area, which prevents pore blockage and overcomes the interfacial issue with the polymer matrix. The effect was studied using Pebax-1657 as a host polymer matrix. At 20 % loading, MMMs with surface-modified ZIF-8@PIM-1 exhibited enhanced CO2/N2 and CO2/CH4 selectivities, increasing from 44.4 to 15.1 to 45.6 and 18.8, respectively, compared to those of MMMs with unmodified ZIF-8. In addition, the CO2 permeability increased by about 40 %, from 71 barrer to 105 barrer, compared to that of pure Pebax-1657. This study demonstrates that simple surface modification with PIM-1 can effectively address the interfacial issues between the polymer matrix and MOF in MMMs.

키워드