Iranian Journal of Chemical Engineering (IJChE)
Scientific Journal

A ternary pebax based mixed matrix membrane incorporated by MOF and [Omim][PF6] for efficient gas separation

Articles in Press

Document Type : Regular Article

Authors

Reza Abedini
Mina Kheirtalab

EOR and Gas Processing Research Lab., Faculty of Chemical Engineering, Babol Noshirvani University of Technology, Babol, Iran

10.22034/ijche.2026.581568.1594
Abstract
In this study, ternary mixed matrix membranes (MMMs) were fabricated using Pebax® 1657 as the polymer matrix, [Omim][PF6] ionic liquid (IL) as a low-molecular-weight additive, and MIL-101(Cr) metal–organic framework (MOF) nanoparticles as fillers for CO2 separation. The IL content was varied from 2–8 wt.% in Pebax blend membranes, while MIL-101 loading in the ternary MMMs ranged from 2–8 wt.%. Structural and thermal analyses, including FTIR, SEM, DSC, and TGA, confirmed interactions between the IL and polymer chains, good dispersion of MIL-101. Incorporation of [Omim][PF6] increased gas permeability, while subsequent incorporation of MIL-101 further improved CO2 transport and separation performance. The optimized P-IL8-M8 membrane, containing 8 wt.% [Omim][PF6] and 8 wt.% MIL-101, exhibited a CO2 permeability of 327.2 Barrer with CO2/CH4 and CO2/N2 ideal selectivities of 31.5 and 83.9, respectively, at 30 °C and 10 bar. Compared with neat Pebax, the optimized ternary MMM showed substantial improvements in both CO2 permeability and gas-pair selectivity. The enhanced performance is interpreted as a synergistic effect of the ionic liquid and MIL-101, with the IL potentially promoting polymer chain mobility and free-volume generation, while the CO2-philic MIL-101 framework may provide additional favorable sites for CO2 sorption and contribute to selective CO2 transport. Although sorption, diffusion coefficients, and fractional free volume were not directly measured, these effects are considered plausible mechanisms consistent with the observed gas transport behavior and structural characterization. The results demonstrate the potential of Pebax/[Omim][PF6]/MIL-101 ternary MMMs for efficient CO2 separation from CH4- and N2-containing gas streams.

Keywords

Pebax
[Omim][PF6]
Mixed matrix membrane
MIL-101
Gas separation
Subjects
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