Synthesis and Transport Properties of Novel MOF/PIM-1/MOF Sandwich Membranes for Gas Separation

Abstract

Metal-organic frameworks (MOFs) were supported on polymer membrane substrates for the fabrication of composite polymer membranes based on unmodified and modified polymer of intrinsic microporosity (PIM-1). Layers of two different MOFs, zeolitic imidazolate framework-8 (ZIF-8) and Copper benzene tricarboxylate ((HKUST-1), were grown onto neat PIM-1, amide surface-modified PIM-1 and hexamethylenediamine (HMDA) -modified PIM-1. The surface-grown crystalline MOFs were characterized by a combination of several techniques, including powder X-ray diffraction, infrared spectroscopy and scanning electron microscopy to investigate the film morphology on the neat and modified PIM-1 membranes. The pure gas permeabilities of He, H2, O2, N2, CH4, CO2 were studied to understand the effect of the surface modification on the basic transport properties and evaluate the potential use of these membranes for industrially relevant gas separations. The pure gas transport was discussed in terms of permeability and selectivity, highlighting the effect of the MOF growth on the diffusion coefficients of the gas in the new composite polymer membranes. The results confirm that the growth of MOFs on polymer membranes can enhance the selectivity of the appropriately functionalized PIM-1, without a dramatic decrease of the permeability.

The origin of size-selective gas transport through polymers of intrinsic microporosity

“…Small gas molecules therefore permeate predominantly via the pore diffusion mechanism rather than the activated solution-diffusion mechanism, leading to a non-linearity that appears to be general and, together with solution processability, a defining feature of PIMs. [23][24][25][26][27] As a result, ageing of PIMs affects small molecules much less than large gas molecules. In addition, such correlations provide an excellent probe for the identification of anomalous phenomena in the case of strong polymer-penetrant interactions.…”

“…Previously, we correlated the gas diffusion coefficient of PIMs [23][24][25][26][27] and TR polymers 28 with gas diameter. Previous studies have also focused on the correlation of the diffusion coefficient of gases and their molecular properties.…”

Preparation of Mixed Matrix Membranes Containing ZIF-8 and UiO-66 for Multicomponent Light Gas Separation

“…In contrast, mixed matrix membranes (MMMs) can be easily scaled up and provide excellent separation performance and long-term operational stability as compared to polymer membranes [10]. An MMM is prepared by blending polymers with microporous material fillers, such as porous carbon, carbon nanotubes, zeolite, and MOFs [11][12][13][14][15][16]. Among the fillers for MMMs, MOFs have attracted significant attention based on their tunable pore structures and flexible frameworks, which have excellent compatibility with polymer matrices.…”

Effects of ZnO Nanoparticle on the Gas Separation Performance of Polyurethane Mixed Matrix Membrane

“…Nowadays, membrane processes are one of the most pioneering technologies for gas separation, specifically in the chemical industry, due to its lower processing and initial cost, lower energy consumption, and less space requirements [ 5 , 6 , 7 , 8 ]. The use of polymeric membranes in capturing CO 2 has drawn the attention of many scientists [ 9 , 10 , 11 ]. This is due to their high permeability and/or selectivity.…”