Nanocomposite Membranes for CO2 Separations: Silica/Brominated Poly(phenylene oxide)

[EMIM][Tf2N]-Modified Silica as Filler in Mixed Matrix Membrane for Carbon Dioxide Separation

This study focuses on the effect of modified silica fillers by [EMIN][Tf₂N] via physical adsorption on the CO₂ separation performance of a mixed matrix membrane (MMM). The IL-modified silica was successfully synthesized as the presence of fluorine element was observed in both Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectrometer (XPS) analyses. The prepared MMMs with different loadings of the IL-modified silica were then compared with an unmodified silica counterpart and neat membrane. The morphology of IL-modified MMMs was observed to have insignificant changes, while polymer chains of were found to be slightly more flexible compared to their counterpart. At 2 bar of operating pressure, a significant increase in performance was observed with the incorporation of 3 wt% Sil-IL fillers compared to that of pure polycarbonate (PC). The permeability increased from 353 to 1151 Barrer while the CO₂/CH₄ selectivity increased from 20 to 76. The aforementioned increment also exceeded the Robeson upper bound. This indicates that the incorporation of fillers surface-modified with ionic liquid in an organic membrane is worth exploring for CO₂ separation.

Synthesis and Gas Transport Properties of Poly(2,6-dimethyl-1,4-phenylene oxide)⁻Silica Nanocomposite Membranes

The emulsion polymerized mixed matrix (EPMM) method is a new approach to prepare nanocomposite membranes, in which inorganic nanoparticles are synthesized in situ at the interface of a dispersed aqueous phase in a continuous phase of polymer solution. In this paper, we report the synthesis and characterization of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO)-based EPMM membranes, in which silica nanoparticles are synthesized by the polymerization of tetraethylorthosilicate (TEOS) in the presence of two different co-solvents, ethanol and acetone, which are soluble in both the aqueous phase and the polymer solution. The EPPM membranes prepared in the presence of acetone show greater conversions of TEOS and a different structure of the synthesized silica nanoparticles compared to the EPMM membranes prepared in the presence of ethanol. The former membranes are both more permeable and more selective for O₂/N₂ and CO₂/CH₄. Both types of EPMM membranes are more permeable than the reference PPO membranes. However, while their O₂/N₂ selectivity is practically unchanged, their CO₂/CH₄ selectivity is decreased compared to the reference PPO membranes.

Preparation, characterization and gas separation properties of nanocomposite materials based on novel silane functionalizing polyimide bearing pendent naphthyl units and ZnO nanoparticles

Nanocomposites of polyimide with silane end group and ZnO nanoparticles with good thermal and mechanical properties were prepared and were used for gas separation.