Mixed matrix membranes based on silica nanoparticles and microcellular polymers for CO₂/CH₄ separation

Abstract

Mixed matrix membranes made from silica nanoparticles and microcellular polymers were prepared from Matrimid® 5218 combined with tetramethoxysilane, tetraethoxysilane, and tetrapropoxysilane via the sol–gel method. The nanoparticles were prepared in situ during membrane casting yielding a homogeneous distribution inside a foamed polyimide structure. Mixed matrix membranes with SiO2 contents up to 16% wt. were treated at 60℃, 100℃, 150℃, and 200℃. Thermal gravimetric analysis and Fourier transform infrared spectroscopy analyses were performed providing information on chemical composition and thermal stability, while the porous structure (average cell diameter and cell density) was studied by scanning electron micrograph. Also, dynamic mechanical analysis was used to determine the glass transition temperature (Tg) and elastic modulus. Finally, the gas transport properties were studied in terms of treatment temperature, feed pressure, SiO2 loading, and testing temperature. CO2 permeability was found to increase by a factor of 3–4 at 3% SiO2 content using tetraethoxysilane in Matrimid, while ideal selectivity for CO2/CH4 separation was constant. Finally, the plasticization effect was practically eliminated by the introduction of SiO2 nanoparticles.

Performance of Nanocomposite Membranes Containing 0D to 2D Nanofillers for CO2 Separation: A Review

“…Chen et al [ 23 ] successfully fabricated hybrid Matrimid ® (BTDA-DAPI polyimide) membranes containing silica nansopheres synthesized through sol-gel mechanism using different precursors. With the addition of 3.11 wt % of silica gel obtained from tetraethoxysilane, the CO 2 permeability increased almost 5 folds (from 9.9 Barrer to 46.3 Barrer) compared to the neat polymer, with a loss in CO 2 /CH 4 selectivity from 35.3 to 28.3.…”

High Selective Mixed Membranes Based on Mesoporous MCM-41 and MCM-41-NH2 Particles in a Polysulfone Matrix

“…Generally, the membranes containing mesoporous silica as filler can be produced by three methods: (a) direct mixing/blending of the silica nanoparticles into the polymer matrix, (b) a sol–gel method in which the silica nanoparticles can be synthesized in situ in the presence of a preformed organic polymer, and (c) in situ polymerization involving the dispersion of the silica in the monomer before the polymerization is carried out (Chen et al, 2016). In this work, the first method was adopted after obtaining the silica nanoparticles by a sol-gel synthesis.…”

CO2-Philic [EMIM][Tf2N] Modified Silica in Mixed Matrix Membrane for High Performance CO2/CH4 Separation

“…Xing & Ho [21] also incorporated fumed silica into a crosslinked polyvinylalkohol-polysiloxane which showed encouraging results in improving the CO 2 permeability and selectivity. In a more recent study, Chen et al [22] achieved 4 times higher of CO 2 permeability using microcellular polymers incorporated with pure silica nanoparticles.…”