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

Abstract

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.

Naphthalene Tetrazole-Based Nickel Metal–Organic Framework as a Filler of Polycarbonate Membranes to Improve CO2 and H2 Separation

“…Those inside the gray zone improved the performance of polycarbonate (PC). For CO 2 /CH 4 separation (Figure a), the hybrid membranes containing silica (PC@Silica-2%) and silica filler modified with ionic liquid PC@Silica-IL-3% are the membranes with the best performance, although the data reported are measured at 2 bar . The incorporation of 5% of a functionalized carbon nanotube with the carboxylic group yields an MMM, PC@C-SWCNT5%, with good performance for this separation since the P (CO 2 ) coefficient increased 3.5-fold with respect to pure PC and a selectivity around 1.2-fold although the experiments were also carried out at 2 bar …”

“…For CO 2 /CH 4 separation ( Figure 8 a), the hybrid membranes containing silica (PC@Silica-2%) and silica filler modified with ionic liquid PC@Silica-IL-3% are the membranes with the best performance, although the data reported are measured at 2 bar. 32 The incorporation of 5% of a functionalized carbon nanotube with the carboxylic group yields an MMM, PC@C-SWCNT5%, with good performance for this separation since the P (CO 2 ) coefficient increased 3.5-fold with respect to pure PC and a selectivity around 1.2-fold although the experiments were also carried out at 2 bar. 33 PC@NiNDTz-10% showed a similar performance to that of PC@2Ph-20% , a hybrid membrane recently reported by us 24 with 20% of a porous organic polymer containing exclusively carbon and hydrogen atoms and with a specific surface area of 1481 m 2 g –1 .…”

Mixed-Matrix Ion Gel Membranes for Gas Separation

“…Different mesoporous silica materials with a variety of particles size, shapes and pore sizes in the range of 2–50 nm have also been used in the development of gas separation membranes. , As with zeolites and MOFs, one of the main problems when blending silica particles and polymers is the possible formation of nonselective voids. In this case, silica can be functionalized by co-condensation, impregnation, and postsynthesis grafting, or ILs can be added to the matrix to improve the compatibility between the two phases …”

“…In this case, silica can be functionalized by co-condensation, impregnation, and postsynthesis grafting, 109 or ILs can be added to the matrix to improve the compatibility between the two phases. 110 In what concerns the development of silica-containing ion gel membranes, Matsuyama's group carried out significant work in this area, particularly using silica nanoparticle networks. For instance, Kamio et al 55 developed an optimized method to fabricate robust double-network (DN) ion gels with a high amount of IL (80 wt %).…”