Improvement in gas separation properties of a polymeric membrane through the incorporation of inorganic nano‐particles

Abstract

The present work tries to introduce a high‐performance nano‐composite membrane by using polydimethylsiloxane (PDMS) as its main polymer matrix to meet some specific requirements in industrial gas separations. Different nano‐composite membranes were synthesized by incorporating various amounts of nano‐sized silica particles into the PDMS matrix. A uniform dispersion of nano‐particles in the host membranes was obtained. The nano‐composite membranes were characterized morphologically by scanning electron microscopy and atomic force microscopy. Separation properties, permeability, and ideal selectivity of C3H8, CH4, and H2 through the synthesized nano‐composite membranes with different nano‐particle contents (0.5, 1, 1.5, 2, 2.5, and 3 wt%) were investigated at different pressures (2, 3, 4, 5, 6, and 7 atm) and constant temperature (35°C). It was found out that a 2 wt% loading of nano‐particles into the PDMS matrix is optimal to obtain the best separation performance. Afterwards, sorption experiments for the synthesized nano‐composite membranes were carried out, and diffusion coefficients of the gases were calculated based on solution‐diffusion mechanism. Gas permeation and sorption experiments showed an increase in sorption and a decrease in diffusion coefficients of the gases through the nano‐composite membranes by adding nano‐particles into the host polymer matrix. Copyright © 2011 John Wiley & Sons, Ltd.

Hydrogen separation and purification using crosslinkable PDMS/zeolite A nanoparticles mixed matrix membranes

“…The findings of current study (results permeability), as shown in Fig. 8, are in an excellent consistent with those of Merkel et al [45], Raharjo et al [46], Prabhakar et al [47], Stern et al [48] and our previous study [33,44]. Robeson in 1991 [49] introduced a trade-off between gas permeabilities and selectivities of polymeric membranes known as the "upper-bound trade-off" curves [50], as shown in Fig.…”

“…It could be observed from the gas permeation results that the pore size closest to the kinetic diameter of permeating molecules to be separated is overally ineffective in improving selectivity of the rubbery PDMS membranes. It was expected that the PDMS/5A MMM is the best membrane among the others for CO 2 (3.3 Å )/ CH 4 (3.8 Å ) separation whereas this results in a very little enhanced selectivity and a declined permeability despite its pore size (4.3 Å ) which is large enough to fit the kinetic diameters of gas molecules and to be the most suitable membrane with desired properties among the zeolites investigated for CO 2 [48] and our previous study [33,44].…”

“…P N and m values for four gases examined in this study as well as ideal selectivities of C 3 H 8 and H 2 over other gases(P C 3 H 8 =P gas and P H 2 =P gas ) at Dp ¼ 0 and Dp ¼ 7 bar for the neat PDMS and the PDMS/zeolite 4A MMMs are reported in Tables 2 and 3, respectively. The pressure functionality of permeability can be influenced principally by the following three factors: plasticization, compaction, and penetrant solubility [44]. The value of m is determined by the overall effect of these factors.…”

Superior Pebax‐1657/amine‐modified halloysite nanotubes mixed‐matrix membranes to improve the CO2/CH4 separation efficiency

“…zeolites, metal–organic frameworks (MOFs) and carbon nanotubes (CNTs)) and non‐porous (e.g. metal oxide) materials 13–16 . Although the embodiment of well‐optimized nanoparticles loading into MMMs can generally boost CO 2 permeability across the membranes, different CO 2 /CH 4 selectivity results have been reported by the researchers.…”

Polysulfone-ionic liquid based membranes for CO2/N2 separation with tunable porous surface features

“…Polymeric membranes are still one of the most common types of membrane used for gas separation, in which the transport takes place according to a solution-diffusion mechanism [25]. Hence, they either need to be fully dense or asymmetric, whereas the separation process happens due to the different affinities between the selective layer and gases [26].…”