Gas permeation, sorption and diffusion through PEBA/SiO2 nanocomposite membranes (chemical surface modification of nanoparticles)

• Separation performance of PEBA membrane was improved using SiO2 nanoparticles.
• SiO2 nanoparticles were chemically modified via esterification reaction.
• The applied chemical modification enhanced dispersion of the nanoparticles.
• The prepared membranes lay close or even above the Robeson's upper bound line.
• Esterification is proposed for preparation of SiO2/polymer NC-membranes.

In the current investigation, separation performance of poly (Ether Block Amid), PEBA (grade 1657), membrane was improved via incorporation of SiO2 nanoparticles into the polymeric matrix. In order to attain excellent dispersion of SiO2 nanoparticles within the polymeric matrix, a chemical surface modification was performed via esterification reaction between the nanoparticles and cis-9-octadecenoic acid (OA). To the best of our knowledge; there is no investigation on employing this type of modification for preparation of SiO2/polymer nanocomposite membranes. Permeation, sorption and diffusion coefficients of pure gases, CO2, H2, CH4 and N2, through the prepared neat and the nanocomposite membranes were studied at temperature of (T = 25 °C) and pressure of (P = 2 bar). The results showed that, with increasing the loading content of nanoparticles from 0 wt% (the neat PEBA membrane) to 8 wt%, ideal permeation selectivity values of CO2/H2, CO2/CH4 and CO2/N2 improve from 9, 18 and 55 to 17, 45 and 124, respectively.