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

In the present study, halloysite nanotubes (HNTs) were firstly functionalized using N-beta-(aminoethyl)-gamma-aminopropyltrimethoxy silane and then employed as nanofillers to fabricate mixed-matrix membranes including poly (ether-block-amide) polymer as the primary material. To characterize the HNTs, as well as the obtained membranes, thermal gravimetric analysis, Fourier-transform infrared spectroscopy, X-ray powder diffraction, and Field emission scanning electron microscopy analyses were employed. Effects of the modified and pure HNTs loadings, as well as feed pressure on CH4 and CO2 permeabilities and ideal CO2/CH4 selectivity of the prepared membranes, were surveyed. The experimental permeation results indicated that incorporation of 1.5 wt% of amine-functionalized HNTs into the polymer matrix improves CO2 permeability and the ideal selectivity by nearly 37 and 24%, respectively, due to the higher CO2 adsorption capacity of the amine-functionalized HNTs.