Fabrication of silanated zeolite T/6FDA-durene composite membranes for CO2/CH4 separation

In this work, zeolite T particles were modified with three different types of silane groups including, 3Aminopropyltrimethoxysilane (APTMS), N-(2aminoethyl)-3-aminopropyl-trimethoxysilane (AAPTMS) and 3-(2-(2-aminoethylamino) ethylamino) propyltrimethoxysilane (AEPTMS) which contain mono amine, diamine and triamine group, respectively, before incorporated into 6FDA-durene polyimide. The physicochemical properties of the particles and the resultant membranes were characterized using XRD, FESEM, EDX, FTIR, TGA and DSC. The results demonstrated that the incorporation of APTMS modified zeolite T particles into 6FDA-durene polymer matrix failed to improve the interfacial adhesion between filler and polymer phases. This phenomenon subsequently contributes to the reduction of CO2 permeability of 93% and decrement of CO2/CH4 selectivity of 29.5% as compared to membrane incorporated with unmodified zeolite T, which showed CO2 permeability and CO2/CH4 selectivity of 844 Barrer and 19.1, respectively. Meanwhile, composite membranes loaded with AAPTMS and AEPTMS modified zeolite T particles have effectively enhanced the filler/polymer interfacial adhesion and separation properties of the membranes. Although the incorporation of AAPTMS zeolite T particles into 6FDA-durene polymer demonstrated 2.7% reduction of CO2 permeability, increment of CO2/CH4 selectivity up to 26.4 was obtained, which successfully lies on Robeson upper limit 2008. Meanwhile, composite membrane embedded with AEPTMS modified zeolite T particles has resulted in the increment of both CO2 permeability and CO2/CH4 selectivity of 857.7 Barrer and 22.5, respectively. Overall, the effect of different amine groups in the modification of zeolite T surface on the performance of the composite membranes has been demonstrated in this work. (C) 2017 Elsevier Ltd. All rights reserved.