The Effect of Complex Modifier Consisting of Star Macromolecules and Ionic Liquid on Structure and Gas Separation of Polyamide Membrane

A novel hybrid membrane was developed on the basis of poly(m-phenylene isophthalamide) (PA) by introducing an original complex modifier into the polymer; this modifier consisted of equal amounts of heteroarm star macromolecules with a fullerene C(60) core (HSM) and the ionic liquid [BMIM][Tf(2)N] (IL). The effect of the (HSM:IL) complex modifier on characteristics of the PA membrane was evaluated using physical, mechanical, thermal, and gas separation techniques. The structure of the PA/(HSM:IL) membrane was studied by scanning electron microscopy (SEM). Gas transport properties were determined by measuring He, O(2), N(2), and CO(2) permeation through the membranes based on PA and its composites containing a 5 wt% modifier. The permeability coefficients of all gases through the hybrid membranes were lower than the corresponding parameters for the unmodified membrane, whereas the ideal selectivity in the separation of He/N(2), CO(2)/N(2,) and O(2)/N(2) gas pairs was higher for the hybrid membrane. The position of the PA/(HSM:IL) membrane on the Robeson’s diagram for the O(2)/N(2) gas pair is discussed.