effect of [bmim][bf4] ionic liquid on performance of poly (ether-block-amide) membrane for gas separation applications

The main purpose of this study was to employ the 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][bf4]) ionic liquid for the modification of polyether-block-amide (pebax) membranes for the gas separation application# accordingly, dual-layer pebax/polyethersulfone (pes) membranes containing the ionic liquid were fabricated to investigate its performance# these membranes were then examined for the separation of co2/n2 and o2/n2 gas mixtures# the ionic liquid was added in 0#5, 1, and 1#5% of the polymer# the experiments were conducted at the temperature of 25 ºc and pressures of 2, 4, and 6 bar# it was found that the incorporation of [bmim][bf4] ionic liquid into the pebax matrix had significant effect on the permeation of co2# based on the results, the optimal addition of 1%wt# ionic liquid has increased the selectivity of carbon dioxide rather than nitrogen by 4#8 times# further addition of ionic liquid has caused a competitive behavior between carbon dioxide and the ionic liquid to have an interaction with peo segment in copolymer resulting in reduced selectivity#