一种新型固体聚合物电解质复合气体分离膜的制备及气体透过性能的研究

Preparation of new solid polymer electrolyte composite membrane and separation of propylene and propane

采用单侧溶液交换法,把PEI/Pebax2533复合膜的Pebax2533外表面与AgBF4交换溶液接触,利用Ag+与Pebax2533分子链段中醚氧键之间的络合作用,将Ag+固定在PEI/Pebax2533复合膜中,从而制备了PEI/Pebax2533/AgBF4固体聚合物电解质复合气体分离膜.通过改变AgBF4交换溶液的浓度来调节复合膜表面银离子的负载量,控制复合膜对丙烯/丙烷的分离性能.随着AgBF4交换溶液浓度的增加,复合膜对烯烃出现明显的促进传递现象,塑性效应明显减弱.当AgBF4交换溶液浓度为8.0 mol/L时,PEI/Pebax2533/AgBF4复合膜丙烯/丙烷的分离系数远远超过1 000,塑性效应基本受到抑制.

A new solid polymer electrolyte PEI/Pebax2533/AgBF4 composite membrane is prepared with complexing method.By immersing the external surface of Pebax2533 layer of PEI/Pebax2533 composite membrane into AgBF4 solution,silver salt will transfer into Pebax2533 layer according to complexation with ether oxygen in Pebax2533 backbone,and a solid polymer electrolyte layer is formed.The silver salt content in the solid polymer electrolyte layer is dominated by the AgBF4 concentration.The increase of AgBF4 concentration enhances carrier facilitated transport of propylene,and lowers its plasticization effect.For PEI/Pebax2533/AgBF4 composite membrane prepared with 8.0mol/L AgBF4 solution,its selectivity for propylene and propane is above 1 000,and the plasticization effect is suppressed completely.