Hydrogen gas separation with controlled selectivity via efficient and cost effective block copolymer coated PET membranes

Abstract

An efficient way is suggested to reduce the cost of block copolymer (BC) membranes while still taking advantage of their unique properties. It is demonstrated that selectivity can be kept almost the same whereas permeability is varied by using thin copolymer films on robust porous PET polymer membranes which acts as a mechanical support. So, a nanoscopic thin selective layer of the block copolymer (PS-b-P4VP) with additive is casted on the PET porous support. Selective extraction of the additive from the block copolymer thin films leads to the formation of a layer with monodispersed pores on the PET support. Measurements of the gas permeability of PET membranes of different pore size with and without block copolymer coating reveal that permeabilities of BC coated membranes decrease whereas selectivities slightly increase in comparison to the porous PET support. Coating of the membranes with BC plays a valuable role for the selectivity against gases like H2 over CO2. The surface morphology of the composite membranes has been determined by atomic force microscopy (AFM) showing the nanoscopic pores. Due to excellent mechanical stability and easy scale up, such membranes may be used in the gas separation technology.