A strategy is reported that combines assembled nanostructures and solvent vapor treatment to manipulatethe gas permeability of graft copolymer membranes. The VC-g-POEM graft copolymer consists of poly(vinyl chloride)(PVC) main chains and poly(oxyethylene methacrylate) (POEM) side chains, and was synthesized via atomtransfer radical polymerization (ATRP). When the PVC-g-POEM membrane was treated with a good solvent vaporsuch as acetone, the CO2 permeability increased from 107 to 145 Barrer (1 Barrer=10-10 cm3(STP)mm-2-1mHg-1),which is approximately a 36% improvement compared to an untreated sample. However, the permeability was significantlyreduced from 107 to 45 and 38 Barrer upon being treated with a selective (methanol) or poor solvent (hexane).
The structure-property relation of the solvent-vapor-treated membranes was investigated using transmissionelectron microscopy (TEM) and small-angle X-ray scattering (SAXS) analysis.