Novel sorbent and membrane materials for CO2 separation, poly(ionic liquid)s made from ionic liquid monomers, poly[p-vinylbenzyltrimethyl ammonium tetrafluoroborate] (P[VBTMA][BF4]) and poly[2-(methacryloyloxy)ethyltrimethy-lamnonium tetrafluoroborate] (P[MATMA][BF4]) have absorption capacities 7.6 and 6.0 times of those of room-temperature ionic liquids, e. g. [bmim][BF4], respectively, with reversible and fast sorption and desorption.