Synthesis of polymeric ionic liquids material and application in CO2 adsorption

We synthesized one quaternary ammonium polymeric ionic liquids (PILs)P[VBTHEA]Cl and three imidazolium PILs of P[VEIm]Br, P[VEIm]BF 4 , P[VEIm]PF 6 by free-radical polymerization in solution. These PILs were characterized by FT-IR, 1 H-NMR, 13 C-NMR, TGA, XRD and SEM. Their CO 2 adsorption capacities were measured under different pressures and temperatures by constant-volume technique. It was observed that quaternary ammonium PILs of P[VBTHEA]Cl have higher adsorption capacity for CO 2 than those imidazolium PILs, following P[VBTHEA]Cl   >   P[VEIm]PF 6   >   P[VEIm]BF 4   >   P[VEIm]Br, which may be ascribed to higher positive charge density on ammonium cation than that on imidazolium cation and thus stronger interaction with CO 2 , consistent with the results from dual-mode adsorption model that ammonium PILs have much higher CO 2 bulk absorption than imidazolium PILs. CO 2 adsorption capacity of P[VBTHEA]Cl is 9.02   mg/g under 295   K and 1   bar, which is comparable to that of some other PILs, and is much higher than that of the corresponding ILs monomer . These PILs have good adsorption selectivity for CO 2 over N 2 and regeneration efficiency.