Molecular dynamics simulations of polyethers and a quaternary ammonium ionic liquid as CO 2 absorbers

Piercarlo Fortunato Cardoso (1) , Juan Fernandez (1) , Luiz Fernando Lepre (2) , Rômulo Augusto Ando (2) , Margarida Costa Gomes (3) , Leonardo J. A. Siqueira (1)

1 Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo
2 Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo
3 ICCF - Institut de Chimie de Clermont-Ferrand

The properties of mixtures of butyltrimethylammonium bis(trifluoromethylsulfonyl)imide, [N4111][NTf2], with poly(ethyleneglycol) dimethyl ether, PEO, were described as a function of PEO chain size by molecular dynamics simulations. Both PEO chain size and mixture composition revealed to play a significant role in determining the structure and the dynamics of the fluids. The remarkably higher viscosity observed for mixtures composed by 0.25 mole fraction of PEO was attributed to the increase in the gauche population of OCCO dihedral of the polyether of longer chains. The negative solvation enthalpy (ΔsolH < 0) and entropy (ΔsolS < 0) revealed a favorable CO2 absorption by the neat and mixture systems. The CO2 absorption was higher in neat PEO, particularly considering longer chains. The gas solubility in the mixtures presented intermediate values in comparison to the neat PEO and neat ionic liquid. The CO2 solutions had their structures discussed in the light of the calculated radial and spatial distribution functions.

Domaines: Chimie

Piercarlo Fortunato Cardoso, Juan Fernandez, Luiz Fernando Lepre, Rômulo Augusto Ando, Margarida Costa Gomes, et al.. Molecular dynamics simulations of polyethers and a quaternary ammonium ionic liquid as CO 2 absorbers. Journal of Chemical Physics, 2018, 148 (13), pp.134908. ⟨10.1063/1.5019431⟩. ⟨hal-01781355⟩