Water effect on CO2 absorption for hydroxylammonium based ionic liquids: A molecular dynamics study

The effect of water content on CO2 absorption in 2-hydroxyethyl-trimethylammonium L-(+)-lactate and tris(2-hydroxyethyl) methylammonium methylsulfate ionic liquids was studied using classical molecular dynamics simulations. The analysis of structural and dynamic properties, together with the energy contributions, showed that molecular-level structuring of CO2-ionic liquids is not affected by the presence of water molecules. Ion-water interactions are developed while maintaining the previous fluids' structuring. The predicted dynamic properties show decreasing molecular mobility, that should lead to increasing viscosity upon water addition for the studied concentration range. Nevertheless, water has a moderate effect on CO2 transport within the studied hydroxylammonium fluids. (C) 2012 Elsevier B.V. All rights reserved.