Departamento de Ingeniería Química, Universidad Complutense de Madrid, 28040 Madrid, Spain.
J Phys Chem B. 2013 Jan 10;117(1):296-306. doi: 10.1021/jp310499p. Epub 2012 Dec 27.
A systematic thermodynamic analysis has been carried out for selecting cations and anions to enhance the absorption of volatile organic compounds (VOCs) at low concentration in gaseous streams by ionic liquids (ILs), using COSMO-RS methodology. The predictability of computational procedure was validated by comparing experimental and COSMO-RS calculated Henry's law constant data over a sample of 125 gaseous solute-IL systems. For more than 2400 solute-IL mixtures evaluated, including 9 solutes and 270 ILs, it was found that the lower the activity coefficient at infinite dilution (γ(∞)) of solutes in the ILs, the more the exothermic excess enthalpy (H(E)) of the equimolar IL-solute mixtures. Then, the solubility of a representative sample of VOC solutes, with very different chemical nature, was screened in a wide number of ILs using COSMO-RS methodology by means of γ(∞) and H(E) parameters, establishing criteria to select the IL structures that promote favorable solute-solvent intermolecular interactions. As a result of this analysis, an attempt of classification of VOCs respect to their potential solubility in ILs was proposed, providing insights to rationally select the cationic and anionic species for a possible development of absorption treatments of VOC pollutants based on IL systems.
采用 COSMO-RS 方法对选择阳离子和阴离子以增强气态流中挥发性有机化合物（VOC）在低浓度下的吸收进行了系统的热力学分析。通过将实验和 COSMO-RS 计算的亨利定律常数数据与 125 个气态溶质-离子液体系统的样本进行比较，验证了计算程序的可预测性。对于评估的超过 2400 种溶质-离子液体混合物，包括 9 种溶质和 270 种离子液体，发现溶质在离子液体中的无限稀释活度系数（γ（∞））越低，等摩尔离子液体-溶质混合物的放热超额焓（H（E））越高。然后，通过 γ（∞）和 H（E）参数，使用 COSMO-RS 方法在大量离子液体中筛选了具有非常不同化学性质的代表性 VOC 溶质样品的溶解度，建立了选择促进有利溶质-溶剂分子间相互作用的离子液体结构的标准。通过这种分析，尝试根据 VOC 在离子液体中的潜在溶解度对 VOC 进行分类，为基于 IL 系统的 VOC 污染物吸收处理的阳离子和阴离子物种的合理选择提供了思路。
