1-ETHYL-3-METHYLIMIDAZOLIUM METHANESULFONATE: LOWTEMPERATURE HEAT CAPACITY AND STANDARD THERMODYNAMIC FUNCTIONS OF FORMATION. PART Iтезисы докладаТезисы
Место издания:G.A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences Ivanovo, Russia
Аннотация:The scientific literature has accumulated a large amount of data on thephysicochemical properties of ionic liquids. To optimize technological processes, as well asexpluatation conditions, it is necessary to have data on the thermodynamic properties of thesesubstances. Despite the fact that ionic liquids have been the subject of research for severaldecades, in the scientific literature and international databases the thermodynamic propertiesof ionic liquids are presented fragmentarily. The object of this work is 1-ethyl-3-methylimidazolium methanesulfonate (EmimMS). The aim of the work is to determine thelow-temperature heat capacity over a wide temperature range and to calculate the standardthermodynamic functions of the EmimMS formation in the crystal and liquid states. The isobaric heat capacity of the crystal and liquid phases of EmimMS wasdetermined in the temperature range from 80 to 380 K by the vacuum adiabatic calorimetry.Two phase transitions were observed: G-type at 203.3±0.5 K and melting at 313.01 ± 0.2 K(Figure 1). Melting parameters were also refined by DSC. At temperatures from 5 to 80 K theheat capacity of EmimMS was assessed by the Kelly method. The temperature dependenciesof EmimMS main thermodynamic functions have been determined in the temperature rangefrom 5 to 380 K (isobaric heat capacity Cp,m(T), standard entropy S0m(T), heat content H0(T) ‒H0(0), Gibbs energy content G0(T) ‒ H0(0)). In the present study the standard entropies andGibbs energies of EmimMS formation in the crystal and liquid state at 298.15 K werecalculated from the experimental data of adiabatic calorimetry in conjunction with dissolutioncalorimetry data [1]. Comparison of the obtained thermodynamic characteristics with theliterature data was carried out.[1] L.A. Tiflova, D.A. Kalinyuk , A.I. Druzhinina, Book of abstracts of XXIII InternationalConference on Chemical Thermodynamics in Russia, 2022, 86.Investigation was supported by the Program “Chemical Thermodynamics and TheoreticalMaterial Science” (AAA-1210313000391) and by the Federal Project "Growth of AdvancedInfrastructure for Research and Development in the Russian Federation" of the nationalproject "Science and Universities" (updating of equipment for scientific research).
