Express thermo-gravimetric method for the vaporization enthalpies appraisal for very low volatile molecular and ionic compounds

An express method for the determination of vaporization enthalpies of extremely low volatile molecular and ionic liquids has been developed using a commercially available TGA. All experimental parameters (mass loss rate, temperature range, and purge gas flow) crucial for reliable measurements were carefully studied using the reference molecular compounds (n-hexadecane, di-butyl phthalate, methyl and ethyl stearate) with the reliable data. Optimal experimental conditions were recommended. Molar vaporization enthalpies of the low volatile reference molecular compounds were reproduced under optimal conditions better than 2 kJ mol−1. Test measurements with the extremely low volatile ionic liquid [C2mim][NTf2] have revealed an agreement with the reliable data already available in the literature within ±3 kJ mol−1. The experimental conditions recommended in this work allow a quick appraisal of vaporization enthalpies of very low volatile materials within 8 h at a reasonable level of accuracy.

Figure optionsDownload as PowerPoint slideHighlights
► An express TGA method for measuring vaporization enthalpies of extremely low volatile molecular and ionic liquids has been developed.
► Optimal experimental conditions were recommended.
► Test measurements with the extremely low volatile ionic liquid [C2mim][NTf2] have revealed an agreement with the reliable data already available in the literature within ±3 kJ mol−1.