Determination of the vaporisation enthalpies for amino acid ionic liquids [Cnmim][Ala](n = 5, 6) and applications of the molar surface Gibbs energy. (November 2020)

• Record Type: Journal Article
• Authors: Fang, Dawei; Liang, Kunhao; Song, Chunxiao; Duan, Chengxuan; Wei, Jie
• Is Part Of: Journal of chemical thermodynamics. Volume 150(2020)
• Publication Date: 2020-11
• Subjects: Amino acid ionic liquid -- Vaporisation enthalpies -- Polarity -- Molar surface Gibbs energy; Thermodynamics -- Periodicals; Thermochemistry -- Periodicals; Thermodynamique -- Périodiques; Thermochimie -- Périodiques; Thermochemistry; Thermodynamics; Periodicals; 541.369
• DOI: 10.1016/j.jct.2020.106164
• Languages: English
• ISSNs: 0021-9614

Abstract

Graphical abstract: Highlights: The Δ 1 g H m o (2 9 8) were obtained by TGA. The δ μ were estimated based on Hildebrand's theory. The traditional Eötvös equation was improved in terms of g s. Abstract: Amino acid ionic liquids (ILs) 1-alkyl-3-methylimidazolium alanine [C n mim][Ala] ( n = 5, 6) were prepared and characterized. The enthalpy of vaporisation at the average temperature, Δ 1 g H m o ( T av ), for the two ILs were determined by means of isothermogravimetrical analysis, and in terms of Δ 1 g C p, m o, the value of Δ 1 g H m o ( T av ) can be adjusted to Δ 1 g H m o (2 9 8); then, the polarity, δ μ, of the two ILs were estimated, in which the order of the δ μ is in consistent with our experiences. In terms of molar surface Gibbs energy, g s, the traditional Eötvös equation was improved, the parameters of new Eötvös one have clear physical meanings: Its slope and intercept are the molar surface entropy, s, and the molar surface enthalpy, h, respectively. In addition, combining g s with Lorentz–Lorenz equation, an expression for predicting surface tension, γ, of the ILs was obtained, and the predicted values of γ are in good agreement with the experimental ones.