Measurements of the liquid-liquid coexistence curves of {(1 − x) dimethyl carbonate + x pentadecane} and {(1 − x) dimethyl carbonate + x heptadecane} in the critical region. (January 2019)

• Record Type: Journal Article
• Authors: Guo, Yimin; Shi, Aiqin; Chen, Zhiyun; Shen, Weiguo
• Is Part Of: Journal of chemical thermodynamics. Volume 128(2019)
• Page Start: 198
• Page End: 206
• Publication Date: 2019-01
• Subjects: Coexistence curve -- Critical exponent -- Critical properties -- Complete scaling theory -- Heat capacity -- Asymmetric coefficient; Thermodynamics -- Periodicals; Thermochemistry -- Periodicals; Thermodynamique -- Périodiques; Thermochimie -- Périodiques; Thermochemistry; Thermodynamics; Periodicals; 541.369
• DOI: 10.1016/j.jct.2018.08.003
• Languages: English
• ISSNs: 0021-9614

Abstract

Highlights: Liquid-liquid coexistences of binary solutions of {dimethyl carbonate + n -alkane} were measured. Critical exponents were obtained and found to be in agreement with the 3-D Ising universality. Asymmetry of the coexistence curves were analyzed by the complete scaling theory. Chain-length dependences of the critical parameters were discussed. Abstract: The liquid-liquid coexistence curves in a temperature range of about 10 K from the upper consolute critical temperature for binary solutions of {dimethyl carbonate + pentadecane} and {dimethyl carbonate + heptadecane} have been precisely measured. The upper consolute mole fraction x c of n -alkane and the upper consolute temperature T c were determined to be x c = 0.210, T c = 312.234 K for {dimethyl carbonate + pentadecane} and x c = 0.183, T c = 320.496 K for {dimethyl carbonate + heptadecane}, respectively. From the data collected in the near critical point, the critical exponent β was deduced and shown to be consistent well with its theoretical value for the 3-D Ising universality class. The dependences of critical properties on the chain length of n -alkane for a series of {dimethyl carbonate + n -alkane} binary solutions were investigated. Furthermore, it was found that the asymmetric behaviors of the coexistence curve could be well described by the complete scaling theory. The contribution of the heat capacity related term to the asymmetric behaviors of the coexistence curves was discussed.