Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Melting Point Equations for the Ternary System Water/Sodium Chloride/Ethylene Glycol Revisited

Published

Author(s)

James D. Benson, Aniruddha Bagchi, Xu Han, John K. Critser, Erik J. Woods

Abstract

Partial phase diagrams are of considerable utility in the development of optimized cryobiological procedures. Recent theoretical predictions of the melting points of ternary solutions of interest to cryobiology have caused us to re-examine measurments that our group made for the ethylene-glycol--sodium chloride--water phase diagram. Here we revisit our previous experiments by measuring melting points at five ethylene- glycol to sodium chloride ratios (R values; R=5, 10, 15, 30, and 45) and five levels of concentration for each ratio. Melting points were averaged from three measurements and plotted as a function of total solute concentration for each R value studied. The new measurements differed from our original experimental values and agreed with predicted values from both theoretical models. Additionally, the data were fit to the polynomial described in our previous report and the resulting equation was obtained: T_{Melting} = (0.383-2.145E-3 R) x+(8.119E-3 - 2.909E-5 R) x^2 where x is the total solute mass-fraction. This new equation provided good fits to the experimental data as well as published values and relates the determined polynomial constants to the R value of the corresponding isopleths of the three dimensional phase diagram, allowing the liquidus curve for any R value to be obtained.
Citation
Cryobiology
Volume
61
Issue
3

Keywords

cryobiology, ethylene glycol, phase diagram, calorimetry

Citation

Benson, J. , Bagchi, A. , Han, X. , Critser, J. and Woods, E. (2010), Melting Point Equations for the Ternary System Water/Sodium Chloride/Ethylene Glycol Revisited, Cryobiology, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=905323 (Accessed March 29, 2024)
Created December 1, 2010, Updated June 2, 2021