Authors:M. Jouti, M. Bouroukba, D. Balesdent and M. Dirand
The enthalpy variations of pure n-tricosane (n-C23H48), pure n-pentacosane (n-C25H52) and sixteen binary mixtures were determined from 282 to 360 K. The differential enthalpy analyses were carried out on the
pure components on the four terminal solid solutions, denoted βo(C23), β′o(C23), β′o(C25), βo(C25) and on the three intermediate phases, called β″1, β′1, β″2of the binary system (C23:C25) using a calorimeter of the Tian Calvet type. These variations can be represented by an analytical expression, which is derived
from Einstein‘s model. The two Rotator phases β-RI and α-RII were also studied.
Authors:Z. Achour-Boudjema, M. Bouroukba, D. Balesdent, E. Provost and M. Dirand
Differential enthalpy analyses were performed on the binaryn-alkane systemn-C24H50-n-C26H54 with a Setaram DSC111 calorimeter of Tian Calvet type.
The measurements provided enthalpy data from 260 to 260 K onn-tetracosane,n-hexacosane and 19 binary mixtures.
An analytical expression, derived from the Einstein model, is proposed for every pure phase in its temperature domain, to
represent the variation in the enthalpy with temperature.
A general expression for the enthalpy as a function of temperature and composition is also given.