Solid-Liquid Equilibria for the Binary Systems Naphthalene or Biphenyl + 1-Tetradecanol or + 1-Hexadecanol

TL;DR

This study investigates solid-liquid equilibria of specific aromatic and aliphatic alcohol mixtures using calorimetry, modeling, and structural analysis, revealing eutectic behavior and interaction parameter insights.

Contribution

It provides new calorimetric data, compares DISQUAC and UNIFAC models, and analyzes interaction parameters and structural factors for these binary systems.

Findings

All systems exhibit a simple eutectic point.

DISQUAC and UNIFAC models describe the phase diagrams effectively.

Temperature dependence of interaction parameters is better captured by DISQUAC.

Abstract

A differential scanning calorimetric technique has been used to obtain solid-liquid equilibrium temperatures for the mixtures naphthalene or biphenyl + 1-tetradecanol, or + 1-hexadecanol. All the systems show a simple eutectic point, whose final composition was determined by means of the Tamman's plots using the needed values of the eutectic heat and of the heat of melting, which are also reported. DISQUAC interaction parameters for the OH/aromatic contacts in the selected systems are given. The present experimental SLE phase diagrams are similarly described by DISQUAC and UNIFAC (Dortmund) models. However, the comparison of DISQUAC and UNIFAC results for systems involving naphthalene and shorter 1-alkanols (methanol-1-octanol) reveals that the temperature dependence of the interaction parameters is more suitable in DISQUAC. The systems are also investigated in terms of the concentration-concentration structure factor. It is shown that the positive deviations from the Raoult's law of the studied solutions become weaker when the homocoordination decreases.