Crystallization of n-octacosane by the rapid expansion of supercritical solutions

Abstract

Crystals of a model wax ( n-octacosane) were produced by the rapid expansion of supercritical solutions (RESS) containing n-octacosane and carbon dioxide. Pre-expansion temperatures and pressures were varied to study their effects on crystal morphology. Four distinct types of particles were observed, including regular hexagonal crystals and irregular fused particles. Particle size decreased and the particle size distribution narrowed with an increase in pre-expansion temperature. On the other hand, changes in pre-expansion pressure showed no significant influence on particle size.