Phase transitions in molecular crystals of n-alkanes: Tri-, tetra-, and pentacosane

Abstract

Phase transitions in normal alkanes, such as tricosane (C₂₃H₄₈), tetracosane (C₂₄H₅₀), and pentacosane (C₂₅H₅₂), were studied by differential scanning calorimetry. The elimination of some procedural errors provided the possibility to obtain true values for the thermodynamic parameters of phase transitions and ascertain their nature. The comparative analysis of heat capacity jumps was performed on the basis of the theory of diffuse first-order phase transitions.