Phase transformations during the growth of paracetamol crystals from the vapor phase

• Published in: Technical physics Vol. 59; no. 7; pp. 1101 - 1103
• Main Authors: Belyaev, A. P., Rubets, V. P., Antipov, V. V., Bordei, N. S.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-07-2014; Springer
• Subjects: Acetaminophen; Classical and Continuum Physics; Physics; Physics and Astronomy; Short Communications; Order Phase Transition; Differential Scanning Calo; Paracetamol; Phase Transformation; Diffuse Phase Transition
• ISSN: 1063-7842; 1090-6525
• DOI: 10.1134/S1063784214070056

Phase transformations during the growth of paracetamol crystals from the vapor phase are studied by differential scanning calorimetry. It is found that the vapor-crystal phase transition is actually a superposition of two phase transitions: a first-order phase transition with variable density and a second-order phase transition with variable ordering. The latter, being a diffuse phase transition, results in the formation of a new, “pretransition,” phase irreversibly spent in the course of the transition, which ends in the appearance of orthorhombic crystals. X-ray diffraction data and micrograph are presented.