a Collaboration research paper of Dr. Nishida and Dr. Hikima was accepted at Journal of

Congratulation! a Collaboration research paper of Dr. Nishida and Dr. Hikima was accepted at Journal of Crystal Growth & Design. The title of the paper is “Visualization of Non-Equilibrium Properties of Crystalline Polymer: Formation of Ring-Lite due to the Gibbs-Thomson Effect and Dark Ring due to the Melting Point Inversion” and the authors are Koji Nishida*, Yuta Hikima, Tsuyoshi Koga, , and Masahiro Ohshima. Dr. Nishida is the principal investigator of this research.  For those of you who are interested in this research, please contact him.

The abstract of the paper is as follows:

Polymer crystallite having ring-like morphology was obtained by combining a non-equilibrium nature of the polymeric material and a rapid temperature jump technique. Termed “ring-lite” here, it consists of the concentrically arranged crystalline and molten regions of a single-component polymer. During the growing process of a spherulite, crystallization temperature Tc was in turn changed between a low and a high temperature at certain intervals. In this way, bimodal melting temperatures Tm due to the Gibbs-Thomson effect were alternately imprinted within an identical spherulite. Subsequently the sample was heated so rapidly that only the region having higher Tm remained in crystalline state. Importantly, inversion of the melting point was also microscopically visualized as “dark-ring”. Contrary to the appearance of ring-lite due to “normal” Gibbs-Thomson effect, we found that a specific  heating rate caused the region having originally lower Tm to remain in crystalline state and that of originally higher Tm to melt, i.e., display inversion of the melting point. The occurrence of the melting point inversion was confirmed by heating rate variation measurements of fast-scan chip calorimetry (FSC).