title: Analysis of stochastic crystallization in micron-sized droplets of undercooled liquid l-arabitol.
abstract: Kinetics of isothermal crystallization of l-arabitol were analyzed from the undercooled liquid state within micron-sized droplets from micro-Raman spectroscopy. This study reveals that crystallization slightly above Tgis controlled by stochastic heterogeneous nucleation inherent to the droplet size. Microscopic Raman investigations performed in droplets give the unique opportunity to analyze the pure metastable Form II of l-arabitol. It was found that Form II is characterized by a molecular packing more compact than that of the stable Form I, inherent to strong intermolecular hydrogen bonding. Kinetics laws obtained by analyzing several droplets at different temperatures, reveal the transient character of Form II, quasi systematically detected during the crystallization process of form I. Form II appears as the first step of crystallization prior to successive short-living metastable states which is necessary to achieve a complete crystallization in Form I. It was found that the kinetics of conversion between the metastable states (Form II) into Form I is dependent on the amount of strong hydrogen bonding distinctive of Form II.
authors.affiliation: Université Lille Nord de France, F-59000 Lille, France; USTL UMET UMR CNRS 8207, F-59655 Villeneuve d'Ascq, France.
authors.forename: Yannick
authors.initials: Y
authors.lastname: Guinet
authors.affiliation: Université Lille Nord de France, F-59000 Lille, France; USTL UMET UMR CNRS 8207, F-59655 Villeneuve d'Ascq, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Carpentier
authors.affiliation: Université Lille Nord de France, F-59000 Lille, France; USTL UMET UMR CNRS 8207, F-59655 Villeneuve d'Ascq, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Paccou
authors.affiliation: Université Lille Nord de France, F-59000 Lille, France; USTL UMET UMR CNRS 8207, F-59655 Villeneuve d'Ascq, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Derollez
authors.affiliation: Université Lille Nord de France, F-59000 Lille, France; USTL UMET UMR CNRS 8207, F-59655 Villeneuve d'Ascq, France. Electronic address: alain.hedoux@univ-lille1.fr.
authors.forename: Alain
authors.initials: A
authors.lastname: Hédoux
mesh_terms: D003460:Crystallization; D007700:Kinetics; D010316:Particle Size; D013059:Spectrum Analysis, Raman; D013402:Sugar Alcohols / Q000737:chemistry*
chemical_list: D013402:Sugar Alcohols; C014999:arabitol
keywords: Glass transition; Hydrogen-bonds; Isothermal crystallization; Metastability; Polymorphism; Raman spectroscopy