title: Reversible Nanoparticle-Micelle Transformation of Ionic Liquid-Sulfonatocalix[6]arene Aggregates.
abstract: The effect of temperature and NaCl concentration variations on the self-assembly of 1-methyl-3-tetradecylimidazolium (C14mim(+)) and 4-sulfonatocalix[6]arene (SCX6) was studied by dynamic light scattering and isothermal calorimetric methods at pH 7. Inclusion complex formation promoted the self-assembly to spherical nanoparticles (NP), which transformed to supramolecular micelles (SM) in the presence of NaCl. Highly reversible, temperature-responsive behavior was observed, and the conditions of the NP-SM transition could be tuned by the alteration of C14mim(+):SCX6 mixing ratio and NaCl concentration. The association to SM was always exothermic with enthalpy independent of the amount of NaCl. In contrast, NPs were produced in endothermic process at low temperature, and the enthalpy change became less favorable upon increase in NaCl concentration. The NP formation was accompanied by negative molar heat capacity change, which further diminished when NaCl concentration was raised.
authors.affiliation: †Université Paris Est, ICMPE (UMR7182), CNRS, UPEC, F 94320 Thiais, France.
authors.forename: Véronique
authors.initials: V
authors.lastname: Wintgens
authors.affiliation: §Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, P.O. Box 286, 1519 Budapest, Hungary.
authors.forename: Zsombor
authors.initials: Z
authors.lastname: Miskolczy
authors.affiliation: ‡Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Sorbonne Universités - UPMC Université Paris 06, UMR CNRS 7590, Muséum National d'Histoire Naturelle, Institut de Recherche pour le Développement UR 206, 4 Place Jussieu, F-75005 Paris, France.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Guigner
authors.affiliation: †Université Paris Est, ICMPE (UMR7182), CNRS, UPEC, F 94320 Thiais, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Amiel
authors.affiliation: §Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, P.O. Box 286, 1519 Budapest, Hungary.
authors.forename: József G
authors.initials: JG
authors.lastname: Harangozó
authors.affiliation: §Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences, P.O. Box 286, 1519 Budapest, Hungary.
authors.forename: László
authors.initials: L
authors.lastname: Biczók