title: Origin of Invariant Gel Melting Temperatures in the c-T Phase Diagram of an Organogel.
abstract: Binary c-T phase diagrams of organogelators in solvent are frequently simplified to two domains, gel and sol, even when the melting temperatures display two distinct regimes, an increase with T and a plateau. Herein, the c-T phase diagram of an organogelator in solvent is elucidated by rheology, DSC, optical microscopy, and transmitted light intensity measurements. We evidence a miscibility gap between the organogelator and the solvent above a threshold concentration, cL. In this domain the melting or the formation of the gel becomes a monotectic transformation, which explains why the corresponding temperatures are nonvariant above cL. As shown by further studies by variable temperature FTIR and NMR, different types of H-bonds drive both the liquid-liquid phase separation and the gelation.
authors.affiliation: Institut Charles Sadron, 23 rue du Loess - BP 84047, 67034 Strasbourg, Cedex 2, France.
authors.forename: Elliot
authors.initials: E
authors.lastname: Christ
authors.affiliation: Laboratoire Charles Coulomb, UMR 5221, CNRS-Université de Montpellier , 34095 Montpellier, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Blanc
authors.affiliation: Institut Charles Sadron, 23 rue du Loess - BP 84047, 67034 Strasbourg, Cedex 2, France.
authors.forename: Abdelaziz
authors.initials: A
authors.lastname: Al Ouahabi
authors.affiliation: Laboratoire Charles Coulomb, UMR 5221, CNRS-Université de Montpellier , 34095 Montpellier, France.
authors.forename: David
authors.initials: D
authors.lastname: Maurin
authors.affiliation: Laboratoire Charles Coulomb, UMR 5221, CNRS-Université de Montpellier , 34095 Montpellier, France.
authors.forename: Rozenn
authors.initials: R
authors.lastname: Le Parc
authors.affiliation: Laboratoire Charles Coulomb, UMR 5221, CNRS-Université de Montpellier , 34095 Montpellier, France.
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Bantignies
authors.affiliation: Institut Charles Sadron, 23 rue du Loess - BP 84047, 67034 Strasbourg, Cedex 2, France.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Guenet
authors.affiliation: Institut Charles Sadron, 23 rue du Loess - BP 84047, 67034 Strasbourg, Cedex 2, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Collin
authors.affiliation: Institut Charles Sadron, 23 rue du Loess - BP 84047, 67034 Strasbourg, Cedex 2, France.|International Center for Frontier Research in Chemistry, 8 allée Gaspard Monge, 67000 Strasbourg, France.
authors.forename: Philippe J
authors.initials: PJ
authors.lastname: Mésini