title: Self-assembled nanotubes and helical tapes from diacetylene nonionic amphiphiles. Structural studies before and after polymerization.
abstract: We synthesized new amphiphiles comprised of a single diacetylenic chain and an oligoethylenoxide polar chain linked by an amide bond. In aqueous medium, they are not soluble at room temperature but form weak gels. Electron microscopy studies have shown that they self-assemble into helical tapes or nanotubes with lengths of several micrometers, and inner and outer diameters of 50 ± 1 and 59 ± 1 nm, respectively. The wall has a thickness of 10 ± 1 nm for both kinds of objects and has an amphiphile bilayer structure. The hydrophobic chains are ordered, and the amide groups are linked with each other by H-bonds. The dissociation of the tubes is a first-order transition with an enthalpy of ca. 40 kJ mol(-1). The nanotubes were photopolymerized to yield purple solutions consisting of helical tapes and almost flat ribbons. The polymers exhibit irreversible thermochromism upon heating.
authors: Laboratory of Functional ChemoSystems, UMR 7199, Faculté de Pharmacie, Université de Strasbourg, 74 route du Rhin, 67401 Illkirch, France.
authors: Aurélia
authors: A
authors: Perino
authors: Marc
authors: M
authors: Schmutz
authors: Stéphane
authors: S
authors: Meunier
authors: Philippe J
authors: PJ
authors: Mésini
authors: Alain
authors: A
authors: Wagner
mesh_terms: D000114:Acetylene / Q000031:analogs & derivatives / Q000737:chemistry*; D000577:Amides / Q000737:chemistry; D005027:Ethylene Oxide / Q000138:chemical synthesis* / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D015394:Molecular Structure; D043942:Nanotubes / Q000737:chemistry*; D010316:Particle Size; D058105:Polymerization; D013499:Surface Properties
chemical_list: D000577:Amides; D005027:Ethylene Oxide; D000114:Acetylene