title: Hierarchical Structure of Supramolecular Polymers Formed by N,N'-Di(2-ethylhexyl)urea in Solutions.
abstract: Supramolecular chain polymers formed by N,N'-di(2-ethylhexyl)urea (EHU) dissolved at low concentrations (up to 0.1 mole fraction) in heptane were investigated with the use of the dielectric spectroscopy. The experimental data show an exceptional ability of the chains for the antiparallel self-aggregation due to dipole-dipole interactions, leading to an anomalous dependence of the static permittivity of EHU + heptane solutions on temperature and concentration of the urea. The primary molecular assembly into polymeric chains is therefore followed by a secondary bundling of the chains which facilitates a longitudinal translation of the chains. That peculiarity and an asymmetry of the alkyl substituent in the EHU molecule making the system a mixture of diastereoisomers of unfavorable packing of the side group, are the most probable molecular mechanisms which prevent the crystallization of EHU-the only known liquid urea derivative.
authors.affiliation: Institute of Molecular Physics, Polish Academy of Sciences , M. Smoluchowskiego 17, PL-60-179 Poznań, Poland.
authors.forename: Jolanta
authors.initials: J
authors.lastname: Świergiel
authors.affiliation: CNRS, Institut Parisien de Chimie Moléculaire, Equipe Chimie des Polymères, Sorbonne Universités, UPMC Univ Paris 06 , 4 Place Jussieu, F-75005 Paris, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Bouteiller
authors.affiliation: Institute of Molecular Physics, Polish Academy of Sciences , M. Smoluchowskiego 17, PL-60-179 Poznań, Poland.
authors.forename: Jan
authors.initials: J
authors.lastname: Jadżyn