title: Dopant effects on 2-ethyl-1-hexanol: a dual-channel impedance spectroscopy and neutron scattering study.
abstract: A two-channel impedance technique has been used to study the relaxation behavior of 2-ethyl-1-hexanol with polar and non-polar dopants at the few percent concentration level over a wide temperature and frequency range. The non-polar dopants shift both the Debye and the primary structural relaxation time in the same direction, to shorter times for 3-methylpentane and to longer times for squalane, consistent with the relative glass transition temperatures (Tg) of the components. By contrast, polar dopants such as water or methanol modify the α-process towards slower dynamics and increased amplitude, while the Debye process is accelerated and with a decreased amplitude. This effect of adding water to alcohol is explained by water promoting more compact structures with reduced Kirkwood correlation factors. This picture is consistent with a shift in the neutron scattering pre-peak to lower scattering vectors and with simulation work on alcohol-water systems.
authors.affiliation: Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604, USA.
authors.forename: Lokendra P
authors.initials: LP
authors.lastname: Singh
authors.affiliation: Laboratoire Léon Brillouin, CNRS /CEA -UMR 12, DSM/IRAMIS/LLB CEA Saclay, 91191 Gif-sur-Yvette Cedex, France.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Raihane
authors.affiliation: Laboratoire Léon Brillouin, CNRS /CEA -UMR 12, DSM/IRAMIS/LLB CEA Saclay, 91191 Gif-sur-Yvette Cedex, France.
authors.forename: Christiane
authors.initials: C
authors.lastname: Alba-Simionesco
authors.affiliation: Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604, USA.
authors.forename: Ranko
authors.initials: R
authors.lastname: Richert
mesh_terms: D058266:Dielectric Spectroscopy; D000441:Hexanols / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D033363:Neutron Diffraction; D014867:Water / Q000737:chemistry
chemical_list: D000441:Hexanols; D014867:Water; C034017:2-ethylhexanol