Dopant effects on 2-ethyl-1-hexanol: A dual-channel impedance spectroscopy and neutron scattering study

作者:Singh Lokendra P*; Raihane Ahmed; Alba Simionesco Christiane; Richert Ranko
来源:Journal of Chemical Physics, 2015, 142(1): 014501.
DOI:10.1063/1.4904908

摘要

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 (T-g) of the components. By contrast, polar dopants such as water or methanol modify the a-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.

  • 出版日期2015-1-7
  • 单位中国地震局