Charge ordering and scattering pre-peaks in ionic liquids and alcohols

Aurélien Perera (1)

1 LPTMC - Laboratoire de Physique Théorique de la Matière Condensée

The structural properties of ionic liquids and alcohols are viewed under the charge ordering process as a common basis to explain the peculiarity of their radiation scattering properties, namely the existence, or absence, of a scattering pre-peak. Through the analysis of models, it is shown that the presence, or absence, of a radiation scattering pre-peak is principally related to the symmetry breaking, or not, of the global charge order, induced by the peculiarities of the molecular shapes. This symmetry breaking is achieved, in practice, by the emergence of specific types of clusters, which manifest how global charge order has changed into a local form. The various atom-atom correlations witness the symmetry breaking induced by this re organization , and this is manifested into a pre-peak in the structure factor. This approach explains why associated liquids such as water do not show a scattering pre-peak. It also explains under which conditions core-soft models can mimic associating liquids.

Domaines: Chimie

Aurélien Perera. Charge ordering and scattering pre-peaks in ionic liquids and alcohols. Physical Chemistry Chemical Physics, 2017, 19 (2), pp.1062 - 1073. ⟨10.1039/C6CP07834F⟩. ⟨hal-01430812⟩