A theoretical model, encompassing the concentration fluctuations of associated and unassociated species, has been developed in order to explain the non-Landau behavior observed in self-associating fluids in the hydrodynamic regime. The complex dynamics for the formation of different species is depicted as a pseudo two-components system formed by unbound molecules coexisting with a unique associated specie, the mean aggregation number of which is dictated by thermodynamic requirements. The model has been tested in the case of a hydrogen-bonding system, 1-octanol, over a wide range of temperatures and wave vectors. The model explains, albeit qualitatively, most of the observed deviations from the Landau behavior observed in the Rayleigh-Brillouin spectra at different values of the k-vector. (C) 2002 American Institute of Physics.
Modeling the hydrodynamic fluctuations of self-associating fluids: An application to the Brillouin scattering of 1-octanol
RAUDINO, Antonio;
2002-01-01
Abstract
A theoretical model, encompassing the concentration fluctuations of associated and unassociated species, has been developed in order to explain the non-Landau behavior observed in self-associating fluids in the hydrodynamic regime. The complex dynamics for the formation of different species is depicted as a pseudo two-components system formed by unbound molecules coexisting with a unique associated specie, the mean aggregation number of which is dictated by thermodynamic requirements. The model has been tested in the case of a hydrogen-bonding system, 1-octanol, over a wide range of temperatures and wave vectors. The model explains, albeit qualitatively, most of the observed deviations from the Landau behavior observed in the Rayleigh-Brillouin spectra at different values of the k-vector. (C) 2002 American Institute of Physics.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
