Experimental observation of triple correlations in fluids

Abstract

We present arguments for the hypothesis that under some conditions, triple correlations of density fluctuations in fluids can be detected experimentally by the method of molecular spectroscopy. These correlations manifest themselves in the form of the so-called 1.5-(i.e., sesquialteral) scattering. The latter is of most significance in the pre-asymptotic vicinity of the critical point and can be registered along certain thermodynamic paths. Its presence in the overall scattering pattern is demonstrated by our processing experimental data for the depolarization factor. Some consequences of these results are discussed.

On applicability of differential mixing rules for statistically homogeneous and isotropic dispersions

“…Earlier, the CGA was efficiently applied to dispersions of particles with complex permittivities to describe electric percolation phenomena in composites of core-shell particles [5], two-step electrical percolation in nematic liquid crystals filled with multiwalled carbon nanotubes [35], and effective parameters of suspensions of nanosized insulating particles [36]. Finally, the idea of compact groups was also used by Sushko to evaluate the effects of multiple short-range reemissions between particles on the mean free path and the transport mean free path of photons in concentrated suspensions [37] and to discover the 1.5 molecular light scattering in fluids near the critical point [38,39]; the results were supported by extensive experimental data.…”