Theoretical analysis and experiments have provided compelling evidence of the presence of long-range nonequilibrium concentration fluctuations during diffusion processes in fluids. In this paper, we investigate the dependence of the features of the fluctuations from the dimensionality of the system. In three-dimensional fluids the amplitude of nonequilibrium fluctuations can become several orders of magnitude larger than that of equilibrium fluctuations. Notwithstanding that, the amplitude of nonequilibrium fluctuations remains small with respect to the concentration difference driving the diffusion process. By extending the theory to two-dimensional systems, such as liquid monolayers and bilayers, we show that the amplitude of the fluctuations becomes much stronger than in three-dimensional systems. We investigate the properties of the fronts of diffusion and show that they have a self-affine structure characterized by a Hurst exponent H=1. We discuss the implications of these results for diffusion in liquid crystals and in cellular membranes of living organisms.
Nonequilibrium fluctuations during diffusion in liquid layers / D.C. Brogioli, A. Vailati. - In: PHYSICAL REVIEW. E. - ISSN 2470-0045. - 96:1(2017), pp. 012136.012136-1-012136.012136-11.
|Titolo:||Nonequilibrium fluctuations during diffusion in liquid layers|
VAILATI, ALBERTO (Corresponding)
|Parole Chiave:||Statistical and Nonlinear Physics; Statistics and Probability; Condensed Matter Physics|
|Settore Scientifico Disciplinare:||Settore FIS/03 - Fisica della Materia|
|Data di pubblicazione:||2017|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1103/PhysRevE.96.012136|
|Appare nelle tipologie:||01 - Articolo su periodico|