Universal behavior of nonequilibrium fluctuations in free diffusion processes
We show that giant nonequilibrium fluctuations are present during the free diffusive remixing occurring in ordinary liquid mixtures and in macromolecular solutions. The static structure factor of the fluctuations is measured by using a quantitative shadowgraph technique. We show that structure factors at different times and from different samples can be rescaled onto a single master curve without any adjustable parameter, thus giving strong evidence that nonequilibrium fluctuations are a universal feature of free diffusion processes.
Brogioli
D
Dipartimento di Fisica and Istituto Nazionale per la Fisica della Materia, Universita di Milano, via Celoria 16, 20133 Milano, Italy.
Vailati
A
Giglio
M