RT Journal Article
T1 Coupled non-equilibrium fluctuations in a polymeric ternary mixture
A1 García Fernández, Loreto
A1 Fruton, P.
A1 Bataller, H.
A1 Ortiz De Zárate Leira, José María
A1 Croccolo, F.
AB We investigate by dynamic shadowgraphy the non-equilibrium fluctuations at the steady state of a thermodiffusion experiment in a polymeric ternary mixture of polystyrene-toluene-n-hexane. The structure function of the refractive index reveals the existence of quite different decay times, thus requiring the analysis of a wide range of correlation times. This is related to the simultaneous presence of three distinct decay modes corresponding to (from fastest to slowest) the relaxation of temperature fluctuations, of the concentration fluctuations of the mixed solvent, and of the concentration fluctuations of the polymer in the binary solvent. An investigation of the decay times at the corresponding diffusive regimes provides a measurement of the thermal diffusivity and the two eigenvalues of the mass diffusion matrix of the ternary mixture. Similar experiments were performed in the past but here, to suppress the confinement effect and obtain a more direct comparison with the theory, a thicker sample is studied. Moreover, also a faster camera is used allowing the experimental observation of faster modes, like the propagative ones. The experimental values of the decay times are eventually compared with those predicted by different available theories. Finally, we present a more complete theoretical model to describe the non-equilibrium fluctuations in the bulk of a ternary mixture at the steady state of a thermodiffusion experiment.
PB Springer
SN 1292-8941
SN 1292-895X
YR 2019
FD 2019-09-01
LK https://hdl.handle.net/20.500.14352/100369
UL https://hdl.handle.net/20.500.14352/100369
LA eng
NO García-Fernández , L., Fruton, P., Bataller, H. et al. Coupled non-equilibrium fluctuations in a polymeric ternary mixture. Eur. Phys. J. E 42, 124 (2019). https://doi.org/10.1140/epje/i2019-11889-4
NO Centre National d´Etudes Spatiales (France)
NO E2S-UPPA
NO TOTAL
NO Bureau de Recherches Géologiques et Minières (France)
NO Agencia Estatal de Investigación (España)
DS Docta Complutense
RD 4 abr 2025