Experiments on Tracer Diffusion in Thin Free-Standing Liquid-Crystal Films

Bechhoefer, John; Géminard, Jean‐Christophe; Bocquet, Lydéric; Oswald, P.

doi:10.1103/physrevlett.79.4922

Cited by 29 publications

(61 citation statements)

References 21 publications

(22 reference statements)

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“…However, the viscous drag exerted by a fluid surrounding the thin film quenches the low-frequency velocity fluctuations and decreases the mobility to a finite value. This was first predicted theoretically by Saffman [53] and later confirmed by experiments on diffusion [52] and Brownian motion [45].…”

Section: Experimental Model Systemsmentioning

confidence: 52%

“…A pure 2D behavior would require that the drag by the surrounding fluid is negligible; this can be actually achieved in the case of mono-or bilayers of liquid crystals suspended under vacuum (see Appendix). However, at variance with lipid bilayers, it must be noticed that liquid crystals tend to form a bulk phase, and thus present surface capillary effects, which are outside the scope of the present work; we suggest that a pure 2D behavior could be observed, e.g., by Fluorescent Recovery After Photobleaching experiments [52], in which the surface tension is almost perfectly uniform. Experiments on two-dimensional model systems have been mostly performed with liquid layers and films suspended in a viscous fluid.…”

Section: Experimental Model Systemsmentioning

confidence: 65%

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Nonequilibrium fluctuations during diffusion in liquid layers

Brogioli

Vailati

2017

Phys. Rev. E

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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.

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Section: Experimental Model Systemsmentioning

confidence: 52%

Section: Experimental Model Systemsmentioning

confidence: 65%

Nonequilibrium fluctuations during diffusion in liquid layers

Brogioli

Vailati

2017

Phys. Rev. E

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“…On the other hand in a case of perfect slip the momentum will be reflected at the boundary, and the backflow effect will be enhanced. This argument can be made quantitative in both cases [5] and has in fact been used to intrepret experimental results on free standing liquid crystal films [6]. However, it turns out that a quantitative calculation for the case of partial slip is difficult.…”

Section: Qualitative Discussionmentioning

confidence: 99%

Influence of wetting properties on diffusion in a confined fluid

2000

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“…The experimental setup was originally designed for the study of thin liquid films [19]. We focused the TEM 00 mode of a …”

Section: Diffusionmentioning

confidence: 99%

Connectivity of the Hexagonal, Cubic, and Isotropic Phases of the C₁₂EO₆/H₂O Lyotropic Mixture Investigated by Tracer Diffusion and X-ray Scattering

Constantin¹,

Oswald²,

Impéror‐Clerc³

et al. 2000

J. Phys. Chem. B

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The connectivity of the hydrophobic medium in the nonionic binary system C 12 EO 6 /H 2 O is studied by monitoring the diffusion constants of tracer molecules at the transition between the hexagonal mesophase and the fluid isotropic phase. The increase in the transverse diffusion coefficient on approaching the isotropic phase reveals the proliferation of bridge-like defects connecting the surfactant cylinders.This suggests that the isotropic phase has a highly connected structure. Indeed, we find similar diffusion coefficients in the isotropic and cubic bicontinuous phases. The temperature dependence of the lattice parameter in the hexagonal phase confirms the change in connectivity close to the hexagonal-isotropic transition. Finally, an X-ray investigation of the isotropic phase shows that its structure is locally similar to that of the hexagonal phase.

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Experiments on Tracer Diffusion in Thin Free-Standing Liquid-Crystal Films

Cited by 29 publications

References 21 publications

Nonequilibrium fluctuations during diffusion in liquid layers

Nonequilibrium fluctuations during diffusion in liquid layers

Influence of wetting properties on diffusion in a confined fluid

Connectivity of the Hexagonal, Cubic, and Isotropic Phases of the C₁₂EO₆/H₂O Lyotropic Mixture Investigated by Tracer Diffusion and X-ray Scattering

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Experiments on Tracer Diffusion in Thin Free-Standing Liquid-Crystal Films

Cited by 29 publications

References 21 publications

Nonequilibrium fluctuations during diffusion in liquid layers

Nonequilibrium fluctuations during diffusion in liquid layers

Influence of wetting properties on diffusion in a confined fluid

Connectivity of the Hexagonal, Cubic, and Isotropic Phases of the C12EO6/H2O Lyotropic Mixture Investigated by Tracer Diffusion and X-ray Scattering

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Product

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Connectivity of the Hexagonal, Cubic, and Isotropic Phases of the C₁₂EO₆/H₂O Lyotropic Mixture Investigated by Tracer Diffusion and X-ray Scattering