Thermal Diffusion in Polymer Blends: Criticality and Pattern Formation

Krekhov, A. P.; Zimmermann, Walter

doi:10.1007/12_2009_33

Cited by 20 publications

(9 citation statements)

References 116 publications

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“…For example, if such a quench propagates through space over the time it may lead to macroscopic coarsening with patterns that are different from those seen in spatially homogeneous quenching [11]. Local temperature quenches can be realized by direct laser heating [11,12] of parts of the binary liquid mixtures or by optical heating [12][13][14] of the surface of the suitably coated colloid suspended in such mixtures. One might think of using optically heated colloids for the buildup of soft solids, therefore, it is interesting to know how local is the phase separation around each colloid and how the coarsening process depends on the adsorption preference of the surface of a colloid.…”

Section: Introductionmentioning

confidence: 99%

Phase separation around a heated colloid in bulk and under confinement

Roy

Maciołek

2018

Soft Matter

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We study the non-equilibrium coarsening dynamics of a binary liquid solvent around a colloidal particle in the presence of a time-dependent temperature gradient that emerges after a temperature quench of a suitable coated colloid surface. The solvent is maintained at its critical concentration and the colloid is fixed in space. The coarsening patterns near the surface are shown to be strongly dependent on the colloid surface adsorption properties and on the temperature evolution. The temperature gradient alters the morphology of the binary solvent near the surface of the colloid as compared to the coarsening proceeding at a constant temperature everywhere. We also present results for the evolution of coarsening in thin films with confining surfaces preferring one species of the binary liquid mixture over the other. Confinement leads to a faster phase segregation process and formation of a bridge connecting the colloid and both confining walls.

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Section: Introductionmentioning

confidence: 99%

Phase separation around a heated colloid in bulk and under confinement

Roy

Maciołek

2018

Soft Matter

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“…the so-called contrast factors of the analyzed mixture [27,28]. An alternative method that is not based on an optical analysis is the thermo-gravitational column technique [29], in which the sample is let evolve to the steady state of the separation, after which small volumes of the fluid mixture at different heights are physically picked-up and analyzed in order to directly measure the value of the concentration as a function of the vertical coordinate, thus leading to a measurement of the thermodiffusion coefficient D T , but without any information about the mass diffusion coefficient D. Other interesting techniques from the optical domain include optical digital interferometry (ODI) [30], thermal diffusion-forced Rayleigh scattering (TDFRS) [31], thermal lens [32] and other techniques that have been reported in the literature [17,28,[33][34][35].…”

Section: Introductionmentioning

confidence: 99%

Mass transport properties of the tetrahydronaphthalene/n-dodecane mixture measured by investigating non-equilibrium fluctuations

Croccolo

Scheffold

Bataller

2013

Comptes Rendus. Mécanique

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We present preliminary near-field light scattering (NFS) data concerning the analysis of the static power spectrum and of the relaxation time constant as a function of the wave vector for non-equilibrium fluctuations (NEFs). The goal of these measurements is to obtain information about the Soret and the mass diffusion coefficients of a binary mixture undergoing thermodiffusion. In particular, we show how the interaction between NEFs and the gravity force gives rise to a critical wavelength that provides additional information about the Soret coefficient. We suggest that a quantitative analysis can be performed by means of this non-invasive optical technique. In our setup, the sample is monitored parallel to the imposed temperature gradient, thus being insensitive to the refractive index profile along the vertical axis, while at the same time we are able to detect the light scattered by the refractive index fluctuations in horizontal planes. We select a shadowgraph layout for the NFS setup due to the extremely small wave vectors we aim to analyze. From a double-frame differential analysis of the acquired images, we obtain both the static power spectrum and the dynamics of NEFs. As a proof-of-principle experiment, we present Soret and diffusion coefficient data on a liquid mixture of tetrahydronaphthalene/n-dodecane.

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“…For materials with a strong Soret effect, quantified by the Soret coefficient S T , small temperature gradients are sufficient to generate large concentration and therefore large viscosity gradients, so that the direct effects of temperature gradients can be neglected. Suchlike experimentally favorable large values of S T can be achieved by shifting the mean temperature of the binary fluid in the one-phase region close to the critical temperature of the mixture, where a transition to the two-phase region takes place [41,42,43,44].…”

Section: Model Viscositiesmentioning

confidence: 99%

Anomalous diffusion in viscosity landscapes

et al. 2011

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Anomalous diffusion is predicted for Brownian particles in inhomogeneous viscosity landscapes by means of scaling arguments, which are substantiated through numerical simulations. Analytical solutions of the related Fokker-Planck equation in limiting cases confirm our results. For an ensemble of particles starting at a spatial minimum (maximum) of the viscous damping we find subdiffusive (superdiffusive) motion. Superdiffusion occurs also for a monotonically varying viscosity profile. We suggest different substances for related experimental investigations.

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Thermal Diffusion in Polymer Blends: Criticality and Pattern Formation

Cited by 20 publications

References 116 publications

Phase separation around a heated colloid in bulk and under confinement

Phase separation around a heated colloid in bulk and under confinement

Mass transport properties of the tetrahydronaphthalene/n-dodecane mixture measured by investigating non-equilibrium fluctuations

Anomalous diffusion in viscosity landscapes

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