Biomedical subjects

Emanuel Bertrand

Publications and source records attributed to Emanuel Bertrand.

3 recordsLinked to original sources

PubMed2005

Polymer bridging probed by magnetic colloids.

Superparamagnetic particles offer a new way to probe the kinetics of adhesive processes. Two different scenarios of physical adhesion are studied. The thermal activation of van der Waals adhesion is well described by an Arrhenius model. In contrast, it is necessary to go beyond the Arrhenius description to understand the thermal activation of bridging between colloidal particles by a polymer at equilibrium adsorbance. We show that polymer bridging requires some removal of adsorbed polymer and is strongly influenced by the proximity of a glass transition within the adsorbed polymer.

Adhesiveness↗

PubMed2004

Long-range critical wetting: observation of a critical end point.

Alkanes deposited on aqueous substrates exhibit two different types of wetting behavior: alternatively to the usual first-order wetting transition, a sequential-wetting scenario of a long-range critical wetting transition preceded by a first-order thin-thick transition may be observed. Here, we present the first successful experimental attempt to locate the transition point between the standard first-order wetting and the long-range critical wetting: a critical end point, observed in a mixture of pentane and hexane which is deposited on an aqueous solution of glucose. Furthermore, we present the first direct measurement of the contact angle in the intermediate wetting state (frustrated-complete wetting) in the sequential-wetting scenario of hexane on brine and compare to theoretical predictions.

Alkanes↗

PubMed2002

From shear thickening to shear-induced jamming.

We show that applying shear to a suspension may lead to either thickening or permanent jamming, depending on the volume fraction of the considered suspension. Interpreting measurements of conductivity under shear, we invoke a dynamical structural transition to explain the origin of shear thickening in suspensions of non-Brownian particles. We finally suggest that shear thickening and shear-induced jamming be regarded as two consequences of this dynamical structural transition.

Journal Article↗