Soret effect in interacting micellar solutions.
We show that electrostatic effects have a dramatic influence on thermal diffusion of charged micelles. In the dilute regime, the Soret coefficient strongly decreases with the solution ionic strength, and scales as the square of the Debye-Hückel length. Yet, collective effects yield a reversed scenario even at fairly low surfactant concentration. We find that single-particle behavior can be explained using an interfacial tension mechanism proposed by Ruckenstein, which also fairly accounts for collective effects and opens the way to a general picture of thermal diffusion in disperse systems.
Piazza
Roberto
R
INFM-Politecnico di Milano, Dipartimento di Ingegneria Nucleare, via Ponzio 34/3, 20133 Milano, Italy. roberto.piazza@polini.it
Guarino
Andrea
A