Collective thermoelectrophoresis of charged colloids

Thermally driven colloidal transport is, to a large extent, due to the thermoelectric or Seebeck effect of the charged solution. We show that, contrary to the generally adopted single-particle picture, the transport coefficient depends on the colloidal concentration. For solutions that are dilute in the hydrodynamic sense, collective effects may significantly affect the thermophoretic mobility. Our results provide an explanation for recent experimental observations on polyelectrolytes and charged particles and suggest that for charged colloids collective behavior is the rule rather than the exception.