Charging of heated colloidal particles using the electrolyte Seebeck effect

Arghya Majee (1) , Alois Würger (1)

1 LOMA - Laboratoire Ondes et Matière d'Aquitaine

We propose a novel actuation mechanism for colloids, which is based on the Seebeck effect of the electrolyte solution: Laser heating of a nonionic particle accumulates in its vicinity a net charge Q, which is proportional to the excess temperature at the particle surface. The corresponding long-range thermoelectric field E∝1/r² provides a tool for controlled interactions with nearby beads or with additional molecular solutes. An external field E_{ext} drags the thermocharged particle at a velocity that depends on its size and absorption properties; the latter point could be particularly relevant for separating carbon nanotubes according to their electronic bandstructure.

Domaines: Matière Molle [cond-mat.soft]

Arghya Majee, Alois Würger. Charging of heated colloidal particles using the electrolyte Seebeck effect. Physical Review Letters, 2012, 108 (11), pp.118301. ⟨10.1103/PhysRevLett.108.118301⟩. ⟨hal-00678357⟩