Screened Electrostatics of Charged Particles on a Water Droplet

Alois Würger (1)

1 CPMOH - Centre de physique moléculaire optique et hertzienne

We study the electrostatic properties of charged particles trapped at an interface in a water-in-oil microemulsion. The electrostatic potential and the counterion distribution in the water droplet are given in terms of the ratio of the Debye screening length ⁻¹ and the droplet radius R. In the limit R→∞ we recover the well-known results for a flat interface. Finite-size corrections are obtained in terms of the small parameter 1/R. Part of the counterions spread along the interface and form a charged layer of one Debye length thickness. In particular, there is a uniform surface charge contribution. We derive explicit expressions for the electric field, the mobile charge density, and the charge-induced pressure on the interface.

Domaines: Matière Molle [cond-mat.soft]

Alois Würger. Screened Electrostatics of Charged Particles on a Water Droplet. European Physical Journal E: Soft matter and biological physics, 2006, 19, pp.5. ⟨10.1140/epje/e2006-00002-y⟩. ⟨hal-00341447⟩