For a positive charge U (z) is positive above the plane z = 0 and negative below. According to Boltzmann statistics, this leads to a depletion of positive charges above the plane and an enrichment below the plane. The expected charge difference between the upper and lower half-plane at the same z is given by ∆q = q E U (z)/kT -E U (-z)/kT . Integration along the positive z-direction assuming |U (z)| kT yields ∆q ∝ q 2 µ eff /R d . Since µ eff ∝ R d and the electric field at the droplet center E z ∝ ∆q/R d , it follows that the interaction energy U µ,Ez between the dipole inside the droplet and the electric field generated by the displacement from a single ion in the environment is inversely proportional to the droplet radius. Negative charges will be enriched above the plane and depleted below the plane. The resulting electric fields are additive. The total effect of ν + cations and ν - anions will therefore be proportional to