DIFFUSIONAL CHARGING OF DROPS IN A WEAKLY IONIZED AQUEOUS AEROSOL

A mathematical model is developed to describe the diffusional charging of drops of water in a weakly charged aerosol. The model accounts the selectivity with which ions of different sign are absorbed by the sur face of the drops as a result of different dependences of the activati on energy for reactions involving the absorption of positive and negat ive ions on the electric potential jump DELTAphi congruent-to 0.25 V a t the water-air interface. It is shown that the well-known empirical r elation q = -rDELTAphi expressing the dependence of the charge of a dr op q on its radius r follows from the model that is presented.