THE EFFECT OF RELATIVE HUMIDITY ON COAGULATION AND SURFACE LOSSES OF AMMONIUM CHLORIDE SMOKE

Abstract

Studies have been made of the change with time in the particulate number and rate of loss to surfaces of ammonium chloride smoke at various relative humidities ranging from 15% to 98%. The results are adequately described by the theory given previously with appropriate values for the loss and coagulation constants. The rate of disappearance of the smoke increased with increasing relative humidity, particularly above a value of about 60%. This circumstance is due to an increased loss rate from the system and not to increased coagulation. Though the possibility of 'protecting' an aerosol against coagulation is remote, it would appear possible to render certain aerosols more persistent in humid atmospheres by treatment affecting loss processes rather than coagulation.