THE ROLE OF ADSORPTION IN HETEROGENEOUS NUCLEATION, I: ADSORPTION OF WATER VAPOR ON SILVER IODIDE AND LEAD IODIDE

Abstract

The adsorption of water vapor on silver iodide and lead iodide was measured, to determine whether a relationship exists between the ability of a particle to take up water vapor on its surface and its nucleating ability. It was found that nucleating ability is closely linked with the capacity of a solid to adsorb water vapor on its surface. From the adsorption isotherms on the silver iodide and lead iodide at ?2OC, and supplementary experiments, it was determined that it is not necessary for the nucleating system to go through water saturation before ice-crystal formation can occur.