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.