Physical adsorption of argon on boron nitride. A two-surface analysis of high-temperature adsorption data

Publisher Website
Google Scholar
Abstract
A study has been made of the low-coverage physical adsorption of argon on hexagonal boron nitride using a precision volumetric apparatus. Isotherms are reported at six temperatures in the range 198–273°K at surface coverages of less than about 3% of the BET monolayer volume. Electron micrographs indicate that two crystalline surfaces are exposed, corresponding to the basal plane and crystal edges. The isotherm data exhibit characteristics of adsorption on a slightly heterogeneous surface and are best-fitted to an adsorption model in which a two-energy surface is assumed. Adsorption is assumed to obey Henry's law on one surface and a submonolayer model isotherm on the other. Various models are used and compared and the data analyzed to yield values for the gas-solid interaction energy and surface area for the two surfaces. Estimates are also given for the interaction energy of neon, krypton, and xenon with boron nitride. Comparisons are made between theoretical and experimental values for the interaction energy of the inert gases with graphite and boron nitride.