Abstract
A simple and inexpensive procedure is presented for the measurement of gaseous accommodation coefficients upon liquid or solid surfaces. The gas of interest is passed in laminar flow through an annular reactor and the profile of deposition is subsequently determined. The Cooney-Kim-Davies theoretical treatment of deposition in cylindrical systems is adapted to describe uptake on the walls of the annular reactor as a function of accommodation coefficient and diffusion coefficient. The accommodation coefficient ( alpha ) of ammonia on oxalic acid is determined in both cylindrical and annular systems and good agreement is found. Uptake of nitrogen dioxide on wet alkaline surfaces yields a value for alpha of 2.5 x 10 super(-4), and on solely wet surfaces a value of 8.7 x 10 super(-5). Nitric and nitrous acids deposit to aqueous sodium carbonate/glycerol surfaces with values of alpha of 1.5 x 10 super(-2) and 4.3 x 10 super(-3), respectively.