Theoretical consideration on sticking probabilities

Molecular sticking probabilities are important in determining the mass transfer in atmospheric processes, e.g. in the growth of atmospheric aerosols. In this paper we review experimental results from molecular beam experiments and theoretical evidence from molecular dynamics simulation. The theoretical evidence is backed up by a simplified model of classical two-body collision between an incident molecule and a surface molecule in which energy and momentum are exchanged. As a result, general values of sticking coefficients can differ somewhat from unity but it should not be much less than that in conditions and processes having atmospheric relevance like in the uptake of sulphuric acid by atmospheric droplets. The value currently used for sulphuric acid sticking probability ranges from 0.02 to 1.0, but our analysis implies that it should be very near unity.