The solution of gases in water has a wide range of interests. These include atmospheric, environmental and industrial chemistry. We ,are particularly interested in the rate and mechanism of the processes involved, in attempt to understand the permeability of gases through foams.
The poster presents the results from computer simulations using the method of Molecular Dynamics. The initial studies involved the calculation of free energy profiles, orientational profiles, and changes in the cylindrical distribution function along the normal to the surface, where the solutes were CO2, N 2, CH3CN and Ar. Both CO2 and CH3CN show a strong adsorption layer, while N 2 and Ar do not have this feature. The molecules show a weak tendency to lie transverse to the surface normal at the surface. CO2 shows a weak tendency to pull the nearest neighbour water molecules above the surface.
We ,are now calculating the reaction rates and sticking coefficients for the surface. In the case of CO 2 an equilibrium is formed between gaseous phase and adsorbed state, making the transition from liquid to adsorbed layes the rate determining process. This is not the case for Nitrogen, where molecules at thermal velocities and above do not feel the adsorption well, but collide against the barrier and are reflected.