Dynamical mixing of interstellar clouds: the effects of adsorption on to grains

It has previously been shown that, when the process of dynamical mixing of diffuse and dense material is included, the predictions of chemical models are in much better agreement with observations of organic species and of the C/CO ratio in dark interstellar clouds. However, in these calculations, the effects of adsorption on to grains and of possible reactions on grain surfaces were neglected. In the present study, these processes have been incorporated in a dynamical mixing model, together with photoejection as the complementary desorption mechanisms