The growth kinetics of surface films of propyltrimethoxysilane (PTMS) deposited on aluminum and iron oxide surfaces exhibit oscillatory adsorption. This phenomenon involves non-linear oscillations in surface coverage of the adsorbate, as measured by x-ray photoelectron spectroscopy (XPS), as a function of exposure time and solution concentration. In this paper, a mathematical model is presented to describe the experimentally observed time-dependent behaviour. The oscillatory nature of the adsorption can be modelled by a superposition of adsorption and desorption processes. The model quantitatively describes the rate and non-linearity of these processes. Using this model, the influence of the substrate upon the various adsorption processes is described quantitatively. A model for the physical origins of the three processes is presented.
|Number of pages||4|
|Journal||Surface and Interface Analysis|
|Publication status||Published - Aug 2000|
|Event||8th European Conference on Applications of Surface and Interface Analisys, ECASIA 99 - Sevilla, Spain|
Duration: 4 Oct 1999 → 8 Oct 1999