The effect of experimental conditions on the oscillatory adsorption of propyltrimethoxysilane on aluminium oxide surfaces

The adsorption of propyltrimethoxysilane PTMS.dip-coated onto aluminium oxide substrates has been studied using X-ray photoelectron spectroscopy XPS.. In particular, the influence of solution pH and PTMS concentration upon the initial rate of adsorption has been investigated. While the phenomenon of oscillatory adsorption is observed for all of the experimental conditions investigated, the pH and concentration of the PTMS solution have a significant influence upon the dipping time required to reach the first maximum in surface coverage. The dependence of the observed oscillatory adsorption upon these experimental parameters is consistent with the adsorption mechanism for this system previously described by the authors. q1999 Elsevier Science B.V. All rights reserved