Density functional study of the adsorption of aspirin on the hydroxylated (001) α-quartz surface

In this study the adsorption geometry of aspirin molecule on a hydroxylated (0 0 1) alpha-quartz surface has been investigated using DFT calculations. The optimized adsorption geometry indicates that both, adsorbed molecule and substrate are strongly deformed. Strong hydrogen bonding between aspirin and surface hydroxyls, leads to the breaking of the original hydroxyl-hydroxyl hydrogen bonds (Hydrogenbridges) on the surface. In this case new hydrogen bonds on the hydroxylated (0 0 1) alpha-quartz surface appear which significantly differ from those at the clean surface. The 1.11 eV adsorption energy reveals that the interaction of aspirin with alpha-quartz is an exothermic chemical interaction. (C) 2009 Elsevier B.V. All rights reserved.