Microtribological study of internal surfaces of fluorinated mesoporous silica films.

Fluorinated mesoporous silica films were synthesized via sol-gel co-condensation and coated on glass substrates. Surfactant template concentrations were varied to examine the effect of encapsulated organic functionality on the microtribological properties of films using atomic force microscopy. Films were tested as synthesized and also after being abraded to expose interior mesostructured surfaces. Results indicate that templating allows fluorinated moieties to become encapsulated within the film, which affect the tribological properties of the exposed internal surfaces. Depending on the amount of template added, the interior surfaces were able to achieve a friction level comparable to that of conventional monolayers. The dependence of friction on sliding speed revealed that fluorinated templated films have tribological properties intermediate to those of a nonfunctional surface and a conventional fluorinated monolayer.