Europhys. Lett., 63 (3) , pp. 401-407 (2003)
Influence of surface morphology on the wettability of cluster-assembled carbon filmsL. Ostrovskaya1, A. Podestà2, P. Milani2 and V. Ralchenko3
1 Institute for Superhard Materials - Avtozavodskaya str. 2, 254074 Kiev, Ukraine
2 INFM, Dipartimento di Fisica, Università di Milano Via Celoria 16, 20133 Milano, Italy
3 General Physics Institute - Vavilova str. 38, 119991 Moscow, Russia
(Received 27 December 2002; accepted in final form 2 June 2003)
We have evaluated the surface energy and characterized the wettability of cluster-assembled carbon films deposited on polyethylene, and substrates by a sessile-drop method using water and glycerol. The effective surface energy of nanostructured carbon is of the order of 30 as calculated using the Fowkes approach. The advancing contact angle (66-83 ) is found to increase with surface roughness, i.e. the surface becomes more hydrophobic as the roughness increases. This behavior is ascribed to gas trapping in pores of the film with a self-affine surface. It is argued that the wettability of nanostructured carbon and other cluster-assembled coatings can be tuned simply by controlling the surface topography, through a suitable control of the deposition parameters, such as the cluster size distribution.
68.08.Bc - Wetting.
68.35.Ct - Interface structure and roughness.
81.07.-b - Nanoscale materials and structures: fabrication and characterization.
© EDP Sciences 2003