Regensburg 2004 – scientific programme

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CPP: Chemische Physik und Polymerphysik

CPP 12: Colloids and Nanoparticles II

CPP 12.2: Talk

Monday, March 8, 2004, 16:00–16:15, H 39

Wetting at the nanometric scale — •Hauke Schollmeyer¹, Antonio Checco², Jean Daillant^1,3 und Patrick Guenoun¹ — ¹Service de Physique de l’Etat Condense, C.E.A. Saclay, F-91898 Orsay Cedex, France — ²Department of Physics, Brookhaven National Laboratory, Upton, New York 11973 — ³LURE, CNRS/CEA/MJENR, bat. 209D, Centre Universitaire Paris-sud, F-91898 Orsay Cedex, France

We have investigated the partial wetting of micrometric and nanometric alkane droplets on model substrates using true non-contact atomic force microscopy. The large droplet sizes accessible using this technique allowed us to determine the contact line curvature dependence of contact angle with unprecedented accuracy. Whereas previous studies aimed at explaining such a dependence by a line tension effect, our results and calculations on a model system exclude such an effect. Our results point to an extreme sensitivity to weak substrate heterogeneities confirmed by numerical simulations. Our goal is to prove this result for model substrates without heterogeneities. For this we use self assembled monolayer of long chained alkanes on silicon substrate. At room temperature these form a smooth and solid surface.