Dresden 2009 – wissenschaftliches Programm
DS 16.21: Poster
Dienstag, 24. März 2009, 09:30–12:30, P5
Static and dynamic contact angle measurements on self-assembled monolayers covalently bond on silicon surfaces. — •David Polster, Harald Graaf, and Christian von Borczyskowski — Center of Nanostructured Materials and Analytics, University of Technology Chemnitz, 09107 Chemnitz, Germany
Contact angle measurements were carried out on self-assembled monolayers, which were prepared by covalently bond 1-decene and methyl-10-undecenoate (UND) on silicon surfaces. Beside the pure monolayers also mixtures of the two molecules were investigated, where the surface mole fraction of UND was tuned by different mixture solution ratios. The prepared films have been studied with static and dynamic contact angle measurements, using water as a polar liquid and diiodmethane as a dispersive liquid. By the static contact angle measurement the surface energy of the monolayers as well as their polar and dispersive parts were determined. Dynamic contact angle measurements, where the advancing and the receding angles of droplets of the probe liquids are measured, give information on the surface roughness and heterogeneity and furthermore are used to calculate the molar free energies of the surface. For the mixed monolayers a decrease in the contact angles and molar free wetting energy was found with increasing ratio of UND in the monolayer. In contrast, molar free dewetting energy und contact angle hysteresis was nearly constant.