IMAGING OF FEATURES ON SURFACES BY CONDENSATION FIGURES

Condensation of a vapor to a liquid on a cold surface that is not wet completely by this liquid leads to the formation of an array of drople ts. If the surface is heterogeneous in its physical properties (especi ally its interfacial free energy), the patterns of these arrays reflec t this heterogeneity. The distribution of droplets of water (condensat ion figures or CFs) observed by optical microscopy on a surface can be correlated with the molecular structure of that surface. The substrat es used to investigate the formation and morphology of the CFs were pa tterned, self-assembled monolayers of different alkanethiolates on gol d and of alkyl siloxanes on glass. Analysis of CFs is a valuable nonde structive technique for characterizing heterogeneities in surfaces.