Fraunhofer Institute for Applied Optics and Precision Engineering IOF
Fraunhofer Institute for Applied Optics and Precision Engineering IOF
Eine Vielzahl von Oberflächen wird unter extensiver Verwendung von Chemikalien gereinigt. Beispiele dafür im Bereich Glasoberflächen sind u.a. Fensterscheiben, Duschkabinen, Spiegel und Optikkomponenten im Innen- und Außeneinsatz. Dies belastet in hohem Maße die Umwelt und könnte durch den Einsatz von Oberflächen mit einstellbaren Benetzungseigenschaften, bis hin zur Selbstreinigung, erheblich reduziert werden.

Design and analysis of functional surface structures: Hydrophobicity, oleophilicity, etc.

The wetting properties of optical and technical surfaces are of crucial importance for their functional properties in many applications. Examples are self-cleaning superhydrophobic surfaces (architectural glass) and technical surfaces with optimal oleophilic wettability (e.g. highly stressed mechanical parts).

A significant factor for the wetting properties of a surface is, aside from its chemical properties, the surface roughness. Therefore, the technological implementation requires a specific surface structure. For this purpose, a novel method has been developed at Fraunhofer IOF that links roughness and wetting properties through roughness analysis and data evaluation.

For the characterization of wetting properties, a contact angle measurement system is used. The modular instrument allows for automatic drop dosage, sample tilt for roll and slide-off experiments, heating of sample and test fluid as well as comprehensive methods of data acquisition for static or dynamic contact angles analysis.

Literature:

Luisa Coriand, Monika Mitterhuber, Angela Duparré, and Andreas Tünnermann, "Definition of roughness structures for superhydrophobic and hydrophilic optical coatings on glass," Appl. Opt. 50, C257-C263 (2011)