Jonas Groten defended thesis
It has already been a little while ago since Jonas Groten successfully defended his PhD thesis entitled "Light induced switching of wetting properties and mechanical stability of superhydrophobic surfaces".
In a very carefull study he found a way to translate the small polarity changes in azo benzene films induced by UV irradiation into dramatic changes in the wettability of nanorough surfaces. The trick was to generate surfaces with a wetting behavior close to a phase transition between two wetting states. The minor differences induced by the cis-trans isomerization within the polymers is then sufficient to cross the border between superwetting and Wenzel wetting or Wenzel wetting and superhydrophobicity.
Jonas has also worked on making nanorough surfaces less vulnerable to shear stress. He basically combined larger microstructures with the nanoroughness such that the microstructures would pick up most of the mechanical load and thereby protect the nanostructures.
His work resulted in two publications so far:
Groten J., Rühe J.
Surfaces with Combined Microscale and Nanoscale Structures: A Route to Mechanically Stable Superhydrophobic Surfaces?
Langmuir, 2013, 29,, 3765–3772
DOI: 10.1021/la304641q
Groten, J., Bunte, C., Rühe, J.
Light induced switching of surfaces at wetting transitions through photoisomerization of polymer monolayers
Langmuir, 2012; 28: 15038-15046.
DOI: 10.1021/la302764k
Some impressions of the doctoral celebrations:
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