Macro- and Microscopic Investigation of Anti-icing Properties of Anodized Aluminum Surfaces
Daan Heskes1, Valentina Rizzi2, Matteo Chiesa1, Walter Navarrini2, Maria Vittoria Diamanti2, Marco Stefancich1
1 Laboratory for Energy and NanoScience (LENS), Institute for Future Energy Systems (iFES), Masdar Institute of Science and Technology, P.O.Box 54224, Abu Dhabi, UAE
2Dipartimento di Chimica, Materiali ed Ingegneria Chimica ”G. Natta”, Politecnico di Milano, via L. Mancinelli, 7, 20131 Milano, Italy
In this work the (anti-)icing properties of anodized aluminium with different surface chemistries are investigated. In order to obtain anti icing coatings use is made of the surface chemistry as well as the structure of the surface, which are often also related to the hydrophobicity of surface . Recently it was shown that anodized alumina surface, which have a honeycomb like surface structure, can exhibit superhydrophobic properties . In addition to the structural part of the coating also different surfaces chemistries are investigated; bare alumina, silanized and perfluorinated anodized alumina surfaces as well as liquid impregnated surfaces. Characterization is done macroscopically as well as microscopically. Macroscopically the ice adhesive energy, the contact angle and contact angle hysteresis is experimentally measured. The ice adhesive energy is obtained by subjecting the iced samples to a guided impact test. On the Microscopic scale the properties of the surface are investigated using different methods of Atomic Force Microscopy. In order make fully use of the Atomic Force Microscopy imaging also the different surface chemistries on flat samples are examined. First the surface topography of the sample probed to obtain the surface roughness. Using Scanning Kelvin Probe Microscopy the surface potential of the different samples are mapped . Combining these scales of measurement can enhance the understanding of these kinds of surfaces.
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