Decoupling the effects of surface texture and chemistry on the wetting of metallic glasses

We report the effects of surface patterning on the wetting of Pt57.5Cu14.7Ni5.3P22.5 and Pd43Cu27Ni10P20 metallic glasses. To maintain the integrity of surface chemistry of the metallic glasses, we optimize thermoplastic patterning protocol and use chemical-free demolding. Our results show that single-scale surface microstructures can render inherently hydrophilic Pt57.5Cu14.7Ni5.3P22.5 metallic glass hydrophobic when its chemical state is preserved. We also observe that because of oxidation, Pd43Cu27Ni10P20 metallic glass remains hydrophilic regardless of its surface topography, though its wettability evolves (i.e. decreases) with time due to airborne contamination. These results suggest that to draw an unambiguous conclusion about the role of surface texture, concomitant changes in surface chemistry must be avoided. (C) 2018 Elsevier B.V. All rights reserved.