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Updated: Aug 17, 2026

A Method to Manipulate Surface Tension of a Liquid Metal via Surface Oxidation and Reduction
Published on: January 26, 2016
Surface and capillary forces encountered by zinc sulfide microspheres in aqueous electrolyte
Graeme Gillies1, Michael Kappl, Hans-Jürgen Butt
1Max-Planck-Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
Abstract:
The colloid probe technique was used to investigate the interactions between individual zinc sulfide (ZnS) microspheres and an air bubble in electrolyte solution. Incorporation of zinc ions into the electrolyte solution overcomes the disproportionate zinc ion dissolution and mimics high-volume-fraction conditions common in flotation. Determined interaction forces revealed a distinct lack of long-ranged hydrophobic forces, indicated by the presence of a DLVO repulsion prior to particle engulfment. Single microsphere contact angles were determined from particle-bubble interactions. Contact angles increased with decreasing radii and with surface oxidation. Surface modification by the absorption of copper and subsequently potassium O-ethyldithiocarbonate (KED) reduced repulsive forces and strongly increased contact angles.
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