Zavabeti A.,RMIT University |
Daeneke T.,RMIT University |
Chrimes A.F.,RMIT University |
Chrimes A.F.,Institute of Chemical and Bioengineering |
And 5 more authors.
Nature Communications | Year: 2016
Components with self-propelling abilities are important building blocks of small autonomous systems and the characteristics of liquid metals are capable of fulfilling self-propulsion criteria. To date, there has been no exploration regarding the effect of electrolyte ionic content surrounding a liquid metal for symmetry breaking that generates motion. Here we show the controlled actuation of liquid metal droplets using only the ionic properties of the aqueous electrolyte. We demonstrate that pH or ionic concentration gradients across a liquid metal droplet induce both deformation and surface Marangoni flow. We show that the Lippmann dominated deformation results in maximum velocity for the self-propulsion of liquid metal droplets and illustrate several key applications, which take advantage of such electrolyte-induced motion. With this finding, it is possible to conceive the propulsion of small entities that are constructed and controlled entirely with fluids, progressing towards more advanced soft systems. © 2016 The Author(s).
Van Vegten N.,Institute of Chemical and Bioengineering |
Haider P.,Institute of Chemical and Bioengineering |
MacIejewski M.,Institute of Chemical and Bioengineering |
Krumeich F.,Institute of Chemical and Bioengineering |
Baiker A.,Institute of Chemical and Bioengineering
Chimia | Year: 2010
Gold nanoparticles supported on TiO2 were probed by adsorption of methyl mercaptane (MM), and the process was quantified gravimetrically. This method allowed discrimination between weakly adsorbed (physisorbed) and strongly bound (chemisorbed) methyl mercaptane. Strong adsorption of MM occured on exposed Au faces, while low-temperature pre-treatment (30 °C) completely suppressed adsorption of MM on the TiO2 support. The thus obtained high selectivity of MM adsorption on Au enabled characterization of the gold surface area and the resulting values are comparable with other noble metal systems of similar average particle size. The estimated adsorption stoichiometry indicates that the entire Au surface is probed. © Schweizerische Chemische Gesellschaft.