Surfaces that have been coated with rare earth oxides develop water-repelling properties only after contact with air. Even at room temperature, chemical reactions begin with hydrocarbons in the air. In the journal Scientific Reports, researchers from the University of Basel, the Swiss Nanoscience Institute and the Paul Scherrer Institute report that it is these reactions that are responsible for the hydrophobic effect.
Rare earths are metals found in rare earth minerals. They are used today in, among other things, automotive catalytic converters and batteries, in the production of screens and lamps, and as a contrast agent in magnetic resonance imaging. Their broad range of applications means that there is a high demand for rare earths, and this demand is constantly increasing.
Additional uses for rare earths were opened up after American researchers reported in 2013 that surfaces that have been coated with rare earth oxides become water-repellent.
Scientists from the University of Basel, the Swiss Nanoscience Institute and the Paul Scherrer Institute have now worked with the company Glas Trösch to examine these hydrophobic properties more closely.
Water-repellency develops only after chemical reactions
The researchers coated glass pieces with rare earth oxides, nitrides and fluorides and analyzed how well they could be wetted with water.
They could not detect any hydrophobic properties when the coating was freshly deposited. It was only chemical reactions with gaseous hydrocarbons found in the ambient air that increased the surfaces’ roughness and reduced wetting by water.
The gaseous organic compounds from the ambient air are first adsorbed by the surface and then react with the oxides to form carbonates and hydroxides until the surface is completely covered with these compounds. This process takes place even at room temperature.
“We were surprised that the hydrophobic effect was caused by the surface aging,” says Professor Ernst Meyer, from the Department of Physics at the University of Basel, commenting on the results of the project supported by the Commission for Technology and Innovation (CTI).
These conclusions are very revealing from a scientific point of view because catalytic processes also frequently take place at room temperature, which makes it important to understand the surface’s physical properties.
The examined materials are, however, unsuitable for the industrial production of water-repellent glass surfaces, because the glass requires a sophisticated storage process before it shows the desired hydrophobic characteristics.
Elçin Külah, Laurent Marot, Roland Steiner, Andriy Romanyuk, Thomas A. Jung, Aneliia Wäckerlin, & Ernst Meyer
Surface chemistry of rare-earth oxide surfaces at ambient conditions: reactions with water and hydrocarbons
Scientific Reports (2017), doi: 10.1038/srep43369
Prof. Dr. Ernst Meyer, University of Basel, Department of Physics, tel. +41 61 207 37 24, email: firstname.lastname@example.org
Prof. Dr. Thomas A. Jung, University of Basel, Department of Physics, tel. +41 56 310 45 18, email: email@example.com
Reto Caluori | Universität Basel
Unconventional superconductor may be used to create quantum computers of the future
19.02.2018 | Chalmers University of Technology
Hubble sees Neptune's mysterious shrinking storm
16.02.2018 | NASA/Goddard Space Flight Center
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
19.02.2018 | Materials Sciences
19.02.2018 | Materials Sciences
19.02.2018 | Life Sciences