January 12, 2015
Scientists at the US Department of Energy’s Oak Ridge National Laboratory are learning how the properties of water molecules on the surface of metal oxides can be used to better control these minerals and use them to make products such as more efficient semiconductors for organic light emitting diodes and solar cells, safer vehicle glass in fog and frost, and more environmentally friendly chemical sensors for industrial applications.
The behavior of water at the surface of a mineral is determined largely by the ordered array of atoms in that area, called the interfacial region. However, when the particles of the mineral or of any crystalline solid are nanometer-sized, interfacial water can alter the crystalline structure of the particles, control interactions between particles that cause them to aggregate, or strongly encapsulate the particles, which allows them to persist for long periods in the environment. As water is an abundant component of our atmosphere, it is usually present on nanoparticle surfaces exposed to air.
A great scientific challenge is to develop ways to look closely at the interfacial region and understand how it determines the properties of nanoparticles. The ORNL researchers are taking advantage of two of the lab’s signature strengths—neutron and computational sciences—to reveal the influence of just a few monolayers of water on the behavior of materials.
Read more at neutrons.ornl.gov.
Related Publication: Wang, H.-W. et. al. (2014). Vibrational Density of States of Strongly H-bonded Interfacial Water: Insights From Inelastic Neutron Scattering and Theory. Journal of Physical Chemistry C, 118, 10805-1083. https://doi.org/10.1021/jp500954v
Related Publication: Wang, H.-W. et. al. (2013). Structure and Stability of SnO2 Nanocrystals and Surface-bound Water Species. Journal of the American Chemical Society, 135, 6885-6895. doi.org/10.1021/ja312030e