Bodil Holst

_{Professor, Department of Physics and Technology, University of Bergen, Norway}

Bending Rigidity of 2D Silica and Anti-icing Properties of Graphene

In this talk I will present two topics linked in that they are both investigating properties of 2D materials. Bending rigidity is a very important material property for many applications, for example flexible electronics. I will show how neutral helium atom scattering (HAS) provides a unique method for measuring the bending rigidity of 2D materials. I will present results where we use HAS to measure the bending rigidity of 2D silica (SiO2) [1]. This is only the second 2D material after graphene where the bending rigidity has been measured. Due to the nature of the silica, the 2D material has a bilayer structure. I will show that just this slight decrease in thickness seems to be enough that the bending rigidity can be well determined from the bulk mechanical constants (Youngs Modulus and Poisson’s Ratio). I will also discuss how the bending rigidity can give information about the large-scale quality (defect density) of a 2D material. In the second part of the talk I present results on the anti-icing properties of graphene in comparison to functionalised graphene. In a recent publication [2] we show that fluorinated graphene gives a world record in delay of ice formation at high humidity conditions. From 90 minutes at -15°C to several hours at -5°C. Due to its high robustness and optical transparency graphene is a very attractive material for anti-icing coatings i.e. for car windows, camera lenses etc. as well as for other surfaces such as airplane wings, wind turbines etc.

References:
1) C. Büchner, S. D. Eder, T. Nesse, D. Kuhness, P. Schlexer, G. Pacchioni, J. R. Manson, M. Heyde, B. Holst, H.-J. Freund, Bending Rigidity of 2D Silica, PRL, 120, 226101 (2018)
2) N. Akhtar, G. Anemone, D. Farias, B. Holst, Flourinated Graphene Provides Long Lasting ice inhibition in high humidity, Carbon, 141, 451-456 (2018)