Regensburg 2016 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

CPP: Fachverband Chemische Physik und Polymerphysik

CPP 43: Poster: The Physics of Water Interactions with Biological Matter

CPP 43.2: Poster

Mittwoch, 9. März 2016, 18:15–21:00, Poster B2

On the influence of the intermolecular potential on the wetting properties of water on silica surfaces — •Elvira Pafong, Julian Geske, and Barbara Drossel — Institut für Festkörperphysik, Technische Universität Darmstadt

Porous amorphous silica is widely used for technological applications such as catalysators, nanotechnology, or biomedicine. Often, an aqueous solution is given into the pores, and it is therefore essential to understand the structure, dynamics and wetting behavior of water in such nanoporous systems. Due to the ability of water to form hydrogen bonds with the surface silanol groups of the silica material, the surfaces are believed to be highly hydrophilic and the water is expected to wet the pores even at moderate filling ratios. However, this is not seen in our molecular dynamics simulations using the standard Brodka-Zerda form of the Lennard Jones potential. We therefore perform an in-depth study of the effect of the choice of the potential and of the thickness of the silica walls on the behavior of water in partially filled pores and on top of silica slabs. We find that the Gulman potential gives more realistic wetting behavior. We also find that the thickness of the silica slab must be chosen carefully in other to well reproduce the electrostatic and van-der-Waals interactions between water and silica surfaces.