| AVS 64th International Symposium & Exhibition | |
| Biomaterial Interfaces Division | Thursday Sessions |
| Session BI+AS-ThA |
| Session: | Biomolecules and Biophysics at Interfaces |
| Presenter: | Laila Moreno Ostertag, Max Planck Institute for Iron Research, Germany |
| Authors: | L. Moreno Ostertag, Max Planck Institute for Iron Research, Germany T. Utzig, Max Planck Institute for Iron Research, Germany P. Stock, Max Planck Institute for Iron Research, Germany M. Valtiner, TU Bergakademie Freiberg, Germany |
| Correspondent: | Click to Email |
When two surfaces come in close contact, several forces arise and, depending on the nature of the surfaces, these forces will show different magnitude. This principle may also be applied to diverse biological systems. Van der Waals forces have been on the radar for a century or so, and the identification of electrostatic interactions can be traced back to ancient times. It has also been clear that the behavior of such surfaces in terms of their polarity is associated to another type of force, called hydrophobic interactions.1,2 The combination of these contributions leads to a better understanding of the interactions as the surfaces get closer together.
In this regard, we have revisited the hydrophobic interactions theory by studying the interaction forces between apposing symmetric surfaces of varying hydrophobicity via Atomic Force Microscopy and correlating them to the behavior of water at the interface. Short hydrophobic chains ending in either non-polar, hydrophobic groups or in charged heads and combinations of them were attached to smooth surfaces and tested under constant ionic force conditions. Mathematical modeling of the interactions was applied to the experimental results in order to obtain numerical parameters that are associated to the surface properties. Interesting results that are in apparent contradiction with the expected trend of the hydration parameters were found but can be explained by what we suggest is a breakdown of the water structure at the interface, which in turn can contribute to the understanding of attraction or repulsion between certain biological systems in aqueous media.
1. Hammer, M. U.; Anderson, T. H.; Chaimovich, A.; Shell, M. S.; Israelachvili, J., The search for the hydrophobic force law. Faraday Discussions 2010,146 (0), 299-308.
2. Donaldson, S. H.; Røyne, A.; Kristiansen, K.; Rapp, M. V.; Das, S.; Gebbie, M. A.; Lee, D. W.; Stock, P.; Valtiner, M.; Israelachvili, J., Developing a General Interaction Potential for Hydrophobic and Hydrophilic Interactions. Langmuir 2015,31 (7), 2051-2064.