Regensburg 2016 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

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

CPP 43.4: Poster

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

3D-Depth Profiling of Soft and Hydrated Polymeric Surfaces using Atomic Force Microscopy — •Martin Dehnert, Manuel Uhlig, Diana Voigt, and Robert Magerle — Fakultät für Naturwissenschaften, TU Chemnitz, Germany

Tapping mode atomic force microscopy (AFM) is widely used for imaging surfaces of soft materials such as polymers, biological cells, tissues, and even liquids. With tapping mode AFM the shape of the surface (the height image) is measured simultaneously with the phase image from which local mechanical properties of the specimen can be inferred. On soft polymeric materials, however, the tip can indent several tens of nanometers into the surface, which can cause artefacts in both height and phase images. [1] The position of the unperturbed surface and the tip indentation can be determined from point-wise measurements of the amplitude and the phase as function of the tip-sample distance. [1] Furthermore, the tip indentation can be used as depth coordinate for reconstructing three-dimensional depth profiles of the tip-sample interaction. [2] Here, we compare 3D-depth profiles of soft and hydrated polymeric surfaces, for example, polystyrene-functionalized graphene oxide, fluid polymers, and hydrated collagen fibrils by means of dynamic and static force distance measurements. We discuss the different contributions to the tip-sample-interaction and show how the unperturbed surface of compliant materials can be measured.

[1] A. Knoll, R. Magerle, G. Krausch, Macromolecules 34, 4159 (2001)

[2] E.-C. Spitzner, C. Riesch, R. Magerle, ACS Nano 5, 315 (2011)