Berlin 2015 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 34: P6: Biomaterials and Biopolymers

CPP 34.1: Poster

Dienstag, 17. März 2015, 14:00–16:00, Poster C

Nanoscale viscoelastic properties of hydrated collagen-based films probed with static and dynamic AFM — •Manuel Uhlig, Eike-Christian Spitzner, and Robert Magerle — Chemische Physik, Fakultät für Naturwissenschaften, TU Chemnitz, 09107 Chemnitz, Germany

The amount and distribution of water in collagen-based films determines their mechanical properties and shape. We investigate the effect of hydration on reconstituted collagen fibrils and gelatin films (i.e., denaturated collagen) by controlling the relative humidity of the surrounding air. Measurements are performed with atomic force microscopy (AFM) including static and dynamic force spectroscopy as well as stress relaxation experiments. By combining these methods, the mechanical response is characterized over a wide range of time scales. We obtain maps of the specimen's viscoelastic properties in the near-surface region. For each material, one single AFM probe (Si, with a force constant of 15 N/m) is used during the entire experiment, thus allowing comparison of different tip-sample interaction mechanisms. Gelatin films show a distinct, humidity induced transition from a stiff to a compliant, viscoelastic state. In contrast, collagen fibrils soften more gradually with increasing relative humidity.