Dresden 2011 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 7: Interfaces and Thin Films II

CPP 7.9: Vortrag

Montag, 14. März 2011, 16:15–16:30, ZEU 114

Measuring the Elasticity of Polymer Films with AFM Nanoindentation — •Cagri Üzüm, Anna Burmistrova, Marcel Richter, Johannes Hellwig, Dmitry Volodkin, and Regine v. Klitzing — Stranski-Laboratorium, Institut für Chemie, TU Berlin, Strasse des 17.Juni 124, 10623 Berlin, Germany

Mechanical properties of polymeric films and microparticles have to be revealed once they are to be used in biological applications [1]. For submicron structures, the (visco)elasticity can be measured by means of AFM nanoindentation. Together with its nanoscale imaging ability, this makes the AFM a unique technique in the relevant area.

In this contribution, elastic properties (Young's modulus) of poly(L-lysine)/hyaluronan (PLL/HA) thin films as well as other hydrogel films/particles were investigated. Young's modulus was observed to depend strongly on the temperature and the cross-linker density while the film thickness itself had only a minor effect. Either colloidal probes or blunt tips were used as nanoindenters. The well-known problem of determining the exact indenter-sample contact point was tried to be overcome by various data handling processes [2].

[1] Picart, C., Senger, B., Sengupta, K., Dubreuil, F., Fery, A. Colloids Surf., A 303, 30-36 (2007)

[2] Dimitriadis, E.K., Horkay, F., Maresca, J., Kachar, B., Chadwick, R.S. Biophys. J. 82, 2798 (2002)