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Electrostatically Self-Assembled Multilayers of Chitosan and Xanthan Studied by Atomic Force Microscopy and Micro-Interferometry |
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| Authors: | Gjertrud Maurstad Andreas R Bausch Pawel Sikorski Bjørn T Stokke |
| Institution: | 1. Biophysics and Medical Technology, Dept. of Physics, The Norwegian University of Science and Technology, NTNU, NO-7491 Trondheim, Norway, Fax: +47 73597710
Lehrstuhl für Biophysik, E22, Technische Universität München, James-Franck-Strasse 1, D-85748 Garching, Germany;2. Lehrstuhl für Biophysik, E22, Technische Universität München, James-Franck-Strasse 1, D-85748 Garching, Germany;3. Biophysics and Medical Technology, Dept. of Physics, The Norwegian University of Science and Technology, NTNU, NO-7491 Trondheim, Norway, Fax: +47 73597710 |
| Abstract: | The thickness and surface morphology of electrostatically self-assembled films of chitosan and xanthan (persistence length of ∼120nm) have been studied using dual-wavelength Reflection Interference Contrast Microscopy (DW-RICM) and tapping mode Atomic Force Microscopy (AFM). The multilayers were prepared at two ionic strengths (5mM and 150mM). When the multilayers were assembled at 150 mM a network like morphology was observed after one bilayer. This structure was found to be of large influence in the further growth of the multilayers, with the same kind of network structure being observed at all number of bilayers. A lack of swelling behaviour, as well as the network structure and the poresize of the network, is suggested to originate from the high chain stiffness of xanthan. |
| Keywords: | atomic force microscopy (AFM) chitosan DW-RICM xanthan |