Berlin 2012 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 7: Poster: Biopolymers and Biomaterials (jointly with BP)

CPP 7.10: Poster

Montag, 26. März 2012, 17:30–19:30, Poster A

Phase transitions in Chitosan/DPPC membrane multilayer as a function of hydration — Zoraya E. Lopez Cabana, Carmen M. Gonzalez Henriquez, •Ulrich G. Volkmann, Patrick Huber, Marcelo Cisternas, Rosario Ortega, and Mauricio Sarabia — Surface Lab, Facultad de Fisica, Pontificia Universidad Catolica de Chile, Chile

The main goal of this investigation is the formation of porous membranes of chitosan, a natural polymer. The porous character favors the incorporation of humidity that affects the thermal behavior of the multilayer. The membranes have been formed by spin coating on silicon wafers at 2000/6000 rpm. The thickness of the membrane was studied with Very High Resolution Null Ellipsometry and their topography by Atomic Force Microscopy (AFM). On top of the chitosan membrane a precise concentration of DPPC was evaporated by Physical Vapor Deposition (PVD) and homogeneous DPPC films (∼80 Åthickness) were obtained. The characterization of the phase transition temperature of the multilayer Chitosan/DPPC was realized by imaging ellipsometry and in situ AFM and Raman spectroscopy. These transitions are consistent with those found by Meyer et al. [1].

[1] Meyer, H. W.; Semmler, K.; Rettig, W.; Pohle, W.; Ulrich, A. S.; Grage, S.; Selle, C.; Quinn, P. J. Chem. Phys. Lipids 2000, 105, 149-166.

C.M. G.H. acknowledges a scholarship from VRI Nr. 10/2010 (PUC). Work supported by FONDECYT project Nr. 1100882. Raman spectroscopy supported by FONDEF project Nr. D97F1001.