Regensburg 2013 – scientific programme

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BP: Fachverband Biologische Physik

BP 14: Biomaterials and Biopolymers I (joint with CPP)

BP 14.12: Talk

Tuesday, March 12, 2013, 12:45–13:00, H34

Study of phase transitions on DPPC bilayers deposited by PVD on top of low viscosity chitosan scaffolds of different thicknesses — •Maria J. Retamal, Carmen Gonzalez, Mauricio Sarabia, Marcelo Cisternas, and Ulrich G. Volkmann — Surface Lab, Fac. de Fisica, P. Universidad Catolica de Chile, Chile

The porous nature of chitosan and its non-solubility in water could be an efficient matrix able to absorb water molecules and their delivery to a system. Chitosan of low viscosity (CH) and 1,2 *dipalmitoyl-sn-3-phosphoglycerocholine (DPPC) over silicon wafer (SiO2/Si(100)) as substrate were used to conform an artificial membrane, silicon wafer/CH-DPPC. The deposition was made by Physical Vapor Deposition (PVD) and thickness was controlled in situ with Very High Resolution Ellipsometry (VHRE), achieving chitosan films with precise thicknesses between 10Å and 200Å, and a 60Å thin DPPC bilayer on top. We focus on the precise thickness control of the thin films, and the related formation of interstitial channels, that favor the prolonged humidification in the system and the discovery of the most suitable thickness of the chitosan scaffold for best artificial membrane formation and stability. The characterization of the artificial membrane was realized using VHRE, IE (Imaging Ellipsometry) and Atomic Force Microscopy (AFM), with the finality to determine the possible phase transition temperatures.

M.J. R. and C. G. acknowledges CONICYT and VRI Nr. 10/2010 (PUC), respectively. Work supported by FONDECYT project Nr. 1100882.