8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

P4.40Fri 911:10-14:00Adsorption of a pseudo-natural polyelectrolyte (chitosan)on the oppositely charged monolayer at the air-waterinterface studied by synchrotron X-RaysRoberto Nervo, 1 Oleg Konovalov, 1 and Marguerite Rinaudo 21 ESRF - European Synchrotron Radiation Facility, 6 Rue Jules Horowitz, 38000, Grenoble,France2 CERMAV - CNRS, Saint Martin d’Heres, FranceThe aim of this research was to investigate the adsorption of chitosan, a pseudo-natural polyelectrolyte,on an oppositely charged surface consisting of a surfactant monolayer (behenic acid) at theair-water interface. The structure of the adsorbed layers and the effect of the net charge of the polymericchains on the arrangement of the surfactant molecules in the monolayer were determined bysurface sensitive X-Ray techniques: Reflectivity (XRR) and Grazing Incidence Diffraction (GID).[1, 2] The purpose was to study a model system in order to explain the adsorption mechanismand the structure of the adsorbed polyelectrolyte on the oppositely charged surface of a particle.The interfacial complex layer stabilizes the particles and protects their integrity against differentstresses (pH, ionic concentration, osmotic shock?). These systems formed may be used in manyapplications such as the fabrication of composite nanoparticles suitable for delivery and/or storageof drugs. Objects like micelles and nano- or microvesicles or capsules decorated with naturaland biocompatible polyelectrolytes adsorbed at the interface may have controlled and tunable netcharge by tuning the physicochemical parameters like pH and concentration of the polymer subphase.[3, 4, 5] The thickness and the in-plane structure of the adsorbed layers were characterizedby XRR and GID using synchrotron radiation. Obtained results show that the polyelectrolyte adsorbedto the surfactant monolayer as a thin film, the adsorption mechanism was studied too. [1]Christofolini L. , et al. Langmuir 2005, 21, 11213-11219 [2] Edler K. J. , et al. Langmuir 2009, 25,4047-4055 [3] Babak V. G. , et al. Colloids and Surfaces A 1999, 147, (1-2), 139-148 [4] RinaudoM. Progress in Polymer Science 2006, 31, (7), 603-632 [5] Quemeneur F. , et al. Soft Matter 2010,6, 4471-448140