INFIQC   05475
INSTITUTO DE INVESTIGACIONES EN FISICO- QUIMICA DE CORDOBA
Unidad Ejecutora - UE
artículos
Título:
Effect of chitosan on distearoylphosphatidylglycerol (DSPG) films at air/water and liquid/liquid interfaces
Autor/es:
C. I. CÁMARA, M. V. COLQUI, N. WILKE, A. JIMENEZ-KAIRUZ Y L. M.YUDI.
Revista:
ELECTROCHIMICA ACTA
Editorial:
PERGAMON-ELSEVIER SCIENCE LTD
Referencias:
Lugar: Amsterdam; Año: 2013 vol. 94 p. 124 - 133
ISSN:
0013-4686
Resumen:
The effect of chitosan on distearoylphosphatidylglycerol (DSPG) films was analyzed by cyclic voltammetry,surface pressure-area and surface potential-area isotherm and Brewster Angle Microscopy.Experiments of cyclic voltammetry at a liquid/liquid interface demonstrated a blocking effect of DSPGto tetraethylammonium (TEA+) cation transfer from the aqueous to the organic phase. This effect wasreversed by the presence of chitosan, which modifies the film structure. Special emphasis was placed onthe nature of the supporting aqueous electrolyte (LiCl or CaCl2). In the presence of LiCl the permeabilityof the film increases when chitosan is present in the aqueous phase, minimizing the blocking effect of thefilm on TEA+ transfer probably due to the presence of bare zones at the interface. Oppositely, in presenceof Ca2+, the enhancement of permeability was not observed, probably due to the impediment of chitosanto penetrate into the very tightly compacted film of DSPG. Electrochemical experiments were completedwith viscosity measurements to explain the variation of diffusion coefficients for TEA+. Isotherms ofcompression for DSPG monolayers modified with chitosan, demonstrate that this polymer produces anexpansion of the DSPG film and modifies the compression factor, for both electrolytes studied. Images ofBrewster angle microscopy evidence an increase in the optical thickness of the DSPG films in presenceof chitosan indicating that the polymer interacts with DSPG molecules at low and high molecular areas.