INTEMA   05428
INSTITUTO DE INVESTIGACIONES EN CIENCIA Y TECNOLOGIA DE MATERIALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Phase separation nanostructure of hybrid organic-inorganic sol-gel materials for silver-based antibacterial coatings
Autor/es:
RAÚL A. PROCACCINI; YOHAI, LUCIA; HUGO F. GIRALDO MEJÍA; SERGIO A PELLICE
Lugar:
Darmstadt
Reunión:
Congreso; Materials Science and Engineering Congress; 2018
Institución organizadora:
Darmstadt University of Technology
Resumen:
Hybrid organic-inorganic materials synthetized through the sol-gel chemistry had reached a huge range of potential applications dealing with optical requirements, corrosive processes, energy storage and biologic functionalities, among others. Although this kind of materials is known by its high chemical purity, homogeneity and tailored properties, their inner nanostructure at the nanoscale level present complex phase separation morphologies. While organic and inorganic components trend to form arrange the structure in well separated phases, the use of alkylalkoxydes imposes a covalent link between both components, at the molecular level, avoiding the formation of micrometric organic or inorganic domains. This phenomenon carries to the development of a nanometric and bicontinuous phase structure with huge consequences in the diffusive properties of the obtained material, allowing to the development of drugs delivery systems or ion releasing materials, for instance. In this study, the phase separation nanostructure of a hybrid organic-inorganic sol-gel material, based on the hydrolytic condensation of glycidoxypropyl-trimethoxysilane (GPTMS) and tetraethoxysilane (TEOS), was analyzed as a function of the organic/inorganic ratio. In order to evaluate the diffusive properties of this kind of materials, silver releasing and antibacterial properties were evaluated upon coatings developed from silver enriched hybrid sols. Through the use of small angle x-ray scattering (SAXS) with a synchrotron radiation source allowed to determine the development of a bicontinuous spinodal-like phase separation highly stable upon thermal densification and degradation process and the evolution of silver nanoparticles upon lixiviation tests. Complementary Fourier transformed IR spectroscopy (FTIR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) tests allowed to determine the thermal stability of the complex hybrid structure. On the other hand, antibacterial properties were preliminarily studied through immersion in aqueous E. Coli culture by meassurements of the optical density (OD) at 600 nm.