INVESTIGADORES
PROCACCINI Raul Ariel
congresos y reuniones científicas
Título:
Development of silver clusters in hybrid silica based coatings through the sol-gel process
Autor/es:
RAÚL A. PROCACCINI; MARIO APARICIO AMBRÓS; SILVIA M. CERÉ; SERGIO PELLICE
Lugar:
Estrasburgo
Reunión:
Congreso; Hybrid Materials 2011; 2011
Institución organizadora:
Elsevier
Resumen:
The sol-gel technology makes possible the obtaining of hybrid materials with very
precise characteristics according to a particular application. It brings up the possibility
of functionalize materials by the introduction of different components, as inorganic salts
or organic additives, inside the sol-gel structure. Consequently, functionalization of solgel
materials with metallic ions or nanoparticles is worldwide and persistently explored
mainly because of its optical properties. The use of silver also brings other properties of
sanitary interest due to its well-known biocide activity. Ag+ has an effective action
against bacteria life inhibiting their DNA replication process, increasing the
permeability of the cytoplasmic membrane and inhibiting the respiratory enzymes
causing asphyxia of the bacteria. A long-term biocide coating could be very useful for
the development of hygienic surfaces in places such as public transports, hospitals,
schools and everywhere the health of people could be exposed to bacteria-contaminated
surfaces. The biocide activity of those coatings will depend, essentially, on the
capability of silver to migrate through the hybrid matrix towards the surface, where the
hazardous bacteria are placed. Then, the aggregation state of silver atoms takes
substantial significance because of its influence on their diffusion parameters.
The aim of the present work is to determine the self-organization of silver atoms inside
hybrid organic-inorganic structures under different synthesis conditions and deposition
parameters. In this way, two different hybrid sols, from TEOS, MTES, GPTMS and
silica nanoparticles, were doped with Ag+ from its nitrate salt. Pyridine was used as
silver stabilizer through formation of coordination compounds. Resulting coatings were
thermally treated at different temperatures in air atmosphere. An exhaustive analysis
was performed by SAXS through synchrotron light, GIXRD, XPS and UV-visible
spectroscopy. Evolution of silver clusters was followed through the whole sol-gel
process allowing to optimize the efficiency of the hybrid coating foreseen a long-term
bactericidal effect.