Desenvolvimento de nanobiocompósitos contendo nanopartículas de prata para aplicações bactericidas / Development of novel silver nanoparticles-based nanocomposites for bactericidal applications

AUTOR(ES)
DATA DE PUBLICAÇÃO

2010

RESUMO

The work reported here was aimed at developing chitosan/AgNPs based nanobiocomposits for bactericidal applications. The studies were divided into four main steps, viz.,: i) optimization of the silver colloids stabilition process, in which the use of chitosan resulted in the best stability, ii) a detailed investigation on the interactions between chitosan and AgNPs, as well as the optimization of the chitosan :AgNPs ratio to promote the best bactericidal effect, iii) development of a new synthetic route without using NaBH4, in a search for an environmentally-friendly route, and iv) incorporation of the chitosan:AgNps nanobiocomposites in a PVA matrix for application as smart food packaging. The nanobiocomposites were characterizaed via UV-vis and FT IR spectroscopies, DLS, Zeta potential, TEM and DR-X. Biological essays had also been carried out, as well as tensilestress and thermo analyses (DSC and TGA). The best bactericidal effect was observed for a nanobiocompostie comprising chitosan:AgNPs at a ratio of 4:1 (wt/wt). The synthetic route employing sodium citrate as reducing agent resulted in AgNPs with average diameters of 2 5 nm, as well as bigger nanoparticles with diameters of ca. 300 nm, depending on the reaction time and citrate concentration. The incorporation of the chitosan:AgNPs composites in the PVA matrix resulted in the formation of a bactericidal composite with good mechanical and thermal properties, suitable for applications as smart food packing.

ASSUNTO(S)

nanopartículas de prata chitosan ação bactericida silver nanoparticle nanocomposite nanocompósitos quitosana bactericidal action

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