RESUMEN

In this paper, a simple, bottom up, bioinspired technique is proposed for the synthesis of highly stable colloids of silica supported spherical silver nanoparticles (SiO2@Ag) that act as efficient catalytic and antimicrobial coatings for an organic substrate, filter paper. The core - shell structure and the highly branched dendritic polymer, poly(ethylene)imine, enabled the precise control of growth rate and morphology of silica and silver nanoparticles. The polymer also enabled the deposition of these nanoparticles onto an organic substrate, filter paper, through immersion by modifying its surface. The catalytic and antibacterial properties of these samples were assessed. The results obtained from this analysis showed a complete degradation of an aqueous pollutant, 4-nitrophenol, for 6 successive catalytic cycles without intermediate purification steps. Furthermore, the polymeric silica-silver suspension proved to express antibacterial activity against both Gram-positive and Gram-negative bacteria (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa). The antibacterial properties were evaluated according to the disk diffusion method, whereas the Minimum Inhibitory Concentration was also determined. The samples were examined by Scanning Electron Microscopy, Transmission Electron Microscopy, X-ray diffraction analysis, z-potential analysis, Fourier Transform Infrared Spectroscopy and Ultraviolet-visible Spectroscopy.

Asunto(s)

Antibacterianos , Coloides , Pruebas de Sensibilidad Microbiana , Dióxido de Silicio , Plata , Plata/química , Plata/farmacología , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/síntesis química , Dióxido de Silicio/química , Dióxido de Silicio/farmacología , Catálisis , Coloides/química , Nanopartículas del Metal/química , Polímeros/química , Polímeros/farmacología , Polímeros/síntesis química , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Papel , Staphylococcus aureus/efectos de los fármacos , Pseudomonas aeruginosa/efectos de los fármacos , Propiedades de Superficie , Tamaño de la Partícula , Nitrofenoles/química

RESUMEN

Silica-organic matrix-silver, nano-catalysts, were synthesized employing four different hyperbranched poly(ethylene imines) (MW 2000 to 750,000) to reduce Ag+ to metal nanoparticles and the formation of formation SiO2 shells. The latter is performed at pH 7,5 employing three different pH regulating agents Hepes, Trizma, and Phosphate Salts. Characterization of the resulting materials with spectroscopy (FTIR), thermogravimetry (TG), scanning electron microscopy (SEM), and ζ-potential is reported. Kinetic studies of standard reactions, 4-nitrophenol and 4-nitroaniline reduction to 4-aminophenol and p-phenylenediamine, respectively by UV-Visible spectroscopy are also included. This data in brief article is related to the "Investigation of two Bioinspired Reaction Mechanisms for the Optimization of Eco Composites-Nano Catalysts Generated from Hyperbranched Polymer Matrices" manuscript submitted to reactive & functional polymers.