ABSTRACT Reflectivity spectra of polycrystalline Ag electrodes “activated” for surface enhanced R... more ABSTRACT Reflectivity spectra of polycrystalline Ag electrodes “activated” for surface enhanced Raman scattering (SERS) by oxidation reduction cycles were measured as a function of potential in 0.1 M KCl and 0.1 M KCl + 50 mM pyridine. They exhibit a broad absorption at ca 3.2 eV due to surface plasmon excitation. No charge transfer absorption in the 300–800 nm wavelength range is found for adsorbed pyridine.
Abstract The increment of environmental pollution from heavy metals released by industrial or urb... more Abstract The increment of environmental pollution from heavy metals released by industrial or urban sources drives the development of new smart adsorbents. In particular, copper pollution is a rising concern due to its presence in industrial streams and electronic wastes. Mesoporous silica is a useful adsorbent for copper uptake but it requires the incorporation of specific functionalities to enhance the uptake and selectivity. Branched polyethylenimine (PEI) is a specific copper chelate agent but its bulky structure hinders the loading on mesoporous supports. In this work, the incorporation of PEI on a hierarchical porous silica with wrinkled meso/macroporosity (w-SiO2) resulted in a smart adsorbent with higher copper adsorption capacity. After the uptake, the annealing of the adsorbed PEI-copper complex leads to a w-SiO2/CuO nanocomposite with outstanding antimicrobial properties and catalytic activity due to the enhanced copper bioavailability. The minimum inhibitory concentration of supported copper oxide on silica for E. coli in LB broth medium was 825.5 μg Cu/ml. Oxidation of the electron donor molecule ABTS in the presence of this nanocomposite and H2O2 is a first demonstrator of the potential application as a peroxidase-like nanozyme. The use of adsorbents with hierarchical porosity to support bulky functionalities with high selectivity is a novel strategy for heavy metals upcycling.
Pesticides represent a significant source of contamination for urban and suburban surface, ground... more Pesticides represent a significant source of contamination for urban and suburban surface, ground and seawaters.
La quimica tradicional se ha venido ocupando de las moleculas, que estan formadas por los atomos ... more La quimica tradicional se ha venido ocupando de las moleculas, que estan formadas por los atomos de los elementos de la tabla periodica vinculados entre ellos por fuertes enlaces. En las ultimas decadas, los quimicos se han puesto a considerar sistemas formados por grupos de moleculas vinculados por interacciones mas debiles. Los han llamado supermoleculas y su estudio ha dado lugar a la quimica supramolecular.
The Science of the total environment, Jan 15, 2016
Cadmium contained in soil and water can be taken up by certain crops and aquatic organisms and ac... more Cadmium contained in soil and water can be taken up by certain crops and aquatic organisms and accumulate in the food-chain, thus removal of Cd from mining or industrial effluents - i.e. Ni-Cd batteries, electroplating, pigments, fertilizers - becomes mandatory for human health. In parallel, there is an increased interest in the production of luminescent Q-dots for applications in bioimaging, sensors and electronic devices, even the present synthesis methods are economic and environmentally costly. An alternative green pathway for producing Metal chalcogenides (MC: CdS, CdSe, CdTe) nanocrystals is based on the metabolic activity of living organisms. Intracellular and extracellular biosynthesis of can be achieved within a biomimetic approach feeding living organisms with Cd precursors providing new routes for combining bioremediation with green routes for producing MC nanoparticles. In this mini-review we present the state-of-the-art of biosynthesis of MC nanoparticles with a critica...
Titania nanoparticles and gels are synthesized in reverse micelles with either an ionic (AOT) or ... more Titania nanoparticles and gels are synthesized in reverse micelles with either an ionic (AOT) or a non-ionic (Triton X-100) surfactant in alkanes with low water contents. Acids were in some cases dissolved in the aqueous phase. Whereas the size of the sol nanoparticles is independent of the micellar composition, the kinetics of the sol-gel transition are not. The gelation time is shorter for the non-ionic surfactant and becomes longer as the acid content in the water increases, and for smaller anions of equal charge.
Short Summary In this work we have been able to synthesize Silica nanoparticles containing PFD de... more Short Summary In this work we have been able to synthesize Silica nanoparticles containing PFD designed as Oxygen carriers to the skin, who could act as effective vectors to introduce the molecule into stable cosmetic formulations.
... Buenos Aires, Argentina. Sara A. Bilmes INQUIMAE, Facultad de Ciencias Exactas y Naturales,... more ... Buenos Aires, Argentina. Sara A. Bilmes INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabell6n II. 1428 Buenos Aires, Argentina 83 E. Matijević et al. (eds.), Surface ...
Journal of Electroanalytical Chemistry and Interfacial Electrochemistry, 1984
... 40, avenue du Recteur Pineau, 86022 Poitiers (France) SARA BILMES Uninersidad Nacional de La ... more ... 40, avenue du Recteur Pineau, 86022 Poitiers (France) SARA BILMES Uninersidad Nacional de La Plata, Instituto de Inoestigaciones Fisecoquitnicas Teoricas y Applicadas, Sucursal 4, Casilla de Correa 16, 1900 La Plata ... 0.6 0.8 0 0.2 0.4 0.6 0.8 E /V(RHE) E , , /VIR.H_E.1 Fig ...
Journal of the Chemical Society, Faraday Transactions, 1996
Page 1. Roughening of thin silver films in aqueous electrolytes Sara A. Bilmes INQ UIMAE, Faculta... more Page 1. Roughening of thin silver films in aqueous electrolytes Sara A. Bilmes INQ UIMAE, Facultad de Ciencias Exactas, Universidad de Buenos Aires. Ciudad Universitaria Pab II . (1428) Buenos Aires, Argentina The reactivity ...
ABSTRACT Reflectivity spectra of polycrystalline Ag electrodes “activated” for surface enhanced R... more ABSTRACT Reflectivity spectra of polycrystalline Ag electrodes “activated” for surface enhanced Raman scattering (SERS) by oxidation reduction cycles were measured as a function of potential in 0.1 M KCl and 0.1 M KCl + 50 mM pyridine. They exhibit a broad absorption at ca 3.2 eV due to surface plasmon excitation. No charge transfer absorption in the 300–800 nm wavelength range is found for adsorbed pyridine.
Abstract The increment of environmental pollution from heavy metals released by industrial or urb... more Abstract The increment of environmental pollution from heavy metals released by industrial or urban sources drives the development of new smart adsorbents. In particular, copper pollution is a rising concern due to its presence in industrial streams and electronic wastes. Mesoporous silica is a useful adsorbent for copper uptake but it requires the incorporation of specific functionalities to enhance the uptake and selectivity. Branched polyethylenimine (PEI) is a specific copper chelate agent but its bulky structure hinders the loading on mesoporous supports. In this work, the incorporation of PEI on a hierarchical porous silica with wrinkled meso/macroporosity (w-SiO2) resulted in a smart adsorbent with higher copper adsorption capacity. After the uptake, the annealing of the adsorbed PEI-copper complex leads to a w-SiO2/CuO nanocomposite with outstanding antimicrobial properties and catalytic activity due to the enhanced copper bioavailability. The minimum inhibitory concentration of supported copper oxide on silica for E. coli in LB broth medium was 825.5 μg Cu/ml. Oxidation of the electron donor molecule ABTS in the presence of this nanocomposite and H2O2 is a first demonstrator of the potential application as a peroxidase-like nanozyme. The use of adsorbents with hierarchical porosity to support bulky functionalities with high selectivity is a novel strategy for heavy metals upcycling.
Pesticides represent a significant source of contamination for urban and suburban surface, ground... more Pesticides represent a significant source of contamination for urban and suburban surface, ground and seawaters.
La quimica tradicional se ha venido ocupando de las moleculas, que estan formadas por los atomos ... more La quimica tradicional se ha venido ocupando de las moleculas, que estan formadas por los atomos de los elementos de la tabla periodica vinculados entre ellos por fuertes enlaces. En las ultimas decadas, los quimicos se han puesto a considerar sistemas formados por grupos de moleculas vinculados por interacciones mas debiles. Los han llamado supermoleculas y su estudio ha dado lugar a la quimica supramolecular.
The Science of the total environment, Jan 15, 2016
Cadmium contained in soil and water can be taken up by certain crops and aquatic organisms and ac... more Cadmium contained in soil and water can be taken up by certain crops and aquatic organisms and accumulate in the food-chain, thus removal of Cd from mining or industrial effluents - i.e. Ni-Cd batteries, electroplating, pigments, fertilizers - becomes mandatory for human health. In parallel, there is an increased interest in the production of luminescent Q-dots for applications in bioimaging, sensors and electronic devices, even the present synthesis methods are economic and environmentally costly. An alternative green pathway for producing Metal chalcogenides (MC: CdS, CdSe, CdTe) nanocrystals is based on the metabolic activity of living organisms. Intracellular and extracellular biosynthesis of can be achieved within a biomimetic approach feeding living organisms with Cd precursors providing new routes for combining bioremediation with green routes for producing MC nanoparticles. In this mini-review we present the state-of-the-art of biosynthesis of MC nanoparticles with a critica...
Titania nanoparticles and gels are synthesized in reverse micelles with either an ionic (AOT) or ... more Titania nanoparticles and gels are synthesized in reverse micelles with either an ionic (AOT) or a non-ionic (Triton X-100) surfactant in alkanes with low water contents. Acids were in some cases dissolved in the aqueous phase. Whereas the size of the sol nanoparticles is independent of the micellar composition, the kinetics of the sol-gel transition are not. The gelation time is shorter for the non-ionic surfactant and becomes longer as the acid content in the water increases, and for smaller anions of equal charge.
Short Summary In this work we have been able to synthesize Silica nanoparticles containing PFD de... more Short Summary In this work we have been able to synthesize Silica nanoparticles containing PFD designed as Oxygen carriers to the skin, who could act as effective vectors to introduce the molecule into stable cosmetic formulations.
... Buenos Aires, Argentina. Sara A. Bilmes INQUIMAE, Facultad de Ciencias Exactas y Naturales,... more ... Buenos Aires, Argentina. Sara A. Bilmes INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabell6n II. 1428 Buenos Aires, Argentina 83 E. Matijević et al. (eds.), Surface ...
Journal of Electroanalytical Chemistry and Interfacial Electrochemistry, 1984
... 40, avenue du Recteur Pineau, 86022 Poitiers (France) SARA BILMES Uninersidad Nacional de La ... more ... 40, avenue du Recteur Pineau, 86022 Poitiers (France) SARA BILMES Uninersidad Nacional de La Plata, Instituto de Inoestigaciones Fisecoquitnicas Teoricas y Applicadas, Sucursal 4, Casilla de Correa 16, 1900 La Plata ... 0.6 0.8 0 0.2 0.4 0.6 0.8 E /V(RHE) E , , /VIR.H_E.1 Fig ...
Journal of the Chemical Society, Faraday Transactions, 1996
Page 1. Roughening of thin silver films in aqueous electrolytes Sara A. Bilmes INQ UIMAE, Faculta... more Page 1. Roughening of thin silver films in aqueous electrolytes Sara A. Bilmes INQ UIMAE, Facultad de Ciencias Exactas, Universidad de Buenos Aires. Ciudad Universitaria Pab II . (1428) Buenos Aires, Argentina The reactivity ...
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