A new curcuminoid molecule () has been designed and synthesized, containing a central -(CH)-COOH chain at the α carbon of the keto-enol moiety in the structure. The carboxylic acid group is added to react with exposed amino groups on silica oxide nanoparticles (nSiO), forming an amide bond to attach the curcuminoid moiety to the nSiO covalently. The Kaiser test quantifies the functionalization degree, yielding 222 μmol of curcuminoid per gram of nanoparticles.
View Article and Find Full Text PDFNO is one of the main greenhouse gases, which is mainly generated by the combustion of fossil fuels. In addition to its contribution to global warming, this gas is also directly dangerous to humans. The present work reports the structural and gas sensing properties of the CaCuTiO compound prepared by the sol-gel technique.
View Article and Find Full Text PDFIn the present work, we report the use of bacterial cells for the production of CdS/CdSe Core/Shell quantum dots (QDs), a complex nanostructure specially designed to improve their performance as photosensitizer in photovoltaic devices. The method requires the incorporation of L-cysteine, CdCl and NaSeO to cultures and allows a tight control of QDs properties. The obtained CdS/CdSe QDs were photophysically and structurally characterized.
View Article and Find Full Text PDFArsenic (As) contamination of water is a serious problem in developing countries. In water streams, arsenic can be as As(V) and As(III), the latter being the most toxic species. In this work, an innovative adsorbent based on CaTiO nanoparticles (CTO) was prepared by the sol-gel technique for the removal of As(III) from aqueous solution.
View Article and Find Full Text PDFThe type of metal oxide affects the activity and selectivity of Fe₂O₃⁻SiO₂⁻MeO₂⁻Pt (Me = Ti, Sn, Ce) catalysts on the hydrogenation of cinnamaldehyde. The double shell structure design is thought to protect the magnetic Fe₂O₃ cores, and also act as a platform for depositing a second shell of TiO₂, SnO₂ or CeO₂ metal oxide. To obtain a homogeneous metallic dispersion, the incorporation of 5 wt % of Pt was carried out over Fe₂O₃⁻SiO₂⁻MeO₂ (Me = Ti, Sn, Ce) structures modified with (3-aminopropyl)triethoxysilane by successive impregnation-reduction cycles.
View Article and Find Full Text PDFThe relative dislocation density of aluminum and copper samples is quantitatively measured using linear Resonant Ultrasound Spectroscopy (RUS). For each metallic group, four samples were prepared with different thermomechanical treatments in order to induce changes in their dislocation densities. The RUS results are compared with Nonlinear Resonant Ultrasound Spectroscopy (NRUS) as well as Second Harmonic Generation (SHG) measurements.
View Article and Find Full Text PDFRecently, we reported the production of Cadmium sulfide (CdS) fluorescent semiconductor nanoparticles (quantum dots, QDs) by acidophilic bacteria of the genus. Here, we report that the addition of inorganic phosphate to ATCC 19703 cultures favors the biosynthesis of CdS QDs at acidic conditions (pH 3.5).
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