Buscar
Mostrando ítems 1-10 de 29
Copper Hexacyanoferrate Formation on the Modified Silica Surface with DAB-Am-16 Dendrimer
(Wiley-v C H Verlag Gmbh, 2011-01-01)
The third generation (G-3) polypropylenimine hexadecaamine dendrimer (DAB-Am-16) was grafted onto the silica gel surface. The modified silica interacts easily with Cu(2+) and then with potassium ferrocyanide to form copper ...
Fractal character of the SAXS correlation volume in poly(ethylene glycol)/silica hybrid wet gels
(Springer, 2010-05-01)
Small-angle X-ray scattering (SAXS) was employed to study the nanostructural properties of poly(ethylene glycol)(PEG)/silica hybrid wet gels prepared from hydrolysis of tetraethoxysilane (TEOS) in mixtures with PEG/(PEG + ...
Sol-Gel Erbium-Doped Silica-Hafnia Planar and Channel Waveguides
(2003-11-27)
Erbium activated SiO2 -HfO2 planar waveguides, doped with Er3+ concentrations ranging from 0.01 to 4 mol%, were prepared by sol-gel method. The films were deposited on v-SiO2 and silica-on-silicon substrates using dip-coating ...
Erbium-activated HfO2-based waveguides for photonics
(2003-12-01)
70SiO2 - 30HfO2 planar waveguides, activated by Er3+ concentration ranging from 0.3 to 1 mol%, were prepared by solgel route, using dip-coating deposition on silica glass substrates. The waveguides showed high densification ...
Nucleation and crystallization of titania nanoparticles in silica titania planar waveguides: A study by low frequency Raman scattering
(2004-07-28)
SiO2 (1-x) - TiO2 (x) waveguides, with the mole fraction x in the range 0.07 - 0.20 and thickness of about 0.4 μm, were deposited on silica substrates by a dip-coating technique. The thermal treatments at 700-900°C, used ...
Rare earth doped HfO2 nanoparticles embedded in SiO2-HfO2 planar waveguides. Preparation, optical, structural and spectroscopic characterization
(2003-01-01)
In this work we present results on the preparation of planar waveguides based on HfO2 and HfO2-SiO2. Stable sols containing europium and erbium doped HfO2 nanoparticles have been prepared and characterized. The nanosized ...
Estudo das características cromatográficas na determinação de ânions em trocadores de sílica gel organofuncionalizada em amostras de água da Bacia do Rio Jardim, DF.
(In: ENCONTRO DE JOVENS TALENTOS DA EMBRAPA CERRADOS, 3., 2007, Planaltina, DF. Resumos apresentados. Planaltina, DF: Embrapa Cerrados, 2007. p. 65., 2011)
Características cromatográficas na determinação de cátions em trocadores de sílica gel organofuncionalizada em amostras de água da Bacia do Rio Jardim, DF.
(In: ENCONTRO DE JOVENS TALENTOS DA EMBRAPA CERRADOS, 3., 2007, Planaltina, DF. Resumos apresentados. Planaltina, DF: Embrapa Cerrados, 2007. p. 66., 2011)