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Monolithic diphasic gels of mullite by sol-gel process under ultrasound stimulation
(1998-12-01)
Diphasic gel in the mullite composition was prepared from a colloidal sol of boehmite mixed with a hydrolyzed tetraethoxisilane (TEOS) solution. The boehmite sol was obtained by peptization of a poorly crystallized or very ...
Influence of viscoelastic characteristics of the colloidal suspensions on the formation of SnO2 supported membranes
(1997-12-01)
SnO2 supported membranes have been prepared by sol-casting on alumina tubular substrate, using aqueous colloidal suspensions prepared by sol-gel route. The viscoelastic behaviour during sol ageing was analyzed by dinamic ...
Oxygen related defects excitation and photoconductivity dependence of SnO2 sol-gel films with several light sources
(1999-12-01)
Since oxygen vacancies act as donors in SnO2, the electrical properties are related to deviation from stoichiometric composition. Depending on stoichiometry SnO2 can be highly insulating or may exhibit fairly high n-type ...
Sol-gel synthesis and characterization of Fe(2)O(3) center dot CeO(2) doped with Pr ceramic pigments
(Springer, 2008-07-01)
Undoped x center dot alpha-Fe(2)O(3) y center dot CeO(2) and doped with praseodymium ceramic pigments were obtained by the sol-gel method after heat treatment at 800 degrees C for 2 h. These pigments were characterized by ...
Pore size distribution of unsupported SnO2 membranes prepared by sol-gel process - Code: EP21
(1994-01-01)
Unsupported SnO2 membranes were prepared by sol-gel process and characterized by N2 adsorption-desorption isotherms and X-ray diffraction. Results show that the texture of dried samples does not change appreciably with the ...
Photoelectrochemical properties of sol-gel Nb2O5 films
(Kluwer Academic Publ, 1997-01-01)
Structural, optical, electro and photoelectrochemical properties of amorphous and crystalline sol-gel Nb2O5 coatings have been determined. The coatings are n-type semiconductor with indirect allowed transition and present ...