Search results for "Synthèse hydrothermale"
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Synthèses optimisées et caractérisations avancées de nanotubes de titanate et de leurs fonctionnalisations : vers l'élaboration de nanovecteurs de mo…
2017
The aim of this PhD thesis is to develop new nanohybrids based on titanate nanotubes (TiONts) in order to use them as nanocarrier of a therapeutic molecule: a stilbene phenol, 4'-hydroxy-4-(3-aminopropoxy)-trans-stilbene (HAPtS), which is a transresveratrol derivative.TiONts are synthesized by a hydrothermal treatment from a precursor of rutile titanium dioxide. Two methods of hydrothermal synthesis have been studied (the static and dynamic ones): the second approach uses an original hydrothermal device which provides a vigorous mechanical stirring during the hydrothermal process with controllable stirring time par hour. A parametric study was carried out to evaluate the effect of reaction …
Protonic ceramic fuel cell : elaboration and characterization. Investigation of the BaZr0.8Y0.2O3-d electrolyte by electrochemical impedance spectros…
2021
One of the current global challenges is to find novel, clean and efficient techniques for the energy production. The use of electrochemical cells and hydrogen is one of the solutions. These cells convert the excess energy produced by conventional systems into hydrogen by steam electrolysis. The hydrogen can be stored and transformed into electricity when needed in the fuel cell mode. Among the different electrochemical cells, protonic ceramic electrochemical cells have attracted much attention due to their high efficiency at intermediate temperature (400 – 600 °C). In addition, these systems offer the advantage of not diluting the fuel in electrolysis mode. This thesis work focuses on the e…
Syntheses of TiO2 anatase nanocrystals with controlled size distribution. Influence of the crystallites size on the Raman spectrum and investigation …
2006
The determination of the size and the size distribution of anatase TiO2 nanopowders using Raman spectroscopy is presented. Several synthesis methods (soft chemistry, water-in-oil microemulsion, continuous hydrothermal synthesis) are used in order to control the size (from 3 to 20 nm), shape, phase and size distribution. The shift and width of the anatase Eg peak are often used to obtain the nanoparticles size. Homever, this peak is also sensitive to nonstoichiometry and others parameters. Low-frequency Raman scattering does not suffer from this problem. Size distibutions obtained by Raman spectroscopy and MET micrographs are compared. Finally, in situ Raman spectroscopy is used to study the…