0000000000413888
AUTHOR
Mohamed Sennour
showing 5 related works from this author
Morphological Control of Hydrothermal Ni(OH)2 in the Presence of Polymers and Surfactants: Nanocrystals, Mesocrystals, and Superstructures
2008
International audience; Polymers with different hydrophilic groups [polyvinylpyrrolidone (PVP), ammonium polyacrylate (APA), and hydroxypropylmethyl cellulose (HPMC)] and surfactants [cetyltrimethylammonium bromide (CTAB) and sodium dodecylbenzensulfonate (SDBS)] were used as additives to modify the crystallization of β-Ni(OH)2 in hydrothermal conditions. Marked morphological changes in the β-Ni(OH)2 particles were observed depending on the additive concentration and on the duration of the hydrothermal treatment. The final morphology is the result of a complex, time-dependent self-assembly and growth process. Well-defined particles with sizes from submicrometer range to a few micrometers co…
Fluorescence and spin properties of defects in single digit nanodiamonds
2009
International audience; This article reports stable photoluminescence and high-contrast optically detected electron spin resonance (ODESR) from single nitrogen-vacancy (NV) defect centers created within ultrasmall, disperse nanodiamonds of radius less than 4 nm. Unexpectedly, the efficiency for the production of NV fluorescent defects by electron irradiation is found to be independent of the size of the nanocrystals. Fluorescence lifetime imaging shows lifetimes with a mean value of around 17 ns, only slightly longer than the bulk value of the defects. After proper surface cleaning, the dephasing times of the electron spin resonance in the nanocrystals approach values of some microseconds, …
Metallic interconnects for SOFC : characterization of their corrosion resistance in hydrogen/water atmosphere and at the operating temperatures of di…
2006
International audience; Chromia forming alloys are one of the best candidates for the interconnecting materials in solid oxide fuels cells (SOFC). Recent research has enabled to decrease the operating temperature of the SOFC from 1000 °C to 800 °C. However, low electronic conductivity and high volatility of the chromia scale need to be solved to improve performance of interconnects. In the field of high temperature oxidation of metals, it is well known that the addition of reactive elements into alloys or in thin film coatings, improve the oxidation resistance of alloys at high temperature. The elements of the beginning of the lanthanide group and yttrium are the most efficient. The goal of…
Continuous hydrothermal synthesis in supercritical conditions as a novel process for the elaboration of Y-doped BaZrO3
2021
Abstract The present work describes a novel process for the elaboration of a ceramic material. Y-doped barium zirconate, an electrolyte material for Protonic Ceramic Fuel cell, was synthesized by a continuous hydrothermal process in supercritical conditions (410 °C/30.0 MPa) using nitrate precursors and NaOH reactants. The use of supercritical water allowed the formation of particles of about 50 nm in diameter with a narrow size distribution. X-Ray Diffraction examination revealed that a major perovskite phase with few BaCO3 and YO(OH) impurities was obtained. BaCO3 is assumed to form due to faster kinetics than Y-doped BaZrO3 resulting in a Ba-deficient perovskite phase. The Ba-deficiency …
Metallic interconnects for SOFC: Characterisation of corrosion resistance and conductivity evaluation at operating temperature of differently coated …
2007
Abstract One of challenges in improving the performance and cost-effectiveness of solid oxide fuel cells (SOFCs) is the development of suitable interconnect materials. Recent researches have enabled to decrease the operating temperature of the SOFC from 1000 to 800 °C. Chromia forming alloys are then among the best candidates for interconnects. However, low electronic conductivity and volatility of chromium oxide scale need to be solved to improve interconnect performances. In the field of high temperature oxidation of metals, it is well known that the addition of reactive element into alloys or as thin film coatings, improves their oxidation resistance at high temperature. The elements of …