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RING OPENING POLYMERIZATION OF TETRAHYDROFURAN CATALYSED BY MAGHNITE-H^+

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Chinese Journal of Polymer Science 2012年第1期30卷 56-62页

作者： Khadidja Benkenfoud Amine Harrane Mohammed Belbachir laboratoire de chimie des Polymeres departement de chimie Faculte des SciencesUniversite d'Oran Es-SeniaBP No 1524 El M'Naouar31000 OranAlgeria

The cationic ring-opening polymerization of tetrahydrofiiran using maghnite-H~＋ is ***-H~＋,is a non-toxic solid catalyst issued from proton exchanged montmorillonite ***,also called ＂poly（butandiol） ether＂,with acetate and hydroxyl end groups was successfully *** of reaction temperature, weight ratio of initiator/monomer and reaction time on the conversion of monomer and on the molecular weight are investigated.A cationic mechanism of the reaction was *** chemistry can be considered as a suitable route for preparing poly（THF） as a soft segment for thermoplastic elastomers.

关键词： Montmorillonite Maghnite Ring opening polymerization THF

Adsorption properties of Rosmarinus officinalis oil as green corrosion inhibitors on C38 steel in 0.5 M H_2SO_4

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Acta Metallurgica Sinica(English Letters) 2010年第1期23卷 13-20页

作者： E.El Ouariachi J.Paolini M.Bouklah A.Elidrissi A.Bouyanzer B.Hammouti J-M.desjobert J.Costa laboratoire de chimie Appliqu'ee et Environnement Facult'e des SciencesUniversit'e Mohamed PremierBP71760000 OujdaMorocco UMR CNRS 6134 Laboratoire de Chimie des Produits NaturelsUniversit'e de CorseFrance

Rosmarinus officinalis essential oil obtained by hydrodistillation was tested as corrosion inhibitor of steel in 0.5 M H2SO4 using weight loss measurements, and electrochemical .polarisation methods. Results obtained indicate that the corrosion rate is reduced and R. officinalis oil adsorbs on the metal surface and then inhibits corrosion process. Its inhibition efficiency increases with oil increasing content to reach 61% at 1 g/L. Polarisation curves indicate that RO acts as a cathodic inhibitor. The inhibition efficiency of naturally oil remains slightly constant with the rise of temperature. Chemical analysis of R. officinalis essential oil was carried out using capillary GC and GC/MS. The oil composition was characterized by high amount of oxygenated monoterpene （77%） with 1,8-cineol （52.1%） as main component. Discussion of adsorption was investigated on the the isotherm adsorption of essential oil on basis of essential oil composition. Finally the steel has been also reported.

关键词： Rosmarinus officinalis oil Adsorption Corrosion Inhibition Steel 1,8-cineol

Characterization and Photoluminescence Properties of Alumina Nanowires Elaborated by Arc-Plasma

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Journal of Materials Science & Technology 2006年第1期22卷 127-129页

作者： C.Arnoult X.devaux H.Rinnert M.Vergnat laboratoire de Physique des materiaux UMR CNRS 7556Ecole des MinesCS14234F54042 Nancy cedexPrance

Ultrafine powders containing alumina nanowires are synthesized by DC arc plasma from pure aluminium metal. Nanowires grow only when reactive gases are composed of nitrogen and less than ten percent of oxygen. Nanowires have the diameters ranging from 20 to 80 nm and lengths ranging from hundreds nanometers to tens of micrometers. A first assumption of the mechanism process is proposed, in which nanowires grow starting directly from the aluminium. Photoluminescence measurements show that the powders have three emission peaks around 435, 530 and 750 nm resulting from different kinds of defects such as oxygen vacancies, aluminium interstitial ions and surface defects.

关键词： Nanowires Alumina Arc plasma Photoluminescence

Synthesis, Structural Study and Phase Transitions Characterization by Thermal Analysis and Vibrational Spectroscopy of an Ammonium Rubidium Arsenate Tellurate

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Chemical Research in Chinese Universities 2016年第6期32卷 902-911页

作者： GHORBEL Khouloud LITAIEM Hajer KTARI Lilia GARCIA-GRANDA Santiago DAMMAK Mohamed laboratoire de chimie Inorganique(LCI) Universitd de Sfax Facultd des Sciences de Sfax BP 1171 Sfax 3000 Tunisia laboratoire de chimie Physique et Analytique Faeulte de Chimie Universitte d 'Oviedo Oviedo 33006 Espagne

The Rb2.42（NH4）0.58（HAsO4）（H2AsO4）. Te（OH）6 crystals（denoted by RbNAsTe） crystallize in the monoc-linic system, space group P21/n with the following parameters： a=1.3059（5） nm, b=0.6755（3） nm, c=1.6675（6） rim,β=94.126（4）°, Z=4 and V=1.46733（10） nm^3. Thermal analyses（DSC, DTA and TG） confirm the presence of the phasetransition and the temperatttre of the decomposition. The vibrational spectroscopy study at room temperature showthe presence and the independence of anionic groups, cationic groups, and give more importance to the hydrogenbonds. Raman spectra were recorded in the temperature range of 298--503 K. The temperature dependence of theRaman line shift, intensity reduction and the half width detects the phase transitions and confirms their nature. So, thephase transition at 453 K corresponds to the superprotonic-ionic conduction phase transition, and those at 483 and491 K correspond to the decomposition of our material.

关键词： RbNAsTe X-Ray diffraction Differential scanning calorimetry Phase transition Raman spectrometry

TiO_2 nanotubes as solid-phase extraction adsorbent for the determination of polycyclic aromatic hydrocarbons in environmental water samples

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Journal of Environmental Sciences 2011年第5期23卷 860-867页

作者： Bochra Bejaoui Kefi Latifa Latrous El Atrache Hafedh Kochkar Abdelhamid Ghorbel laboratoire des Matériaux Utiles Institut National de Recherche et d'Analyse Physico-chimiqueple technologique Sidi-Thabet 2020 Tunis Tunisia laboratoire de chimie Analytique et Electrochimie Département de Chimie Facultédes Sciences de TunisCampus Universitaire2092 EL Manar TunisTunisia laboratoire de chimie des Matériaux et Catalyse Facultédes Sciences de TunisCampus Universitaire2092 EL Manar Tunis Tunisia

An analytical method based on TiO2 nanotubes solid-phase extraction （SPE） combined with gas chromatography （GC） was established for the analysis of seven polycyclic aromatic hydrocarbons （PAHs）： acenaphtylene, acenaphthene, anthracene, fluorene, phenanthrene, fluoranthene and pyrene. Factors affecting the extraction efficiency including the eluent type and its volume, adsorbent amount, sample volume, sample pH and sample flow rate were optimized. The characteristic data of analytical performance were determined to investigate the sensitivity and precision of the method. Under the optimized extraction conditions, the method showed good linearity in the range of 0.01-0.8 μg/mL, repeatability of the extraction （RSD were between 6.7% and 13.5%, n = 5） and satisfactory detection limits （0.017-0.059 μg/mL）. The developed method was successfully applied to the analysis of surface water （tap, river and dam） samples. The recoveries of PAHs spiked in environmental water samples ranged from 90% to 100%. All the results indicated the potential application of titanate nanotubes as solid-phase extraction adsorbents to pre-treat water samples.

关键词： Ti02 nanotubes hydrothermal treatment solid phase extraction gas chromatography polycyclic aromatic hydrocarbons

Naked Eye and Selective detection of Copper(II) in Mixed Aqueous Media Using a Cellulose-based Support

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Chemical Research in Chinese Universities 2019年第4期35卷 598-603页

作者： FETTOUCHE Souad BOUKHRISS Aicha TAHIRI Mohamed CHERKAOUI Omar BAZI Fathallaah GMOUH Said laboratoire Recherche sur les materiaux Textile(REN4TEX) Ecole Supeneure des Induseries de Textile et de L'habillement(ESITH)CasablancaBP 7731Maroc laboratoire Hydrogeochimie et Bassin versant Faculte des Sciences Ain ChockUniversite Hassan IICasablancaB. P 5366Maroc Laboratore chimie Analytique et Physico-chimie des materiaux Faculte des Sciences Ben M'sik Universitie Hassan II CasablancaBP 150Macro laboratoire d'lngeniene et materiaux(LIMAT) Faculte des Sciences Ben MsikUniv er site Hassan IICasablanceBP 150Maroc

A new colorimetric sensor based-azo dye for Cu^2+ detection was synthesized and characterized by FTIR and NMR spectroscopies. The results showed that the azo dye had a high selective and sensitive recognition toward Cu^2+. The solution containing the sensor changed color from pink to pale yellow with a hypsochromic shift in the presence of Cu^2+. The sensor selectivity and sensitivity toward Cu^2+ ions were investigated by colorimetry and UV-Vis spectroscopy. For practical applications, a cellulosic textile test strip for high-selectivity detection of Cu^2+ ions in aqueous solution was developed using the synthesized azo dye as chromogenic chemosensor molecule, while using a solid cellulose textile as a substrate. As a result, a spectacular color change of the test strip was observed do pending on the amount of copper ions in contact with the strip, which allows an estimation of Cu^2+ concentration by naked eye.

关键词： Copper(II) ions detection Azo dye Chromogenic chemosensor Cellulose-based probe

Characterization and photoluminescence properties of ultrafine copper molybdate(α-CuMoO_4) powders prepared via a combustion-like process

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International Journal of Minerals,Metallurgy and Materials 2016年第11期23卷 1340-1345页

作者： Mohamed Benchikhi Rachida El Ouatib Sophie Guillemet-Fritsch Lahcen Er-Rakho Bernard Durand laboratoire de Physico-chimie des Matériaux Inorganiques Faculté des Sciences Ain Chock Université Hassan Ⅱ Casablanca Institut Carnot CIRIMAT CNRS Université de Toulouse

We report a simple method for preparing copper（II） molybdate（CuMoO_4） powders via a combustion-like process. A gel was first prepared by the polymerizable complex method, where citric acid was used as a complexing and polymerizing agent and nitric acid was used as an oxidizing agent. The thermal decomposition behavior of the（CuMo）-precursor gel was studied by thermogravimetry–differential thermal analysis（TG–DTA）, Fourier transform infrared spectroscopy（FTIR）, and X-ray diffraction（XRD）. We observed that the crystallization of CuMoO_4 powder was completed at 450°C. The obtained homogeneous powder was composed of grains with sizes in the range from 150 to 500 nm and exhibited a specific surface area of approximately 5 m^2/g. The average grain size increased with increasing annealing temperature. The as-prepared CuMoO_4 crystals showed a strong green photoluminescence emission at room temperature under excitation at 290 nm, which we mainly interpreted on the basis of the Jahn-Teller effect on [MoO_4^（2-）] complex anions. We also observed that the photoluminescence intensity increased with increasing crystallite size.

关键词： copper molybdate chemical synthesis photoluminescence Jahn-Teller effect

Samarium( II )-electrocatalyzed chemoselective reductive alkoxylation of phthalimides

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Organic Chemistry Frontiers 2022年第5期9卷 1308-1314页

作者： Yu-Feng Zhang Mohamed Mellah Universite Paris-Saclay CNRSInstitut de Chimie Moleculaire et des Materiaux d’OrsayBatiment 42091405 OrsayFrance

The unprecedented samarium electrocatalyzed reductive alkoxylation of phthalimides in a single step is *** mild conditions,using electrogenerated Sm(II)with TMSCl(trimethyl chlorosilane),N-substituted 3-alkoxyl isoind... 详细信息

关键词： catalyzed reductive substituted

High Temperature Stability of Platinum Nanoparticles on Few-Layer Graphene Investigated by In Situ High Resolution Transmission Electron Microscopy

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Nano Research 2011年第5期4卷 511-521页

作者： Izabela Janowska Maria-Simona Moldovan Ovidiu Ersen Herve Bulou Kambiz Chizari Marc J. Ledoux Cuong Pham-Huu laboratoire des materiaux Surfaces et ProcEdEs pour la Catalyse （LMSPC UMR 7515 CNRS） 25 rue Becquerel F-67087 Strasbourg Cedex 02 France Institut de Physique et chimie des materiaux de Strasbourg （IPCMS UMR 7504 CNRS） 23 rue du Loess F-67037 Strasbourg Cedex 08 France

Heterogeneous catalytic reactions involve the use of highly dispersed active phases such as metal, metal oxide, or metal sulphide nanoparticIes on thermally stable supports. Fluctuations of the reaction temperature during the reactions can induce sintering of the particles. The stability of such small particles represents a crucial parameter in the development of new families of catalysts with high activity in many fields. Here we report the stability of platinum nanoparticles （2-3 nm） on a few-layer graphene （FLG） surface as studied by in situ high temperature transmission electron microscopy.

关键词： Graphene platinium nanoparticles diffusion catalysis TEM annealing