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141.
Polypyrrole (PPy) coatings were synthesized on copper by electrochemical polymerization of pyrrole monomer in aqueous acidic and basic solutions by cyclic voltammetry. The coatings were characterized with CV, UV-visible absorption spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM) techniques. The corrosion protection aspects of PPy coatings have been investigated using the potentiodynamic polarization technique and electrochemical impedance spectroscopy (EIS). The potentiodynamic polarization measurements show that the PPy coating has ability to protect the copper against corrosion. It was concluded that a complete corrosion protective PPy film could not be obtained through direct electro-oxidation procedure. This may be due to copper dissolution in the monomer oxidation potential range. 相似文献
142.
Abdollah Omrani Abbas Ali Rostami Fatemeh Ravari 《Journal of Thermal Analysis and Calorimetry》2013,111(1):677-683
The decomposition kinetics of glycerol diglycidyl ether (GDE)/3,3-dimethylglutaric anhydride/nanoalumina composite have been investigated by thermogravimetry analysis under nonisothermal mode. The activation energy, E a, of the solid-state decomposition process was evaluated using the advanced isoconversional method. From the experimental data, the dependence of conversion on temperature and activation energy was constructed allowing calculating the master plots. Our results showed that the decomposition mechanism at temperatures below 400 °C could be fitted by R2 kinetic model with E a = 143 kJ mol?1. The information about the kinetic parameters based only on thermal degradation data has been used for quick lifetime estimation at different temperatures. The Vyazovkin method was also employed to predict the times to reach α = 0.5 at isothermal mode using the activation energy calculated by the advanced isoconversional approaches. Scanning electron microscopy (SEM) analysis was carried out to investigate the fracture surface morphology. It was revealed from the SEM images that the presence of nanoalumina results in reinforcement of GDE matrix. 相似文献
143.
Potential cycling in the range from -0.2 to +1.2 V is used for the electrodeposition of hydrous iridium oxide films onto a screen-printed electrode from a saturated solution of alkaline iridium(III) solution. The iridium oxide redox couple shows a stable and obvious reversible redox, with the formal potential being pH dependent in the range 1-14. The properties, stability and electrochemical properties of iridium oxide films were investigated by cyclic voltammetry. A modified electrode showed excellent catalytic activity toward the oxidation of neurotransmitters (catecholamines) over a wide pH range (2-8). The electrocatalytic behavior is further exploited as a sensitive detection scheme for adrenaline and dopamine by hydrodynamic amperometry. Under the optimized conditions, the calibration curves are linear in the concentration range 0.1-70 and 0.1-15 microM for dopamine and adrenaline determination, respectively. The detection limit and sensitivity are 30 nM and 30 nA/microM for adrenaline and 15 nM and 80 nA/microM for dopamine. Finally, the analytical performance of the modified electrode was demonstrated for the elimination of interference by uric acid in catecholamines determination when present in a 1000-fold concentration excess. 相似文献
144.
Mohammad Hossein Habibi Shahram Tangestaninejad Abdollah Fallah‐Shojaie Iraj Mohammadpoor‐Baltork Reza Mokhtari Neil R. Brooks William Clegg 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(11):m494-m495
The molecule of the title compound, [Hg(C13H9N2O2S)2], has approximate twofold rotation symmetry, with the Hg atom in an essentially linear two‐coordinate HgS2 environment supported by secondary π interactions with the nitrophenyl rings of both ligands. The ligands are in the imine–thiolate rather than the amine–thione tautomeric form. 相似文献
145.
Synthesis of some novel fused oxo‐ and thiopyrimidines via an intramolecular friedel‐crafts reaction
Akbar Mobinikhaledi Naser Foroughifar Abdollah Javidan Ehsan Amini 《Journal of heterocyclic chemistry》2007,44(3):557-559
146.
Mohammad Hossein Tavakoli Ebrahim Mohammadi-Manesh Abdollah Ojaghi 《Journal of Crystal Growth》2009,311(17):4281-4288
A series of 2D finite element numerical simulations of induction heating process for an oxide Czochralski crystal growth system has been done for different shapes and locations of a metal crucible. Comparison between the computational results shows the importance of crucible shape, geometry and its position with respect to the RF-coil on the electromagnetic field and heat generation distribution in the growth setup. 相似文献
147.
We have investigated the effect of zinc oxide as a photocatalyst and durable flame‐retardant on cellulosic fibers. Zinc oxide nanocrystals were successfully synthesized and deposited onto cellulosic fibers using sol‐gel process at low temperature. The samples were characterized by means of several techniques such as scanning electron microscopy, transmission electron microscopy, diffuse reflectance spectroscopy, X‐ray diffraction and thermogravimetric analysis. The photocatalytic activity was tested by measuring the photodegradation of methylene blue under UV‐Vis illumination. Moreover, flame‐retardancy was tested by vertical flame spread test. The optimum add‐on value for donating flame‐retardancy onto cellulosic fabric was obtained to be in the range of 15.24 to 23.20 g of the ZnO per 100 g of fabric. Thermogravimetric analysis of pure and flame‐retarded samples were accomplished and discussed. The results obtained are in agreement with Wall effect theory and Coating theory. The originality of this work on introducing photoactive flame‐retarded fibers is highly valuable for industrial implementation. 相似文献
148.
Very recently, Chen et al. proposed a security-enhanced key agreement protocol based on Chebyshev chaotic map. They claimed that the proposed protocol can achieve session key agreement shared among the server and user with security and users anonymity. Although, in this paper, we will prove that Chen et al.’s protocol cannot guarantee security and user anonymity against internal adversary who is a legal user. Furthermore, we give some improvements to dominate the mentioned shortcomings. The analysis shows that our proposed improvements are secure and efficient. 相似文献
149.
Mehdi Rahimi-Nasrabadi Mir Mahdi Zahedi Seied Mahdi Pourmortazavi Rouhollah Heydari Hossein Rai Jalal Jazayeri Abdollah Javidan 《Mikrochimica acta》2012,177(1-2):145-152
Dispersive liquid-liquid microextraction as a rapid, simple and efficient method coupled with high performance liquid chromatography-UV-Vis detection was used for sample preparation and subsequent determination of carbazole, tri nitro carbazole (TrNC) and tetra nitro carbazole in water samples. The influence of several important variables on the extraction efficiency has been evaluated. The methods works best with chloroform as an extractant and acetonitrile as the dispersive solvent. Under optimum conditions, the calibration curve is linear in the range from 0.007 to 1.75?μg?mL?1 for TNC, 0.006 to 1.52?μg?mL?1 for TrNC, and 0.008–2.10?μg?mL?1 for carbazole. The limits of detection (LODs; at a signal-to-noise ratio of 3), range from 1.7 to 1.1?ng?mL?1, for TNC, TrNC and carbazole. Also, the relative standard deviations (RSD, n?=?6) for the extraction of TNC (at 174?ng?mL?1), TrNC (at 151?ng?mL?1) and carbazole (at 84?ng?mL?1) vary between 4.1 and 5.2%. The enrichment factors range from 179 to 186. The method was successfully applied to the determination of TNC, TrNC and carbazole in environmental samples. Figure
Dispersive liquid-liquid microextraction is presented for the determination of carbazole based explosives (tri nitro carbazole (TrTNC) and tetra nitro carbazole (TNC)) using high performance liquid chromatography and UV–vis detection. 相似文献
150.
A novel, simple and facile layer by layer (LBL) approach is used for modification of glassy carbon (GC) electrode with multilayer of catalase and nanocomposite containing 1-(3-Aminopropyl)-3-methylimidazolium bromide (amine terminated ionic liquid (NH2-IL)) and titanium nitride nanoparticles (TiNnp). First a thin layer of NH2-IL is covalently attached to GC/TiNnp electrode using electro-oxidation method. Then, with alternative self assemble positively charged NH2-IL and negatively charged catalase a sensitive H2O2 biosensor is constructed, whose response is directly correlated to the number of bilayers. The surface coverage of active catalase per bilayer, heterogeneous electron transfer rate constant (ks) and Michaelis–Menten constant (KM) of immobilized catalase were 3.32 × 10−12 mol cm−2, 5.28 s−1 and 1.1 mM, respectively. The biosensor shows good stability, high reproducibility, long life-time, and fast amperometric response with the high sensitivity of 380 μA mM−1 cm−2 and low detection limit of 100 nM at concentration range up to 2.1 mM. 相似文献