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71.
Jan Urbaniak Jan M. Skowroński Barbara Olejnik 《Journal of Solid State Electrochemistry》2010,14(9):1629-1635
In the present work, a simple method of preparation of FeCl4−- graphite intercalation compounds from HCl/FeCl3 solution with the aid of chemical oxidant is presented. Based on X-ray diffraction measurements it was concluded, that stages
8, 6, and 5 FeCl4−-graphite intercalation compounds were obtained. The compounds thus obtained were thermally treated to obtain Fe2O3-exfoliated graphite composites. The dispersion of Fe2O3 in the exfoliated graphite flakes was examined with the aid of the energy dispersive X-ray analysis combined with a scanning
electron microscopy. Electrochemical behavior of electrodes was investigated in 6 M KOH solution. Electrochemical investigations
proved the formation of FeOOH on the surface of exfoliated graphite during the anodic process. Besides, electrochemical investigations
showed that the lower limit potential strongly affects the redox behavior of the Fe2O3-EG electrode. 相似文献
72.
This article presents theoretical advances in computational modeling of dissolution at mineral–water interfaces with specific
emphasis on silicates. Two different Monte Carlo methods have been developed that target equilibrium properties and kinetics
in silicate–water dissolution. The equilibrium properties are explored using the combined reactive Monte Carlo and configurational
bias Monte Carlo (RxMC-CBMC) method. The new RxMC-CBMC method is designed to affordably simulate the three-dimensional structure
of the mineral with explicit water molecules. The kinetics of the overall dissolution process is studied using a stochastic
kinetic Monte Carlo method that utilizes rate constants obtained from accurate ab initio calculations. Both these methods
provide important complementary perspective of the complex dynamics involving chemical and physical interactions at the mineral–water
interface. The results are compared to experimental and previous computational data available in the literature. 相似文献
73.
74.
Maria Cyfert Barbara Latko Maria Wronska 《Monatshefte für Chemie / Chemical Monthly》1980,111(3):619-626
The influence of NaClO4, NaCl and Na2SO4 on the oxidation of Fe(phen)
3
2+
by Ce(IV) was investigated by means of the stopped-flow method. At the concentrations range of NaClO4 and NaCl 0.1–1.0M the rate constant values decrease from 1.03·105 to 0.56·105M–1s–1 and from 1.08·105 to 0.81·105M–1s–1 respectively.In varying concentrations of Na2SO4 solutions (0.05–0.35M) the rate constant values decrease from 1.05·105M–1s–1 to 0.45·105M–1s–1.Taking into account the negative salt effect the mechanism of the reaction progress is proposed. 相似文献
75.
Jinhua Wang Dr. Barbara Wicher Dr. Victor Maurizot Prof. Ivan Huc 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(3):1031-1038
Quinoline based aromatic amide foldamers are known to adopt stable folded conformations. We have developed a synthetic approach to produce similar oligomers where all amide bonds, or part of them, have been replaced by an isosteric vinylene group. The results of solution and solid state structural studies show that oligomers exclusively containing vinylene linkages are not well folded, and adopt predominantly flat conformations. In contrast, a vinylene segment flanked by helical oligoamides also folds in a helix, albeit with a slightly lower curvature. The presence of vinylene functions also result in an extension of π-conjugation across the oligomer that may change charge transport properties. Altogether, these results pave the way to foldamers in which both structural control and specific electronic properties may be engineered. 相似文献
76.
Zbigniew Gregorowicz Barbara Piwowarska Franciszek Buhl und Krystyna Kania 《Fresenius' Journal of Analytical Chemistry》1968,237(5):347-351
Zusammenfassung Es wurde eine UV-spektrophotometrische Methode zur Bestimmung der 2,2-Dicinchoninsäure beschrieben. Messung erfolgt bei pH 10 bei dem Absorptionsmaximum von 260 nm. Der Bestimmungsbereich beträgt 1,71–20,52 g der 2,2-Dicinchonin-Ionen in 25 ml Lösung. Ba2+, Sr2+, Ca2+, Mg2+, Ni2+, Co2+, Zn2+, Hg2+ und Al3+ in 100fachem sowie Pb2+ in 10fachem Überschuß verursachen keine Störungen. Blei in 20 fachem sowie Ag+ und Hg2
2+ in einfachem Überschuß verursachen Ausscheidung von Niederschlägen.
Summary An UV-spectrophotometric method for the determination of 2,2-dicinchonic acid is described. The absorption is measured in a solution of pH 10 at the maximum of 260 nm.The range of application of the method was 1,71 to 20,52 g of DC2– ions in 25 ml of solution. Ba2+, Sr2+, Ca2+, Mg2+, Ni2+, Co2+, Al3+, Zn2+, Hg2+ ions present in hundredfold excess do not interfere with the determination. Ag+, Hg2 2+ ions in one-fold and Pb2+ ion in twenty-fold excess cause the deposition of a precipitate, but five-fold and ten-fold excess of Pb2+ does not interfere.相似文献
77.
Barbara Burnat Tadeusz Blaszczyk Andrzej Leniart 《Journal of Solid State Electrochemistry》2014,18(11):3111-3119
Stainless steel ISO 5832–9 type is often used to perform implants which operate in protein-containing physiological environments. The interaction between proteins and surface of the implant may affect its corrosive properties. The aim of this work was to study the effect of selected serum proteins (albumin and γ-globulins) on the corrosion of ISO 5832–9 alloy (trade name M30NW) which surface was modified by titania coatings. These coatings were obtained by sol–gel method and heated at temperatures of 400 and 800 °C. To evaluate the effect of the proteins, the corrosion tests were performed with and without the addition of proteins with concentration of 1 g L?1 to the physiological saline solution (0.9 % NaCl, pH 7.4) at 37 °C. The tests were carried out within 7 days. The following electrochemical methods were used: open circuit potential, linear polarization resistance, and electrochemical impedance spectroscopy. In addition, surface analysis by optical microscopy and X-ray photoelectron spectroscopy (XPS) method was done at the end of weekly corrosion tests. The results of corrosion tests showed that M30NW alloy both uncoated and modified with titania coatings exhibits a very good corrosion resistance during weekly exposition to corrosion medium. The best corrosion resistance in 0.9 % NaCl solution is shown by alloy samples modified by titania coating annealed at 400 °C. The serum proteins have no significant effect onto corrosion of investigated biomedical steel. The XPS results confirmed the presence of proteins on the alloy surface after 7 days of immersion in protein-containing solutions. 相似文献
78.
Using chiral probes shown to be sensitive to the presence of mobile phase additives, a memory effect for these additives by an amylosic column was demonstrated. Exposure to these additives gave prolonged chromatographic performance changes even after their removal from the mobile phase. This finding is consistent with strong binding of the additives to the stationary phase. A procedure to remove bound additives was developed. 相似文献
79.
80.