共查询到20条相似文献,搜索用时 15 毫秒
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Samples of zirconium ferrocyanide have been prepared under different conditions of precipitation, and their properties, composition
and ion-exchange behaviour are reported. The distribution ratios of 21 metal ions are given and some topical separations have
been achieved using these data. 相似文献
3.
Membranes based on the inorganic ion-exchanger chromium ferrocyanide have been prepared, which exhibit linear response to ferrocyanide over the concentration range 10(-1)-10(-4)M. Although the electrode is not very specific for ferrocyanide, it can be used for potentiometric titration of metal ions with ferrocyanide ion or vice versa. Hg(2+), Th(6+), UO(2+)(2), Pb(2+), Cu(2+) and Zn(2+) have been determined in this way. 相似文献
4.
The interaction of aniline and p-anisidine with chromium ferrocyanide has been studied. Maximum uptake of both anilines was observed around pH 7. The adsorption data obtained at neutral pH were found to follow Langmuir adsorption. Anisidine was a better adsorbate because of its higher basicity. In alkaline medium (pH>8) both aniline and anisidine reacted with chromium ferrocyanide to give colored products. Analysis of the products by GC-MS showed benzoquinone and azobenzene as the reaction products of aniline while p-anisidine afforded a dimer. IR analysis of the amine-chromium ferrocyanide adduct suggests that the outer metal ion of chromium ferrocyanide and amino group of amines are responsible for the interaction. A possible reaction mechanism for the product formation in alkaline medium has been proposed. The present study suggests that metal ferrocyanides might have played an important role in the stabilization of organic molecules through their surface activity in the prebiotic condensation reactions. 相似文献
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Mirza Aijaz Beg 《Colloid and polymer science》1957,153(2):164-166
Summary In general the addition of non-electrolyte to hydrophobic sols results into an irregular change in the stability of the latter,
towards electrolyte coagulation. Precipitation concentration of potassium chloride for copper ferrocyanide sol changes in
the presence of ethyl alcohol, glycol or glycerol. Ethyl alcohol sensitizes while others stabilise the sol to different extents.
In presence of these alcohols, electrolytic coagulation of copper ferrocyanide sol is attended by a decrease in the conductance
and hydrogen ion concentration as compared to a pure sol (sol without non-electrolyte).
Zusammenfassung Im allgemeinen verursacht das Zufügen von Nicht-Elektrolyten zu hydrophoben Solen eine irregul?re ?nderung der Stabilit?t der letzteren hinsichtlich der Elektrolytkoagulation. Die F?llungskonzentration von Kaliumchlorid für Kupfer-Ferrocyanid-Sol ?ndert sich bei Gegenwart von ?thylalkohol, Glykol oder Glycerin. ?thylalkohol sensibilisiert, w?hrend die anderen das Sol in verschiedenem Ausma\ stabilisieren. In Gegenwart dieser Alkohole ist die Elektrolytkoagulation des Kupfer-Ferrocyanid-Sols von einer Abnahme der Leitf?higkeit und der Wasserstoffionenkonzentration, verglichen mit den reinen Solen ohne Nicht-Elektrolyt begleitet.相似文献
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S. L. Alekseeva S. N. Bolotin T. G. Tsyupko 《Russian Journal of Applied Chemistry》2007,80(3):376-378
Sorption of Cr(VI) on AV-17 and EDE-10P anion exchangers, KU-2 and KB-4 cation exchangers, activated charcoal, and foamed graphite (STRG) is studied. 相似文献
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C. Papadopoulou G. Kanias I. Hadzistelios 《Journal of Radioanalytical and Nuclear Chemistry》1976,31(2):389-396
A simple ion exchange procedure has been developed for the separation of chromium from the other chemical elements in biological
tissues. This procedure combined with neutron activation analysis has been applied successfully to the determination of chromium
in a reference biological material. The precision was ±11%, the accuracy 3% and the sensitivity found was 10 ng with only
20 hrs irradiation at 2.8·1013 n·cm−2·sec−1 flux The main steps of the procedure are: wetdigestion of the irradiated tissue, oxidation to chromium (VI), fixation onto
an anion resin in sulfate form, washing of the resin with 1N H2SO4, collection of chromium by reductive elution for counting and finally determination of the chemical yield by reactivation. 相似文献
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Stannic sol was prepared and its precipitation values were studied by BaCl2 and AlCl3 by employing the surface leaving method in the light of the equation. Different concentrations of these electrolytes were added to the sol and the corresponding times of coagulation were determined. The relation between 1/c?a of electrolyte and their respective times of coagulation was found to be linear. The constantsa, m, andn were determined for each electrolyte. 相似文献
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Dris Ben Hmamou Rachid Salghi Abdelkader Zarrouk Belkheir Hammouti Omar Benali Hassan Zarrok Salem Salim Al-Deyab 《Research on Chemical Intermediates》2013,39(8):3475-3485
In this work, the effect of potassium ferrocyanide (Pf) on the corrosion of mild steel in solutions of phosphoric acid (H3PO4) has been investigated in relation to the concentration of the inhibitor by weight loss, potentiodynamic polarization and AC impedance (EIS) measurements. The results obtained revealed that this compound is good a mixed-type inhibitor. The effect of temperature on the corrosion behavior with the addition of optimal concentration of Pf was studied in the temperature range 298–328 K. The value of inhibition efficiency decreases slightly with the increase in temperature. Changes in impedance parameters (charge transfer resistance, R t, and double layer capacitance, C dl) were indicative of adsorption of Pf on the metal surface, leading to the formation of a protective film. Adsorption of Pf on the C38 steel surface was found to obey the Langmuir adsorption isotherm. Some thermodynamic functions of dissolution and adsorption processes were also determined. 相似文献
11.
Summary Membrane potentials across parchment supported manganese ferrocyanide membrane for various electrolytes over a wide concentration
range have been studied. It was found that the membrane potential increases with dilution of the external electrolyte solutions.
The fixed charge density of the membrane has been evaluated byAltug andHair's method and comes out to be −0.06 N. The variation of the transport number of the counterions in the membrane phase and
perm-selectivity of the membrane with dilution have also been studied.
Zusammenfassung Es wurden Membranpotentiale von Manganferrocyanid-Membranen auf Pergamenttr?gern in L?sungen verschiedener Elektrolyte über weite Konzentrationsbereiche untersucht. Das Membranpotential nahm mit der zunehmenden Verdünnung zu. Die fixierte Ladungsdichte wurde nachAltug undHair ermittelt und betrug −0.06 N. Die ?nderung der überführungszahl der Gegenionen in die Membranphase und die Permselektivit?t der Membran wurden ebenfalls bestimmt.相似文献
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The pyridinium molybdoarsenate membrane shows a response to pyridinium ions and can be used to determine the concentration of these ions in the range 10(-3)-1M. The potentials generated across the membrane are reproducible and the response time is less than 1 min. There is no interference from certain inorganic and organic ions. The electrode can be used in the pH range 3-6 as well as in non-aqueous medium. Small additions of cetyltrimethylammonium bromide cause large shifts in the membrane potentials. A membrane, after being treated with this surfactant, shows a wider range of response to pyridinium ions. Precipitation titration of pyridinium nitrate has been monitored by using this membrane electrode. 相似文献
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Amorphous and crystalline thorium tungstate have been prepared by mixing 0.1M thorium nitrate and 0.1M sodium tungstate under different conditions. The physico-chemical properties, chemical stability, composition, TGA, DTA, X-ray, infrared absorption and ion-exchange behaviour of thorium-tungstate are reported and discussed. Distribution coefficients of metal ions on thorium tungstate have been determined at pH 2-3 and 5.5-6.5. Selective ion-exchange separations of bismuth and mercury from other metal ions have been achieved on a column of thorium tungstate. 相似文献
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Evidence is presented which throws doubt on the preparation of chromium III tri-stearate by aqueous metathetic reaction. 相似文献
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In 0.1M NH(3)-NH(4)Cl buffer (pH 9.2) a sensitive 2-electron reduction wave of estazolam is obtained by single-sweep oscillopolarography. The peak potential is -1.08 V (vs. SCE). The peak height is proportional to the concentration of estazolam over the range 1.0 x 10(-7)-9.0 x 10( partial differential)M. The detection limit is 5.0 x 10(-8)M. The behaviour of the reduction wave has been studied and applied to the determination of estazolam. The reduction process is irreversible and the wave shows adsorptive characteristics, the behaviour obeying the Frumkin adsorption isotherm. The adsorption coefficient beta is 1.16 x 10(6) 1./mole and the interaction factor alpha is -1.06. The mechanism of the electrode reaction is discussed. 相似文献
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A technique for the separation and preconcentration of Cr(VI) and Cr(III) in fresh waters is presented. The analytical procedure involves the use of anion- and cation-exchange columns. The columns are eluted and the eluate is analysed for chromium using a graphite furnace atomic absorption spectrometer. The recovery of Cr(VI) and Cr(III) is 97.86 ± 1.31% and 102.36 ± 1.25% (95% confidence), respectively. The detection limits are 0.019 and 0.020 μg 1?1 for 200 ml of sample (twice the standard deviation of eleven replicate blanks). The method is rapid and the need for minimum sample handling avoids contamination problems. 相似文献
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Summary Emulsifying powers of various surfactants have been determined by bringing the emulsion systems at isoelectric point by polyvalent inorganic ions. Several useful binding parameters have been calculated.
Zusammenfassung Es wurde die emulgierende Wirkung verschiedener Tenside untersucht. Dazu wurden die Emulsionen durch polyvalente anorganische Ionen auf den isoelektrischen Punkt gebracht. Aus den Konzentrationen, bei denen Ladungsumkehr erfolgte, wurden verschiedene Bindungsparameter abgeschätzt.相似文献
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《Thermochimica Acta》1986,103(2):267-273
The thermal degradation of K2HPCr2O10, Na3PCr3O13 · 3H2O, K3PCr4O16 and (NH4)3PCr4O16 has been investigated by TG and DTA methods. The main decomposition process for the three firstly mentioned compounds occurs at around 400°C and is associated with the rupture of P-O-Cr bonds. The ammonium salt shows a different behaviour and decomposes explosively at 230°C. In the case of K2HPCr2O10 a new polyoxoanion of formula K4P2Cr4O19 is generated as an intermediate during the thermal degradation. Detailed stoichiometries, sustained by the TG/DTA results as well as by the chemical and infrared spectroscopic analyses of the solid residues could be given. It is shown that, in all cases, CrPO4 is one of the decomposition products. 相似文献