Electrochemical Study of Indium in a Water‐Stable 1‐Ethyl‐3‐Methylimidazolium Chloride/Tetrafluoroborate Room Temperature Ionic Liquid

The electrochemistry of indium species was investigated at glassy carbon, tungsten and nickel electrodes in a basic 1‐ethyl‐3‐methylimidazolium chloride/tetrafluoroborate ionic liquid. Amperometric titration experiments suggest that In(III) chloride is complexed as [InCl₅]^2? in this ionic liquid. The electrochemical reduction of [InCl₅]^2? to indium metal is preceded by overpotential driven nucleations. The effective anodic dissolution of indium to indium(III) requires, however, the presence of sufficient chloride ions at the electrode surface. The electrodeposition of indium at glassy carbon and tungsten electrodes proceeds via three‐dimensional instantaneous nucleation with diffusion‐controlled growth of the nuclei. At the nickel electrode, the deposition proceeds via three‐dimensional progressive nucleation with diffusion‐controlled growth of the nuclei. Raising the deposition temperature decreases the average radius of the individual nuclei, r. Scanning electron microscopic and x‐ray diffraction data indicated that bulk crystalline indium electrodeposits could be prepared on nickel substrates within a temperature range between 30 and 120 °C.     

The Kinetics of Indium Electroreduction from Chloride Solutions

The electroreduction of indium on indium electrode (99.98%) in perchlorate-containing chloride electrolytes is studied by the methods of linear sweep and cyclic voltammetry, impedance spectroscopy, and chronoamperometry. The indium electroreduction is limited by diffusion, the reaction rate constant is 1.3 10^–4 cm/s at the indium salt concentration of 0.1 M. The values of the apparent rate constant for the charge transfer stage found by linear sweep and cyclic voltammetry and also by impedance spectroscopy are 2.37 × 10^–3, 3.62 × 10^–3, 3.06 × 10^–3 cm/s, respectively. The values of diffusion coefficient of indium(III) ions calculated according to the Cottrell equation based on chronoamperametric measurements and from the Warburg impedance found by impedance spectroscopy are in good agreement. The presence of the Gerischer impedance is stated, which suggests that a homogeneous reaction of formation of indium chloride complexes proceeds and its mechanism is chemical-electrochemical.

     

Gold Nanoparticles Formation via Au(III) Complex Ions Reduction with l‐Ascorbic Acid

In this paper, the kinetics and mechanism of gold nanoparticles formation during the redox reaction between [AuCl₄]− complex and l ‐ascorbic acid under different conditions were described. It was also shown that reagent concentration, chloride ions, and pH influence kinetics of nucleation and growth. To establish rate constants of these stages, the model of Finke and Watzky was applied. From Arrhenius and Eyring dependencies, the values of activation energy (22.5 kJ mol⁻¹ for the nucleation step and 30.3 kJ mol⁻¹ for the growth step), entropy (about −228 J K⁻¹ mol⁻¹ for the nucleation step and −128 J K⁻¹ mol⁻¹ for the growth step), and enthalpy (19.8 kJ mol⁻¹ for nucleation and 27.8 kJ mol⁻¹ for particles growth) were determined. It was also shown that the disproporationation reaction had influence on the rate of nanoparticles formation and may have impact on final particles morphology.     

Electrochemical deposition of indium: nucleation mode and diffusional limitation

the electrochemical deposition of indium metal from InCl₃ solutions was investigated. Cyclovoltammetric experiments showed that the initial hydrogen evolution reaction, observed together with the metal deposition on Pt surface, is blocked when the surface is covered by In. At large cathodic potentials, the current is diffusion-limited. The scan rate dependence of cyclovoltammograms allowed the determination of the diffusion coefficient of In³⁺ ions, 8.18 × 10^–6 cm²/s, using the Delahay equation. The activation energy of diffusion, determined from the temperature dependence of cyclovoltammograms, is about 0.3 eV (23 kJ/mol). Chrono-amperometric experiments are consistent with the cyclovoltammetry; the In³⁺ diffusion coefficient determined using the Cottrell law is in good agreement with the value determined by the Randles-?ev?ik equation. Moreover the use of the nucleation models developed by Scharifker and Hills showed a progressive nucleation mode. Electron microscopy observations and X-ray diffraction patterns confirmed the formation of crystalline indium deposits.     

Theory of phase transition kinetics with growth site impingement. I. Homogeneous nucleation

The nonlinear integral equations governing phase transition kinetics with homogeneous nucleation and growth site impingement are developed and solved to the first order for the two-dimensional case. It is shown that the fractional transformed area at time t is given approximately by a(t) = Kt³/(1 + Kt³). The iteration method used to get the solution is applicable to certain other nonlinear differential and integral equations. It is shown that the theory predicts the total number of growth sites formed, and that the nucleation rate and growth constants can be deduced from this and the gross kinetic data. The extension of the method of three-dimensional growth is indicated.     

Altered protein synthesis in rat kidney cells exposed to semiconductor materials

It is thought that the extensive industrial use of arsenic, gallium and indium, which have applications as the materials for III–V semiconductors, will increase human exposure to these compounds in the near future. We have undertaken the development of new biological indicators for assessing exposure to these elements. Element-specific alterations in protein synthesis patterns were expected to occur following exposure to arsenic compounds. We examined alterations in protein synthesis in primary cultures of rat kidney proximal tubule epithelial cells by sodium arsenite, gallium chloride and indium chloride, utilizing two-dimensional gel electrophoresis. After incubation with the chemicals for 20 h, newly synthesized proteins were labeled with [³⁵S]methionine. A protein with a molecular weight (M_r) of 30 000 was markedly induced on exposure to 10 μM arsenite or 300 μM gallium chloride, and synthesis of proteins with M_r values of 85 000, 71 000, 65 000, 51 000, 38 000 and 28 000 were also increased by exposure to arsenite and gallium chloride. No significant changes were observed upon exposure to indium. Some of these increased proteins could be heat-shock proteins.     

Complexation Equilibria of Indium in Aqueous Chloride,Sulfate and Nitrate Solutions: An Electrochemical Investigation

Electrochemical methods have been used to determine the speciation and stability constants of various aqueous indium complexes. Qualitative behavior is observed using UV–Vis spectroscopy and cyclic voltammetry. Equilibrium constants are determined using differential pulse voltammetry. In a titration where the titrant and sample contain equal concentrations of acid and In³⁺ ions and equivalent concentrations of ligand and supporting electrolyte anions, respectively, small changes in ligand concentration can be made quickly and accurately while maintaining the overall ionic strength. From the change in the half-wave reduction potential as a function of ligand concentration, the coordination number and the stability constants of sulfate, chloride and nitrate complexes were determined. We also highlight the difficulties finding a supporting electrolyte that does not interact with the In³⁺ ion. On the one hand, it was not possible to prevent the slow formation of chloride in perchlorate electrolytes containing indium. On the other hand, we show that, at concentrations of nitrate anions commonly used in such experiments, nitrate complexes form. In the light of these new findings, previously published stability constants of indium using nitrate-based supporting electrolytes should be used cautiously.     

Growth and characterization of ZnO nanowire arrays electrodeposited into anodic alumina templates in DMSO solution

ZnO nanowire arrays were grown by potentiostatic cathodic electrodeposition on aluminum anodic oxide template (AAO) from dimethyl sulfoxide (DMSO) solutions containing zinc chloride and molecular oxygen as precursors. The nanowires presented high aspect ratio and exhibited a very high crystallinity with a wurtzite crystal structure with preferential orientation along the (0001) crystallographic axis. Chronoamperometric experiments were performed on gold bulk electrodes in order to model this preferential mode growth of ZnO nanowires, which has not been previously reported for similar precursors in DMSO solution. The analysis of the corresponding chronoamperograms revealed that chloride ions influence the oxide nucleation and growth mechanism. It was found that in the absence of KCl as a supporting electrolyte, the data fitted an instantaneous three-dimensional diffusion-controlled (IN-3D)_diff nucleation and growth mechanism (NGM). The presence of KCl, instead favored a progressive three-dimensional (PN-3D)_diff NGM. With these results, a model for the more complex nanowire’s growth inside the pores of the AAO template is proposed.     

Selective extraction of thallium(III) in the presence of gallium(III), indium(III), bismuth(III) and antimony(III) by salting-out of an aqueous mixture of 2-propanol

Thallium(III), in the presence of other triply charged ions such as gallium, indium, bismuth and antimony in aqueous solution, was quantitatively and selectively extracted into 2-propanol/water phase by addition of NaCl ranging from 2.5 to 4.0 mol dm⁻³. The extraction efficiencies of gallium, indium, bismuth and antimony were much lower than that of thallium(III). Thus a maximal selective separation of thallium(III) from these elements could be attained using a 2-propanol/water mixture. Thallium(III) was extracted as TlCl₄⁻ with Na⁺. The detailed extraction mechanism in the presence of chloride, water in the organic phase and counter ions is discussed.     

The use of indium(III) as a complexing counter-ion to enable the separation of chloride,bromide, and iodide using isotachophoresis

A new method has been devised to enable the determination of halide anions by isotachophoresis. This method uses an electrolyte system that employs indium(III) as a counter-ion to manipulate the effective mobilities of sample species by means of complexation reactions. This new procedure successfully enabled the simultaneous determination of the halide ions chloride, bromide, and iodide when a 12 mmol L^–1 nitrate-based leading electrolyte containing 3.5 mmol L^–1 indium(III) at pH 3.0 was used.     

Diagrams of the formation of In2S3 and In2Se3 films on vitroceramic upon precipitation, according to potentiometric titration

Boundary conditions and ranges of the formation of indium(III) sulfide and selenide upon precipitation by thiocarbamide and selenocarbamide are determined. Potentiometric titration of indium chloride (InCl₃) in the concentration range of 0.0001 to 0.100 mol/L by a solution of sodium hydroxide is performed. It is found that the following pH ranges are optimal for In₂S₃ and In₂Se₃ film precipitation: from 3.0 to 4.5 and from 9.0 to 14.0. Indium selenide layers 100 to 300 nm thick are prepared on vitroceramic by hydrochemcial precipitation.     

The system HCl+InCl3+H2O from 5 to 55°C: Application of Harned's rule

Electromotive-force measurements of cells containing hydrochloric acid and indium chloride have been made to determine the variation of the log of the activity coefficient of hydrochloric acid with change in the amount of indium chloride in the solution. The simpler Harned equations have been used to fit the data. The quadratic terms in the Harned equations for the activity coefficients of HCl in the salt mixtures are required for a good fit of the 968 experimental emf data points at all the experimental ionic strengths and temperatures. The more convenient Pitzer ion-interaction treatment of the data will be reported in a separate publication which will include the values of the Pitzer parameters for pure InCl₃(aq), and mixing parameters for H⁺–In⁺³ and H⁺–In⁺³–Cl^–. A comprehensive investigation on the mixed electrolyte solutions at 11 different constant total ionic strengths ranging from 0.05 to 3.5 mol-kg^–1 was made at 11 temperatures from 5 to 55°C using the cell without liquid junction of the type: Pt,H₂(g, 1 atm)|HCl(m _A)+InCl₃(m _B)+H₂O|AgCl,AG (A).     

Determination of copper in zinc by proton activation analysis

A method for the determination of copper in zinc by proton activation analysis using the⁶³Cu(p, n)⁶³Zn reaction has been developed.⁶³Zn has to be separated chemically from gallium and copper activities formed out of the zinc matrix and from indium activity formed out of cadnium impurity. Gallium radionuclides are retained on a cation exchanger in chloride medium and the residual activity is extracted in di-isopropyl ether. Copper and indium are subsequently extracted with cupferron in chloroform. The method was applied to BCR reference materials with a copper concentration at the μg.g^?1 level. The detection limit amounts to 0.5 μg.g^?1.     

The influence of DMSO on the formation and photoelectrochemical properties of CdS thin films by electrodeposition method

The homodispersed CdS nanoparticles were prepared on Sn-doped indium oxide substrates (ITO) to form smooth and uniform CdS thin films by electrodeposition method from a dimethyl sulfoxide (DMSO) solution containing cadmium chloride and sulfur. The structure and morphologies of samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. The results indicate that DMSO played an important role in formation of CdS nanofilms by affecting the nucleation and growth of the CdS nanoparticles. So, a DMSO-assisted growth process was proposed as a plausible mechanism for the formation of smooth and uniform CdS nanofilms. According to the photoelectrochemical test, the CdS thin film prepared in 30 % DMSO + 70 % H₂O system exhibited maximum photocurrent and open circuit potentials. This is because the deposited CdS nanoparticles had better dispersity on ITO, which facilitated the propagation and kinetic separation of photogenerated charges.     

Synthesis of Bis(tricarbonylcyclopentadienylmolybdenum)bismuth(III) Chloride and Its Reaction with Metals

Polynuclear organometallic compounds [CpMo(CO)₃]₂BiCl and [CpMo(CO)₃]BiCl₂ were prepared by reaction of bismuth with tricarbonylcyclopentadienylmolybdenum chloride in dimethyl sulfoxide (DMSO). [CpMo(CO)₃]₂BiCl is reduced with magnesium or indium in tetrahydrofuran to give bismuth, [CpMo(CO)₃]₃Bi, and magnesium or indium chloride. In the presence of DMSO, the reaction of [CpMo(CO)₃]₂BiCl with magnesium or indium yields bismuth and the organomolybdenum derivative of magnesium or lithium, respectively.     

Synthesis,characterization and antibacterial activity of indium(III) complexes with adamantane-ring containing Schiff bases

Indium(III) chloride tetrahydrate and Schiff-base ligands derived from adamantaneamine and 3-/4-methoxysalicylaldehyde gave two complexes, C₂₂H₃₂Cl₃InN₂O₃ (1) and C₃₆H₄₄C_l3InN₂O₄ (2), respectively. The complexes were characterized by IR, ¹H NMR, elemental analysis, molar conductance, thermal analysis, and single-crystal X-ray diffraction. Complex 1 crystallizes in the monoclinic system, P2₁/n space group with the asymmetric unit consisting of one indium(III), one N-(3-methoxysalicylidene)-aminoadamantane (L¹), three chlorides and one N,N-dimethylformamide molecule. The indium is six-coordinate with reversed triangular-prism geometry via three oxygens and three chlorides. Complex 2 crystallizes in the triclinic system, P 1 space group; the asymmetric unit consists of one indium(III), two N-(4methoxysalicylidene)-aminoadamantane (L²), and three chlorides. The indium is five-coordinate with distorted trigonal-bipyramidal geometry via two oxygens and three chlorides. Antibacterial activities of the complexes have been investigated against Escherichia coli and Staphylococcus aureus.     

Subtoichiometric determination of indium and tin by radioactivation analysis

A method of radioactivation analysis has been developed for the determination of indium and tin. It is based on substoichiometric extraction of indium diethyldithiocarbamate into carbon tetrachloride from a slightly ammoniacal solution in the presence of potassium cyanide. With this method, indium can be determined via^116m In (T=54 min) and tin via^113m In (T=104 min) which is formed by the reaction¹¹²Sn(n, ψ)¹¹³Sn. The method has been applied to the determination of indium in metallic zinc and of tin in tin-doped gallium arsenide, and 0.4 ppb of indium was analyzed in a zinc sample.     

Na5P3O10-Ca(OH)2-CO2-H2O体系纳米CaCO3的成核与生长

通过化学分析、SEM显微分析技术,结合Rosin-Ramiler概率统计理论,从介观层次研究Na5P3O10-Ca(OH)2-CO2-H2O体系纳米CaCO3的合成反应及其成核和生长过程。结果表明,Na5P3O10对Ca(OH)2的碳化反应具有抑制作用。随着[Na5P3O10]的增加,体系中CaCO3的成核速率B^0逐渐增大。在[Na5P3O10]＝0ppm时,CaCO3结晶的生长由长程扩散和凝聚生长控制;[Na5P3O10]=380.4,760.9ppm时,前期受短程扩散和界面反应控制、后期受长程扩散控制。Na5P3O10的存在,抑制了纳米CaCO3的晶体生长。     

Zerstörungsfreie aktivierungsanalytische Bestimmung von Mikro- und Ultramikromengen Indium in Reinstthallium und Thalliumverbindungen

Two non-destructive neutron activation methods has been described for the determination of indium in thallium metal and thallium compounds. The sensitivity of the first method based on^114mIn corresponds to 1×10^?6g (standard deviation 4,5–8%). The second method (by means of^116mIn) permits the determination of ultramicro amounts of indium up to 5×10^?11g with a standard deviation of 15%. The influence of many elements (such as Ga, Cu, Al, Cd, Zn, Pb, Ca, Mg, Bi, Fe) has been examined. The methods have been applied to the determination of indium in thallium metal, oxide, nitrate, sulphate and chloride. The data obtained agreed whith those of the spectrochemical determination.     

Role of orientation in kinetics of nucleation and growth of crystals in polymers

A theoretical framework is provided for generalizing the inferences drawn from the results of earlier experimental studies of kinetics of crystallization in oriented poly(ethylene terephthalate). The framework is obtained by combining extensions of classical nucleation theories in polymers^3,4 and a theory of crystal growth with anisotropic incorporation of segments into growing crystals.¹⁵ It is shown that, while a very strong dependence of rate of primary nucleation on orientation does exist, there is a only a much weaker dependence of rate of crystal growth on the orientation of the crystallizing polymer. The theoretical formulation provided here would allow qualitative estimates for comparison with experiments.