Kinetics of Formation and Curing of Oligoether Urethane Allyl Ester

Kinetic parameters of formation of P-9AD oligoether urethane allyl ester with terminal double bonds and of its curing with dinitrile oxide were determined. The dependence of the rate constant on the allyl alcohol concentration and temperature was studied. The mechanism of reaction of P-9A prepolymer with allyl alcohol was proposed. The kinetic and thermodynamic parameters of curing of oligoether urethane allyl ester with dinitrile oxide were determined. The mechanism of reaction of P-9AD oligoether urethane allyl ester with dinitrile oxide was proposed.     

Effect of How Copper Oxide Is Obtained on the Behavior of Copper Oxide Electrodes in Lithium-Ion Power Cells

The electrochemical parameters of copper oxide electrodes in hermetically sealed lithium power cells were studied in relation to routes of copper oxide preparation, with the aim to diminish the share of side reactions.     

THEORETICAL STUDY OF THE EFFECT OF rGO/GO COMPOSITE COMPOSITION ON THE HYDROGEN FUEL CELL CHARACTERISTICS

Journal of Structural Chemistry - Properties of the hydrogen fuel cell composed only of graphene oxide (GO) and reduced graphene oxide (rGO) are theoretically studied. The optimal parameters of...     

Structurally diverse coordination compounds of zinc as effective precursors of zinc oxide nanoparticles with various morphologies

The structurally diverse coordination compounds of zinc were designed and synthesized using two types of building blocks: short‐chain carboxylate ions and hexamethylenetetraamine. They were characterized by X‐ray crystallography, infrared spectroscopy and thermal analysis. The studied compounds were used as precursors for production (via controlled thermal conversion) of zinc oxide nanoparticles. The conversion process was optimized in terms of two parameters (heating rate and maximum temperature). Such an approach, combined with proper design of the precursor structure, allows fabrication of various zinc oxide micro‐ and nanoparticles. The influence of a precursor structure and modifications of conversion parameters on size and morphology of ZnO particles were studied and discussed.     

Peculiarities of cellulose nitrate combustion in ballasted systems

Russian Chemical Bulletin - The dependence of the combustion parameters of cellulose nitrate (nitrocellulose, NC) mixtures with magnesium oxide on the content of the energetic component was studied...     

Catalytic Properties of Platinum(II,III) Oxide in Ammonia Oxidation

Catalytic properties of Pt₃O₄ platinum oxide were studied in the high-temperature range. The optimal parameters of ammonia oxidation on the oxide catalyst, kinetic characteristics of the reaction were determined.     

Electrolytic Deposition of Molybdenum Oxide from Aqueous Solutions at Room Temperature

The conditions of electrolytic deposition of molybdenum oxide from aqueous solutions at room temperature were studied and the optimal parameters of electrolysis, which provide deposits with necessary physical and structural characteristics, were chosen.     

Process Parameters of Oxidative Chlorination of Benzene with the Participation of Nitrogen(IV) Oxide

The efficiency of replacing oxygen with nitrogen(IV) oxide in oxidative chlorination of benzene was studied. The optimal process parameters: temperature, time of contact, and relative content of reagent, were determined.     

Gas Evolution and Absorption in a Sealed Nickel-Zinc Battery with Nickel Oxide Electrode Fabricated from Spherical Nickel Hydroxide

The range of variation of the barometric parameters of a sealed nickel-zinc battery with nickel oxide electrode made of spherical nickel hydroxide was studied under the conditions of cycling and exposure in charged and discharged states.     

The effect of platinum oxide films on reaction kinetics at platinum electrodes

It has been known for some time that the pre-treatment of platinum electrodes often effects subsequent electrochemical reactions. Part of the effect of pre-treatment is due to the fact that anodized or chemically oxidized platinum electrodes become coated to some degree with a film of platinum oxide. This work was concerned with quantitative measurement of kinetic parameters as a function of the extent of oxide film formation. Whenever possible, variations in reaction mechanisms are proposed.

Most of the experimental evidence has been taken from current-potential curves but the techniques of chronopotentiometry and microscopy were also used.

The reduction of vanadium^V chromium^VI, arsenic^V, iodate and oxygen were investigated as well as the oxidation of vanadium^IV, arsenic^III, oxalic acid, and formic acid. The presence of the platinum oxide film effected the reactions studied in a variety of ways but in every case some variation in the kinetic parameters of the reactions studied was recorded. For a number of cases, a modified oxygen bridge theory was found useful.     

Synthesis of ultrafine refractory oxides zirconia-hafnia-yttria by sol-gel technology

A transparent gel was prepared using a hydrolytically active solution of zirconium, hafnium, and yttrium alkoxoacetylacetonates. This gel served to synthesize ultrafine zirconia-hafnia-yttria complex oxide. The product dispersity was studied as affected by the parameters of xerogel heat treatment. The thermal behavior of the xerogel was studied by DSC-TGA. Elemental analysis (laser mass spectrometry) and phase analysis of the synthesized materials were carried out. Average crystallite sizes were calculated by the Scherrer relationship. The particle morphology was studied by TEM. Specific surface areas were determined. Sintering of ultrafine oxide powders was studied at 1000, 1200, and 1400°C.     

Kinetic regularities of recovery of metals from raw materials of industrial origin

Kinetics of recovery of metals from the wastes and poor ores, which contain oxide and sulfide minerals of copper, vanadium, and silver with an azomethine solution in organic solvent was studied. The optimal parameters of the recovery were suggested.     

Effect of genesis on the properties and hydrogen reducibility of NiO-ZnO mixed oxides

The physico-chemical properties and reactivity tested by hydrogen reduction have been studied for two series of NiO-ZnO mixed oxides of various composition. The solid nickel oxide or zinc oxide in interaction with the solution of nitrate of the second component were used as the precursors in each series. The differences in some physico-chemical parameters of the samples in both series were correlated with their reduction behaviour, followed both in iso- and non-isothermal regime. Moreower, the influence of various factors modifying the reactivity of mixed oxides was also investigated and the results were compared with those obtained from earlier studied analogous systems of quite different origin.This revised version was published online in November 2005 with corrections to the Cover Date.     

Hydrothermal synthesis and photocatalytic activity of highly dispersed ZnO powders

The micromorphology of highly dispersed ZnO powders formed from Zn(OH)₂ gels under hydrothermal conditions is studied by powder X-ray diffraction, X-ray diffraction analysis, and low-temperature nitrogen adsorption. The parameters of hydrothermal synthesis (heating rate, treatment duration, and temperature) are found to effect the microstructural characteristics of the products. The photocatalytic activity of the synthesized zinc oxide samples in the model reaction of Methyl Orange photodegradation is studied. The synthesis parameters for preparing ZnO powders with high photocatalytic activity are determined.     

Preparation of PMMA/mesoporous diatomite nanocomposites by in situ SR&;NI ATRP

The catalytic effect of lead oxide nano- and microparticles (PbO) on the thermal behavior and decomposition kinetics of energetic formulations composed of nitrocellulose (NC), triethyleneglycol dinitrate (TEGDN) and diaminoglyoxime (DAG) was investigated by simultaneous thermogravimetric analysis and differential scanning calorimetry. The results show that lead oxide nano- and microparticles could significantly alter thermal pattern of the studied energetic compositions. The effect of lead oxide content on thermal behavior of energetic compositions was also studied, and the results revealed that addition of different amounts of lead oxide caused to shift in the DSC peaks. Moreover, the catalyst decreases activation energy of the decomposition stage of energetic composition at about 20–40 kJ mol^?1. However, the catalyst enhances decomposition temperature of TEGDN/NC/DAG energetic compositions. By the aid of DSC data resulted by non-isothermal methods, the thermokinetic parameters such as activation energy (E _a), frequency factor (A), the critical ignition temperature of thermal explosion, the self-accelerating decomposition temperature (T _SADT) and also thermodynamic parameters of the studied energetic compositions were calculated and compared.     

Alkylation of Isobutane with Butenes on Zirconium Sulfate Catalysts

Sulfated zirconia catalysts supported on silica gel and aluminum oxide were prepared by impregnation, and their structure and acid-base and catalytic properties were studied. The parameters of synthesis and characteristics of this catalyst, which ensure high activity and selectivity in liquid-phase alkylation of isobutane with butenes, were determined.     

Catalytic effect of zinc oxide on the reduction of barium sulfate by methane

Reduction of barium sulfate by methane was investigated in this work. The thermogravimetric method was used to obtain kinetic parameters of the reaction in the temperature range of 900–975 °C at atmospheric pressure. The kinetics of the reaction has been studied both in the absence and presence of zinc oxide as a catalyst. The conversion–time data have been interpreted by using the grain model, and the effect of catalyst on the kinetic parameters has been elucidated. It was found that zinc oxide acted as fairly strong catalyst for the reaction, especially at higher temperatures. At about 975 °C the reaction rate constant was increased more than 7 times by using 2% of zinc oxide. This enhancement in the rate constant is valuable for industries.     

Hydration of medium reactive industrial magnesium oxide with magnesium acetate

Medium reactive magnesium oxide reacts incompletely with available water to form magnesium hydroxide. To enhance the hydration of medium reactive magnesium oxide, the effect of magnesium acetate as hydrating agent was studied. The extent to which different parameters (concentration of magnesium acetate, solution temperature and solid to liquid ratio of MgO to magnesium acetate) influence the hydration rate of a medium reactive industrial sample of magnesium oxide were evaluated. The degree of rehydration measured as percentage Mg(OH)₂being formed, increases from approximately 56% using 0.5 M magnesium acetate solutions at 25°C to 64% at 50°C, to more than 70% at 70°C. The major part of rehydration of the medium reactive MgO sample occurs within the first few minutes of the reaction for all three temperatures studied. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effect of diluent and reaction parameter on selective oxidation of propane over MoVTeNb catalyst using nanoflow catalytic reactor

The selective oxidation of propane to acrylic acid over an MoVTeNb mixed oxide catalyst, dried and calcined before reaction has been studied using high-throughput instrumentation, which is called nanoflow catalytic reactor. The effects of catalyst dilution on the catalytic performance of the MoVTeNb mixed oxide catalyst in selective oxidation of propane to acrylic acid were also investigated. The effects of some reaction parameters, such as gas hourly space velocity （GHSV） and reaction temperature, for selective oxidation of propane to acrylic acid over diluted MoVTeNb catalyst have also been studied. The configuration of the nanoflow is shown to be suitable for screen catalytic performance, and its operating conditions were mimicked closely to conventional laboratory as well as to industrial conditions. The results obtained provided very good reproducibility and it showed that preparation methods as well as reaction parameters can play significant roles in catalytic performance of these catalysts.     

Preparation of Mesoporous γ-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> from Aluminum Hydroxide Peptized with Organic Acids

The relationships of the formation of aluminum oxide from aluminum hydroxide peptized with organic acids (propionic, maleic, malonic, tartaric) were studied. The pore structure parameters of the hydroxide samples and of aluminum oxide samples obtained from them are strongly influenced by acid peptization. The nature of the acid influences the extent of defectiveness of the γ-Al₂O₃ structure, manifested in the density of aluminum oxide, measured by helium pycnometry. The possibility and conditions for preparing mesoporous γ-Al₂O₃ suitable for use in chemical and petrochemical processes were determined.