Solid-liquid equilibrium diagrams of common ion binary salt hydrate mixtures involving nitrates and chlorides of magnesium, cobalt, nickel, manganese, and iron(III)

The solid-liquid equilibrium diagrams of binary mixtures involving magnesium nitrate hexahydrate with cobalt nitrate hexahydrate, nickel nitrate hexahydrate (partly), manganese nitrate tetrahydrate, and iron(III) nitrate nonahydrate and of magnesium chloride hexahydrate with cobalt and nickel chlorides hexahydrates and manganese chloride tetrahydrate, and the of two manganese salts were determined. Those diagrams that showed a simple eutectic were fitted by the Ott equation and where the required BET parameters were available, the magnesium salt rich parts of the liquidus were modeled by means of this method.     

Effect of Organic Ligands Used in Sol-Gel Process on the Formation of Mullite

The preparation of mullite by the sol-gel method using organic polydentate ligands and the effect of the raw materials and organic polydentate ligands on the formation of mullite were investigated. Two series of samples were prepared using tetraethoxyorthosilicate (TEOS) and aluminum nitrate nonahydrate, or dibutoxyethylacetoacetatoaluminum (Al(OBu)₂(AcAcEt)) as the silica and alumina sources, respectively, and using ethylene glycol (EG), 1,3-propanediol (PD), 1,3-butanediol (BD), 2-methyl-2, 4-pentanediol (MPD), diethlene glycol monoethyl ether (DEME) and ethoxyethanol as the ligands. When the alumina source was aluminum nitrate nonahydrate, mullite was apt to appear in the order of EG>PD>MPD. When Al(OBu)₂(AcAcEt) was the alumina source, the tendency toward the appearance of mullite crystalline phase was EG>BD>DEME>MPD. Between the two alumina sources, aluminum nitrate nonahydrate gave mullite much easier than Al(OBu)₂(AcAcEt). These relationships were discussed from the viewpoints of the coordination ability of the ligands and the miscibility between the silica and alumina.     

Ferroelectric poly(vinylidene fluoride) PVDF films derived from the solutions with retainable water and controlled water loss

To obtain β‐phase dominant ferroelectric poly(vinylidene fluoride) (PVDF) homopolymer thin films on aluminum‐coated silicon substrates, the retaining and loss of water were manipulated by introducing several hydrated and hygroscopic chemicals in the precursor solutions, including aluminum nitrate nonahydrate, aluminum chloride hexahydrate, chromium nitrate nonahydrate, tetra‐n‐butylammonium chloride, and one hygroscopic but nonhydrated chemical, ammonium acetate. Their ability of retaining water during the thermal annealing of the films and the relationship between water retaining and the effects on promoting the β phase were investigated. The results showed an ideal scenario was that the added hydrated salts should be able to retain substantial amount of water during the PVDF crystallization to effectively promote the β phase but completely dehydrate or decompose at the further elevated annealing temperature in order to obtain β‐phase dominant PVDF film without substantially incorporating water and deteriorating the electrical properties. As one of the hydrated chemicals well satisfying the above requirements, Al(NO₃)₃·9H₂O, of different amounts was introduced to the PVDF precursor solutions and the optimal resulting β‐phase dominant ferroelectric PVDF thin films exhibited smooth morphology, low dielectric loss, high remnant polarization of 89 mC/m², and large effective piezoelectric coefficient d₃₃ of ?14.5 pm/V (under the clamping of the substrate). © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2410–2418, 2009     

Kinetics and mechanism of thermal decomposition of ammonium nitrate and sulfate mixtures

Fundamental kinetic aspects of the decomposition of mixtures and double salts of ammonium nitrate and ammonium sulfate were studied. The effect of water and sulfuric acid additives on the thermal decomposition rate of ammonium nitrate and sulfate mixtures was examined. The constant of proton exchange between nitric acid and the sulfate anion in molten ammonium nitrate was estimated.     

Measurement of thermophysical properties of ammonium salts in the solid and molten states

The thermal conductivity, specific heat capacity and thermal diffusivity of solid and molten ammonium thiocyanate, ammonium formate, ammonium acetate and ammonium nitrate were measured in the temperature range 80–190C, including the solid and liquid phases, by using the AC-heated strip (wire) technique. The results indicate that the thermal conductivities depend on the type of the ammonium salt. It was found that the mechanism of heat transfer is due to phonons in the region below the melting points of the salts, while above this region the main mechanism is due to conduction.     

Al3+ solvation in solutions of aluminum nitrate in a protic ionic liquid: Nuclear magnetic resonance verification of the solvation shell composition

The closest environment of Al³⁺ cations was analyzed in detail in solutions of aluminum nitrate in the prototypical protic ionic liquid ethyl ammonium nitrate (EAN) using ¹H and ¹⁴N nuclear magnetic resonance (NMR) spectra. For Al (NO₃)₃–EAN mixtures with different water content, a quantitative analysis of the integral intensities of the ¹H and ¹⁴N signals was carried out and the composition of the first solvation shell of the aluminum cation was refined.     

Differential drop calorimetry for the determination of enthalpy of fusion

Drop calorimetry was modified in order to adapt it to the measurement of the enthalpy of fusion of materials with above-ambient fusion temperatures, T_F, such as salt hydrates suitable as phase change materials. In the modified form, differential drop calorimetry, the energy delivered to the molten sample at temperatures above T_F and by the crystalline sample at temperatures below T_F are extrapolated to T_F to give the enthalpy of freezing. The calorimetric system was calibrated electrically and with acetamide (T_F=353.3 K) and applied to the congruently melting magnesium nitrate hexahydrate, cadmium nitrate tertrahydrate, ammonium alum, and several hydrated salt mixtures.     

Iron-mediated radical halo-nitration of alkenes

Radical halo-nitration of alkenes using iron(III) nitrate nonahydrate and halogen salt has been developed. The present reaction proceeds by radical addition of nitrogen dioxide generated by thermal decomposition of iron(III) nitrate nonahydrate and subsequent trapping of the resultant radical by a halogen atom in the presence of halogen salt. Application of this method to synthesis of nitroalkenes is also described. The practicality of the present method using nontoxic and inexpensive iron reagents has been shown by the application to broad alkenes.     

Zur Kinetik der chloridkatalysierten thermischen Zersetzung von Ammoniumnitrat

On the Kinetics of Chloride Catalyzed Thermal Decomposition of Ammonium Nitrate The activation energies and frequency factors of thermal decomposition reactions of ammonium nitrate and mixtures of ammonium nitrate and chloride have been determined by volumetric measurement of the gaseous decomposition products evolved on linear hcating. The rate constants obtained from these values show that thermal stability and initial decomposition temperature of ammonium nitrate are considerably reduced by addition of small amounts of chloride.     

Phase stabilization of ammonium nitrate by double addition of potassium nitrate and melamine

Methods for providing stabilization of ammonium nitrate and expanding the application field of this oxidizing agent in gas-generating compositions used for various purposes were sought for. The results of a study of the physicochemical properties of ammonium nitrate with a melamine–potassium nitrate double additive introduced by mechanical mixing and crystallization from an aqueous (nonaqueous) solution at the boiling point are presented. The phase diagrams of the ammonium nitrate–melamine and ammonium nitrate–melamine–potassium nitrate systems, based on the results of a differential-thermal analysis, demonstrated that a phase-stable ammonium nitrate can be formed by using the method of crystallization from an aqueous (nonaqueous) solution at the boiling point. The resulting samples were examined by IR spectroscopy and X-ray diffraction analysis, and a conclusion was made that a new thermodynamically stable phase can be formed in the system with individual additives, and the introduction of a double additive leads to a combined effect: a thermodynamically stable crystal structure is formed, with the simultaneous slowing down of the nucleation and growth of a new phase in the course of a phase transformation.     

Mercurous nitrate as a reductimetric reagent : The determination of hydroxylamine and nitrates

Hydroxylamine can be determined indirectly using standard mercurous nitráte, by treating the test solution with an excess of standard ferric alum, and back titrating the excess.The same procedure cannot be recommended for the determination of hydrazine and hydroquinone. The results with hydrazine were irregular and generally low. With hydroquinone, the brown colour of the oxidation product masked the endpoint.An attempt was made to determine nitrate after reduction with ferrous ammonium sulphate, but the high acidity required is unfavourable for mercurous nitrate titration, and results are only accurate to about 1 per cent.     

Hydrolysis of aluminum sulfates in the presence of ammonium sulfite

Hydrolysis of aluminum sulfate and potash alum in the presence of an ammonium sulfite additive in the temperature range T _boil-200°C was studied. A possible reaction mechanism was suggested. The composition and structure of the precipitates formed were determined and certain differences in their morphology were noted. Recommendations for practical implementation of the method of hydrolytic recovery of aluminum from solutions of its sulfate salts were given.     

Electrochromatography in the separation of ions: Separation of alkaline earth metals

Complete Separation of ternary mixtures of Ca, Mg and Sr or Ba ions with ammonium chloride and less complete but detectable separation of the same mixtures with ammonium nitrate have been achieved, as well as a few binary separations of the type Ca-Ba, Ca-Sr, Ca-Mg, Mg-Sr and Mg-Ba.     

Silica Supported Ferric Nitrate Nonahydrate: Selective Oxidation of Benzoins Under Mild Conditions

Abstract

Benzils are selectively obtained in high yields by the oxidation of benzoins under mild reaction conditions using silica supported ferric nitrate nonahydrate.     

Production of a Concentrate of Rare-Earth Metals from Wet-Process Phosphoric Acid

Desorption of rare-earth metals (REMs) (lanthanum, yttrium, and ytterbium), as well as iron and aluminum, from the KU-2 sulfocation exchanger phase with solutions of mineral acids and ammonium nitrate and sulfate of various concentrations was studied. New data on the distribution of REMs in these systems were obtained. It was found that it is the most rational to use an ammonium nitrate solution with concentration of 300 g L^–1. It is recommended to precipitate a concentrate of REMs from the resulting desorbate with ammonium carbonate, with the subsequent separation of the suspension by the electrofl otation method.     

Electron microscope investigations on the morphology of aluminium hydroxides

Summary The results are given of an investigation by means of the electron microscope and electron diffraction of the morphology of amorphous aluminium hydroxide and boehmite. The ageing process of amorphous aluminium hydroxide prepared from aluminium nitrate, ammonium alum and amalgamated aluminium was studied.

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Zusammenfassung Untersuchungen im Elektronenmikroskop und mit Elektronenbeugung über die Morphologie vom amorphen Aluminiumhydroxyd und B?hmit werden beschrieben. Die Alterung von amorphem Aluminiumhydroxyd, hergestellt aus Aluminiumnitrat, Ammoniumalaun und amalgamiertem Aluminium wurde untersucht.

     

Thermophysical studies on uranyl nitrate hexahydrate–Iron (III) nitrate nonahydrate system

Individual nitrates, UO₂(NO₃)₂·6H₂O and Fe(NO₃)₃·9H₂O as well as their binary mixtures in various mol ratios have been studied using simultaneous thermal techniques and X-ray powder diffraction measurements. Nature and stoichiometry of hydroxynitrates of iron and uranium were altered by changing the heating rates for the equal mass of binary nitrate mixtures under identical gas flow conditions. Evolved gas analysis and thermogravimetric measurements indicated the absence of direct interaction between two nitrates in the binary nitrate mixtures. Both the nitrates decomposed independently in the mixtures to their respective oxides. These results have been supported by X-ray powder diffraction measurements. Phase diagram of UO₂(NO₃)₂·6H₂O–Fe(NO₃)₃·9H₂O system containing 0–100 mol% of UO₂(NO₃)₂·6H₂O was constructed using differential thermal analysis technique. The formation of the eutectic at 33 °C for 50 mol% uranyl nitrate hexahydrate–50 mol% iron (III) nitrate nonahydrate mixture has been observed for the first time.     

纳米硅铝介孔分子筛的合成及其催化裂化性能

采用低温晶化法一步合成了纳米硅铝介孔分子筛( 记为Z-1),并通过XRD、BET、N2吸/脱附曲线和TEM等手段对其结构性质进行了表征.结果表明:所合成的分子筛具有类似MCM-41的六方结构,较好的介孔特征,孔分布狭窄,纳米级晶粒( 40～50 nm ).用氨气程序升温脱附（NH3-TPD）法测试了其酸强度;并采用脉冲法,以异丙苯和1,3,5-三异丙苯的催化裂化为探针反应,考察了该分子筛的催化裂化性能和水热稳定性.Z-1与后嫁接法制得的AlMCM-41相比,呈现出较高的催化活性、选择性和蒸气稳定性.     

Expeditious oxidation of alcohols to carbonyl compounds using iron(III) nitrate

An efficient and solvent-free protocol for the oxidation of alcohols to corresponding carbonyl compounds using iron(III) nitrate nonahydrate has been developed.     

Thermal behavior of ammonium dinitramide and amine nitrate mixtures

Journal of Thermal Analysis and Calorimetry - This paper focuses on the thermal behavior of mixtures of ammonium dinitramide (ADN) and amine nitrates. Because some mixtures of ADN and amine nitrate...