THE EFFECT OF A FOREIGN SUBSTANCE ON THE TRANSITION: NH4NO3IVNH4NO3 III

1946 ◽  
Vol 24b (4) ◽  
pp. 93-108 ◽  
Author(s):  
Alan N. Campbell ◽  
A. Jean R. Campbell

It is shown that the above transition can be repressed (metastably) by using in place of pure ammonium nitrate a solid solution of potassium nitrate in ammonium nitrate. With such a solid solution containing 8 to 10% potassium nitrate, the temperature of the transition III → IV is depressed to about −20 °C. Such solid solutions can be prepared either by fusing the components together or by crystallizing from a mixed aqueous solution.

1948 ◽  
Vol 26b (6) ◽  
pp. 499-502 ◽  
Author(s):  
John Whetstone

X-ray investigations by means of powder photographs show that solid solution formation between potassium nitrate and ammonium nitrate in simple admixture after grinding together may take place, and is considerably accelerated when the temperature is raised from ordinary temperatures to above 40 °C., at which NH4NO3 III is stable (transition temperature 32 °C.). The preparation of homogeneous mixed crystals of ammonium nitrate and potassium nitrate by co-crystallization of the salts from aqueous solution is described.


Nature ◽  
1961 ◽  
Vol 190 (4782) ◽  
pp. 1190-1191 ◽  
Author(s):  
R. V. COATES ◽  
J. M. CREWE

2019 ◽  
Vol 98 ◽  
pp. 04003
Author(s):  
Guilhem Bourrié ◽  
Jihaine Ben Nacib ◽  
Georges Ona-Nguema ◽  
Fabienne Trolard

As there exists extended solid solutions between ferrous and magnesian silicates, experiments were conducted to check if ferrous and magnesian hydroxides can co-precipitate in a solid solution. Results show that no solid solution forms and instead Fe(II) and Mg(II) hydroxides precipitate separately with the same solubilities as pure components. However, in fougerite, F(III), Fe(II) and Mg(II) coexist in a brucitic type hydroxide, with an extended solid solution. This implies that fougerite formation results from Fe(III) precipitation, Fe(III) being surrounded by divalent Fe(II) and Mg(II) to comply with the exclusion rule: Fe(III) ions cannot be direct neighbours. Consequently, Fe(III) - Fe(II) - Mg(II) smectites cannot form by oxidation of a ferrous magnesian brucitic layer, but by silication of fougerite. The impossibility of formation of a solid solution between Fe(II) hydroxide and Mg(II) hydroxide, while their electric charge and ionic radii are identical can be explained by the differences of electronegativities of the elements. Fe(II) and Mg(II) can dimerize separately in aqueous solution, but an heterodimer cannot form.


2013 ◽  
Vol 85 (11) ◽  
pp. 2089-2095 ◽  
Author(s):  
Erich Königsberger

The importance of solid-solution–aqueous-solution (SSAS) equilibria requires the incorporation of solid solutions into thermodynamic models for industrially and environmentally relevant applications. Insights from appropriate measurements and recent database developments have made such extensions feasible. Examples illustrating various types of stable and metastable equilibria involving solid solutions will be given.


Polymers ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 148
Author(s):  
Hirokazu Fukumoto ◽  
Kazuhiko Ishihara ◽  
Shin-Ichi Yusa

A mixed aqueous solution of hydrophilic poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) and poly(acrylic acid) (PAAc) becomes cloudy under acidic conditions at room temperature. The pendant carboxylic acid groups in PAAc form hydrogen bonds with the ester and phosphate groups in PMPC. While the polymers aggregate under acidic conditions, neither one associate under basic conditions because of the deprotonation of the pendant carboxy groups in PAAc. We observed that the interpolymer complex formed from PMPC, and PAAc was dissociated in aqueous solutions with increasing temperature, which is an upper critical solution temperature behavior. With increasing temperature, the molecular motion increased to dissociate the interpolymer complex. The phase transition temperature increased with increasing polymer and salt concentrations, and with decreasing pH.


Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 640
Author(s):  
Hideaki Sasaki ◽  
Keisuke Sakamoto ◽  
Masami Mori ◽  
Tatsuaki Sakamoto

CeO2-based solid solutions in which Pd partially substitutes for Ce attract considerable attention, owing to their high catalytic performances. In this study, the solid solution (Ce1−xPdxO2−δ) with a high Pd content (x ~ 0.2) was synthesized through co-precipitation under oxidative conditions using molten nitrate, and its structure and thermal decomposition were examined. The characteristics of the solid solution, such as the change in a lattice constant, inhibition of sintering, and ionic states, were examined using X-ray diffraction (XRD), scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM−EDS), transmission electron microscopy (TEM)−EDS, and X-ray photoelectron spectroscopy (XPS). The synthesis method proposed in this study appears suitable for the easy preparation of CeO2 solid solutions with a high Pd content.


2020 ◽  
Vol 58 (1) ◽  
pp. 71-83
Author(s):  
Elahe Mansouri Gandomani ◽  
Nematollah Rashidnejad-Omran ◽  
Amir Emamjomeh ◽  
Pietro Vignola ◽  
Tahereh Hashemzadeh

ABSTRACT Turquoise, CuAl6(PO4)4(OH)8·4H2O, belongs to the turquoise group, which consists of turquoise, chalcosiderite, aheylite, faustite, planerite, and UM1981-32-PO:FeH. In order to study turquoise-group solid solutions in samples from the Neyshabour and Meydook mines, 17 samples were selected and investigated using electron probe microanalysis. In addition, their major elements were compared in order to evaluate the feasibility of distinguishing the provenance of Persian turquoises. The electron microprobe data show that the studied samples are not constituted of pure turquoise (or any other pure endmember) and belong, from the chemical point of view, to turquoise-group solid solutions. In a turquoise–planerite–chalcosiderite–unknown mineral quaternary solid solution diagram, the chemical compositions of the analyzed samples lie along the turquoise–planerite line with minor involvement of chalcosiderite and the unknown mineral. Among light blue samples with varying hues and saturations from both studied areas, planerite is more abundant among samples from Meydook compared with samples from Neyshabour. Nevertheless, not all the light blue samples are planerite. This study demonstrates that distinguishing the deposit of origin for isochromatic blue and green turquoises, based on electron probe microanalysis method and constitutive major elements, is not possible.


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