scholarly journals Effect of V2O5 on crystallization tendency and chemical durability of Mo-bearing aluminoborosilicate glass

2020 ◽  
Vol 7 (4) ◽  
pp. 045201
Author(s):  
Qihui Lian ◽  
Xingquan Zhang ◽  
Hongjia Ji ◽  
Pengpeng Yu ◽  
Xiaofeng Guo ◽  
...  
Keyword(s):  
Chemical Durability ◽  
Aluminoborosilicate Glass ◽  
Crystallization Tendency

Phase separation in sol gel-derived ceramic films of silica-zirconia, alumina-zirconia, and titania-zirconia system

1994 ◽  
Vol 52 ◽  
pp. 646-647
Author(s):  
J. Tong ◽  
L. Eyring
Keyword(s):  
Fracture Toughness ◽  
Phase Separation ◽  
Sol Gel ◽  
Great Influence ◽  
High Strength ◽  
Chemical Durability ◽  
Separation Method ◽  
Toughening Mechanism ◽  
Ceramic Films ◽  
Zirconia Toughened Alumina

There is increasing interest in composites containing zirconia because of their high strength, fracture toughness, and its great influence on the chemical durability in glass. For the zirconia-silica system, monolithic glasses, fibers and coatings have been obtained. There is currently a great interest in designing zirconia-toughened alumina including exploration of the processing methods and the toughening mechanism.The possibility of forming nanocrystal composites by a phase separation method has been investigated in three systems: zirconia-alumina, zirconia-silica and zirconia-titania using HREM. The morphological observations initially suggest that the formation of nanocrystal composites by a phase separation method is possible in the zirconia-alumina and zirconia-silica systems, but impossible in the zirconia-titania system. The separation-produced grain size in silica-zirconia system is around 5 nm and is more uniform than that in the alumina-zirconia system in which the sizes of the small polyhedron grains are around 10 nm. In the titania-zirconia system, there is no obvious separation as was observed in die alumina-zirconia and silica-zirconia system.

scholarly journals Comparative Physical Study of Three Pharmaceutically Active Benzodiazepine Derivatives: Crystalline versus Amorphous State and Crystallization Tendency

2021 ◽  
Vol 18 (4) ◽  
pp. 1819-1832
Author(s):  
Sofia Valenti ◽  
Maria Barrio ◽  
Philippe Negrier ◽  
Michela Romanini ◽  
Roberto Macovez ◽  
...  
Keyword(s):  
Amorphous State ◽  
Physical Study ◽  
Benzodiazepine Derivatives ◽  
Crystallization Tendency

Preparation of Calcium Phosphate Glasses Containing Nb2O5 and TiO2

2018 ◽  
Vol 782 ◽  
pp. 47-52
Author(s):  
Patrícia Suemi Sato ◽  
Hirotaka Maeda ◽  
Akiko Obata ◽  
Toshihiro Kasuga
Keyword(s):  
Controlled Release ◽  
Calcium Phosphate ◽  
Calcium Titanate ◽  
Chemical Durability ◽  
Phosphate Glasses ◽  
Dissolution Test ◽  
Buffer Solution ◽  
High Chemical ◽  
Positive Effects ◽  
Tris Buffer Solution

60CaO-30P2O5-(10 ̶ x)Nb2O5-xTiO2 (x = 0 ~ 10, mol%) glasses were prepared in order to obtain biomaterials with high chemical durability and therapeutic ions releasability. Dissolution test of these glasses using Tris buffer solution showed the controlled release of niobate ions from Nb2O5-containing glasses and the formation of calcium titanate in some of them. These behavior might induce positive effects for bone regeneration.

INFLUENCE OF La2O3 ADDITIONS ON CHEMICAL DURABILITY AND DIELECTRIC PROPERTIES OF BOROALUMINOSILICATE GLASSES

2012 ◽  
Vol 19 (06) ◽  
pp. 1250062 ◽  
Author(s):  
X. H. ZHANG ◽  
Y. L. YUE ◽  
H. T. WU
Keyword(s):  
Dielectric Properties ◽  
Chemical Durability ◽  
Tangent Loss ◽  
Frequency Range ◽  
Scanning Calorimetry ◽  
Glass Transition Temperatures ◽  
Weight Losses ◽  
Quenching Method ◽  
Scanning Electron

Boroaluminosilicate glasses containing La2O3 were prepared by the normal quenching method. The glass transition temperatures (Tg) were measured by differential scanning calorimetry (DSC). The structural role of RO was investigated by nuclear magnetic resonance (NMR). Chemical durability was evaluated by weight losses of glass samples after immersion in HC1 solution. High resolution scanning electron microscopy (HR-SEM) was used to examine the surface micrographs of corroded glass samples. The dielectric constant and tangent loss were measured in the frequency range 10–106 Hz. The results revealed that chemical durability and dielectric properties increased with increasing La2O3 content.

Applicability of Iron Phosphate Glass Medium for Loading NaCl Originated From Seawater Used for Cooling the Stricken Power Reactors

2013 ◽  
Author(s):  
Hidekazu Kobayashi ◽  
Ippei Amamoto ◽  
Takuma Yokozawa ◽  
Teruo Yamashita ◽  
Takayuki Nagai ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Glass Transition ◽  
Phosphate Glass ◽  
Glass Formation ◽  
Coefficient Of Thermal Expansion ◽  
Glass Melting ◽  
Glass Network ◽  
Iron Phosphate ◽  
Chemical Durability ◽  
Raw Material

As the part of investigation for immobilization of the sludge as one of the radioactive wastes arising from the treatment of contaminated water at Fukushima Dai-ichi nuclear power plant, applicability of vitrification method has been evaluated as a candidate technique. The aim of this study is to evaluate the influence of NaCl as one of the main constituents of sludge, on glass formation and glass properties. Two kinds of iron phosphate glass (IPG) media in the xFe2O3-(100-x)P2O5, with x = 30 and 35 (mol%) were chosen and the glass formation, structure and properties including density, coefficient of thermal expansion, glass transition temperature, onset crystallization temperature and chemical durability of NaCl-loaded IPG were studied. The results are summarized as follows. Sodium chloride, NaCl could be loaded into IPG medium as Na2O and Cl contents and their loading ratio could be up to 19 and 15 mol%, respectively. Majority of Cl content of raw material NaCl was thought to be volatilized during glass melting. Loading NaCl into IPG induces to depolymerize glass network of phosphate chains, leads to decrease both glass transition and onset crystallization temperatures, and to increase coefficient of thermal expansion. NaCl-loaded IPG indicated good chemical durability in case of using 35Fe2O3-65P2O5 medium.

Solubility, structure transition and chemical durability of Th-doped Nd2Zr2O7 pyrochlore

2021 ◽  
Vol 137 ◽  
pp. 103774
Author(s):  
Lielin Wang ◽  
Jiangbo Li ◽  
Hua Xie ◽  
Qingyun Chen ◽  
Yuqi Xie
Keyword(s):  
Chemical Durability ◽  
Structure Transition

Aluminophosphate Glasses with High Sulfate Content

1994 ◽  
Vol 353 ◽  
Author(s):  
Sergey V. Stefanovsky ◽  
Igor A. Ivanov ◽  
Anatolii N. Gulin
Keyword(s):  
Diffusion Coefficients ◽  
Glass Structure ◽  
Chemical Durability ◽  
Electric Resistivity ◽  
Melting Points ◽  
Sulfate Content ◽  
Leach Rate ◽  
High Sulfate ◽  
Aluminophosphate Glasses ◽  
And Diffusion

AbstractTo immobilize a high sulfate radioactive wastes a system Na2O-A12O3-P2O5-SO3 has been chosen as one where glasses have a relatively low melting points and good chemical durability. Glasses within partial system 44 Na2O, 20 A12O3 (36-x) P2O5 x SO3 have been prepared at 1000 °C. A possibility of assimilation up to 12 mole % of SO3 has been established. The basic properties of sulfate-containing glasses as density, microhardness, thermal expansion coefficient, transformation and deformation temperatures, viscosity, electric resistivity, leach rate of ions and diffusion coefficients of 22Na, 35S, 90Sr and 137Cs have been measured. Glass structure by infrared and EPR spectroscopies has been investigated.

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