scholarly journals The chemistry of melting oxynitride phosphate glasses

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Francisco Muñoz
Keyword(s):  
Mechanical Stability ◽  
Glass Network ◽  
Short Review ◽  
Phosphate Glasses ◽  
Oxide Glasses ◽  
Ionic Conductors ◽  
Crystalline Materials ◽  
Composition And Structure ◽  
Bonding Density ◽  
Good Number

Abstract Oxide glasses are the most commonly studied non-crystalline materials in Science and Technology, though compositions where part of the oxygen is replaced by other anions, e.g. fluoride, sulfide or nitride, have given rise to a good number of works and several key applications, from optics to ionic conductors. Oxynitride silicate or phosphate glasses stand out among all others because of their higher chemical and mechanical stability and their research continues particularly focused onto the development of solid electrolytes. In phosphate glasses, the easiest way of introducing nitrogen is by the remelting of the parent glass under a flow of ammonia, a method that allows the homogeneous nitridation of the bulk glass and which is governed by diffusion through the liquid-gas reaction between NH3 and the PO4 chemical groupings. After nitridation, two new structural units appear, the PO3N and PO2N2 ones, where nitrogen atoms can be bonded to either two or three neighboring phosphorus, thus increasing the bonding density of the glass network and resulting in a quantitative improvement of their properties. This short review will gather all important aspects of the synthesis of oxynitride phosphate glasses with emphasis on the influence of chemical composition and structure.

TEM studies of amorphization processes and amorphous structures

1988 ◽  
Vol 46 ◽  
pp. 448-449
Author(s):  
T. E. Mitchell ◽  
R. B. Schwarz
Keyword(s):  
Amorphous Materials ◽  
Fission Products ◽  
Rapid Quenching ◽  
Surface Films ◽  
List Type ◽  
Oxide Glasses ◽  
Crystalline Materials ◽  
Amorphous Structures ◽  
Amorphous Surface ◽  
Interfacial Films

Traditional oxide glasses occur naturally as obsidian and can be made easily by suitable cooling histories. In the past 30 years, a variety of techniques have been discovered which amorphize normally crystalline materials such as metals. These include [1-3]:Rapid quenching from the vapor phase.Rapid quenching from the liquid phase.Electrodeposition of certain alloys, e.g. Fe-P.Oxidation of crystals to produce amorphous surface oxide layers.Interdiffusion of two pure crystalline metals.Hydrogen-induced vitrification of an intermetal1ic.Mechanical alloying and ball-milling of intermetal lie compounds.Irradiation processes of all kinds using ions, electrons, neutrons, and fission products.We offer here some general comments on the use of TEM to study these materials and give some particular examples of such studies.Thin specimens can be prepared from bulk homogeneous materials in the usual way. Most often, however, amorphous materials are in the form of surface films or interfacial films with different chemistry from the substrates.

scholarly journals Development of a New Sr-O Parameterization to Describe the Influence of SrO on Iron-Phosphate Glass Structural Properties Using Molecular Dynamics Simulations

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4326
Author(s):  
Pawel Goj ◽  
Aleksandra Wajda ◽  
Pawel Stoch
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Interatomic Potential ◽  
Glass Structure ◽  
Ion Pairs ◽  
Glass Network ◽  
Iron Phosphate ◽  
Phosphate Glasses ◽  
Potential Applications ◽  
Dynamics Simulations

Iron-phosphate glasses, due to their properties, have many potential applications. One of the most promising seems to be nuclear waste immobilization. Radioactive 90Sr isotope is the main short-lived product of fission and, due to its high solubility, it can enter groundwater and pose a threat to the environment. On the other hand, Sr is an important element in hard tissue metabolic processes, and phosphate glasses containing Sr are considered bioactive. This study investigated the effect of SrO addition on a glass structure of nominal 30Fe2O3-70P2O5 chemical composition using classical molecular dynamics simulations. To describe the interaction between Sr-O ion pairs, new interatomic potential parameters of the Buckingham-type were developed and tested for crystalline compounds. The short-range structure of the simulated glasses is presented and is in agreement with previous experimental and theoretical studies. The simulations showed that an increase in SrO content in the glass led to phosphate network depolymerization. Analysis demonstrated that the non-network oxygen did not take part in the phosphate network depolymerization. Furthermore, strontium aggregation in the glass structure was observed to lead to the non-homogeneity of the glass network. It was demonstrated that Sr ions prefer to locate near to Fe(II), which may induce crystallization of strontium phosphates with divalent iron.

scholarly journals Adhesion and Stability of Nanocellulose Coatings on Flat Polymer Films and Textiles

2020 ◽  
Author(s):  
Raha Saremi ◽  
Nikolay Borodinov ◽  
Amine Mohamed Laradji ◽  
Suraj Sharma ◽  
Igor Luzinov ◽  
...  
Keyword(s):  
Polymer Films ◽  
Food Packaging ◽  
Mechanical Stability ◽  
Polymer Coatings ◽  
High Specific Surface Area ◽  
Force Microscopy ◽  
Polycarboxylic Acids ◽  
Composition And Structure ◽  
Filtration Properties ◽  
Physical And Chemical

Renewable nanocellulose materials received increased attention owing to their small dimensions, high specific surface area, high mechanical characteristics, biocompatibility, and compostability. Nanocellulose coatings are among many interesting applications of these materials to functionalize different by composition and structure surfaces, including plastics, polymer coatings, and textiles with broader applications from food packaging to smart textiles. Variations in porosity and thickness of nanocellulose coatings are used to adjust a load of functional molecules and particles into the coatings, their permeability, and filtration properties. Mechanical stability of nanocellulose coatings in a wet and dry state are critical characteristics for many applications. In this work, nanofibrillated and nanocrystalline cellulose coatings deposited on the surface of polymer films and textiles made of cellulose, polyester, and nylon are studied using atomic force microscopy, ellipsometry, and T-peel adhesion tests. Methods to improve coatings adhesion and stability using physical and chemical cross-linking with added polymers and polycarboxylic acids are analyzed in this study. The paper reports on the effect of the substrate structure and ability of nanocellulose particles to intercalate into the substrate on the coating adhesion.

scholarly journals Thermal properties of Na2O–P2O5–Fe2O3 polyphosphate glasses

2020 ◽  
Vol 142 (1) ◽  
pp. 203-209 ◽  
Author(s):  
Paweł Goj ◽  
Małgorzata Ciecińska ◽  
Magdalena Szumera ◽  
Paweł Stoch
Keyword(s):  
Thermal Properties ◽  
Phosphate Glass ◽  
Transformation Temperature ◽  
Glass Network ◽  
Iron Phosphate ◽  
Phosphate Glasses ◽  
Continuous Change ◽  
Glass Transformation ◽  
Immobilization Techniques ◽  
Iron Phosphate Glasses

Abstract Iron phosphate glasses are materials that can have many applications like durable matrixes in waste immobilization techniques, biomaterials, optoelectronic devices, etc. Their possible usage is related to their glass network and thermal properties. The influence of Na2O content on thermal properties and crystallization ability of iron phosphate glass of base composition 30 Fe2O3–70 P2O5 mol% were studied. Increasing the content of Na2O causes a decrease in transformation temperature and increase in ΔCp. Characteristic temperatures, thermal stability and crystallizing phases were determined. Increasing content of sodium causes depolarization of iron phosphate glass network which causes a continuous change in ΔCp and glass transformation temperature. Discontinuous change in some glass properties suggests structure rebuilding about 30 mol% of Na2O.

scholarly journals Impact of ZnO Addition on Er3+ Near-Infrared Emission, the Formation of Ag Nanoparticles, and the Crystallization of Sodium Fluorophosphate Glass

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 527
Author(s):  
Luukas Kuusela ◽  
Alexander Veber ◽  
Nadia G. Boetti ◽  
Laeticia Petit
Keyword(s):  
Ag Nanoparticles ◽  
Near Infrared ◽  
Glass Network ◽  
Silver Ions ◽  
Heat Treating ◽  
Infrared Emission ◽  
Phosphate Glasses ◽  
Behavior Study ◽  
The Impact ◽  
Near Infrared Emission

The impact of the progressive addition of ZnO up to 5 mol% on the thermal, structural, and optical properties of Er3+-doped phosphate glasses within the system NaPO3-NaF-ZnO-Ag2O is discussed. The glass network was found to depolymerize upon the addition of ZnO. This promotes a slight increase in the intensity of the emission at 1.5 µm as well as enhances the silver ions clustering ability under the heat treating. The Ag-nanoparticles formed after moderate heat-treatment can further enhance the emission at 1.5 µm, whereas an excessive amount of the clusters leads to the opposite effect. The addition of ZnO helps to slightly increase the glass ability of the system. The crystallization behavior study revealed that surface crystallization is observed for all the glasses. It is found that even a small ZnO addition changes the crystalline phases formed after devitrification. Moreover, the addition of ZnO decreases the crystallization tendency of the glass.

The Structure of Salt Doped Superionic Oxide Glasses by Neutron Diffraction

1990 ◽  
Vol 210 ◽  
Author(s):  
L. BÖRjesson
Keyword(s):  
Neutron Diffraction ◽  
Silver Halide ◽  
Glass Network ◽  
Oxide Glasses ◽  
Host Matrix ◽  
Intermediate Range ◽  
Structure Factors ◽  
Extra Peak ◽  
New Type ◽  
Conductivity Models

AbstractComparative neutron diffraction experiments have been performed on metal-halide MX (M = Ag, Li, Na; X = CI, Br, I) doped oxide glasses and their corresponding low conducting host glasses, e.g. M2O-2B2O3 and MPO3. The experiments reveal large changes in the intermediate range structure as the dopant salt is introduced, whereas the short range order of the host matrix is virtually unaffected by the dopant salts. An extra peak at anomalously low Q values (Q = 0.7-0.8 Å-I) appears in the structure factors of the silver-halide glasses which indicates the building up of a new type of intermediate range ordering with a characteristic length of 8-10 Å. The observation is tentatively ascribed to a-microscopic biphase system consisting of an expanded hosi glass network, unaffected on a microscopic scale, in which the silver-halide tends to form microclusters within the voids. In contrast, sodium- and lithiumhalides do not give rise to distinct new features in the structure factor. Instead a considerable smearing out of the first sharp diffraction peak of the host glaiss is observed. This indicates a partial breakdown of the intermediate range ordering of the host matrix. The results are discussed in relation to structure-conductivity models suggested for superionic glasses.

scholarly journals Adhesion and Stability of Nanocellulose Coatings on Flat Polymer Films and Textiles

Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3238
Author(s):  
Raha Saremi ◽  
Nikolay Borodinov ◽  
Amine Mohamed Laradji ◽  
Suraj Sharma ◽  
Igor Luzinov ◽  
...  
Keyword(s):  
Polymer Films ◽  
Food Packaging ◽  
Mechanical Stability ◽  
Polymer Coatings ◽  
High Specific Surface Area ◽  
Force Microscopy ◽  
Polycarboxylic Acids ◽  
Composition And Structure ◽  
Filtration Properties ◽  
Physical And Chemical

Renewable nanocellulose materials received increased attention owing to their small dimensions, high specific surface area, high mechanical characteristics, biocompatibility, and compostability. Nanocellulose coatings are among many interesting applications of these materials to functionalize different by composition and structure surfaces, including plastics, polymer coatings, and textiles with broader applications from food packaging to smart textiles. Variations in porosity and thickness of nanocellulose coatings are used to adjust a load of functional molecules and particles into the coatings, their permeability, and filtration properties. Mechanical stability of nanocellulose coatings in a wet and dry state are critical characteristics for many applications. In this work, nanofibrillated and nanocrystalline cellulose coatings deposited on the surface of polymer films and textiles made of cellulose, polyester, and nylon are studied using atomic force microscopy, ellipsometry, and T-peel adhesion tests. Methods to improve coatings’ adhesion and stability using physical and chemical cross-linking with added polymers and polycarboxylic acids are analyzed in this study. The paper reports on the effect of the substrate structure and ability of nanocellulose particles to intercalate into the substrate on the coating adhesion.

The Polarizability and Optical Characteristics of Zinc Phosphate Glasses Doped Terbium Embedded with Copper Oxide Nanoparticles

2019 ◽  
Vol 290 ◽  
pp. 35-40 ◽  
Author(s):  
Syariffah Nurathirah S. Yaacob ◽  
M.R. Sahar ◽  
E.S. Sazali ◽  
S. Sulhadi
Keyword(s):  
Refractive Index ◽  
Molar Volume ◽  
Zinc Phosphate ◽  
Glass Network ◽  
High Refractive Index ◽  
Copper Oxide Nanoparticles ◽  
Phosphate Glasses ◽  
X Ray Diffraction ◽  
Cuo Nps ◽  
Vis Spectroscopy

Tuning the concentration of nanoparticles (NPs) to accommodate wider application demanded a better understanding of the physicals and structural properties of the glass. A series of zinc phosphate glasses with the composition of (57-x) P2O5- 40ZnO-3Tb2O3 –xCuO, (0 ≤ x ≤ 2 mol %) has been prepared by melt quenching technique and their physical and optical characterization have been studied. The X-Ray Diffraction technique and UV-Vis Spectroscopy have been used to characterize the glass sample. The XRD confirms the amorphous nature of the prepared glasses. The physical properties of glasses with different CuO NPs such as density, molar volume, refractive index and electronic polarizability are determined. It is found that both density and molar volume decreases with increasing CuO NPs concentration. The optical band gap (4.54 eV-2.96 eV) and the Urbach energy (0.19 eV-0.54 eV) are showing a decreasing trend with the increasing amount of CuO NPs.This is due to the formation of non-bridging oxygen, (NBO) in the glass network. The glass exhibits high refractive index ~2.40 and polarizability ~1.12 ×10-23 cm3 and is useful for solid-state laser and optoelectronic devices.

Glass Network Evolution with Bi3+/Ti4+Substitution in Phosphate Glasses Formulated with a Constant Oxygen/Phosphorus Ratio. EXAFS, XANES, and31P Double Quantum MAS NMR

2003 ◽  
Vol 15 (25) ◽  
pp. 4709-4716 ◽  
Author(s):  
Lionel Montagne ◽  
Sylvie Daviero ◽  
Gérard Palavit ◽  
Abdelillah Shaim ◽  
Mohamed Et-Tabirou
Keyword(s):  
Glass Network ◽  
Network Evolution ◽  
Phosphate Glasses ◽  
Mas Nmr ◽  
Double Quantum

Characterization of Aluminophosphate Glasses Containing Pr3+, Er3+, Gd3+ and Yb3+ Ions

2008 ◽  
Vol 39-40 ◽  
pp. 61-64 ◽  
Author(s):  
M. Elisa ◽  
Ileana Cristina Vasiliu ◽  
Cristiana Eugenia Ana Grigorescu ◽  
B. Grigoras ◽  
H. Niciu ◽  
...  
Keyword(s):  
Rare Earth ◽  
Absorption Spectra ◽  
Glass Network ◽  
Phosphate Glasses ◽  
Rare Earth Ions ◽  
Electronic Transitions ◽  
Ir Absorption ◽  
Optical Phonons ◽  
Infra Red ◽  
Aluminophosphate Glasses

A wet non-conventional method for preparing aluminophosphate glasses is presented. Aluminophosphate glasses belonging to the oxide system Li2O-BaO-Al2O3-La2O3-P2O5, doped with rare-earth ions (Pr3+, Er3+, Gd3+, and Yb3+) were obtained. The influence of the doping ions on the optical properties of the phosphate glasses has been investigated in relation with micro-structural and local electronic phenomena The optical behavior of Li2O-BaO-Al2O3-La2O3-P2O5 glasses doped with 3% mol. rare-earth ions has been studied by ultra-violet-visible-near-infra-red (UV-VISNIR) spectroscopy. The transmission spectra revealed electronic transitions between 4f and 6s inner orbital of the rare-earth ions. Structural information via optical phonons was provided by infra-red (IR) absorption spectra in the range 400-4000 cm-1. IR optical phonons are characteristic for the vitreous phosphate network, showing out the glass network-forming role of P2O5. The absorption spectra present the main PO2 and P-O-P symmetrical stretch modes besides P-O-P bend mode, P-OH, P=O, PO3 2-, asymmetrical and symmetrical vibration modes. Fluorescence spectra of the rareearth- doped aluminophosphate glasses, in the visible range, were obtained by laser excitation at 514.5 nm. The fluorescence signals revealed specific electronic transitions, which provide visible and near-infra-red emission. Glasses containing rare-earth ions exhibit luminescence at the following wavelengths: Pr3+ ions at 820 nm and 880 nm, Er3+ ions at 520 nm, 550 nm and 560 nm, Gd3+ ions at 530 nm, 540 nm, 550 nm 820 and 880 nm, Yb3+ions at 530 nm, 540 nm, 550 nm and 980 nm.

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