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Search Results: 1 - 10 of 3840 matches for " phosphate glass "
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Elaboration and Structural Investigation of Iron (III) Phosphate Glasses  [PDF]
Said Aqdim, Malika Ouchetto
Advances in Materials Physics and Chemistry (AMPC) , 2013, DOI: 10.4236/ampc.2013.38046
Abstract:

The regular melting-quenching method allowed isolating very large vitreous domains within the ternary system Li2O-P2O5-Fe2O3 at 1100. The vitrification and crystallization effects are discussed in terms of phosphorus pentaoxide concentration (mol%). In the course of the present study, we analyzed chemical durability along the glass domain and many sample glasses were isolated. We noticed that our compounds demonstrated very high chemical resistance to attack, even with very highly concentrated mineral acid solutions. This behavior can be assigned to the presence of poorly crystalline phases in these glasses, which tended to increase as the Fe2O3 content increased. This property is a prerequisite for many interesting industrial applications. XRD, IR spectroscopy and SEM micrographs allowed an efficient investigation of the structural changes versus composition within ternary diagrams. The results were found to be consistent with the regular structural changes of phosphate glasses.

Crystallization Kinetics of Melt-Blended Low-Density Phthalic Anhydride with a Low-Tg Tin-Phosphate  [PDF]
Laila M. Al-Harbi
Open Journal of Polymer Chemistry (OJPChem) , 2014, DOI: 10.4236/ojpchem.2014.43005
Abstract:

Polyamide prepared by the reaction of ethylene diamine with different ratios between 1,6-glyconic acid and phthalic anhydride. The differential scanning calorimetry (DSC) is used to study the nonisothermal and isothermal crystallization of low density polyamides in phosphate glass (Pglass)-polymer hybrid blends. The % crystallinity decreased as the Pglass volume increased. The half-life (t1/2) for crystallization decreased as the propagation rate constant rose for both the polymer matrices with increasing Pglass concentrations. The results show that the Pglass is improved nucleating agent for formation of the Pglass-polymer hybrids up to 35% Pglass and the energy necessary to break decreased. The stability of the reaction of ethylene diamine with phthalic anhydride and glyconic acid was qualitatively investigated using molecular orbital calculations.

Hybrid Composites of Phosphate Glass Fibre/Nano-Hydroxyapatite/Polylactide: Effects of Nano-Hydroxyapatite on Mechanical Properties and Degradation Behaviour  [PDF]
Lizhe He, Chenkai Zhu, Jiahao Wu, Xiaoling Liu
Journal of Materials Science and Chemical Engineering (MSCE) , 2018, DOI: 10.4236/msce.2018.611002
Abstract: Hydroxyapatite/polylactide (HA/PLA) composites have been intensively investigated for their potential as biodegradable fixation devices to heal bone fractures. However, most of these composites failed to achieve a bone-mimicking level of mechanical properties, which is an essential demand of the targeted application. In this study, the nano-hydroxyapatite/polylactide composites were used as the matrix and continuous phosphate glass fibres (PGF) served as the major reinforcement to obtain the nano-HA/PGF/PLA hybrid composites. While the PGF volume fraction remained constant (25%), the nano-HA content (in weight) varied from 0% to 20%. As nano-HA loading increased, the flexural modulus of the composites increased from 8.70 ± 0.35 GPa to 14.97 ± 1.30 GPa, and the flexural strengths were enhanced from 236.31 ± 10.83 MPa to 310.55 ± 22.88 MPa. However, it is found that the degradation rates are higher with more nano-HA loaded. Enhanced water absorption ability, as well as increased voids in the composites is possible reasons for the accelerated degradation of composites with higher nano-HA loading. The hybrid composites possess mechanical properties that are superior to most of the HA/PLA composites in previous research while maintaining the biodegradability. With a proper loading of nano-HA in composites of 10 weight percent, the composites are also found with improved mechanical properties without catastrophic degradation. The composites developed in this study have great potential as biodegradable bone fixation device with enhanced load-bearing ability as confirmed and superior bioactivity as anticipated.
Study of a new ytterbium doped phosphate laser glass
Shixun Dai,Lili Hu,A. Sugiyama,Y. Izawa,Zhuping Liu,Zhonghong Jiang
Chinese Science Bulletin , 2002, DOI: 10.1360/02tb9062
Abstract: Physical, and spectral properties of a new commercial ytterbium doped phosphate laser glass with big size, NEW/Yb, was researched. Assessing from thermal mechanical property, nonlinear property, crystalline phase, micro defects and spectroscopic properties of NEW/Yb and Kigre’s QX/Yb glasses, it is found that thermal-optical properties and glass internal quality of NEW/Yb glass are superior to QX/Yb glass. For NEW/Yb, the emission cross-section and fluorescent lifetime have a value of 0.53×10 pm2 and 2.2 ms, which are higher than those of QX/Yb.
Study of a new ytterbium doped phosphate laser glass

DAI Shixun,HU Lili,A Sugiyama,Y Izawa,LIU Zhuping,JIANG Zhonghong,

科学通报(英文版) , 2002,
Abstract: Physical, and spectral properties of a new commercial ytterbium doped phosphate laser glass with big size, NEW/Yb, was researched. Assessing from thermal mechanical property, nonlinear property, crystalline phase, micro defects and spectroscopic properties of NEW/Yb and Kigre's QX/Yb glasses, it is found that thermal-optical properties and glass internal quality of NEW/Yb glass are superior to QX/Yb glass. For NEW/Yb, the emission cross-section and fluorescent lifetime have a value of 0.53×10 pm2 and 2.2 ms, which are higher than those of QX/Yb.
Thermodynamic study on elimination of platinum inclusions in phosphate laser glasses for inertial confinement fusion applications
Qinyuan Zhang,Lili Hu,Zhonghong Jiang
Chinese Science Bulletin , 1999, DOI: 10.1007/BF03182732
Abstract: A new method to calculate the formation enthalpies and free energies of compounds based on standard electromotive force of cation, φ0, and free energies of formation, G 298 0 , or formation enthalpies, H 298 0 , of chloride was proposed. A linear relationship between φ0 and G 298 0 , φ0 and H 298 0 , and G 298 0 , and H 298 0 was found respectively. The parameters used for thermodynamic calculation were calculated. The calculated values of the formation enthalpies and the free energies of formation of platinum compounds, such as Pt3,(PO4 21, and Pt(PO3)2, were given for the first time. The mechanism of eliminating platinum inclusions in phosphate laser glass by POCl3, gas bubbling was interpreted from thermodynamic aspect.
Thermodynamic study on elimination of platinum inclusions in phosphate laser glasses for inertial confinement fusion applications

Qinyuan Zhang,Lili Hu,Zhonghong Jiang,

科学通报(英文版) , 1999,
Abstract: A new method to calculate the formation enthalpies and free energies of compounds based on standard electromotive force of cation, φ0, and free energies of formation, G2980, or formation enthalpies, H 2980, of chloride was proposed. A linear relationship between φ0 and G2980, φ0 and H 298 0, and G2980, and H 2980 was found respectively. The parameters used for thermodynamic calculation were calculated. The calculated values of the formation enthalpies and the free energies of formation of platinum compounds, such as Pt3,(PO4 21, and Pt(PO3)2, were given for the first time. The mechanism of eliminating platinum inclusions in phosphate laser glass by POCl3, gas bubbling was interpreted from thermodynamic aspect.
Effect of Both Acid and Base Etching on Phosphate Laser Glass Surfaces
ZHANG Lei, HUANG Li, DING Jia, CHEN Hui-Yu, CHEN Wei, HU Li-Li
无机材料学报 , 2012, DOI: 10.3724/sp.j.1077.2012.00627
Abstract: The effect of chemical etching processes on phosphate laser glass surfaces was investigated. Under different process conditions (e.g. sonication and agitation), conventionally polished and subsequently washed phosphate glass plates were treated by submerging in both HCl and KOH solution either with or without BaCl2. Subsequently, Raman spectra and X―ray photoelectron spectroscope (XPS) of the treated surfaces were measured. The precipitation of metal cations and depolymerization of the glass network structure are the two main chemical reactions in both solutions: One refers to the substitution of P―O―H for P―O―M, the other is that the Q2 tetrahedra, the basic structural unit of the original metaphosphate glass, has gradually been replaced by the Q1 or Q0 tetrahedra. Finally, the reaction models of phosphate laser glasses dissolved in both HCl and KOH solution are proposed.
Surface Treatment of P2O5-BaO-Al2O3-K2O Phosphate Laser Glass
YANG Gang,QIAN Qi,YANG Zhong-Min
无机材料学报 , 2010, DOI: 10.3724/sp.j.1077.2010.00196
Abstract: The surface of P2O5-BaO-Al2O3-K2O phosphate glass was modified by using both a chemical etching process and a subsequent high-temperature heat treatment, which can effectively remove the surface defects of phosphate glass and the surface contaminations caused by traditional polishing technology. The process of etching phosphate glass in hydrochloric acid was studied to investigate the etching mechanism and determine the etching optimum conditions. It is found that the etching reactions between hydrochloric acid and glass make the phosphate glass surface smooth while a crystal layer is formed on the glass surface. The optimum etching process is as follows, etching in a 9mol/L HCl solution for 30min. After further heating the glass at 550℃, the crystal layer can be removed as crystal particles on glass surface melt, which results in the increase of the transmittance of glass. The results show that a process combining chemical etching the phosphate glass with subsequent heating treatment is an effective method to improve the surface quality of the phosphate glass.
Chemical Durability and Structural Proprieties of the Vitreous Part of the System xCaO-(40-x)ZnO-15Na2O-45P2O5  [PDF]
Zineb Chabbou, Said Aqdim
Advances in Materials Physics and Chemistry (AMPC) , 2014, DOI: 10.4236/ampc.2014.410021
Abstract: The influence of CaO on the glass forming characteristics and properties of Na2O-CaO-ZnO-P2O5 glasses has been investigated. According to the studies that we performed on phosphate based glass within system xCaO-(40-x)ZnO-15Na2O-45P2O5 (10 ≤ x ≤ 30; mol%), it was found that the increase of CaO and substitution of ZnO can give a good chemical durability. Both Cristallographies X-ray and IR spectroscopy have confirmed the structure change when the CaO content increases in the glass. This change results in the formation of metaphosphate and/or rings of metaphosphate groups at the expense of pyrophosphate. So it indicates the formation of Ca-O-P bonds in the network glass that replaces hydrated P-O-Na and P-O-P bands. The phosphate chains units can be bonded together in rings forming meta-phosphate groups. These rings likely lead to the formation of agglomerates of crystalline phases, which is the main cause of the increase in the chemical durability of the glasses when the CaO content increases. The latter may lead to wider use of these materials, especially in the biomedical field.
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