scholarly journals Structures and Dissolution Behaviors of Quaternary CaO-SrO-P2O5-TiO2 Glasses

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1736
Author(s):  
Sungho Lee ◽  
Fukue Nagata ◽  
Katsuya Kato ◽  
Takayoshi Nakano ◽  
Toshihiro Kasuga
Keyword(s):  
Bone Formation ◽  
Network Structure ◽  
Glass Network ◽  
Chemical Durability ◽  
Phosphate Glasses ◽  
Mixed Composition ◽  
Mixed Cation ◽  
Glass Series ◽  
Strontium Ions ◽  
Quenching Method

Calcium phosphate glasses have a high potential for use as biomaterials because their composition is similar to that of the mineral phase of bone. Phosphate glasses can dissolve completely in aqueous solution and can contain various elements owing to their acidity. Thus, the glass can be a candidate for therapeutic ion carriers. Recently, we focused on the effect of strontium ions for bone formation, which exhibited dual effects of stimulating bone formation and inhibiting bone resorption. However, large amounts of strontium ions may induce a cytotoxic effect, and there is a need to control their releasing amount. This work reports fundamental data for designing quaternary CaO-SrO-P2O5-TiO2 glasses with pyro- and meta-phosphate compositions to control strontium ion-releasing behavior. The glasses were prepared by substituting CaO by SrO using the melt-quenching method. The SrO/CaO mixed composition exhibited a mixed cation effect on the glassification degree and ion-releasing behavior, which showed non-linear properties with mixed cation compositions of the glasses. Sr2+ ions have smaller field strength than Ca2+ ions, and the glass network structure may be weakened by the substitution of CaO by SrO. However, glassification degree and chemical durability of pyro- and meta-phosphate glasses increased with substituted all CaO by SrO. This is because titanium groups in the glasses are closely related to their glass network structure by SrO substitution. The P-O-Ti bonds in pyrophosphate glass series and TiO4 tetrahedra in metaphosphate glass series increased with substitution by SrO. The titanium groups in the glasses were crosslink and/or coordinate phosphate groups to improve glassification degree and chemical durability. Sr2+ ion releasing amount of pyrophosphate glasses with >83% SrO substitution was larger than 0.1 mM at day seven, an amount that reported enhanced bone formation by stimulation of osteogenic markers.

scholarly journals Elaboration and characterization of new phosphate glasses based on natural phosphate and red clay: influence of the chemical composition on the chemical durability

2019 ◽  
Vol 9 (3) ◽  
pp. 222-235 ◽  
Author(s):  
Oumaima Jamal Eddine ◽  
Mehdi El Bouchti ◽  
Omar Cherkaoui ◽  
Hassan Hannache ◽  
Said Gmouh
Keyword(s):  
Chemical Composition ◽  
Structural Investigation ◽  
Fluorescence Analysis ◽  
Chemical Durability ◽  
Phosphate Glasses ◽  
Red Clay ◽  
Natural Phosphate ◽  
X Ray ◽  
Quenching Method

New phosphate glass formulations based on Moroccan natural phosphate minerals alone or with Moroccan red clay additive (containing the P2O5-SiO2-CaO-Al2O3-MgO-Fe2O3-K2O-Na2O-TiO2 complex) have been successfully prepared by the quenching method. The chemical composition of each of the elaborated phosphate glasses was determined by X-ray fluorescence analysis (XRF). These investigated phosphate glasses have an excellent homogeneity as was verified by SEM. Their amorphous behavior was confirmed by XRD and DSC. The increase in density and glass transition temperature due to the addition of clay is believed to be related to the crosslinking of the phosphate chains. Structural investigation of these phosphate glasses was carried out using FTIR and Raman spectroscopies. The results obtained show that the composition of these glasses contains a mixture of ultraphosphate and polyphosphate structural units. The concentrations of this mixture depending on the initial composition of the glass components. A correlation between the chemical composition and the chemical durability of the investigated glasses was studied. The results showed that the dissolution rate of the glasses decreases by increasing the clay composition up to a point. This can be explained by assuming the formation of oxygen bridges and strong bonds within the various glasses.

scholarly journals Elaboration and structural characterization of phosphate glasses with composition 37.5Na2O-25[(1-x)MgO-xNiO]-37.5P2O5 (0≤x≤1)

2018 ◽  
Vol 7 (6) ◽  
pp. 416-422 ◽  
Author(s):  
Laila Lamrous ◽  
Redouane Farid ◽  
Abdelaziz El Jazouli ◽  
Saida Krimi ◽  
Mustapha Haddad ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Structure ◽  
Chemical Properties ◽  
Glass Network ◽  
Chemical Durability ◽  
Phosphate Glasses ◽  
Melt Quenching ◽  
Physico Chemical

Phosphate glasses, with molar compositions 37.5Na2O-25[(1-x)MgO-xNiO]-37.5P2O5 (0 ≤ x ≤ 1), have been prepared using the conventional melt quenching technique. The free nickel glass is colorless while the glasses containing nickel are yellow. The effect of Ni2+ ions on structural and physico-chemical properties of these glasses has been investigated by XRD, DTA, EPR, Raman, FTIR spectroscopies and by density and chemical durability measurements. Substitution of Ni2+ for Mg2+ strengthens the glass network, as shown by the decrease of the molar volume, the increase of the glass transition temperature, and the improvement of the chemical durability. This behavior is a consequence of the replacement of Mg-O bonds by more covalent Ni-O bonds. The glass structure consists of tri-phosphate (P3O10) 5- and di-phosphate (P2O7) 4- groups, and Mg/NiO6 octahedra, with Mg-O-P and Ni-O-P linkages.

Electronic-Ionic Conductivity of Lithium- Vanado- Phosphate Glasses

2017 ◽  
Vol 14 (1) ◽  
pp. 9-14
Author(s):  
Eraiah B
Keyword(s):  
Activation Energy ◽  
Ionic Conductivity ◽  
Structural Changes ◽  
Glass Network ◽  
Phosphate Glasses ◽  
Melt Quenching ◽  
Calculated Activation Energy ◽  
Quenching Method ◽  
Increasing Temperature ◽  
Calculated Activation

The new glassesof glass system x Li 2 O-50 V 2 O 5 -(50-x) P 2 O 5 were prepared by using conventional melt quenching method. The densities of these glasses have been measured by Archimedes method and corresponding molar volumes have also been calculated. The conductivity of these glasses was measured as a function of temperature and composition. The variations of conductivity versus temperature follow Arrehenius type relationship. Conductivity decreases with increasing Li 2 O content and increase with increasing temperature. The calculated activation energy decreases up to 15mol% of Li 2 O, it increases from 15mol% to 30 mol% of Li 2 O and again it suddenly drops at 40 mol% of Li 2 O. This may be due to structural changes in glass network and these glasses exhibit both electronic and ionic conductivity.

The Effect of Al2O3/SiO2 on the Structure and Properties of Na2O-CaO-Al2O3-SiO2 Glasses

2012 ◽  
Vol 509 ◽  
pp. 339-345 ◽  
Author(s):  
Jun Xie ◽  
Zi Fan Xiao ◽  
Wei Hong Zheng ◽  
Ye Liu ◽  
Jin Shu Cheng
Keyword(s):  
Network Structure ◽  
Bending Strength ◽  
Chemical Properties ◽  
Glass Network ◽  
Soda Lime ◽  
Chemical Durability ◽  
Structure And Properties ◽  
Structure Of Glasses ◽  
Strength Tests ◽  
Thermo Stability

In the paper, a series of Na2O-CaO-Al2O3-SiO2 system glasses following similar compositions to the soda-lime-silicate float glasses and possessing more excellent physi-chemical properties were prepared with different Al2O3/SiO2 ratio. The structure of glasses have been studied by IR and density tests. The investigation of Al2O3/SiO2 on the performance was carried out by bending strength tests, linear dilatometry and chemical durability tests in aqueous and alkaline environment. The results showed that the number of no bridging oxygens decreased with increasing the Al2O3/SiO2 ratio, the glass network structure and density increased, which leading to enhance the bending strength, thermo-stability and chemical durability of glass.

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.

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.

Network structure of tellurite phosphate glasses: Optical absorption and infrared spectra

1993 ◽  
Vol 73 (1) ◽  
pp. 71-74 ◽  
Author(s):  
A. Abdel‐Kader ◽  
R. El‐Mallawany ◽  
M. M. ElKholy
Keyword(s):  
Optical Absorption ◽  
Infrared Spectra ◽  
Network Structure ◽  
Phosphate Glasses

Silver Nanoparticles Included Er3+/Sm3+ Co-Doped Phosphate Glass: Evaluation of Thermal Stability and Infrared Absorption

2017 ◽  
Vol 268 ◽  
pp. 62-66 ◽  
Author(s):  
S. Rashidah Misron ◽  
Ramli Arifin ◽  
Sib Krishna Ghoshal
Keyword(s):  
Thermal Stability ◽  
Phosphate Glass ◽  
Infrared Absorption ◽  
Glass Network ◽  
Ir Absorption ◽  
Ag Nps ◽  
Bending Vibrations ◽  
Host Matrix ◽  
Stretching Vibrations ◽  
Quenching Method

Three lithium-sodium-phosphate glass samples with molar composition of (48.5–x)P2O5-20Na2O-30Li2O-0.5Sm2O3-1.0Er2O3-xAgNPs (where x = 0.01 g, 0.03 g and 0.05 g) are prepared using melt quenching method. The thermal stability and infrared absorption of synthesized samples are evaluated as a function of Ag NPs contents. Thermal and structural characterizations are made using differential thermal analysis (DTA) and Fourier transformed infrared (FTIR) spectroscopy, respectively. Thermal stability is found to vary in the range of 171 °C to 197 °C. FTIR spectra revealed various characteristic bonding vibrations related to the glass network structures. The IR absorption band around 570 cm-1 is assigned to the P-O-P bending vibrations while the occurrence of bands around 759 cm-1 and 913 cm-1 are allocated to the P-O-P symmetric stretching vibrations. The asymmetric stretching vibrations of (PO3)2- and (PO2)- units are observed around 1045 cm-1 and 1254 cm-1 , respectively. The appearance of a band around 1735 cm-1 is allocated to the free H2O molecules because of moisture attack to the sample. Influences of Ag NPs in the host matrix are analyzed and explained.

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