The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
Alida Bellosi - One of the best experts on this subject based on the ideXlab platform.
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Doped calcium–Aluminium–Phosphate cements for biomedical applications
Journal of Materials Science: Materials in Medicine, 2011Co-Authors: Valentina Medri, Marco Mazzocchi, Alida BellosiAbstract:Calcium–Aluminium–Phosphate cements (CAPCs) for biomedical applications, mainly intended for applications in the dental field as non-resorbable fillers, were obtained by reacting Ca-aluminates compounds, i.e. CaO·Al_2O_3 (CA) and CaO·2 Al_2O_3 (CA_2), with Al(H_2PO_4)_3 aqueous solution. Hydroxyapatite was also introduced as a bioactive dispersed phase. Suitable elements like Sr and La were used to increase the radiopacity of the set yielded pastes towards X-ray wavelength used in clinical diagnostic radiographic equipments. La and Sr doped Ca-aluminates powders have been synthesized by solid state reaction at 1,400°C from a mixture of CaCO_3, Al_2O_3, La_2O_3 and SrCO_3. The characteristics of the obtained powders were analyzed and related to the starting compositions and synthesis procedures. The microstructure, setting time, radiopacity and compressive strength of the CAPCs have been investigated and discussed.
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doped calcium Aluminium Phosphate cements for biomedical applications
Journal of Materials Science: Materials in Medicine, 2011Co-Authors: Valentina Medri, Marco Mazzocchi, Alida BellosiAbstract:Calcium–Aluminium–Phosphate cements (CAPCs) for biomedical applications, mainly intended for applications in the dental field as non-resorbable fillers, were obtained by reacting Ca-aluminates compounds, i.e. CaO·Al2O3 (CA) and CaO·2 Al2O3 (CA2), with Al(H2PO4)3 aqueous solution. Hydroxyapatite was also introduced as a bioactive dispersed phase. Suitable elements like Sr and La were used to increase the radiopacity of the set yielded pastes towards X-ray wavelength used in clinical diagnostic radiographic equipments. La and Sr doped Ca-aluminates powders have been synthesized by solid state reaction at 1,400°C from a mixture of CaCO3, Al2O3, La2O3 and SrCO3. The characteristics of the obtained powders were analyzed and related to the starting compositions and synthesis procedures. The microstructure, setting time, radiopacity and compressive strength of the CAPCs have been investigated and discussed.
N. Sangwaranatee - One of the best experts on this subject based on the ideXlab platform.
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Effect of Alkali Oxides on Luminescence Properties of Eu3+-doped Aluminium Phosphate Glasses
Materials Today: Proceedings, 2019Co-Authors: Natthakridta Chanthima, N. Sangwaranatee, Y. Tariwong, Jakrapong KaewkhaoAbstract:Abstract Trivalent europium doped Aluminium Phosphate glasses with different alkali oxides (Li2O, Na2O and K2O) have been prepared by melt quenching technique at 1200 °C. Photoluminescence properties of the obtained glasses have been studied and characterized. Also, Absorption and radiative properties of glasses are evaluated using the Judd–Ofelt (JO) theory. The emission spectra of all glasses remain the characteristic emission peak of Eu3+ with a dominant peak at 612 nm, corresponding to the 5D0 → 7F2 transition by monitoring an excitation wavelength at 393 nm. In the present glass system it was found that lithium oxide has higher intensity of emission spectra than sodium oxide and potassium oxide. The JO intensity parameters (Ω2, Ω4, Ω6) and subsequent radiative properties for the 5D0 → 7FJ (J = 1,2,3,4) transitions are determined. These glasses have potential candidate in the development as red laser source applications.
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Effect of Eu3+ Ions on the Physical, Optical and Luminescence Properties of Aluminium Phosphate Glasses
Key Engineering Materials, 2018Co-Authors: Natthakridta Chanthima, Y. Tariwong, Jakrapong Kaewkhao, N. SangwaranateeAbstract:The physical, optical and luminescence properties of lithium Aluminium Phosphate glasses different doping europium oxide have been investigated to evaluate their properties for solid-state lighting applications. The density and molar volume measurements were carried out at room temperature. The absorption spectra were investigated in the UV-Vis-NIR region from 250 to 2500 nm. The emission spectra, excited with 394 nm excitation wavelength showed four emission transitions corresponding to 5D0→7F1 (591 nm), 5D0→7F2 (612 nm), 5D0→7F3 (648 nm) and 5D0→7F4 (698 nm). The optimal concentration of Eu2O3 in lithium Aluminium Phosphate glasses was 1.00 mol%.
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Effect of alkali oxide on optical and luminescence properties of Sm 3+ doped Aluminium Phosphate glasses
Materials Today: Proceedings, 2018Co-Authors: N. Sangwaranatee, Natthakridta Chanthima, Y. Tariwong, Jakrapong KaewkhaoAbstract:Abstract Physical, optical and luminescence properties of lithium Aluminium Phosphate (LAPSm), sodium Aluminium Phosphate (NAPSm) and potassium Aluminium Phosphate (KAPSm) glasses doped with 0.5 mol% of Sm2O3 have been investigated. The results found that all glass samples are clear, homogenous and transparency. The optical absorption spectra are shown strong absorption bands in the visible (VIS) and near-infrared (NIR) region for all doped samples. The emission spectra of all doped glass samples exhibited four peaks correspond to the energy transition 4G5/2 → 6H5/2 (562 nm), 4G5/2 → 6H7/2 (597 nm), 4G5/2 → 6H9/2 (644 nm) and 4G5/2 → 6H11/2 (704 nm) have been observed under 401 (6H5/2 → 6P3/2) nm excitation wavelength. Also, the CIE chromaticity analysis yields reddish-orange light emission for all glass samples. It was observed that the emission intensity LAPSm glass is higher than NAPSm and KAPSm glasses. Hence LAPSm glass could be considered as a good optical glass for Sm3+ dopant for reddish-orange emission material.
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Physical, optical and luminescence properties of Sm 3+ doped lithium Aluminium Phosphate glass system
Materials Today: Proceedings, 2018Co-Authors: Natthakridta Chanthima, Y. Tariwong, Jakrapong Kaewkhao, Mitra Djamal, N. SangwaranateeAbstract:Abstract Sm3+ doped lithium Aluminium Phosphate glasses have been investigated in different concentration of Sm3+ ions. The physical, optical and luminescence properties were studied to evaluate their potential to using as orange color emitting materials. The result of physical properties indicated that the density, the molar volume and the refractive index of glass samples were increased with an increase of Sm2O3 content. The absorption spectra of glass samples were recorded in the wavelength range of 250-2000 nm. The absorption bands centered at 401, 473, 947, 1080, 1232, 1379, 1482 and 1532 nm have been observed. From the photoluminescence spectra, the glasses are showed strong emission at 597 nm which corresponds to 4G5/2→6H7/2 transition under excitation wavelength at 401 nm. The optimal concentration of Sm2O3 in lithium Aluminium Phosphate glasses was 0.5 mol%.
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Luminescence properties and Judd-Ofelt analysis of Sm3+ doped lithium Aluminium Phosphate glasses
Materials Today: Proceedings, 2018Co-Authors: Natthakridta Chanthima, N. Sangwaranatee, Y. Tariwong, Jakrapong Kaewkhao, Mitra DjamalAbstract:Abstract Lithium Aluminium Phosphate glasses doped with samarium oxide were prepared by melt-quenching technique and investigated their physical, optical and luminescence properties. The result of physical properties indicated that the density and the molar volume of glass samples were increased with an increase of Sm 2 O 3 content. The absorption spectra of glass samples were recorded in the wavelength range of 250-2000 nm, these glasses have shown strong absorption bands in the visible (Vis) and near-infrared (NIR) region at 401 and 1232 nm. The emission spectra of glasses, excited with 401 nm excitation wavelength showed four emission bands centered at 561, 597, 644 and 704 nm. From Judd-Ofelt analysis, the J-O parameter (Ω 2 , Ω 4 , Ω 6 ), radiative transition possibility ( A R ), stimulated emission cross-section (σ(λ p )) and branching ratios ( β R ) were indicated that the glass samples an interesting potential for using glass as laser medium with 597 nm emitting.
Neil B Milestone - One of the best experts on this subject based on the ideXlab platform.
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a new type of layered Aluminium Phosphate nh4 3 co nh3 6 3 al2 po4 4 2 assembled about acobalt iii hexammine complex
Chemical Communications, 1997Co-Authors: Keith R Morgan, Graeme J Gainsford, Neil B MilestoneAbstract:The formation of a novel layered Aluminium Phosphate containing a new type of layer stoichiometry is reported; the reaction is carried out under basic conditions using cobalt hexammine as a template.
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a novel layered Aluminium Phosphate co en 3al3p4o16 3h2o assembled about a chiral metal complex
Journal of The Chemical Society Chemical Communications, 1995Co-Authors: Keith R Morgan, Graeme J Gainsford, Neil B MilestoneAbstract:The synthesis and structure of a novel layered Aluminium Phosphate formed about a chiral metal complex is reported.
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A novel layered Aluminium Phosphate [Co(en)3Al3P4O16·3H2O] assembled about a chiral metal complex
Journal of The Chemical Society Chemical Communications, 1995Co-Authors: Keith R Morgan, Graeme J Gainsford, Neil B MilestoneAbstract:The synthesis and structure of a novel layered Aluminium Phosphate formed about a chiral metal complex is reported.
Joe L White - One of the best experts on this subject based on the ideXlab platform.
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Aluminium Phosphate adjuvants prepared by precipitation at constant ph part ii physicochemical properties
Vaccine, 2000Co-Authors: Lana S Burrell, Clifford T Johnston, Darrell G Schulze, Jim Klein, Joe L WhiteAbstract:The impact of the pH of precipitation on the physicochemical properties of Aluminium Phosphate adjuvants was investigated by precipitating Aluminium Phosphate adjuvants under constant pH conditions at pH values from 3.0 to 7.5 at intervals of 0.5. The pH of precipitation did not affect the morphology, but the point of zero charge (PZC) and rate of acid neutralization varied directly with pH of precipitation. Aggregation and protein adsorption capacity exhibited a parabolic relationship to the pH of precipitation. Minimum protein adsorption and maximum aggregation were observed at pH 5.5. In contrast to adjuvants precipitated from the same reactants but under uncontrolled pH conditions, the pH of all of the adjuvants precipitated under constant pH conditions remained constant for a 3-month aging period at room temperature.
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Aluminium Phosphate adjuvants prepared by precipitation at constant ph part i composition and structure
Vaccine, 2000Co-Authors: Lana S Burrell, Clifford T Johnston, Darrell G Schulze, Jim Klein, Joe L WhiteAbstract:Aluminium Phosphate adjuvant was precipitated under constant pH conditions in an effort to characterize materials formed at defined precipitation conditions. A reaction vessel was designed to provide a continuous steady-state process. An aqueous solution containing Aluminium chloride and sodium dihydrogen Phosphate was pumped into the reaction vessel at a constant rate. A second pump infused a sodium hydroxide solution at the rate required to maintain the desired pH. Precipitations were performed between pH 3.0 and 7.5, at intervals of pH 0.5. The adjuvants were characterized using 27Al NMR, FTIR, Raman and X-ray diffraction methods along with elemental analysis. The results of this study indicate that a continuum of amorphous Aluminium hydroxyPhosphates were formed having properties that changed as a continuous function of the precipitation pH. The Phosphate content decreased as the pH of precipitation increased. 27Al NMR spectra revealed that the majority of the Aluminium was octahedrally coordinated, with a small percentage of tetrahedrally coordinated Aluminium. The density of the adjuvants was directly related to the pH of precipitation. The most prominent feature of the IR and Raman spectra is the P–O stretching vibration of the structural PO4 groups. The positions of these bands decreased linearly as the precipitation pH increased. The results of selective deuteration FTIR experiments are consistent with high surface area materials as most of the OH groups were exposed near the surface of the adjuvant.
F J Luque - One of the best experts on this subject based on the ideXlab platform.
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Quantifying Aluminium Phosphate–sulphate minerals as markers of acidic conditions during the Permian–Triassic transition in the Iberian Ranges, E Spain
Chemical Geology, 2016Co-Authors: Violeta Borruel-abadía, R De La Horra, F J Luque, José F. Barrenechea, Ana Belén Galán-abellán, Jacinto Alonso-azcárate, José López-gómezAbstract:Abstract In this paper, a method based on element mapping of randomly selected areas of thin sections on electron microprobe is proposed to quantify the relative contents of strontium-rich hydrated Aluminium Phosphate-sulphate (APS) minerals in siliciclastic continental sedimentary rocks. The main problems for these minerals to be quantified are related to their small size, low concentrations, and optical properties. By comparing the element maps obtained for the rocks in the study area of the Iberian Ranges (E Spain) with the results of whole rock analysis and with factors indicating the presence of life (bioturbation, palaeosols, and macro-plant remains), it has been possible to correlate relatively high levels of APS minerals in the first sedimentary record (Canizar Formation) after the Permian–Triassic boundary, with the lack of living organisms. The APS are related to early diagenetic phases precipitated at low pH conditions and are therefore markers of formation in an acidic environment. Our findings suggest a long period of sustained acidic conditions followed by an environmental change linked with the recovery of life and with lower APS mineral contents. This change is detected at the top of the Canizar Formation, at the end of the Spathian. The method proposed could be used as a tool to address the environmental changes that took place during the Permian–Triassic transition in continental environments.
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quantifying Aluminium Phosphate sulphate minerals as markers of acidic conditions during the permian triassic transition in the iberian ranges e spain
Chemical Geology, 2016Co-Authors: Violeta Borruelabadia, Ana Belen Galanabellan, J F Barrenechea, R De La Horra, F J Luque, Jacinto Alonsoazcarate, Jose LopezgomezAbstract:Abstract In this paper, a method based on element mapping of randomly selected areas of thin sections on electron microprobe is proposed to quantify the relative contents of strontium-rich hydrated Aluminium Phosphate-sulphate (APS) minerals in siliciclastic continental sedimentary rocks. The main problems for these minerals to be quantified are related to their small size, low concentrations, and optical properties. By comparing the element maps obtained for the rocks in the study area of the Iberian Ranges (E Spain) with the results of whole rock analysis and with factors indicating the presence of life (bioturbation, palaeosols, and macro-plant remains), it has been possible to correlate relatively high levels of APS minerals in the first sedimentary record (Canizar Formation) after the Permian–Triassic boundary, with the lack of living organisms. The APS are related to early diagenetic phases precipitated at low pH conditions and are therefore markers of formation in an acidic environment. Our findings suggest a long period of sustained acidic conditions followed by an environmental change linked with the recovery of life and with lower APS mineral contents. This change is detected at the top of the Canizar Formation, at the end of the Spathian. The method proposed could be used as a tool to address the environmental changes that took place during the Permian–Triassic transition in continental environments.
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palaeoenvironmental implications of Aluminium Phosphate sulphate minerals in early middle triassic continental sediments se iberian range spain
Sedimentary Geology, 2013Co-Authors: Ana Belen Galanabellan, J F Barrenechea, M I Benito, R De La Horra, F J Luque, Jacinto Alonsoazcarate, Alfredo ArcheAbstract:Abstract The presence of Sr-rich Aluminium-Phosphate sulphate (APS) minerals in continental sedimentary rocks from the Canizar and Eslida Formations along the eastern part of the Iberian Range (Spain) is considered as evidence of acidic and oxidising conditions during Early–Middle Triassic times. The formation of APS minerals occurred shortly after sedimentation, in early diagenetic stages, prior to the compaction of the sediments and most probably was related to the circulation of acidic meteoric waters. Such conditions might result from a sustained, damaged environment or from multiple environmental crises, but would have delayed the recovery of life after the end-Palaeozoic mass extinction. APS minerals occur as small disseminated and idiomorphic pseudo-cubic crystals (0.5 to 6 μm long) or as massive and polycrystalline aggregates replacing fragments of fine-grained metamorphic rocks (mainly metapelites). Textural data indicate that the formation of the APS minerals predated the quartz and illite cements, and that they resulted from the destabilisation of pre-existing minerals, as evidenced by the replacement of slate fragments by APS minerals and hematite and by the close association of the disseminated APS crystals and kaolinite with altered detrital mica plates. Electron microprobe analyses and X-ray diffraction study of the APS minerals indicate a rather homogeneous composition in different parts of the basin, corresponding to solid solutions among woodhouseite, svanbergite, crandallite and goyazite. The sources of strontium in the APS minerals remain unclear. Phosphorous was primarily supplied by dissolution of detrital Phosphates under acidic conditions, and sulphur derives from the weathering of pyrite.
