Thermal analysis and high-temperature X-ray diffraction of
The sample goes through alternative amorphous and crystalline stages before final crystallization of β-tricalcium phosphate takes place. The high-temperature XRD studies offered the great advantage of being both a synthesis and a physico-chemical characterization technique which along with thermal analysis and infrared spectroscopy gave a
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New insights into the crystallization process of sol‐gel
phase along with a calcium silicate-phosphate phase which decomposes into rhe-nanite from 2 hours of thermal treatment at this temperature. At the crystallization temperature (700°C) combeite remains as the main crystalline phase. Additionally Na 2Ca 2Si 2O 7 crystalline phase is formed. Our results provide a basic platform for
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Physico-chemical and thermochemical studies of the
The hydrolytic evolution of amorphous tricalcium phosphate shows two main exothermic events Physical and chemical transformations during the hydrolytic treatment 4.2. Enthalpy variations during the hydrolytic treatment residual lyophilized amorphous phase contained in calcium phosphate after hydrolytic treatment
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Controlled Crystallization of the Amorphous Phase in
S Stemmer G Roebben O Van der Biest Evolution of grain boundary films in liquid phase sintered silicon nitride during high-temperature testing Acta Materialia 10.1016/S(98) 46 15 () (1998).
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Conversion of amorphous calcium phosphate to
Tracking Amorphous Precursor Formation and Transformation during Induction Stages of Nucleation. Evolution of Amorphous Calcium Phosphate to Hydroxyapatite Probed by Gold Nanoparticles. Formation and phase evolution of calcium phosphates modulated by ion exchange ionomer Nafion. CrystEngComm 2020 22
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(PDF) Unreactiveness of calcium phosphates and
XRD patterns of TCP (1) before and (2) after heat treatment and (3) HAPn–HPMC composite. treatment and (3) TCP–HPMC composite. no chemical bonding is formed between the calcium phosphate crystallites to be embedded in HPMC parti- phosphates and HPMC during heat treatment.
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Defining Crystalline/Amorphous Phases of Nanoparticles
In this study we elucidate the structural distinctions between amorphous and crystalline Ni2P nanoparticles synthesized using tri-n-octylphosphine (TOP) through X-ray absorption spectroscopy (XAS) X-ray diffraction (XRD) and inductively coupled plasma (ICP). We determine the differences in their chemical and atomic structure which have not been previously reported yet are essential for
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The Crystallization of Amorphous Calcium Carbonate is
1 Introduction. Since the discovery of the central role of amorphous calcium carbonate (ACC) in the crystallization pathways of biogenic calcium carbonate in sea urchin larva 1 the use of amorphous precursors has been recognized as a common strategy employed by many organisms across various phyla to build biominerals with superior properties. 2-5 This strategy has also inspired the
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Examination of alkali-activated material nanostructure
X-ray amorphous to poorly crystalline 10–12 . In contrast the main binding phase in an alkali-acti-vated cement based on fly ash is an alkali alumi-nosilicate hydrate (N-A-S-(H)) gel framework with a highly polymerised disordered pseudo-zeolitic structure containing low amounts of structural water 1 . The N-A-S-(H) gel is X-ray amorphous
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Phase Evolution of Thermally Treated Amorphous Tricalcium
X-ray amorphous tricalcium-phosphate nanoparticles (ATCP) produced by flame spray synthesis were heat-treated at temperatures between 500 and 1000°C and analyzed in situ by X-ray powder diffraction.
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USB2Amorphous low-calcium content silicate
USB2 US15/544 605 USA USB2 US B2 US B2 US B2 US A US A US A US B2 US B2 US B2 Authority US United States Prior art keywords hydraulic binder molar ratio hydraulic amorphous cooling Prior art date Legal status (The legal status is an
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Defining Crystalline/Amorphous Phases of Nanoparticles
In this study we elucidate the structural distinctions between amorphous and crystalline Ni2P nanoparticles synthesized using tri-n-octylphosphine (TOP) through X-ray absorption spectroscopy (XAS) X-ray diffraction (XRD) and inductively coupled plasma (ICP). We determine the differences in their chemical and atomic structure which have not been previously reported yet are essential for
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Rapid evaluation of bioactive Ti-based surfaces using an
May 02 2019 · Generally heat treatment in air induced TiO 2 rutile formation on the surface while NaOH treatment led to the formation of a porous surface layer rich in Ti Na and O which was further
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Hidden amorphous phase and reentrant supercooled liquid in
Mar 17 2017 · In situ synchrotron diffraction. Figure 2a b show the evolution of X-ray structure factor S(Q) for Pd 41.25 Ni 41.25 P 17.5 and Pd 40 Ni 40 P 20 alloys obtained by in situ high-energy
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(PDF) Thermal Treatment of Flame-Synthesized Amorphous
In the uncalcined amorphous sample however the crystalline phase obtained after irradiation was identified (Fig. 6) as being mainly HA.(4) Ca P Ratio The Ca P ratios of the bulk material calculated from the refined phase compositions remained constant at 7501C and above but a higher ratio was determined for lower temperatures (Table I).
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Evaluation of amorphous magnesium phosphate (AMP) based
Oct 07 2016 · The promoters accelerate the conversion of the amorphous phase into a poorly crystalline (or nanocrystalline) phase by reducing the activation energy of the hydrolysis reaction. From a commercial perspective there must be a mention of the α -BSM products from ETEX Corp using amorphous calcium phosphate (ACP) 2 3 .
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(PDF) Effect of Heat Treatments on HVOF Hydroxyapatite
Amorphous calcium phosphate is a metastable phase and always tends to revert back to a more stable crystal- line structure through a process of crystallization.
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Conversion of amorphous calcium phosphate to
Tracking Amorphous Precursor Formation and Transformation during Induction Stages of Nucleation. Evolution of Amorphous Calcium Phosphate to Hydroxyapatite Probed by Gold Nanoparticles. Formation and phase evolution of calcium phosphates modulated by ion exchange ionomer Nafion. CrystEngComm 2020 22
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Microstructural evolution during the heat treatment of
We have used a variety of techniques to assess microstructural evolution during the heat treatment of nanocrystalline Ni–W alloys. Aside from routine grain-size measurements characterization of the solute distribution and evidence for grain-boundary relaxation provide a more complete picture of the processes activated during annealing.
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Structural and compositional features of amorphous calcium
The phase evolution in amorphous calcium phosphate (ACP with a Ca/P ratio of 1 1) derived from the fast nitrate synthesis using different conditions was studied in temperature range 20-980°C.
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Crystallization of metastable and stable phases from
Apr 01 2020 · Single-phase metastable α ¯and stable β-tricalcium phosphates mixtures with each other and the calcium pyrophosphates in a desired composition were processed by heat treatment of the hydrolyzed precipitates for producing prospective biomaterials.
Get PriceAmorphous calcium phosphate is a major component of the
Sep 02 2008 · Many invertebrates from different phyla build their mineralized skeletons by first depositing an amorphous disordered mineral precursor that subsequently transforms into a crystalline phase (1–6).Whether or not vertebrate mineralization proceeds in this manner has been the subject of a long-standing debate (7–15).Mature bone mineral is a highly substituted crystalline phase of calcium
Get PriceMechanical improvement of calcium carbonate cements by in
Pure amorphous calcium carbonate (ACC) is unstable and transforms to a crystalline phase when brought into contact with water so fast that it is not suitable for a reasonable cement formulation. Hence we adjusted the rate of ACC phase transformation by using magnesium as phase stabilizer and crystallization inhibitor.
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Tracking Amorphous Precursor Formation and Transformation
The aggregation of calcium phosphate forms a calcium-deficient amorphous phase I Ca-(HPO 4) 1 x ·nH 2 O 2x) early in the induction period which slowly transforms to amorphous phase II Ca-(HPO 4)·mH 2 O by dehydration. Precritical nuclei form within amorphous phase II later in the induction period leading to mineral formation.
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(PDF) Thermal Treatment of Flame-Synthesized Amorphous
In the uncalcined amorphous sample however the crystalline phase obtained after irradiation was identified (Fig. 6) as being mainly HA.(4) Ca P Ratio The Ca P ratios of the bulk material calculated from the refined phase compositions remained constant at 7501C and above but a higher ratio was determined for lower temperatures (Table I).
Get PriceEPA1Amorphous low-calcium content silicate
The invention relates to a hydraulic binder consisting essentially in a hydraulically active amorphous calcium silicate phase having in its constitution less than 20 in weight of a crystalline material. The said hydraulically active amorphous calcium silicate phase is a continuous matrix that may contain embedded fractions of crystalline material being the overall C/S molar ratio of this
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Thermal decomposition of brushite CaHPO4·2H2O to monetite
Recrystallization water loss and the formation of the amorphous phase depend on the heating rate and/or time of exposure at temperature. The conversion temperature is about 220 °C although brushite can convert to monetite at lower temperatures during prolonged exposure to heat.
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Amorphous calcium phosphate is a major component of the
Sep 02 2008 · Many invertebrates from different phyla build their mineralized skeletons by first depositing an amorphous disordered mineral precursor that subsequently transforms into a crystalline phase (1–6).Whether or not vertebrate mineralization proceeds in this manner has been the subject of a long-standing debate (7–15).Mature bone mineral is a highly substituted crystalline phase of calcium
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Amorphous Phase Scientific.Net
Abstract Powder of Fe 72 Nb 4 Si 10 B 14 ( at) glassy alloy was obtained by gas atomization in order to investigate the possibilities of amorphous phase formation due to the high cooling rates (10 3 10 5 K/s) involved in this process. The ratio between the gas volumetric and the metal mass flow rates used was 1.0 and nitrogen (N 2) was used as the atomization gas.
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