Luminescence variations in hydroxyapatites doped with Eu2+ and Eu3+ ions

Graeve, Olivia A.; Kanakala, Raghunath; Madadi, Abhiram; Williams, Brandon C.; Glass, Katelyn C.

doi:10.1016/j.biomaterials.2010.02.009

Cited by 123 publications

(104 citation statements)

References 42 publications

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“…Figure 9 shows that the average particle sizes increased proportionally with the treatment temperature, in contrast to what we have found for some ceramics, in which as the heat treatment temperature is increased, the crystallite size increases, but the particle size stays constant. [23,24] This could be attributed to powder preparation methodology, which results in different powder morphologies. The Y 2 O 3 and hydroxyapatite powders from our previous work were prepared by combustion synthesis; thus, the powder morphology is very different compared to the tungsten powders prepared by precipitation.…”

Section: Resultsmentioning

confidence: 94%

Analysis of Particle and Crystallite Size in Tungsten Nanopowder Synthesis

Graeve

Madadi

Kanakala

et al. 2010

Metall Mater Trans A

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Tungsten nanopowders were synthesized by a low-temperature technique and then heat treated in a gaseous reductive atmosphere in order to study the phase evolution, crystallite size, and particle size of the powders as the heat treatment temperature was modified. Synthesis of the powders was carried out in aqueous media using NaBH 4 as a reducing agent using careful control of the pH of the solutions. The XRD patterns of the as-synthesized powders showed an amorphous phase. After washing, energy dispersive spectroscopy showed that the powders had peaks for oxygen and tungsten. In order to promote crystallization and eliminate the oxygen, the powders were heat treated at 773 K, 923 K, and 1073 K (500°C, 650°C, and 800°C) in a H 2 /CH 4 reducing atmosphere for 2 hours. XRD after heat treatment showed a-W peaks for the powders treated at 1073 K and 923 K (800°C and 650°C) and a mixture of b-W and a-W for the powders treated at 773 K (500°C). The crystallite sizes determined from X-ray peak broadening were 12, 16, and 20 nm, whereas the average particle sizes from dynamic light scattering were 260, 450, and 750 nm, for heat treatment temperatures of 773 K, 923 K, and 1073 K (500°C, 650°C, and 800°C), respectively. The average crystallite size and particle sizes increased proportionally with the treatment temperature, in contrast to what has been found for some ceramics, in which as the heat treatment temperature is increased, the crystallite size increases, but the particle size stays constant.

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Section: Resultsmentioning

confidence: 94%

Analysis of Particle and Crystallite Size in Tungsten Nanopowder Synthesis

Graeve

Madadi

Kanakala

et al. 2010

Metall Mater Trans A

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“…TaC 1Àx (henceforth referred to as TaC) was produced by methods we previously developed [41][42][43] to generate powders with average crystallite size of 25 nm from X-ray line broadening, average particle (aggregate) size of 73 nm from dynamic light scattering [44][45][46][47][48][49][50][51][52][53][54][55][56][57], a C/Ta compound ratio of 0.94 (i.e. powders of composition TaC 0.94 ), an oxygen content of $6.1-7.9 wt.%, and a free carbon content of $2.4 wt.% [43].…”

Section: Methodsmentioning

confidence: 99%

Mechanisms of pore formation in high-temperature carbides: Case study of TaC prepared by spark plasma sintering

Kelly

Graeve

2015

Acta Materialia

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“…354 However, CAP particles could be equally doped with Eu 3þ , Tb 3þ , Gd 3þ , or other lanthanides in order to be made fluorescent. 355,356 Nanocrystals actually offer the advantage of structurally integrating the fluorescent entities within the crystal lattice by doping, thereby transcending numerous drawbacks of using organic dyes, fluorescent proteins, and lanthanide chelates, such as broad spectrum profiles, low photobleaching thresholds, and poor photochemical stability. 357 The pathways of such nanoparticles were successively followed inside pancreatic cells.…”

Section: Prospective Applicationsmentioning

confidence: 99%

Nanosized hydroxyapatite and other calcium phosphates: Chemistry of formation and application as drug and gene delivery agents

2010

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The first part of this review looks at the fundamental properties of hydroxyapatite (HAP), the basic mineral constituent of mammalian hard tissues, including the physicochemical features that govern its formation by precipitation. A special emphasis is placed on the analysis of qualities of different methods of synthesis and of the phase transformations intrinsic to the formation of HAP following precipitation from aqueous solutions. This serves as an introduction to the second part and the main subject of this review, which relates to the discourse regarding the prospects of fabrication of ultrafine, nanosized particles based on calcium phosphate carriers with various therapeutic and/or diagnostic agents coated on and/or encapsulated within the particles. It is said that the particles could be either surface-functionalized with amphiphiles, peptides, proteins, or nucleic acids or injected with therapeutic agents, magnetic ions, or fluorescent molecules. Depending on the additive, they could be subsequently used for a variety of applications, including the controlled delivery and release of therapeutic agents (extracellularly or intracellularly), magnetic resonance imaging and hyperthermia therapy, cell separation, blood detoxification, peptide or oligonucleotide chromatography and ultrasensitive detection of biomolecules, and in vivo and in vitro gene transfection. Calcium phosphate nanoparticles as carriers of therapeutic agents that would enable a controlled drug release to treat a given bone infection and at the same be resorbed in the body so as to regenerate hard tissue lost to disease are emphasized hereby as one of the potentially attractive smart materials for the modern medicine.

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Luminescence variations in hydroxyapatites doped with Eu2+ and Eu3+ ions

Cited by 123 publications

References 42 publications

Analysis of Particle and Crystallite Size in Tungsten Nanopowder Synthesis

Analysis of Particle and Crystallite Size in Tungsten Nanopowder Synthesis

Mechanisms of pore formation in high-temperature carbides: Case study of TaC prepared by spark plasma sintering

Nanosized hydroxyapatite and other calcium phosphates: Chemistry of formation and application as drug and gene delivery agents

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