Pourbaix-Guided Mineralization and Site-Selective Photoluminescence Properties of Rare Earth Substituted B-Type Carbonated Hydroxyapatite Nanocrystals

Rare-earth labeling in biological apatite could provide critical information for the pathologic transition (osteoclastic) and physiologic regeneration (osteogenesis) of bone and teeth because of their characteristic site-sensitive fluorescence in different coordinative conditions of various tissues in many biological processes. However, the rare-earth labeling method for biological apatites, i.e., carbonated-hydroxyapatite, has been rarely found in the literature. In this paper, we report a Pourbaix-diagram guided mineralizing strategy to controllable carbonation and doping of rare-earth ions in the hydroxyapatite (HA) lattice. The carbonation process of hydroxyapatite was achieved by controllable mineralization in hydrothermal condition with K2CO3 as the carbonate source, which results into the pure B-type carbonated hydroxyapatite (CHA) with tunable carbonate substitution degree. All of the as-synthesized materials crystalized into P63/m (No. 176) space group with the lattice parameter of a decreases and c increases with the increasing of carbonate content in the reactants. Structural refinement results revealed that the substitution of planar CO32− is superimposed on one of the faces of PO43− tetrahedral sub-units with a rotation angle of 30° in reference to c-axis. All of the hydrothermally synthesized CHA nanocrystals show hexagonal rod-like morphology with the length of 70–110 nm and diameter of 21–35 nm, and the decreasing length/diameter ratio from 3.61 to 2.96 from low to high carbonated level of the samples. Five rare-earth cations, of Pr3+, Sm3+, Eu3+, Tb3+, and Ho3+, were used as possible probe ions that can be doped into either HA or CHA lattice. The site-preference of Tb3+ doping is the same in the crystallographic site of HA and CHA according to characteristic emission peaks of 5D4–7Fj (j = 3–6) transitions in their photoluminescent spectroscopy. Our work provides a controllable carbonation method for rare-earth labeling hydroxyapatite nanomaterials with potential biologically active implant powders for bone repair and tissue regeneration.

Download Full-text

Nano-carbonated hydroxyapatite precipitation from abalone shell (Haliotis asinina) waste as the bioceramics candidate for bone tissue engineering

Nanomaterials and Nanotechnology ◽

10.1177/18479804211032851 ◽

2021 ◽

Vol 11 ◽

pp. 184798042110328

Author(s):

Hestining A Permatasari ◽

Mona Sari ◽

Aminatun ◽

Tri Suciati ◽

Kiagus Dahlan ◽

...

Keyword(s):

Tissue Engineering ◽

Bone Tissue Engineering ◽

Bone Tissue ◽

Aging Time ◽

Carbonate Content ◽

P Value ◽

Transmission Electron Microscopy Analysis ◽

Crystallinity Degree ◽

Carbonated Hydroxyapatite ◽

Carbonate Substitution

In this study, nano-carbonated hydroxyapatite (n-CHAp) was successfully synthesized with abalone shells ( Halioitis asinina) as the calcium source using precipitation methods with aging time variations, namely, 0 (without the aging process), 24, and 48 h. Based on an analysis of X-ray diffraction characterization, the spectrum of the n-CHAp is shown for all sample variations in aging time. The results of the calculation of lattice parameter values confirm that the phase formed is the B-type CHAp phase with the increasing crystallinity degree, crystallite size, particle size, and polydispersity which is confirmed by the presence of the CO32- functional group at 1438 cm−1 and 878 cm−1, that is, the B-type carbonate substitution characteristic. The presence of the carbonate ions identified as smaller during the extension of aging time causes the decreasing value of the Ca/P mole ratio but still has a value greater than the HAp Ca/P value (1.67), which is 1.80–1.72. Based on the transmission electron microscopy analysis, the nanometer-size of B-type CHAp particles was successfully obtained. According to the criteria for nanostructures, crystallographic properties, carbonate content, and chemical processes, B-type CHAp samples based on abalone shells ( Halioitis asinina) are one of the candidates in bioceramics for bone tissue engineering applications.

Download Full-text

Bioresorbable carbonated hydroxyapatite Ca10−xNax(PO4)6−x(CO3)x(OH)2 powders for bioactive materials preparation

Open Chemistry ◽

10.2478/s11532-009-0018-y ◽

2009 ◽

Vol 7 (2) ◽

pp. 168-174 ◽

Cited By ~ 14

Author(s):

Elena Kovaleva ◽

Maxim Shabanov ◽

Valery Putlyaev ◽

Yury Tretyakov ◽

Vladimir Ivanov ◽

...

Keyword(s):

Crystalline Lattice ◽

Carbonate Content ◽

In Vitro Tests ◽

Content Increase ◽

Bioactive Materials ◽

Carbonated Hydroxyapatite ◽

Carbonate Ion ◽

Carbonate Substitution ◽

Hydroxyapatite Nanocrystals

AbstractThe purpose of this work was to find and investigate a correlation between the carbonate ion content in crystalline lattice and defect structure, and solubility of the materials; finally, to prepare the materials under study for in vitro tests. Various techniques, such as XRD, FTIR, TEM, FESEM/EDX, TG/DTA, AES (ICP), wet chemical analysis, Ca-ionometry, microvolumetric analysis of evolved CO2, BET adsorption, were applied to determine the efficiency of carbonate substitution, and to quantify the elemental composition, as well as to characterize the structure of the carbonated hydroxyapatite and the site(s) of carbonate substitution,. It was shown that AB-type substitution prevails over other types with the carbonate content increase. According to in vitro tests, the bioactivity of the samples is correlated with the carbonate content in carbonate-doped hydroxyapatite due to accumulation of defects in carbonated hydroxyapatite nanocrystals.

Download Full-text

Characterization of Rare-Earth Fluoride Anti-Stokes Phosphors by Scanning arid Transmission Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100064761 ◽

1971 ◽

Vol 29 ◽

pp. 142-143

Author(s):

N. M. P. Low ◽

L. E. Brosselard

Keyword(s):

Electron Microscopy ◽

Rare Earth ◽

Elevated Temperatures ◽

Stoichiometric Composition ◽

Rare Earth Ions ◽

Crystalline Solid ◽

Precipitation Process ◽

Rare Earth Fluoride ◽

Earth Fluoride ◽

Rare Earth Fluorides

There has been considerable interest over the past several years in materials capable of converting infrared radiation to visible light by means of sequential excitation in two or more steps. Several rare-earth trifluorides (LaF3, YF3, GdF3, and LuF3) containing a small amount of other trivalent rare-earth ions (Yb3+ and Er3+, or Ho3+, or Tm3+) have been found to exhibit such phenomenon. The methods of preparation of these rare-earth fluorides in the crystalline solid form generally involve a co-precipitation process and a subsequent solid state reaction at elevated temperatures. This investigation was undertaken to examine the morphological features of both the precipitated and the thermally treated fluoride powders by both transmission and scanning electron microscopy.Rare-earth oxides of stoichiometric composition were dissolved in nitric acid and the mixed rare-earth fluoride was then coprecipitated out as fine granules by the addition of excess hydrofluoric acid. The precipitated rare-earth fluorides were washed with water, separated from the aqueous solution, and oven-dried.

Download Full-text

Preparation of fluoride glasses containing large concentrations of transition metal ions and rare earth ions

International Congress on Applications of Lasers & Electro-Optics ◽

10.2351/1.5057347 ◽

1982 ◽

Author(s):

O. H. El-Bayoumi ◽

M. G. Drexhage ◽

C. T. Moynihan ◽

A. J. Bruce

Keyword(s):

Rare Earth ◽

Transition Metal ◽

Metal Ions ◽

Transition Metal Ions ◽

Rare Earth Ions ◽

Fluoride Glasses

Download Full-text

Synthesis and Properties of SrMoO4 Phosphors Doped with Various Rare Earth Ions for Anti-Counterfeiting Applications

Korean Journal of Materials Research ◽

10.3740/mrsk.2020.30.8.406 ◽

2020 ◽

Vol 30 (8) ◽

pp. 406-412

Author(s):

Tae-Ok Moon ◽

Jae-Yong Jung ◽

Shinho Cho

Keyword(s):

Rare Earth ◽

Rare Earth Ions

Download Full-text

Structural, Morphological and Magnetic Characterization of Sm-substituted Ni-Zn Ferrite

Nanoscience &Nanotechnology-Asia ◽

10.2174/2210681208666181018093813 ◽

2020 ◽

Vol 10 (2) ◽

pp. 152-156 ◽

Cited By ~ 1

Author(s):

Muhammad Hanif bin Zahari ◽

Beh Hoe Guan ◽

Lee Kean Chuan ◽

Afiq Azri bin Zainudin

Keyword(s):

Magnetic Properties ◽

Rare Earth ◽

Saturation Magnetization ◽

Sol Gel ◽

Magnetic Behavior ◽

Rare Earth Ions ◽

Ion Concentration ◽

Zn Ferrite ◽

Auto Combustion ◽

Combustion Technique

Background: Rare earth materials are known for its salient electrical insulation properties with high values of electrical resistivity. It is expected that the substitution of rare earth ions into spinel ferrites could significantly alter its magnetic properties. In this work, the effect of the addition of Samarium ions on the structural, morphological and magnetic properties of Ni0.5Zn0.5SmxFe2-xO4 (x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) synthesized using sol-gel auto combustion technique was investigated. Methods: A series of Samarium-substituted Ni-Zn ferrite nanoparticles (Ni0.5Zn0.5SmxFe2-xO4 where x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by sol-gel auto-combustion technique. Structural, morphological and magnetic properties of the samples were examined through X-Ray Diffraction (XRD), Field-Emission Scanning Electron Microscope (FESEM) and Vibrating Sample Magnetometer (VSM) measurements. Results: XRD patterns revealed single-phased samples with spinel cubic structure up to x= 0.04. The average crystallite size of the samples varied in the range of 41.8 – 85.6 nm. The prepared samples exhibited agglomerated particles with larger grain size observed in Sm-substituted Ni-Zn ferrite as compared to the unsubstituted sample. The prepared samples exhibited typical soft magnetic behavior as evidenced by the small coercivity field. The magnetic saturation, Ms values decreased as the Sm3+ concentration increases. Conclusion: The substituted Ni-Zn ferrites form agglomerated particles inching towards more uniform microstructure with each increase in Sm3+ substitution. The saturation magnetization of substituted samples decreases with the increase of samarium ion concentration. The decrease in saturation magnetization can be explained based on weak super exchange interaction between A and B sites. The difference in magnetic properties between the samples despite the slight difference in Sm3+ concentrations suggests that the properties of the NiZnFe2O4 can be ‘tuned’, depending on the present need, through the substitution of Fe3+ with rare earth ions.

Download Full-text

Structure, Luminescence, and Magnetic Properties of Crystalline Manganese Tungstate Doped with Rare Earth Ion

Materials ◽

10.3390/ma14133717 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3717

Author(s):

Jae-Young Jung ◽

Soung-Soo Yi ◽

Dong-Hyun Hwang ◽

Chang-Sik Son

Keyword(s):

Magnetic Field ◽

Rare Earth ◽

Sintering Temperature ◽

Luminescent Properties ◽

Concentration Quenching ◽

Rare Earth Ions ◽

Precipitation Method ◽

Rare Earth Ion ◽

Co Precipitation ◽

Quenching Phenomenon

The precursor prepared by co-precipitation method was sintered at various temperatures to synthesize crystalline manganese tungstate (MnWO4). Sintered MnWO4 showed the best crystallinity at a sintering temperature of 800 °C. Rare earth ion (Dysprosium; Dy3+) was added when preparing the precursor to enhance the magnetic and luminescent properties of crystalline MnWO4 based on these sintering temperature conditions. As the amount of rare earth ions was changed, the magnetic and luminescent characteristics were enhanced; however, after 0.1 mol.%, the luminescent characteristics decreased due to the concentration quenching phenomenon. In addition, a composite was prepared by mixing MnWO4 powder, with enhanced magnetism and luminescence properties due to the addition of dysprosium, with epoxy. To one of the two prepared composites a magnetic field was applied to induce alignment of the MnWO4 particles. Aligned particles showed stronger luminescence than the composite sample prepared with unsorted particles. As a result of this, it was suggested that it can be used as phosphor and a photosensitizer by utilizing the magnetic and luminescent properties of the synthesized MnWO4 powder with the addition of rare earth ions.

Download Full-text