High Aspect Ratio Hydroxyapatite Nanorods Formed by Polymer Assisted Synthesis

2014 ◽  
Vol 508 ◽  
pp. 52-55
Author(s):  
A. Joseph Nathanael ◽  
R. Yuvakkumar ◽  
Tae Hwan Oh ◽  
Sun Ig Hong
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Morphological Analysis ◽  
Polymer Concentration ◽  
Xrd Analysis ◽  
Controlled Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Length Width ◽  
Size Controlled

High aspect ratio (length/width) of hydroxyapatite (HA) nanorods were prepared by polymer assisted hydrothermal synthesis. The aspect ratio of the nanorods was increased in the presence of polymer in hydrothermal method. Structural analysis was carried out by X-ray diffraction (XRD) analysis to find the purity and the crystal structure of the material. Morphological analysis was carried out by field emission scanning electron microscope (FESEM) to find the morphological variation in the presence of polymer concentration compared to pristine HA. The increased aspect ratio of the HA was visible from the morphological analysis. This shape and size controlled synthesis have an important impact in many field of research.

The Effect of Water Content on the Formation of TiO2 Nanotubes in Ethylene Glycol

2010 ◽  
Vol 173 ◽  
pp. 102-105 ◽  
Author(s):  
Khairul Arifah Saharudin ◽  
Srimala Sreekantan
Keyword(s):  
Crystal Structure ◽  
Aspect Ratio ◽  
Ethylene Glycol ◽  
Water Content ◽  
Anatase Phase ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Degradation Of Methyl Orange ◽  
Scanning Electron

In this paper, anodization of Ti foil was carried out in ethylene glycol (EG) containing 5 wt% NH4F solution and 0 to 1.5 wt% of water at 50 V for 60 min. The pH of the bath was kept constant at ~pH7. The crystal structure was studied by X-Ray Diffraction (XRD) analysis, and the morphology was observed via field emission scanning electron microscopy (FESEM). TiO2 nanotube with aspect ratio of 100 was obtained in EG containing less than 1wt % water. The nanotubes wall was very smooth. Increasing the water content > 1wt % results in short nanotubes of approximately 6.2μm with aspect ratio of 62. As anodized, nanotubes were amorphous and annealed at 400 °C promote 100 % anatase phase. Photocatalytic activity of the nanotubes produced at different water content was also evaluated by the degradation of methyl orange and the detail of the observation was discussed thoroughly in this paper.

Size-controlled Synthesis of Gold Nanoparticles by Thermolysis of a Gold(I)-Sulfide Complex in the Presence of Alkylamines

2009 ◽  
Vol 64 (11-12) ◽  
pp. 1305-1311 ◽  
Author(s):  
Mari Yamamoto ◽  
Yukiyasu Kashiwagi ◽  
Masami Nakamoto
Keyword(s):  
Gold Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Thermal Analyses ◽  
Controlled Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Alkyl Chains ◽  
Transmission Electron ◽  
Gas Chromatography Mass Spectroscopy ◽  
Size Controlled

A size-controlled synthesis of gold nanoparticles has been developed by the thermolysis of AuCl(SMe2) in the presence of alkylamines at 120 °C. In the procedure, the key intermediate was [Au(NH2R)2]Cl, detected by electrospray ionization (ESI) mass spectrometry. This thermally unstable intermediate was reduced by alkylamines under mild conditions to produce alkylamine-capped gold nanoparticles. The average diameters of the gold nanoparticles could be regulated in a range from 4.3 to 6.1 nm by applying primary alkylamines with alkyl chains of different lengths. Larger gold nanoparticles with diameters from 10 to 22 nm were prepared by a combination of alkylamines and alkylcarboxylic acids with various lengths of the alkyl chains. The gold nanoparticles were characterized by transmission electron microscopy (TEM), UV/Vis absorption spectroscopy, powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), gas chromatography/mass spectroscopy (GC/MS), and thermogravimetric and differencial thermal analyses (TG/DTA)

scholarly journals Size-Controlled Synthesis of Fe3O4Magnetic Nanoparticles in the Layers of Montmorillonite

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Katayoon Kalantari ◽  
Mansor B. Ahmad ◽  
Kamyar Shameli ◽  
Mohd Zobir Bin Hussein ◽  
Roshanak Khandanlou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Average Diameter ◽  
Controlled Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Interlamellar Space ◽  
Size Controlled ◽  
Chemical Coprecipitation Method

Iron oxide nanoparticles (Fe3O4-NPs) were synthesized using chemical coprecipitation method. Fe3O4-NPs are located in interlamellar space and external surfaces of montmorillonite (MMT) as a solid supported at room temperature. The size of magnetite nanoparticles could be controlled by varying the amount of NaOH as reducing agent in the medium. The interlamellar space changed from 1.24 nm to 2.85 nm and average diameter of Fe3O4nanoparticles was from 12.88 nm to 8.24 nm. The synthesized nanoparticles were characterized using some instruments such as transmission electron microscopy, powder X-ray diffraction, energy dispersive X-ray spectroscopy, field emission scanning electron microscopy, vibrating sample magnetometer, and Fourier transform infrared spectroscopy.

Preparation of Mullite Whiskers from Powder of Topaz Pure and Doped with Rare Earths

2014 ◽  
Vol 798-799 ◽  
pp. 189-194
Author(s):  
Renato Reis Monteiro ◽  
Antônio Claret Soares Sabioni
Keyword(s):  
Thermal Decomposition ◽  
Aspect Ratio ◽  
Rare Earths ◽  
Glassy Phase ◽  
Xrd Analysis ◽  
Molar Ratio ◽  
Vitreous Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mullite Whiskers

Mullite whiskers were obtained by thermal decomposition of powders of natural topaz, pure and doped with 3 and 5% in weight of La2O3 and Y2O3, at the temperatures of 1300 and 1400°C, for 1h, in air. Pure and doped mullite whiskers showed a molar ratio Al2O3: SiO2 close to 2:1, rich in alumina. The aspect ratio (AR) of whiskers varies with dopant concentrations and temperatures. The ARs for pure whiskers were 28 and 31.5, at the temperatures of 1300 and 1400°C, respectively, showing no glassy phase. For the doped whiskers, there were observed a reduction in the ARs, ranging from 14.13 to 16.10 (3 and 5% La2O3) and from 6.32 to 7.35 (3 and 5% Y2O3), for the temperatures of 1300 and 1400°C, respectively. The Y2O3 was not entirely incorporated, and part of it formed Y2Si2O7 and Y2O3-δ, with δ = 0.33 according to quantitative X-ray diffraction analysis (XRD analysis) with the presence of small amount of vitreous phase.

Synthesis of Plate-Like SrTiO3 Particles

2010 ◽  
Vol 663-665 ◽  
pp. 1024-1027
Author(s):  
Wei Zhao ◽  
Ruo Cai Pan ◽  
Hao Xue
Keyword(s):  
Aspect Ratio ◽  
Grain Growth ◽  
High Aspect Ratio ◽  
Growth Process ◽  
The Other ◽  
X Ray Diffraction ◽  
Templated Grain Growth ◽  
X Ray ◽  
Micro Scale ◽  
Textured Ceramics

Micro-scale plake-like SrTO3 particles were synthesized by two routes of topochemical conversion. One is by growing on Sr3Ti2O7 (S3T2) core particles in molten salt condition, and the other is from the layer-structured SrBi4Ti4O15 (SBT) precursor in a KCl medium. The effects of the morphology and size of the precursor to platelet SrTiO3 crystals were studied. X-ray diffraction analysis revealed that the crystallographic {010} plane of SBT was converted into the pseudo-cubic {001} plane of SrTiO3. The polycrystalline SrTiO3 particles from BST precursor exhibited a plate-like shape with 10-15μm in length and a high aspect ratio, and were more suitable for preparing textured ceramics by templated grain growth process than the platelets from the S3T2 precursors.

scholarly journals PVP Assisted Synthesis of Hydroxyapatite Nanorods with Tunable Aspect Ratio and Bioactivity

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
A. Joseph Nathanael ◽  
Young Ho Seo ◽  
Tae Hwan Oh
Keyword(s):  
Electron Microscopy ◽  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Xrd Analysis ◽  
Reaction Model ◽  
Morphological Variations ◽  
Viability Analysis ◽  
Selected Area Electron Diffraction ◽  
Length Width

Highly crystalline and reasonably uniform hydroxyapatite (HA) nanorods were prepared by polyvinylpyrrolidone (PVP) assisted hydrothermal synthesis which produces high aspect ratio (length/width) nanorods. The aspect ratio of the nanorods was higher in the presence of PVP and increased with increasing concentrations of PVP. X-ray diffraction (XRD) analysis showed that the HA nanorods were of the hexagonal apatite phase. High resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) patterns confirmed that the nanorods grew in thec-axis direction (preferred orientation). The calculated lattice spacing was ~0.35 nm which is thec-axis value of hexagonal HA. Morphological variations of pristine and PVP added HA were evaluated by field emission scanning electron microscopy (FESEM) and TEM, which revealed that the presence of PVP greatly increased the aspect ratio of the HA nanorods. The formation mechanism of the PVP assisted HA was studied and a possible reaction model was given. Cell viability analysis byin vitrostudies showed encouraging results for the high aspect ratio nanorods and indicated a possibility for tuning the activity based on controlling the aspect ratio.

A FACILE SYNTHESIS OF SHAPE- AND SIZE-CONTROLLED α-Fe2O3 NANOPARTICLES THROUGH HYDROTHERMAL METHOD

NANO ◽  
2011 ◽  
Vol 06 (05) ◽  
pp. 469-479 ◽  
Author(s):  
GUANG-HUI WANG ◽  
WEN-CUI LI ◽  
KUN-MING JIA ◽  
AN-HUI LU ◽  
MATHIAS FEYEN ◽  
...  
Keyword(s):  
Amino Acids ◽  
Side Chain ◽  
Controlled Synthesis ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
Facile Synthesis ◽  
X Ray ◽  
Transmission Electron ◽  
Size Controlled ◽  
Shape And Size

α- Fe 2 O 3 nanoparticles have wide-ranging applications such as in catalysis, sensoring, painting, etc. This is the reason to study their controlled synthesis. Here we have investigated the synthesis of uniform α- Fe 2 O 3 nanoparticles using amino acids as morphology control agents. The products were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetry (TG) and differential thermal analysis (DTA). It was found that the type and the amount of amino acids as well as the reaction temperatures have significant influence on the shape and size of the obtained α- Fe 2 O 3 nanoparticles. The use of acidic amino acids (always contain C = O in the side chain) typically leads to the formation of α- Fe 2 O 3 nanoparticles with spindle shape. However, rhombohedrally shaped α- Fe 2 O 3 nanoparticles were formed in presence of basic amino acids (always contain - NH 2 in the side chain). Increasing the amount of amino acid generally results in α- Fe 2 O 3 nanoparticles with decreasing particle sizes.

Some Aspects on Thermal Degradation of Organo-Layer Silicates

2008 ◽  
Author(s):  
Mervat S. Hassan ◽  
Hassan El-Shall ◽  
Chearly Beaty
Keyword(s):  
Aspect Ratio ◽  
Thermal Degradation ◽  
High Aspect Ratio ◽  
Layered Silicates ◽  
X Ray Diffraction ◽  
X Ray ◽  
Naturally Occurring ◽  
Organically Modified ◽  
The Relationship ◽  
Thermal Stability Of

Naturally occurring silicates, like montmorillonite (MMT) have received much attention as reinforcement materials for polymers because of their potentially high aspect ratio and unique intercalation (exfoliation) characteristic. Montmorillonite is of particular interest because it has a layered structure typically about 1nm in thickness and a high aspect ratio ranging from 100 to 1500 that, with proper exfoliation, can lead to platelets with high stiffness and strength dispersed in the polymer matrix. In this paper, we studied the delamination of Egyptian bentonite and Cloisite Na+ (USA) using different onium ions. The organo-clays were characterized by X-ray diffraction (XRD), Differential Scanning Calorimeter (DSC), Derivativethermogravimetry (TGA), Thermogravimetry (TG), and Infrared spectroscopy (IR). Understanding the relationship between molecular structure of the modifying surfactant and the thermal stability of the organically modified layered silicates is critical to its processing and subsequent applications. Therefore, special emphasis is given to the study of the thermal degradation of the modified clays. The results of the thermal degradation of montmorillonite (MMT) and alkyl quaternary ammonium montmorillonite (OMMT) are discussed in this paper.

Identification of acid-insoluble filter-plugging compounds and optimal acid-washing procedures for tubular backpulse pressure filters

TAPPI Journal ◽  
2011 ◽  
Vol 10 (1) ◽  
pp. 17-23
Author(s):  
KEVIN TAYLOR ◽  
RICH ADDERLY ◽  
GAVIN BAXTER
Keyword(s):  
Calcium Sulfate ◽  
Membrane Filter ◽  
Sulfamic Acid ◽  
Xrd Analysis ◽  
Metal Sulfides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gypsum Formation ◽  
Acid Washing ◽  
Hydrolysis Of

Over time, performance of tubular backpulse pressure filters in kraft mills deteriorates, even with regular acid washing. Unscheduled filter replacement due to filter plugging results in significant costs and may result in mill downtime. We identified acid-insoluble filter-plugging materials by scanning electron microscope/energy-dispersion X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis in both polypropylene and Gore-Tex™ membrane filter socks. The major filter-plugging components were calcium sulfate (gypsum), calcium phosphate (hydroxylapatite), aluminosilicate clays, metal sulfides, and carbon. We carried out detailed sample analysis of both the standard acid-washing procedure and a modified procedure. Filter plugging by gypsum and metal sulfides appeared to occur because of the acid-washing procedure. Gypsum formation on the filter resulted from significant hydrolysis of sulfamic acid solution at temperatures greater than 130°F. Modification of the acid-washing procedure greatly reduced the amount of gypsum and addition of a surfactant to the acid reduced wash time and mobilized some of the carbon from the filter. With surfactant, acid washing was 95% complete after 40 min.

A study on using expanded perlite with hydroxyapatite: Reinforced bio-composites

2021 ◽  
pp. 095441192199656
Author(s):  
Erdoğan Karip ◽  
Mehtap Muratoğlu
Keyword(s):  
Body Fluid ◽  
Xrd Analysis ◽  
Cold Isostatic Pressing ◽  
Expanded Perlite ◽  
X Ray Diffraction ◽  
Pressing Method ◽  
X Ray ◽  
Infra Red ◽  
Ft Ir

People are exposed to different kinds of diseases or various accidents in life. Hydroxyapatite (HA) has been widely employed for bone treatment applications. In this study, HA was extracted from sheep bones. Bio-composites were doped with 1, 5, and 10 wt.% of expanded perlite and 5 wt.% of ZrO2–MgO-P2O5. The bio-composites were prepared by the cold isostatic pressing method (250 MPa) and sintered at 900°C for 1 h. In order to evaluate the characteristics of the bio-composites, microhardness, density, X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) analyses were carried out on them. Additionally, the specimens whose characteristics were determined were kept in synthetic body fluid (SBF), and their in vitro behavior was examined. As a result, it was observed that microhardness increased as both the weight and the grain size of the expanded perlite were increased. Calcium silicate, tri-calcium phosphate, and hydroxyapatite were observed in the XRD analysis of all samples, and the formation of apatite structures was increased by addition of ZrO2–MgO–P2O5.

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