scholarly journals Microwave-Assisted Preparation of Zinc-Doped β-Tricalcium Phosphate for Orthopedic Applications

2020 ◽  
Author(s):  
Ali Taha Saleh ◽  
Dheyaa Alameri
Keyword(s):  
Tricalcium Phosphate ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Assisted ◽  
Ftir Spectrometer ◽  
Diffraction Peaks ◽  
Orthopedic Applications ◽  
The Degree Of Crystallinity ◽  
Good Agreement

A novel two-step methodology delivering zinc into the structure of β-tricalcium phosphate (β-TCP) has been investigated. Incorporating wet precipitation of calcium-deficient apatite [Ca9-xZnx(HPO4)(PO4)5(OH)] (x = 0.00–1.00 mol) using a microwave-assisted process followed by two-hour calcination at 1000 °C has been conducted to generate a ratio of 1.48 of Zn doped β-TCP. The products were characterized by X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectrometer, and field emission scanning electron microscope (FESEM). Our results confirmed that the product was crystalline Zn2+-doped β-tricalcium phosphate. The incorporation of Zn+2 into the β-TCP lattice resulted in a shifting of diffraction peaks to higher 2θ values, which were attributed to the substitution of larger-sized Ca+2 ions with smaller-sized Zn2+ ions. A reduction in the intensity of the XRD peaks was also observed due to the reduction in the degree of crystallinity of the samples. Lattice parameters along the a and c-axis showed a gradual decrease in length with an increase in the amount of Zn2+ doping. This decrease was attributed to the replacement of Ca+2 ion by the smaller-sized Zn2+ ions. The microstructure of the powders consisted of microscale aggregates fused together. EDX analysis of all samples showed that the Zn2+ doping had successfully taken place and the amount of Zn2+ present in the samples was in good agreement with the theoretical values.

scholarly journals Hemp Fibre Reinforced Poly(Lactic Acid) Composites

2007 ◽  
Vol 29-30 ◽  
pp. 337-340 ◽  
Author(s):  
M.A. Sawpan ◽  
K.L. Pickering ◽  
Alan Fernyhough
Keyword(s):  
Lactic Acid ◽  
Degree Of Crystallinity ◽  
Poly Lactic Acid ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Hemp Fibre ◽  
Reinforcing Material ◽  
Fibre Loading ◽  
The Degree Of Crystallinity

The potential of hemp fibre as a reinforcing material for Poly(lactic acid) (PLA) was investigated. Good interaction between hemp fibre and PLA resulted in increases of 100% for Young’s modulus and 30% for tensile strength of composites containing 30 wt% fibre. Different predictive ‘rule of mixtures’ models (e.g. Parallel, Series and Hirsch) were assessed regarding the dependence of tensile properties on fibre loading. Limited agreement with models was observed. Differential scanning calorimetry (DSC) and x-ray diffraction (XRD) studies showed that hemp fibre increased the degree of crystallinity in PLA composites.

Experimental Study of Precise Peak Determination in X-Ray Powder Diffraction

1983 ◽  
Vol 27 ◽  
pp. 53-60 ◽  
Author(s):  
T. C. Huang ◽  
W. Parrish ◽  
G. Lim
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
Search Results ◽  
Profile Fitting ◽  
Derivative Method ◽  
Diffraction Peaks ◽  
Peak Search ◽  
Different Characteristics ◽  
Good Agreement ◽  
Statistical Noise

AbstractThe combined derivative method (accompanying paper) was tested with a large number of experimental patterns to illustrate its use in various difficult problems commonly arising in peak search analysis of X-ray diffraction data. Patterns obtained with various step sizes, resolution, counting statistical noise, and profile widths were used. The precision in 2θ determination and overlap resolution are in good agreement with those previously obtained from calculated profiles, raise identification of noise as diffraction peaks was eliminated by using a convolution range proportional to the full width at half maximum. Peak search results (both 2θ and intensity) were also compared to those obtained by profile fitting to illustrate the different characteristics of these two methods.

Study of the structure and thermal characteristics of nanocomposites based on polyvinyl alcohol and intercalated montmorillonite

2019 ◽  
pp. 089270571987919
Author(s):  
Volodymyr Krasinskyi ◽  
Ivan Gajdos ◽  
Oleh Suberlyak ◽  
Viktoria Antoniuk ◽  
Tomasz Jachowicz
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Acrylic Acid ◽  
Polyvinyl Alcohol ◽  
Thermal Characteristics ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
The Degree Of Crystallinity

The structure and thermal characteristics of nanocomposites based on polyvinyl alcohol (PVA) and montmorillonite (MMT) intercalated with polyvinylpyrrolidone were investigated by X-ray diffraction analysis and differential scanning calorimetry. The modification of PVA with intercalated MMT reduces the degree of crystallinity of the resulting nanocomposites but significantly increases their thermal stability. Under ultrasound, the intercalated MMT was completely distributed in a PVA solution and formed a monocrystalline structure. Films based on PVA with modified MMT were cross-linked at 110°C in the presence of 5 wt% acrylic acid and 0.5 wt% Ferrous(II) sulfate as an initiator. The formed films have a homogeneous cross-linked structure.

Periodicities in the X-Ray Diffraction of Low Order ALAS/GAAS Superlattices

1991 ◽  
Vol 230 ◽  
Author(s):  
Joseph Pellegrino ◽  
S. Qadri ◽  
W. Tseng ◽  
W. R. Miller ◽  
J. Comas
Keyword(s):  
Growth Conditions ◽  
X Ray Diffraction ◽  
Satellite Peak ◽  
X Ray ◽  
Migration Enhanced Epitaxy ◽  
Diffraction Peaks ◽  
Superlattice Structures ◽  
And Migration ◽  
Possible Cause ◽  
Good Agreement

AbstractIn this work we examine the physical properties for the superlattice system (GaAs)n1 (AlAs)n2/GaAs(100) for low values of n1 and n2, i.e., n1 = n2 = 3, 6, 12. Normal, interrupted growth, and migration enhanced epitaxy (MEE) growth techniques were used to grow the superlattice structures in a molecular beam epitaxy system. X-ray diffraction spectra were obtained, and the major and satellite peak positions were analyzed to obtain the superlattice periodicity. An analysis of the major diffraction peaks and their associated satellites produced superlattice periodicity in good agreement with theory. Diffraction peaks were also observed in regions adjacent to the primary diffraction peaks which did not occur in the expected satellite positions. An analysis of these peaks relative to the primary peak indicate periodicities corresponding to layer thickness greater than the intended period. One possible cause for these periodicities is growth conditions that exist during the growth of the superlattice which result in the deposition of fractional monolayers. In this study we present results which suggest that an arsenic-deficient growth condition may be a contributing factor in the deposition of fractional monolayers.

scholarly journals Determination of the Degree of Crystallinity of Poly(2-methyl-2-oxazoline)

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4356
Author(s):  
Evgeniy M. Chistyakov ◽  
Sergey N. Filatov ◽  
Elena A. Sulyanova ◽  
Vladimir V. Volkov
Keyword(s):  
Thermal Destruction ◽  
Polymer Melt ◽  
Boron Trifluoride Etherate ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Cationic Ring Opening Polymerization ◽  
The Degree Of Crystallinity

A new method for purification of 2-methyl-2-oxazoline using citric acid was developed and living cationic ring-opening polymerization of 2-methyl-2-oxazoline was carried out. Polymerization was conducted in acetonitrile using benzyl chloride—boron trifluoride etherate initiating system. According to DSC data, the temperature range of melting of the crystalline phase of the resulting polymer was 95–180 °C. According to small-angle X-ray scattering and wide-angle X-ray diffraction data, the degree of crystallinity of the polymer was 12%. Upon cooling of the polymer melt, the polymer became amorphous. Using thermogravimetric analysis, it was found that the thermal destruction of poly(2-methyl-2-oxazoline) started above 209 °C.

Physicochemical Properties of Porous Starches from Different Botanical Origin

2010 ◽  
Vol 159 ◽  
pp. 363-370
Author(s):  
Hua Xi Xiao ◽  
Qin Lu Lin ◽  
Yue Wu ◽  
Wei Tian ◽  
Wei Wu
Keyword(s):  
Potato Starch ◽  
Enzyme Hydrolysis ◽  
Degree Of Crystallinity ◽  
Rice Starch ◽  
Adsorptive Capacity ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Potato Starches ◽  
The Degree Of Crystallinity

Rice, maize and potato starches were hydrolyzed by amylase to obtain porous starches as final product. The adsorptive capacity, desorbed rates, degree of crystallinity and retrogradation properties of native and porous starches were investigated. The results showed that porous starches had the stronger adsorptive capacity and slower desorbed rate compared with native starches. In the three starch materials, the adsorptive capacity of rice starch for liquids was the strongest; the adsorptive capacity of potato starch for liquids was the weakest. the more flavors adsorbed, the more flavors desorbed. X-ray diffraction showed that Enzyme hydrolysis did not result in any significant changes in the degree of crystallinity of starch. The porous starches exhibited lower tendency of retrogradation as assessed by differential scanning calorimetry (DSC).

Poly(Ethylene Oxide)/Styrene Ionomers Blends: Crystallization of Poly (Ethylene Oxide) Component Studied by Wide-Angle X-Ray Diffraction

2007 ◽  
Vol 130 ◽  
pp. 251-256 ◽  
Author(s):  
Czesław Ślusarczyk ◽  
Kazimiera Suchocka-Gałaś
Keyword(s):  
Ethylene Oxide ◽  
Degree Of Crystallinity ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxide Component ◽  
Ionic Groups ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
The Degree Of Crystallinity

Wide-angle X-ray diffraction (WAXD) and the scanning electron microscopy (SEM) were used to determine the morphology of crystalline phase of blends of poly(ethylene-oxide) (PEO) and styrene-acrylic acid (S-AA) copolymers neutralized with sodium ions (Na+). In this study, we investigated the effects of blend composition and the content of ionic groups in amorphous ionomers on the degree of crystallinity and the crystallite sizes. It was found that the degree of crystallinity of PEO in the blends decreases both with increasing S-ANa(6.4) content and with increasing ANa content. The sizes of PEO crystallites, measured both in the direction perpendicular and parallel to the polymer axis, are almost independent of ionic groups content in the amorphous component of the blends but they decrease with increasing S-ANa(6.4) content. For the blends containing small amounts of PEO the confined crystallization of this polymer were observed. The final crystalline morphology of these blends, observed by SEM method, is different in comparison to that formed without spatial confinement.

Crystal Structures of Epitaxially Grown Fe16N2 Single Crystal Films with Giant Magnetic Moments

1992 ◽  
Vol 263 ◽  
Author(s):  
Matahiro Komuro ◽  
Hiroyuki Hoshiya ◽  
Hiroaki Takahashi ◽  
Katsuya Mitsuoka ◽  
Yutaka Sugita
Keyword(s):  
Crystal Orientation ◽  
Magnetic Moments ◽  
Diffraction Method ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
X Ray ◽  
Single Crystal Films ◽  
Crystal Films ◽  
Diffraction Peaks ◽  
Good Agreement

ABSTRACTLattice parameters and crystal orientation for Fe1 6.N2 were determined by an X-ray diffraction method using a three axes goniometer. The lattice parameters of the a-axis and c-axis(a0, c0.) are 5.71 !A and 6.33 !A, respectively. The co corresponds to that of In0, 2,Gao.,s As substrates. Crystal orientation between Fe1 5.N2. films and Ino.,2Gao.,8 As is Fe1 0N2(001)//In0 2.Ga0.2 As(1001) and Fe1 0.N2.(100)//In02Ga0.6As(100). Intensity ratios for these diffraction peaks are in good agreement with calculated values proposed by Jack.

Digital Filtering and Shape Identification in the Analysis of WAXD Patterns of Semicrystalline Polymers

2013 ◽  
Vol 203-204 ◽  
pp. 189-192 ◽  
Author(s):  
Małgorzata Rabiej
Keyword(s):  
Numerical Differentiation ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Amorphous Halo ◽  
Shape Identification ◽  
Diffraction Curve ◽  
X Ray ◽  
The Degree Of Crystallinity ◽  
Quick Determination

Most frequently, the degree of crystallinity of polymers is determined using Wide Angle X-ray Diffraction (WAXD) technique. The method consists in the resolution of WAXD diffraction curve of a polymer into individual crystalline peaks and amorphous halo. This work presents a procedure, which was elaborated to help in a quick determination of the angular positions of crystalline peaks present in the diffraction curve of investigated polymer. The positions of peaks are determined using numerical differentiation. Using these data the computer program WAXSFIT identifies investigated polymer and prepares a set of starting parameters which are used in the calculations of the degree of crystallinity.

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