Electrophoretic Deposition and Characterization of Biocomposites on Magnesium for Orthopedic Applications

2014 ◽  
Vol 922 ◽  
pp. 761-766 ◽  
Author(s):  
Qiao Mu Tian ◽  
Hui Nan Liu

The objective of this study is to produce a uniform and consistent nanophase hydroxyapatite (nHA) and poly (lactic-co-glycolic acid) (PLGA) coating on three-dimensional magnesium (Mg) implants using electrophoretic deposition (EPD) process. Mg is biodegradable, mechanically strong, and promising for orthopedic implant and device applications. However, currently available Mg and its alloys degrade too rapidly to meet clinical needs. To control Mg degradation and promote bone ingrowth, nHA/PLGA composite microspheres were synthesized and deposited onto Mg substrates using EPD process. Annealing was applied to improve the coating adhesion. The surface morphology, composition, and coating cross-section were examined using a scanning electron microscope and energy dispersive X-ray spectrometer. The results showed the presence of calcium, phosphorous, carbon, and oxygen peaks, indicating the successful deposition of nHA/PLGA microspheres on Mg. The corrosion resistance of the coated Mg was evaluated using the Tafel test. The results showed that the nHA/PLGA composite coating improved the corrosion resistance of Mg.

2021 ◽  
Vol 127 ◽  
pp. 388-397
Author(s):  
Rani Puthukulangara Ramachandran ◽  
Chyngyz Erkinbaev ◽  
Sandeep Thakur ◽  
Jitendra Paliwal

2018 ◽  
Vol 139 ◽  
pp. 75-82 ◽  
Author(s):  
A.H. Galmed ◽  
A. du Plessis ◽  
S.G. le Roux ◽  
E. Hartnick ◽  
H. Von Bergmann ◽  
...  

2000 ◽  
Vol 33 (4) ◽  
pp. 1023-1030 ◽  
Author(s):  
M. Ohler ◽  
M. Sanchez del Rio ◽  
A. Tuffanelli ◽  
M. Gambaccini ◽  
A. Taibi ◽  
...  

Section topographs recorded at different spatial locations and at different rocking angles of a highly oriented pyrolytic graphite (HOPG) crystal allow three-dimensional maps of the local angular-dependent scattering power to be obtained. This is performed with a direct reconstruction from the intensity distribution on such topographs. The maps allow the extraction of information on local structural parameters such as size, form and internal mosaic spread of crystalline domains. This data analysis leads to a new method for the characterization of mosaic crystals. Perspectives and limits of applicability of this method are discussed.


Author(s):  
Anatoly Frenkel

We discuss methods of Extended X-ray Absorption Fine-Structure (EXAFS) analysis that provide three-dimensional structural characterization of metal nanoparticles, both mono- and bi-metallic. For the bimetallic alloys, we use short range order measurements to discriminate between random and non-random inter-particle distributions of atoms. We also discuss the application of EXAFS to heterogeneous nanoparticle systems.


2007 ◽  
Vol 330-332 ◽  
pp. 503-506
Author(s):  
Xiao Wei Fu ◽  
Jie Huang ◽  
E.S. Thian ◽  
Serena Best ◽  
William Bonfield

A Bioglass® reinforced polyethylene (Bioglass®/polyethylene) composite has been prepared, which combines the high bioactivity of Bioglass® and the toughness of polyethylene. The spatial distribution of Bioglass® particles within the composite is important for the performance of composites in-vivo. Recent developments in X-ray microtomography (XμT) have made it possible to visualize internal and microstructural details with different X-ray absorbencies, nondestructively, and to acquire 3D information at high spatial resolution. In this study, the volume fraction and 3D spatial distribution of Bioglass® particles has been acquired quantitatively by XμT. The information obtained provides a foundation for understanding the mechanical and bioactive properties of the Bioglass®/polyethylene composites.


2003 ◽  
Vol 58 (1) ◽  
pp. 151-154 ◽  
Author(s):  
Rosa Carballo ◽  
Berta Covelo ◽  
Ezequiel M. Vázquez-Lópeza ◽  
Alfonso Castiñeiras ◽  
Juan Niclós

Abstract A new mixed-ligand complex of copper(II) with 1,10-phenanthroline and 2-methyllactate was prepared. [Cu(HmL)2(phen)] ·2H2O (where HmL = monodeprotonated 2-methyllactic acid) was characterized by elemental analysis, IR, electronic and EPR spectroscopy, magnetic measurements at room temperature, thermogravimetric analysis and X-ray diffractometry. The copper atom is in a tetragonally distorted octahedral environment and the 2-methyllactato ligand is bidentately chelating. The presence of lattice water molecules mediates the formation of a three-dimensional network.


Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 815 ◽  
Author(s):  
Samuel Mbugua Nyambura ◽  
Min Kang ◽  
Jiping Zhu ◽  
Yuntong Liu ◽  
Yin Zhang ◽  
...  

Ni–W/Cr2O3 nanocomposite coatings were synthesized from aqueous sulphate-citrate electrolyte containing Cr2O3 nanoparticles on a steel surface using conventional electrodeposition technique. This study was aimed at investigating the influence of Cr2O3 nanoparticle content on the microstructure, corrosion resistance, and mechanical properties of electrodeposited Ni–W/Cr2O3 nanocomposite coatings. Ni–W binary alloy coatings were deposited and optimized before addition of the nanoparticles to produce high-quality coatings. The microstructure and chemical composition of the Ni–W/Cr2O3 nanocomposite coatings were evaluated using scanning electron microscope (SEM), energy dispersive X-ray spectrometer (EDS), and XRD. Corrosion resistance properties were evaluated using potentiodynamic polarization (Tafel) measurements in 3.5 wt.% NaCl medium. The corrosion resistance and microhardness are significantly higher in Ni–W/Cr2O3 nanocomposite coatings compared to pure Ni–W binary alloy and increase with the increase in content of Cr2O3 nanoparticles in the coatings. Wear resistance is also higher in Ni–W/Cr2O3 nanocomposite coatings.


2016 ◽  
Vol 22 (4) ◽  
pp. 808-813 ◽  
Author(s):  
Chandrashekara S. Kaira ◽  
Carl R. Mayer ◽  
V. De Andrade ◽  
Francesco De Carlo ◽  
Nikhilesh Chawla

AbstractThree-dimensional (3D) nondestructive microstructural characterization was performed using full-field transmission X-ray microscopy on an Sn-rich alloy, at a spatial resolution of 60 nm. This study highlights the use of synchrotron radiation along with Fresnel zone plate optics to perform absorption contrast tomography for analyzing nanoscale features of fine second phase particles distributed in the tin matrix, which are representative of the bulk microstructure. The 3D reconstruction was also used to quantify microstructural details of the analyzed volume.


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