Electrovector Effect of Polarized and Chemically Treated Na2O-CaO-P2O5-SiO2-Al2O3 Bioglasses

2006 ◽  
Vol 309-311 ◽  
pp. 337-340
Author(s):  
Taketo Sasaki ◽  
Masahiro Kobayashi ◽  
Satoshi Nakamura ◽  
Kimihiro Yamashita
Keyword(s):  
Simulated Body Fluid ◽  
Current Density ◽  
Chemical Treatment ◽  
Body Fluid ◽  
Complex Impedance ◽  
Immersion Test ◽  
Depolarization Current ◽  
Impedance Measurements ◽  
Electrical Conductivities ◽  
Thermally Stimulated Depolarization

Na2O-CaO-P2O5-SiO2-Al2O3 (NCPSA) glass was investigated in its electrical polarizability by complex impedance and thermally stimulated depolarization current (TSDC) measurements. Moreover, the NCPSA glass was also subjected to a chemical treatment for bioactivity improvement. The effects of the electrical polarization and the chemical treatment on apatite formability of NCPSA glass were investigated by immersion test using simulated body fluid. From the result of complex impedance measurements, the activation energies for electrical conductivities NCPSA glass was 1.1eV. From the TSDC measurements, the polarized NCPSA glass showed monotonically increasing curves in depolarization current density spectra. The stored electrical charge calculated from TSDC measurements of the NCPSA glass polarized with electrical dc field of 2kV･cm-1 at 600°C for 1h was 4.91 mC･cm-2. The NCPSA glass treated with 1M NaOH indicated apatite formability in SBF and exhibited bioactivity. We disclosed that the combination of electropolarization and chemical treatment changed the apatite formability of the NCPSA glass in SBF, consequently, improved the bioactivity of the glass.

Effect of Electrical Polarization on the Behavior of Bioactive Glass Containing MgO and B2O3 in SBF

2006 ◽  
Vol 309-311 ◽  
pp. 333-336
Author(s):  
Emiko Amaoka ◽  
Erik Vedel ◽  
Satoshi Nakamura ◽  
Yusuke Moriyoshi ◽  
Jukka I. Salonen ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Simulated Body Fluid ◽  
Bioactive Glass ◽  
Body Fluid ◽  
Charged Surface ◽  
Depolarization Current ◽  
Electrical Polarization ◽  
Thermally Stimulated Depolarization Current ◽  
Thermally Stimulated Depolarization ◽  
Calcium Phosphate Precipitation

We investigated the electrical polarizability of MgO and B2O3 containing bioactive glass (MBG). The MBG material with good manufacturing properties but low bioactivity was electrically polarized at a high dc field. The electrical polarizability of MBG was evaluated by thermally stimulated depolarization current (TSDC) measurements and immersion in simulated body fluid (SBF). The early precipitation of calcium phosphate on the negatively charged surface of the treated MBG demonstrated the increased bioactivity of the material and confirmed its polarizability. It is suggested that the electrical interactions between the polarized MBG and ions in SBF promoted the formation of the calcium phosphate precipitation. Accordingly, the increased bioactivity of the MBG in SBF is suggested to demonstrate the conversion of MBG into electrovector ceramics by the polarization treatment.

scholarly journals Preparation and Degradation Characteristics of MAO/APS Composite Bio-Coating in Simulated Body Fluid

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 667
Author(s):  
Zexin Wang ◽  
Fei Ye ◽  
Liangyu Chen ◽  
Weigang Lv ◽  
Zhengyi Zhang ◽  
...  
Keyword(s):  
Simulated Body Fluid ◽  
Composite Coating ◽  
Body Fluid ◽  
Composite Coatings ◽  
Degradation Process ◽  
Ceramic Coatings ◽  
Immersion Test ◽  
Substrate Material ◽  
Atmospheric Plasma

In this work, ZK60 magnesium alloy was employed as a substrate material to produce ceramic coatings, containing Ca and P, by micro-arc oxidation (MAO). Atmospheric plasma spraying (APS) was used to prepare the hydroxyapatite layer (HA) on the MAO coating to obtain a composite coating for better biological activity. The coatings were examined by various means including an X-ray diffractometer, a scanning electron microscope and an energy spectrometer. Meanwhile, an electrochemical examination, immersion test and tensile test were used to evaluate the in vitro performance of the composite coatings. The results showed that the composite coating has a better corrosion resistance. In addition, this work proposed a degradation model of the composite coating in the simulated body fluid immersion test. This model explains the degradation process of the MAO/APS coating in SBF.

Corrosion Resistance of Mg-4Zn Alloy with Amorphous Micro-Arc Oxidation Coating in Simulated Body Fluid

2016 ◽  
Vol 852 ◽  
pp. 1325-1333
Author(s):  
Li Chen Zhao ◽  
Shuang Jin Liu ◽  
Yu Min Qi ◽  
Chun Xiang Cui
Keyword(s):  
Corrosion Resistance ◽  
Simulated Body Fluid ◽  
Current Density ◽  
Polarization Resistance ◽  
Body Fluid ◽  
Corrosion Current Density ◽  
Corrosion Current ◽  
Metal Substrate ◽  
Electrochemical Measurements ◽  
Micro Arc Oxidation

A binary Mg-4Zn alloy was fabricated as a potential degradable biomaterial. To improve the corrosion resistance of Mg-4Zn alloy, an amorphous micro-arc oxidation (MAO) coating was prepared on the Mg-4Zn substrate. Electrochemical measurements and immersion tests were employed to evaluate the corrosion resistance of the specimen in simulated body fluid (SBF). Electrochemical measurements show that the Mg-4Zn alloy covered with a MAO coating has a much lower corrosion current density and a much greater polarization resistance. Immersion tests suggest that the degradation of Mg-4Zn substrate is relatively serious during the initial 8 h of immersion although it has been protected by a MAO coating. When most micro-pores within the MAO coating have been filled with precipitates resulted from the corrosion of the metal substrate, the degradation of the Mg-4Zn substrate is significantly delayed.

Fabrication of Brushite Coating on AZ91D and AZ31 Alloys by Two-Step Chemical Treatment and Its Surface Protection in Simulated Body Fluid

2019 ◽  
Vol 28 (6) ◽  
pp. 3803-3815 ◽  
Author(s):  
Y. Sasikumar ◽  
A. Madhan Kumar ◽  
R. Suresh Babu ◽  
P. Dhaiveegan ◽  
N. Al-Aqeeli ◽  
...  
Keyword(s):  
Simulated Body Fluid ◽  
Chemical Treatment ◽  
Body Fluid ◽  
Surface Protection

Polarization Energy Effect of Electrovector Hydroxyapatite on Bonelike Crystal Growth in SBF

2006 ◽  
Vol 309-311 ◽  
pp. 145-148 ◽  
Author(s):  
Satoshi Nakamura ◽  
Keiichirou Shinohara ◽  
Nobuo Kieda ◽  
Kimihiro Yamashita
Keyword(s):  
Crystal Growth ◽  
Body Fluid ◽  
Early Stage ◽  
Grown Layer ◽  
Energy Effect ◽  
Depolarization Current ◽  
Polarization Energy ◽  
Biomimetic Method ◽  
Thermally Stimulated Depolarization

An electrovector effect of the polarized hydroxyapatite (HA) on crystal growth in a simulated body fluid was clarified to discuss the role of the polarization energy in the effect. The polarization of the HA carried out in high dc field at 300-600°C was confirmed by thermally stimulated depolarization current measurements. The dependence of the thickness of the crystal grown layer on the induced charge was remarkably indicated in the modification of the growth rates. The growth rate under an optimum polarization condition was estimated to be almost 3 times of that by the biomimetic method. At the early stage of the crystal growth, the grown crystals were spherical and their sizes were dependent on the field strength and time for polarization. The polarization is therefore considered to effect the nucleation as well as the crystal growth.

Characteristics of As-Cast and Forged Biodegradable Mg-Ca Binary Alloy Immersed in Kokubo Simulated Body Fluid

2012 ◽  
Vol 445 ◽  
pp. 301-306 ◽  
Author(s):  
M.H. Idris ◽  
Hassan Jafari ◽  
S.E. Harandi ◽  
M. Mirshahi ◽  
S. Koleyni
Keyword(s):  
Simulated Body Fluid ◽  
Body Fluid ◽  
Electrochemical Behaviour ◽  
Calcium Content ◽  
Immersion Test ◽  
Biodegradable Implant ◽  
Forging Process ◽  
Polarization Test ◽  
Simulated Body Fluid Immersion

Biodegradable implant is an alternative to metallic implant and has the advantage of not being necessary to remove once the fracture has healed. Magnesium is particularly desirable since it is biocompatible and has a modulus of elasticity closer to bone. In addition, it shows ability to biodegrade in situ, when used as an implant material. In this research, different percentages of calcium were added to magnesium during melting of the alloy. A selected alloy was forged at different parameters. Both as cast and forged alloys were subjected to polarization test performed in Kokubo simulated body fluid. Immersion test in the fluid was conducted for 96 hours to investigate the formation, growth and morphology of the hydroxyapatite on the surface of the alloys. The results showed that similar electrochemical behaviour took place in the alloys regardless of the calcium content. However, an increase in corrosion rate was observed with increasing calcium content. It was also observed that forging process decreased the corrosion resistance of the alloy. Furthermore, increasing calcium content accelerated the growth of bone-like apatite in the alloy.

Characterization of the Apatite Formation on the Surfaces of Zirconia and Alumina Ceramics in Body Environments

2008 ◽  
Vol 591-593 ◽  
pp. 697-702 ◽  
Author(s):  
Amanda Abati Aguiar ◽  
Valter Ussui ◽  
Christiane Ribeiro ◽  
Marcos A. Scapin ◽  
Dolores Ribeiro Ricci ◽  
...  
Keyword(s):  
Simulated Body Fluid ◽  
Functional Groups ◽  
Chemical Treatment ◽  
Body Fluid ◽  
Apatite Formation ◽  
Alumina Ceramics ◽  
Surface Functional Groups ◽  
Chemical Treatments ◽  
Al2o3 Composite

Induction of an apatite-forming ability on a 100% Y2O3-ZrO2, 100% Al2O3, and 80/20 and 20/80 wt% of zirconia-alumina (Y2O3-ZrO2-Al2O3) composite polycrystals via chemical treatment with 5M H3PO4 have been investigated. The chemical treatments produced Zr-O surface functional groups, which are known to be effective for apatite nucleation in simulated body fluid. It’s believed that Al-OH surface functional groups are not effective for apatite nucleation. I this work was shown that apatite nucleates in substrate of alumina treat and untreated chemically. This implies that Al- OH functional groups are effective for apatite nucleation.

Structure Control of Bioactive Titanate Nanomesh Layers Fabricated on Laser Irradiated Ti-based Bulk Metallic Glass using Hydrothermal-Electrochemical Method

2011 ◽  
Vol 1316 ◽  
Author(s):  
Sayaka Maruyama ◽  
Naota Sugiyama ◽  
Masahiro Yoshimura ◽  
Togo Shinonaga ◽  
Masahiro Tsukamoto ◽  
...  
Keyword(s):  
Simulated Body Fluid ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Electrolyte Solution ◽  
Current Density ◽  
Electrochemical Method ◽  
Body Fluid ◽  
Structure Control ◽  
Hydrothermal Electrochemical Method

ABSTRACTThe surface of Ti-based bulk metallic glass (BMG) was irradiated by the femto-second laser and microgrooves were formed on the surface. The titanate nanomesh layers were fabricated on the micro-grooved BMG surface by hydrothermal-electrochemical (H-E) treatment changing the conditions of the concentration of electrolyte solution (0 and 5 M) and applying current density (0-200 mA/cm2). The bone-inducing capacity of the samples with different H-E treatment was confirmed by soaking them in a simulated body fluid for 12 days. The H-E treatment in higher concentration 5 M NaOH aq. and applying higher current density above 0.5 mA/cm2 exhibited excellent bioactivity inducing large hydroxyapatite crystallites.

Electrovector Effect of Polarized Porous Hydroxyapatite Ceramics

2006 ◽  
Vol 309-311 ◽  
pp. 1043-1046
Author(s):  
Chikako Ikeda ◽  
Mikihiro Ueki ◽  
Satoshi Nakamura ◽  
Takayuki Kobayashi ◽  
Kimihiro Yamashita
Keyword(s):  
Simulated Body Fluid ◽  
Porous Structure ◽  
Electric Current ◽  
Current Density ◽  
Body Fluid ◽  
Electric Current Density ◽  
Porous Hydroxyapatite ◽  
Hydroxyapatite Ceramics ◽  
Scaffold Materials ◽  
Current Densities

Porous HA ceramics has been developed for the scaffold materials because the porous structure has been recognized to be necessary to invasion of body fluid and ingrowth of bone. The synthesized porous HA ceramics with several porosities were electrically polarized, and then the TSDC spectra were measured. The maximum electric current density and the stored polarization charges decreased with increasing the porosity. Therefore it was thought that the decreasing the amount of proton of porous HA ceramics was one of the reasons of decreasing of the maximum electric current densities and the stored charges. The simulated body fluid (SBF) test implied that electrovector effects enhanced the apatite formabilities.

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