Anodic oxidation of titanium in sulphuric acid (H2SO4) for biomedical application
Titanium (Ti) is widely used in the biomedical field because it is light, strong and biocompatible. However, Ti is non-bioactive and does not show any apatite forming ability after being implanted into the body. Anodic oxidation is one of the traditional methods to modify the surface of Ti into tita...
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| Format: | Thesis |
| Published: |
2013
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| Online Access: | http://eprints.uthm.edu.my/5447/ http://eprints.uthm.edu.my/5447/1/NOOR_HAFIZA_MOHD_IDRUS.pdf |
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| Summary: | Titanium (Ti) is widely used in the biomedical field because it is light, strong and
biocompatible. However, Ti is non-bioactive and does not show any apatite forming
ability after being implanted into the body. Anodic oxidation is one of the traditional
methods to modify the surface of Ti into titanium oxide (TiO2), thereby enhancing
the biocompatiblity properties. Anodisation was done by supplying direct current
(d.c) through ananode and a cathode consisting of Ti substrate soaked in the
electrolyte of strong sulphuric acid solution (H2SO4) with pH ranged from 0.3 to 2.1.
Different voltages ranged from 10 to 300 V were applied to investigate its effect on
the TiO2 formation whereas the effect of H2SO4 concentrations on TiO2 production
was studied by using three different concentrations of 0.5 M, 1.5 M and 3.0 M,
respectively. Characterisation was made in terms of microstructure using field
emission scanning electron microscope (FESEM), mineralogy using x-ray diffraction
(XRD) whereas the sample color were captured using a digital camera. In vitro test
was also conducted on anodised Ti by soaking the samples in simulated body fluid
(SBF) for seven days to study the growth of hydroxyapatite (HAP). HAP growth can
be enhanced by ultraviolet (UV) irradiation. An alternative group of in vitro samples
were exposed to UV and the HAP growth rate was compared with those unexposed.
The porosity of TiO2 increased as higher voltage and H2SO4 concentration was used.
Though variable in shape, the porosity of TiO2 was found to be directly proportional
to the applied voltage and electrolyte concentration. The XRD analysis showed that
the anatase phase started at a lower voltage in higher electrolyte concentrations.
Increasing voltage contributed to more anatase formation and also induced rutile
phase. The HAP growth was enhanced by UV irradiation in the in vitro test as HAP
grew more and appeared denser on the surface of TiO2 where UV light was used as
compared to the SBF immersion in dark condition. |
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