Akademik Veri Yönetim Sistemi
Journal Of Biomechanics, cilt.43, ss.8-9, 2010 (SCI-Expanded)
Hydroxyapatite (HA) ceramics have been recognized as substitute
materials for bone and teeth in orthopaedic applications due
to their chemical and biological similarity to human bone.
Macroporous hydroxyapatite can be used as scaffold materials,
if its microstructure is controlled in terms of porosity size and
content. The objective of the present work is to produce tubular
shape hydroxyapatite scaffolds for biomedical applications using a
cost-effective technique of electrophoretic deposition (EPD) which
enables to produce 3D complex shapes. Nano hydroxyapatite
powders were produced and mixed with multi-walled carbon nanotubes (MWCNTs) by hydrothermal process. Calcium acetate
(Ca(CH3COO)3), and phosphoric acid (H3PO4) were used as starting
materials for synthesizing the nano HA powders. Macroporous
HA coatings were deposited on carbon rod by EPD at 60 V for
4 min using n-butanol suspensions mixture containing nano HA
powders (10–20 nm in diameter and 20–50 nm in length and with
85 m2/g surface area) and MWCNTs (10–30 nm in diameter, up to
30 micron in length and with 40–300 m2/g surface area). Nano
composite coatings produced were sintered at 1200°C for 60 min
to burn-out the carbon rod and MWCNTs. It is shown that MWCNTs
provide crackles coating layers after coating and porous structure
after sintering. Obtained macroporous HA coatings were coated
using different EPD parameters in terms of applied voltage and
deposition time. EPD provides a coating thickness of ~200 microns
for a depositions time of 240 seconds. The method enabled
the formation of coatings with variables thickness depending
on the coating durations and applied DC voltage. Synthesized
powders and obtained porous HA were studied by X-ray diffraction,
FT-IR, electron microscopy and energy dispersive spectroscopy.
Hydrothermal mixing of HA-MWCNTs and mechanism of deposition
are also discussed. The methods can capable to produce 3D complex
shape hydroxyapatite scaffolds for clinical applications. The results
demonstrate that the obtained hydroxyapatite tubes are candidate
materials as a scaffold for bone repairing and generation.