Production of Tubular Shape Macroporous Hydroxyapatite Ceramic Tubes Using Electrophoretic Deposition (EPD)


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Üstündağ C. B. , Ioku K., Kaya F. , Kaya C.

Journal Of Biomechanics, cilt.43, no.12, ss.8-9, 2010 (SCI İndekslerine Giren Dergi)

Özet

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.