Colloidal characterization and electrophoretic deposition of hydroxyapatite on titanium substrate

Area of Science:

• Biomaterials Science
• Materials Engineering
• Surface Chemistry

Background:

• Hydroxyapatite (HA) is a key biomaterial for bone regeneration due to its biocompatibility and osteoconductivity.
• Titanium implants are widely used in orthopedics, but their surface properties can be enhanced for better osseointegration.
• Electrophoretic deposition (EPD) offers a versatile method for coating complex shapes like titanium tubes with HA.

Purpose of the Study:

• To optimize the electrophoretic deposition of hydroxyapatite (HA) powders onto a titanium tubular substrate.
• To characterize the HA suspension and deposition process for enhanced coating quality.
• To evaluate the microstructure, stoichiometry, and adhesion strength of the synthesized HA coatings.

Main Methods:

• Modified chemical co-precipitation was used to prepare HA powders.
• HA suspension stability was determined by measuring zeta potential, electromobility, and particle size at various pH levels.
• Electrophoretic deposition was performed under optimized conditions, followed by sintering, microstructure examination, stoichiometry confirmation, and shear strength testing.

Main Results:

• An optimal suspension condition for stable and well-dispersed HA particles was identified.
• The EPD process yielded a sintered HA deposit on the titanium substrate with confirmed stoichiometry.
• Shear strength tests quantified the adhesion strength of the hydroxyapatite coating.

Conclusions:

• The study successfully established an optimized electrophoretic deposition method for creating hydroxyapatite coatings on titanium.
• The characterized HA coatings exhibited favorable properties, including strong adhesion, suitable for biomedical applications.
• The experimental data aligned with theoretical models, validating the deposition process.