Electrophoretic coating of multilayered apatite composite on alumina ceramics

Abstract

By means of an electrophoretic deposition technique followed by sintering, alumina and zirconia ceramics were coated with apatitic composites composed of porous surface and intermediate layers of hydroxyapatite and an adhesive calcium phosphate layer. The electrophoretic deposition of these layers was attained by the use of a mixed solvent of acetylacetone and alcohol as well as the mixed powders of the calcium phosphates and alumina. The adhesive layer was formed by the codeposition of calcium phosphate glass powders (Ca/P = 1/2) with hydroxyapatite, while the open porosity of the surface layer was increased with the addition of alumina to the hydroxyapatite layers. The resultant phases of sintered composite layers were tricalcium phosphate and alumina with a small amount of hydroxyapatite.

Preparation of NiO-YSZ/YSZ bi-layers for solid oxide fuel cells by electrophoretic deposition

“…The rate of electrophoretic deposition depends primarily on the charges on the particles, the electrophoretic mobility of the particles in the solvent, and the applied electric field. The EPD technique has been used successfully in biomedical applications [20,21], luminescent materials [22][23][24], gas diffusion electrodes [25], oxidation resistant coatings [26], multi-layer composites [27], oxide nanorods [28], carbon nanotube films [29], functionally graded ceramics [30,31], layered ceramics [32], superconductors [33], piezoelectric materials [34], thick film of silica [35], and nano-size zeolite membranes [36]. Considering these vast fields of application, the EPD technique is being recognized to hold a great potential for economic fabrication of thin, dense electrolyte as well as porous electrodes for SOFC applications.…”

Nanostructured Hydroxyapatite Coatings for Improved Adhesion and Corrosion Resistance for Medical Implants

“…It has been demonstrated that nano ceramics have thermal expansion coefficients that nearly match the metal alloys due to the large volume fraction of atoms located at the grain boundary, which improves mobility [3,4]. To date, electrophoretic deposition ("EPD") of HA has been limited to conventional materials of micron grain size [5][6][7][8][9]. Mechanical properties of the micron HA are limited by relatively poor bend strength, fracture toughness, and compressive strength.…”

Biomimetic nanostructured hydroxyapatite coatings on metallic implant materials

“…52 The deposition involves the application of electric field to a colloidal suspension resulting in the migration of charged particles under the influence of an electric field (electrophoresis) and subsequent adhesion onto an electrode (substrate). 34,35,53,54 Furthermore, the method uses low-cost equipment, easy to set-up and is able to coat complex shapes and patterns. It is a cheaper method than chemical vapour deposition, sol-gel deposition and sputtering for producing films of a wide range of thickness.…”