Hydroxyapatite nano-powders produced hydrothermally from nacreous material

• Published in: Journal of the European Ceramic Society 2006, Vol.26 (16), p.3639-3646
• Main Authors: Lemos, A.F., Rocha, J.H.G., Quaresma, S.S.F., Kannan, S., Oktar, F.N., Agathopoulos, S., Ferreira, J.M.F.
• Format: Article
• Language: English
• Subjects: Apatite; Biological and medical sciences; Biomedical applications; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Medical sciences; Microstructure-final; Nacre; Nanopowders; Nanoscale materials and structures: fabrication and characterization; Physics; Powders-chemical preparation; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Technology. Biomaterials. Equipments. Material. Instrumentation
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2005.12.011

Nano-powders of pure AB-type carbonated hydroxyapatite (HA) sized of ∼100 nm were successfully produced via hydrothermal transformation (HT) of milled oyster shell powders at 200 °C. Low production cost, worldwide availability and natural-biological origin of raw materials are important features of the investigated process. When fine shell powders were used, the transformation reaction from aragonite to hydroxyapatite was accomplished within about 24 h. Calcite, concentrated at the outer surface of the shells, was less prone to transform into hydroxyapatite under the investigated hydrothermal conditions, even after prolonged reaction time (72 h) or in highly concentrated phosphate solutions.