Hydrothermal syntheses enable us to prepare HAp crystals with various aspect ratios. HAp crystals 50 nm x145 nm, aspect ratio = 2.9) were crystallized from the HAp precursor precipitated from Ca(OH)2 and H3PO4 solutions at 200 °C under 2MPa for 5 h. Among the experimental factors, adding additives are most effective to control the aspect ratio. KOH, K3PO4 and EDTA gave needle-like HAp; aspect ratio = 63 7 and 11, respectively under the similar hydrothermal conditions.
ASJC Scopus subject areas
- Chemical Engineering(all)