TY - JOUR
T1 - Hydrothermal synthesis of hydroxyapatite from natural source
AU - Jinawath, S.
AU - Pongkao, D.
AU - Yoshimura, M.
N1 - Funding Information:
The authors acknowledge the experimental assistance of Ms S. Limpanuphap, the secretarial help of Mr W. Prakaypun, the technical assistance of Mr T. Fujino as well as the financial support by Thailand–Japan Technology Transfer Project (TJTTP) and National Metal and Materials Technology Center (MTEC). Finally, we thank Prof. Dr. R. B. Heimann (Freiberg University, Germany) for his valuable comment.
PY - 2002
Y1 - 2002
N2 - Dicalcium phosphate dihydrate (DCPD) and anhydrous dicalcium phosphate (DCPA) extracted from a by-product in a manufacture of gelatin from bovine bone are used as starting materials for the hydrothermal synthesis of hydroxyapatite (HA) at temperatures of 160 and 200°C under vapor pressures of 1 and 2 MPa, respectively. The suspension of DCPA with water gives a mixture of DCPA and HA as product but after adjusting the Ca/P molar ratio to 1.50 and 1.67 by addition of Ca(OH)2, a single phase of HA with needle-like crystals is obtained. DCPA whiskers are produced in the suspension of DCPD with water but, on addition of Ca(OH)2, the product obtained is again, a mixture of DCPA and HA. The coexistence of DCPA and HA is observed not only in the acidic region at pH 4.6 which is close to the known quasi-invariant point but also in the basic region at pH 12.3. Without addition of Ca(OH)2 to the system, the complete conversion of DCPA or DCPD to HA is not possible.
AB - Dicalcium phosphate dihydrate (DCPD) and anhydrous dicalcium phosphate (DCPA) extracted from a by-product in a manufacture of gelatin from bovine bone are used as starting materials for the hydrothermal synthesis of hydroxyapatite (HA) at temperatures of 160 and 200°C under vapor pressures of 1 and 2 MPa, respectively. The suspension of DCPA with water gives a mixture of DCPA and HA as product but after adjusting the Ca/P molar ratio to 1.50 and 1.67 by addition of Ca(OH)2, a single phase of HA with needle-like crystals is obtained. DCPA whiskers are produced in the suspension of DCPD with water but, on addition of Ca(OH)2, the product obtained is again, a mixture of DCPA and HA. The coexistence of DCPA and HA is observed not only in the acidic region at pH 4.6 which is close to the known quasi-invariant point but also in the basic region at pH 12.3. Without addition of Ca(OH)2 to the system, the complete conversion of DCPA or DCPD to HA is not possible.
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U2 - 10.1023/A:1014774923619
DO - 10.1023/A:1014774923619
M3 - Article
C2 - 15348602
AN - SCOPUS:0036238047
SN - 0957-4530
VL - 13
SP - 491
EP - 494
JO - Journal of Materials Science: Materials in Medicine
JF - Journal of Materials Science: Materials in Medicine
IS - 5
ER -