Ishikawa K, Kon M, Tenshin S, Kuwayama N
School of Dentistry, Tokushima University, Japan.
Dent Mater J. 1990 Jun;9(1):58-69. doi: 10.4012/dmj.9.58.
Hydroxyapatite powders (HAP: Ca10(PO4)6(OH)2) were prepared from calcium nitrate and di-ammonium hydrogen phosphate at various temperatures in aqueous solution in the absence and presence of carbon dioxide. In the absence of carbon dioxide, the crystallinities as well as the calcium to phosphate ratio (Ca/P ratio) of HAP powders increased with an increase in the preparation temperature. Calcium ion deficiency caused low Ca/P ratios of HAP powders. Such HAP powders decomposed thermally to beta-tricalcium phosphate (beta-TCP: Ca3(PO4)2) at 800 degrees C in 3 hours whereas HAP powders with sufficient calcium were stable at 1200 degrees C for 3 hours. In the presence of carbon dioxide as well the crystallinities of HAP powders increased with an increase in the preparation temperature, but carbonate-bearing HAPs were obtained instead of pure HAP. In addition, calcium carbonate was obtained along with carbonate-bearing HAP prepared below 60 degrees C.
在有无二氧化碳存在的情况下，于水溶液中在不同温度下由硝酸钙和磷酸氢二铵制备了羟基磷灰石粉末（HAP：Ca10(PO4)6(OH)2）。在没有二氧化碳的情况下，HAP粉末的结晶度以及钙磷比（Ca/P比）随着制备温度的升高而增加。钙离子缺乏导致HAP粉末的Ca/P比降低。此类HAP粉末在800℃下3小时内热分解为β-磷酸三钙（β-TCP：Ca3(PO4)2），而具有足够钙的HAP粉末在1200℃下3小时内是稳定的。在有二氧化碳存在的情况下，HAP粉末的结晶度也随着制备温度的升高而增加，但得到的是含碳酸盐的HAP而不是纯HAP。此外，在60℃以下制备含碳酸盐的HAP时会同时得到碳酸钙。
