摘要
以CaHPO_4·2H_2O(DCPD)为前驱物,在0.1mol·L^(-1)NaOH溶液中,100～200℃,2～12h条件下水热合成羟基磷灰石(HA)粉末。结果表明:HA晶粒尺寸和结晶程度随反应温度的提高和时间的延长而增大。提高反应温度,有利于晶粒沿c轴方向生长;延长反应时间,有利于晶粒沿a轴方向生长。在120～160℃、2～10h条件下可以得到HA纳米棒。水热合成过程中有缺钙磷灰石(DAP,Ca_(10)～(HPO_4)_x(PO_4)_(6-x)(OH)_(2-x),0≤x≤1)形成,并经历β-TCP→DAP→HA这一转化过程。转化反应为二级反应,活化能为72.91kJ·mol^(-1),推测反应为表面控制反应。
Hydroxyapatite(HA) powders were hydrothermal synthesized by using CaHPO4 . 2H(2)O(DCPD) in 0.1mol . L-1 NaOH solution in an autoclave at 100 similar to 200degreesC for 2 similar to 12h. X-ray diffraction (XRD), transmission electron microscopy (TEM) and fouier transform infrared spectroscopy (FTIR) were used to characterized the morphology, structure, crystal grain size and chemical composition of hydroxyapatite powder. The experiment results show that the width and length of the crystal particle and crystallinity of crystals increased continuously with the electrolyte temperature and reaction time. Increasing the electrolyte temperature make for hydroxyapatite crystal growing along the c axis, whereas, increasing reaction time make for hydroxyapatite crystal growing along the a axis. The sizes of the crystal grain for the Bragg reflection of (002) and (300) planes were 45 similar to 98nm and 30 similar to 64nm at 120 similar to 160degreesC for 2 similar to 10h. The TEM micrograph showed that the nano-hydroxyapatite powders could be obtain under these conditions. Calcium-deficient hydroxyapatite, (DAP, Ca10-x(HPO4)(x)(PO4)(6-x)(OH)(2-x), 0 less than or equal to x less than or equal to 1) was formed under hydrothermal synthesis, because the powders had radicals of HPO42- and the powders were decomposed into the mixture of hydroxyapatite and beta-calcium phosphate after sintering at 800degreesC. The hydrothermal reaction underwent the following process: transferring form DCPD to beta-calcium phosphate (beta-TCP) rapidly, and then from beta-TCP to DAP and HA. The reaction of hydrothermal hydroxyapatite was second order and the active energy was 72.91kJ . mol(-1) and therefore it was inferred that the rate of reaction was surface reaction control process.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2003年第10期1079-1084,共6页
Chinese Journal of Inorganic Chemistry
基金
福建省自然科学基金(No.2000F003)
