中文摘要：

背景：由于纳米羟基磷灰石粒子易团聚,由其制得的复合材料力学性能始终达不到皮质骨的水平。目的：通过新方法制备稳定的羟基磷灰石胶体,克服粒子团聚。方法：在0.05mol/L硝酸钙溶液38mL中分别加入等体积的2-氨乙基磷酸,3-膦酸基丙酸,L-O-磷酸丝氨酸溶液。将7.5mL的0.15mol/L磷酸三铵溶液分别加入到上述每种混合液中,在40,80℃各老化4h。所得的有机磷改性羟基磷灰石通过离心和水洗提纯,冷冻干燥得粉体。结果与结论：红外光谱和X射线衍射证实改性后的物质仍为羟基磷灰石,表面改性剂接枝量很少。Zeta电位分析表明3-膦酸基丙酸-羟基磷灰石、L-O-磷酸丝氨酸-羟基磷灰石可带上负电荷,2-氨乙基磷酸-羟基磷灰石可带上正电荷。3-膦酸基丙酸-羟基磷灰石、L-O-磷酸丝氨酸-羟基磷灰石的粉体在水中超声4h,得到碱性条件下稳定性较好（3d）的淡蓝色胶体;2-氨乙基磷酸-羟基磷灰石再分散胶体在酸性条件下的稳定性略好于中性条件,和碱性条件下相当,但都不理想（〈3h）。表明提高羟基磷灰石胶体的稳定性还需探索新的方法。

英文摘要：

BACKGROUND：Nano-hydroxyapatite particles agglomerate so easily that their polymer-based nanocomposites are inferior to cortical bones in mechanical properties. OBJECTIVE：To prepare stable hydroxyapatite （HA） colloid by new methods. METHODS：38 mL calcium nitrate solution （0.05 mol/L） was mixed with an isovolumetric solution of 2-aminoethyl dihydrogen phosphate （ADP）, 3-phosphonopropionic acid （CEPA） and L-O-phosphoserine （LOP）, respectively. Thereafter, 7.5 mL triammonium phosphate solution （0.15 mol/L） was dropped into each of the mixtures followed by aging at 40 ℃ and 80 ℃ for 4 hours, respectively. The modified HAs （ADP-HA, CEPA-HA, LOP-HA） were purified through centrifugation and water washing, followed by freeze drying. RESULTS AND CONCLUSION：The as-synthesized products were still HA as proved by Fourier transform infrared spectroscopy and X-ray diffraction analyses, with some modifiers on surface. Zeta potentials showed that the CEPA-HA and LOP-HA were negatively charged while the ADP-HA was positively charged. The CEPA-HA and LOP-HA were re-suspended in water through 4-hour ultrasonication, forming light blue colloids with short-term （3 days） stability at pH 11. The ADP-HA suspension possessed slightly higher stability in acidic solution than that in neutral one, similar to the case in alkaline solution. But its stability in all cases （ 3 hours） was far from an ideal one. Creative methods should beunder way to improve HA hydrocolloids’ stability.