基于正交实验优化沉淀法制备针状羟基磷灰石

Preparation of Acicular Hydroxyapatite Based on Orthogonal Experiment

羟基磷灰石(HAP)已在临床得到运用,但其强度低、韧性差、不易成型等缺点依旧制约着其的广泛应用。为制备出理想且能满足临床应用的纳米针状羟基磷灰石,本文在不添加任何分散剂和表面活性剂的条件下以磷酸钠与硝酸钙为原料,氢氧化钠调节pH,使用正交实验设计对沉淀法中针状HAP的制备工艺进行优化。结果表明,反应条件对HAP晶体形貌的影响程度为:温度>滴加速度>pH;当反应pH=9、反应温度为90℃和滴加速度为2mL/min时为其优方案,可制备出性状规则、粒度均匀、结晶度高、趋向于针状的纳米羟基磷灰石粉体。反应温度升高可提高HAP的结晶速度,可增大HAP晶体的大小,使晶形更趋于针状,但温度过高时对长轴的促进作用开始逐渐降低,长径比的增加趋势有所减缓;降低滴加速度,可提高产物结晶程度,有利于针状羟基磷灰石的形成;此外,反应pH值升高虽可加速晶核形成,提高产物的结晶率和产物纯度,但是不利于晶粒长大,且pH过高会减缓形成针状的趋势。

Hydroxyapatite（ HAP） has been used in clinic,but its disadvantages such as low strength,poor toughness and not easy to form are still restricted to its wide application. In order to prepare the ideal and suitable for clinical application of nano-spiced hydroxyapatite,this paper does not add any dispersants and surfactants in conditions with sodium phosphate and calcium nitrate as raw material,sodium hydroxide adjust pH value,using the orthogonal experimental design to optimize the preparation technology for precipitation in the needle HAP. The results show that the effect of reaction conditions on HAP crystal morphology was temperature drop acceleration pH. When pH = 9, the reaction temperature is 90 ℃ and the dropping speed of 2 mL/min for the optimal solution,the rules can be prepared traits,uniform particle size,high crystallinity,tends to the needle-shaped nano-hydroxyapatite powder. Reaction temperature can improve the crystallization rate of HAP,increase the size of the HAP crystals,tend to be more acicular crystal shape,but when the temperature is too high for the promotion of long axis gradually less than short axis,makes the increase of the length to diameter ratio trend slowed.The decrease of the drop acceleration can improve the crystallization degree of the product,which is beneficial to the formation of the acicular hydroxyapatite. Although the increase of pH can accelerate theformation of crystal nucleus,the crystallization rate and product purity of the product can be improved,but it is not conducive to the growth of grain,and the high pH can slow the formation of needle.