硼酸盐玻璃转化制备中空羟基磷灰石微球的研究

Study on Hollow Hydroxyapaptite Microspheres Prepared by a Borate Glass Conversion Process

利用锂钙硼玻璃在磷酸盐溶液中的原位转化反应制备表面多孔且中空的羟基磷灰石(HAP)微球,通过XRD、SEM和BET对微球的物相组成、形貌和球壳的孔结构进行了表征.结果表明,微球具有良好的中空结构,600℃热处理后,微球球壳完全由HAP晶体组成,并显示出一定的机械强度(单个微球的抗压强度达到(2.1±0.6)MPa),球壳的气孔率为85%,平均孔径60nm.此外,对中空HAP微球的形成机理进行了分析.在磷酸盐溶液中,玻璃表面原位生成Ca-P-OH水化物,并在玻璃表面原来Ca2+的位置沉积下来,形成微球壳,而由Li+和B3+占据的位置,因其溶出形成孔隙.这样的结构将使之成为贮库型药物释放系统的载体.

Hollow hydroxappatite（HAP） microspheres consisting of a hollow core and a porous shell were prepared by a Li-Ca-B glass conversion process.The phase composition,morphology and pore structure on the shell wall were investigated using XRD,SEM and BET.The results showed that the as-prepared microspheres possessed good internal hollow structure.The shell wall of the microsphere was made up of HAP crystals fully.After heat-treated at 600℃ for 2h,the compressive strength of the microsphere was determined to be（2.1±0.6）MPa,and the porosity and pore size of the shell wall were 85% and 60nm,respectively.Furthermore,the formation mechanism of the hollow HAP microsphere was also suggested.In phosphate solution,Ca-P-OH hydrate was in-situ formed on the surface of the glass and precipitated in the position initially occupied by Ca2＋,while the pores were formed in the position initially occupied by Li＋ and B3＋.These hollow HAP microspheres may be useful for drug delivery.