Transparent Aggregates of Nanocrystalline Hydroxyapatite
Transparent Aggregates of Nanocrystalline Hydroxyapatite
复制标题
纳米晶羟基磷灰石的透明聚集体
DOI：
10.1021/cg501080c
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
H. Birkedal
中科院分区：
文献类型：
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作者：
Anders C. S. Jensen;C. J. Ibsen;Duncan S Sutherland;H. Birkedal
纳米颗粒组装成透明聚集体已经引起了对纳米颗粒的结晶或无定形聚集体形式的强烈研究兴趣。在本工作中，我们制作了短程有序的几毫米大小的透明柠檬酸盐修饰的磷酸钙纳米粒子的聚集体，并讨论了它们的形成机制。以柠檬酸盐为生长和组装修饰剂，合成了羟基磷灰石（HAP）纳米晶和无定形磷酸钙（ACP）微粒。用0至7.5%柠檬酸盐/Ca 2+制备这些微粒的毫米级透明聚集体。结晶度，即，微粒中纳米晶HAP和ACP之间的比率通过用内标物对粉末X射线衍射数据进行Rietveld精修来测定。发现其随柠檬酸盐浓度的增加而降低。柠檬酸盐也降低了在低柠檬酸盐浓度的纳米微晶的大小。柠檬酸盐添加量超过0.3%时，微晶尺寸不再随柠檬酸盐添加量的增加而减小。
Assemblies of nanoparticles into transparent aggregates have solicited strong research interest in the form of both crystalline or amorphous aggregates of nanoparticles. In the present work, we make short-range ordered several millimeter-sized transparent aggregates of citrate modified calcium phosphate nanoparticles and discuss the mechanism of their formation. Microparticles of hydroxyapatite (HAP) nanocrystals and amorphous calcium phosphate (ACP) were synthesized with citrate as a growth and assembly modifier. Millimeter-sized transparent aggregates of these microparticles were made with 0 to 7.5% citrate/Ca2+. The degree of crystallinity, i.e., the ratio between nanocrystalline HAP and ACP in the microparticles, was determined by Rietveld refinement of powder X-ray diffraction data with an internal standard. It was found to decrease with increasing citrate concentration. Citrate also reduced the nanocrystallite size at low citrate concentrations. Above ∼3% added citrate, the crystallite size did not ...