Synthesis of high surface area hydroxyapatite nanoparticles by mixed surfactant-mediated approach.
Synthesis of high surface area hydroxyapatite nanoparticles by mixed surfactant-mediated approach.
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DOI：
10.1021/la050029m
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发表时间：
2005-03
期刊：
影响因子：
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通讯作者：
M. Uota;H. Arakawa;Nana Kitamura;T. Yoshimura;J. Tanaka;T. Kijima
中科院分区：
文献类型：
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作者：
M. Uota;H. Arakawa;Nana Kitamura;T. Yoshimura;J. Tanaka;T. Kijima
研究了一种表面活性剂介导的高表面积羟基磷灰石（HAp）纳米颗粒的制备方法，该方法是利用含有表面活性剂的混合反应混合物，将羟基磷灰石（HAp）前驱体包覆硬脂酸钙，煅烧合成具有高表面积的羟基磷灰石纳米颗粒。将酸性磷酸钙水溶液与非氧乙烯十二烷基醚（C12EO9）和聚氧乙烯（20）山梨醇单硬脂酸酯（Tween 60）混合，然后在25℃下用铵盐水溶液处理。C12EO9为单表面活性剂体系可得到20-40 nm大小的片状HAp纳米颗粒，而Tween 60为单表面活性剂体系和混合体系可得到2-8 nm宽的板状HAp纳米颗粒，并被硬脂酸钙包裹。在500℃下煅烧，后两种体系中硬脂酸包封的HAp纳米颗粒被分解成高表面积的HAp纳米颗粒。特别是，混合体系中HAp纳米颗粒的比表面积高达364 m2 g(-1)，大约是单一体系中160 m2 g（-1）的3倍。前者具有显著的高表面积，这是由于脱壳的HAp纳米颗粒的粘附性很小，这是由于C12EO9分子吸附在硬脂酸封装的HAp纳米颗粒的外表面，抑制了它们的团聚或界面配位，从而产生了颗粒分离作用。结果表明，混合使用两种不同的表面活性剂作为包封模板剂和颗粒分离剂对合成高表面积HAp纳米颗粒特别有效。
A new surfactant-mediated approach was developed to synthesize hydroxyapatite (HAp) nanoparticles with high surface areas by calcination of their precursors encapsulated with calcium stearate using mixed surfactant-containing reaction mixtures. Acidic aqueous solution of calcium phosphate was mixed with both or either nonaoxyethylene dodecyl ether (C12EO9) and polyoxyethylene(20) sorbitan monostearate (Tween 60) and then was treated with aqueous ammonium at 25 degrees C. The C12EO9-based single surfactant system yielded an aggregate of platy HAp nanoparticles 20-40 nm in size, whereas the Tween 60-based single and mixed systems led to lath-shaped HAp nanoparticles 2-8 nm wide and encapsulated with calcium stearate. On calcination at 500 degrees C, the stearate-encapsulated HAp nanoparticles in the latter two systems were deorganized into high surface area HAp nanoparticles. Particularly, the HAp nanoparticles in the mixed system exhibited a specific surface area as high as 364 m2 g(-1) that is roughly 3 times larger than 160 m2 g(-1) for those in the single system. The significantly high surface area for the former is attributed to much less adhesion of decapsulated HAp nanoparticles, which originated from the particle-separating effect of the C12EO9 molecules adsorbed on the outer surface of the stearate-encapsulated HAp nanoparticles to inhibit their agglomeration or interfacial coordination. The present results demonstrate that the mixed use of two different surfactants as a source of encapsulating and templating agent and a particle-separating agent is specifically effective for the synthesis of high surface area HAp nanoparticles.