Hexagonal hydroxyapatite formation on TiO2 nanotubes under urea modulation
Hexagonal hydroxyapatite formation on TiO2 nanotubes under urea modulation
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DOI：
10.1039/c0ce00971g
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发表时间：
2011-05
期刊：
影响因子：
3.1
通讯作者：
Xiong Lu;Hongping Zhang;Ya-nan Guo;Yingbo Wang;Xiang Ge;Y. Leng;F. Watari
中科院分区：
文献类型：
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作者：
Xiong Lu;Hongping Zhang;Ya-nan Guo;Yingbo Wang;Xiang Ge;Y. Leng;F. Watari
利用TiO2纳米管和尿素的组合调制，在水热条件下合成了六方棱柱状羟基磷灰石（HA）晶体。以TiO2纳米管为模板，在水热条件下诱导HA晶体成核。对比纳米管表面和平面上透明质酸的形成，发现纳米管表面有利于六角形透明质酸的结晶。选择尿素作为沉淀剂，控制腐植酸生长，调节腐植酸形态。水热温度要高到足以导致尿素分解，以保证HA的形成。密度泛函理论（DFT）计算表明，尿素与（100）表面的结合能高于与（001）表面的结合能，从而抑制了HA（100）表面的生长，这可能影响了HA晶体的形态发育。研究表明，透明质酸晶体的生长可以在成核和生长阶段进行调控。这也暗示了计算机模拟可以在选择合适的沉淀剂以获得具有特殊设计形态的晶体方面发挥重要作用。
Hexagonal prism-like hydroxyapatite (HA) crystals were synthesized under hydrothermal conditions utilizing the combination modulation of TiO2 nanotubes and urea. TiO2 nanotubes were used as templates to induce HA crystal nucleation under hydrothermal conditions. Comparison of HA formation on nanotubular surfaces and flat surfaces demonstrated that nanotubular surfaces favored prism-like hexagonal HA crystallization. Urea was selected as the precipitation agent to control the HA growth and mediate its morphology. The hydrothermal temperature should be high enough to lead the decomposition of urea in order to ensure HA formation. Density functional theory (DFT) calculation showed that the urea had higher binding energy with (100) surfaces than with (001) surfaces, and therefore could inhibit the growth of (100) surfaces of HA, which possibly influenced the morphological development of HA crystals. This study demonstrated that HA crystal growth could be modulated in its nucleation and growth stage. It also implied that computer simulation might play an important role to select the suitable precipitation agent in order to obtain crystals with specially designed morphology.