Short-Range Structure of Yttrium Alumino-Silicate Glass for Cancer Radiotherapy: Car-Parrinello Molecular Dynamics Simulations
Short-Range Structure of Yttrium Alumino-Silicate Glass for Cancer Radiotherapy: Car-Parrinello Molecular Dynamics Simulations
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DOI：
10.1002/adem.200980081
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发表时间：
2010-07-01
影响因子：
3.6
通讯作者：
Tilocca, Antonio
中科院分区：
文献类型：
--
作者：
Christie, Jamieson K.;Tilocca, Antonio
本文提出了硅铝钇（YAS）玻璃的Car-Parrinello分子动力学（CPMD）模拟。铝硅酸盐玻璃微球作为肿瘤放射治疗中钇放射性同位素载体；详细了解钇是如何在玻璃网络中结合的，这对于控制血液中放射性钇的不必要释放是很重要的。我们的模拟集中在与实际应用相关的特定成分上，表明硅和铝形成了一个无序的玻璃网络，其中Si主要是四配位的，而Al主要是四配位和五配位的。钇离子具有网络修饰作用，通过破坏Si(Al)-O键和配位产生的非桥氧（NBO）来破坏铝-硅酸盐网络。钇在玻璃中的局部环境是相当灵活的：在5到8个氧原子之间，以NBO明显占优势，被发现与中心的Y阳离子协调，导致相应的O-Y-O角的广泛和多模态分布。
We present Car-Parrinello molecular dynamics (CPMD) simulations of yttrium alumino-silicate (YAS) glass. Alumino-silicate glass microspheres are used as vectors of yttrium radioisotopes in cancer radiotherapy; understanding in detail how yttrium is bound within the glass network is important to control the unwanted release of radioactive yttrium in the bloodstream. Our simulations, focused on a specific composition relevant to practical applications, show that silicon and aluminum form a disordered glass network, where Si is mainly four-coordinated, whereas, Al is mainly four- and five-coordinated. Yttrium cations have a network-modifying role, disrupting the alumino-silicate network by breaking Si(Al)-O bonds and coordinating the resulting non-bridging oxygens (NBO). The local environment of yttrium in the glass turns out to be rather flexible: between five and eight oxygen atoms, with a marked predominance of NBO, are found coordinated to a central Y cation, leading to a corresponding broad and multimodal distribution of O-Y-O angles.