Immiscibility of Nucleating Aluminum Oxide Nanoparticles in Vapor
Immiscibility of Nucleating Aluminum Oxide Nanoparticles in Vapor
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DOI：
10.1021/acs.jpcc.8b08355
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发表时间：
2018-10
期刊：
影响因子：
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通讯作者：
Shinnosuke Ishizuka;Y. Kimura;J. Kawano;R. Escribano;T. Yamazaki;T. Hama;Rikako Sato
中科院分区：
文献类型：
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作者：
Shinnosuke Ishizuka;Y. Kimura;J. Kawano;R. Escribano;T. Yamazaki;T. Hama;Rikako Sato
现在已知成核过程中的多步途径是普遍存在的，因此对于理解晶体形成过程至关重要。在过饱和的母相中，许多类型的源分子凝结形成无定形或液体状中间体，其随后转化为晶体。这样的中间体可能具有与块体晶体的化学式不一致的化学式。即使在相对简单的气相均质成核中，多组分混合物在纳米尺度上的作用仍然未知。在这里，通过结合实验方法，使用原位红外（IR）测量的气相中的均匀成核和自动量子化学探索的反应路线，我们表明，在铝-O二元系统中的成核纳米粒子的类液体性质诱导不混溶相分离。在缺氧的气氛中，氧化铝纳米颗粒从过饱和蒸汽中形成，具有由Al金属头和各向异性金属头组成的独特形状。
Multistep pathways in nucleation are now known to be ubiquitous and thus crucial to understand crystal formation processes. In a supersaturated mother phase, many types of source molecules are coagulated to form an amorphous or liquid-like intermediate, which subsequently transforms to a crystal. Such an intermediate possibly has a chemical formula that is inconsistent with that of the bulk crystal. Even in relatively simple vapor-phase homogeneous nucleation, the roles of the multicomponent mixtures at the nanoscale remain unknown. Here, by combining an experimental approach using in situ infrared (IR) measurements of homogeneous nucleation in the vapor phase and automatic quantum-chemical explorations of reaction routes, we show that a liquid-like nature of nucleating nanoparticles in the Al–O binary system induces immiscible phase separation. In an oxygen-deficient atmosphere, aluminum oxide nanoparticles form from supersaturated vapor with a unique shape composed of an Al metal head and an anisotropic...