Hierarchical Structuring in Block Copolymer Nanocomposites through Two Phase‐Separation Processes Operating on Different Time Scales
Hierarchical Structuring in Block Copolymer Nanocomposites through Two Phase‐Separation Processes Operating on Different Time Scales
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DOI：
10.1002/adfm.201300091
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发表时间：
2013-03
影响因子：
19
通讯作者：
Elina Ploshnik;K. Langner;Amit Halevi;Meirav Ben-Lulu;A. Müller;J. Fraaije;G. J. Agur Sevink;R. Shenhar
中科院分区：
文献类型：
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作者：
Elina Ploshnik;K. Langner;Amit Halevi;Meirav Ben-Lulu;A. Müller;J. Fraaije;G. J. Agur Sevink;R. Shenhar
调整纳米颗粒的尺寸和表面化学允许人们控制它们在嵌段共聚物中的位置，但这通常限于跨域的一维分布。在这里，聚（环氧乙烷）稳定的金纳米粒子（Au-PEO）的分层组装成六边形包装的聚苯乙烯-嵌段-聚（甲基丙烯酸甲酯）（PS-B-PMMA）的介观结构的双金属薄膜内的集群进行了描述。对不同纳米颗粒填充分数和PEO配体分子量下的结构演变的仔细检查表明，导致这种结构内结构的机制是在不同时间尺度上操作的两相分离过程的存在。PEO配体的长度不仅影响粒子间的距离，而且还影响相分离过程。这些结论得到了新的介观模拟，这提供了额外的洞察动力学和热力学因素，负责这种行为的支持。
Tailoring the size and surface chemistry of nanoparticles allows one to control their position in a block copolymer, but this is usually limited to one‐dimensional distribution across domains. Here, the hierarchical assembly of poly(ethylene oxide)‐stabilized gold nanoparticles (Au‐PEO) into hexagonally packed clusters inside mesostructured ultrathin films of polystyrene‐block‐poly(methyl methacrylate) (PS‐b‐PMMA) is described. A close examination of the structural evolution at different nanoparticle filling fractions and PEO ligand molecular weights suggests that the mechanism leading to this structure‐within‐structure is the existence of two phase separation processes operating on different time scales. The length of the PEO ligand is shown to influence not only the interparticle distances but also the phase separation processes. These conclusions are supported by novel mesoscopic simulations, which provide additional insight into the kinetic and thermodynamic factors that are responsible for this behavior.