Long-Range Ordering of Symmetric Block Copolymer Domains by Chaining of Superparamagnetic Nanoparticles in External Magnetic Fields
Long-Range Ordering of Symmetric Block Copolymer Domains by Chaining of Superparamagnetic Nanoparticles in External Magnetic Fields
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DOI：
10.1021/ma300500z
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发表时间：
2012-03
期刊：
影响因子：
5.5
通讯作者：
V. Raman;A. Bose;B. Olsen;T. Hatton
中科院分区：
文献类型：
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作者：
V. Raman;A. Bose;B. Olsen;T. Hatton
从理论和计算上研究了一种通过超顺磁性纳米粒子在磁场中的排列和链接来实现对称二嵌段共聚物纳米畴中长程取向有序的新方法。纳米颗粒的尺寸，体积分数，和磁化强度的影响进行了探讨，使用混合粒子场（HPF）技术的颗粒，选择性地分离成一个域的对称的二嵌段共聚物组件。观察到一个纳米畴的颗粒的临界选择性，在该临界选择性之上，形成强的对准结果，在该临界选择性之下，形成相对无序的结构。二维模拟表明，对于给定的纳米颗粒体积分数，只有与嵌段共聚物域间距相称的纳米颗粒尺寸才能产生排列良好的纳米结构。纳米颗粒明显大于畴间距打破了层状相的对称性，并导致不良的取向，而高缺陷密度观察到的小…
A new method to achieve long-range orientational order in symmetric diblock copolymer nanodomains through the alignment and chaining of superparamagnetic nanoparticles in a magnetic field is investigated computationally and theoretically. The effects of nanoparticle size, volume fraction, and magnetization strength are explored using the hybrid particle field (HPF) technique for particles that selectively segregate into one domain of a symmetric diblock copolymer assembly. A critical selectivity of the particles for one nanodomain is observed, above which strong alignment results and below which comparatively disordered structures are formed. The 2D simulations reveal that, for a given nanoparticle volume fraction, only a nanoparticle size commensurate with the block copolymer domain spacing yields well-aligned nanostructures. Nanoparticles significantly larger than the domain spacing break the symmetry of the lamellar phase and result in poor alignment, while high defect densities are observed for smalle...