Confined Pattern-Directed Assembly of Polymer-Grafted Nanoparticles in a Phase Separating Blend with a Homopolymer Matrix.
Confined Pattern-Directed Assembly of Polymer-Grafted Nanoparticles in a Phase Separating Blend with a Homopolymer Matrix.
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DOI：
10.1021/acs.macromol.6b00228
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发表时间：
2016
期刊：
影响因子：
5.5
通讯作者：
Karim A
中科院分区：
文献类型：
--
作者：
Zhang R;Lee B;Bockstaller MR;Douglas JF;Stafford CM;Kumar SK;Raghavan D;Karim A
将纳米粒子（NP）成分控制成具有明确形状、组成和连通性的上层结构，是许多技术应用中新型杂化材料开发的持续挑战。我们的研究表明，浸泡在化学性质不同的聚合物基质中的聚合物系链纳米颗粒的相分离为在熔融聚合物薄膜中制造确定的亚微米尺寸的非晶态NP域提供了一种有效且可扩展的方法。我们研究这一现象，以期通过定向纳米粒子组装来理解和控制相分离过程。特别地，我们考虑了分散在聚甲基丙烯酸甲酯（PMMA）基质中的聚苯乙烯接枝金纳米颗粒（AuPS）的等温退火薄膜。随着纳米颗粒组成的增加，观察到典型的二元聚合物共混相分离相关的形态转变，从离散的AuPS结构域到双连续的逆结构域结构，然而与母体PS/PMMA均聚共混体系相比，AuPS/PMMA聚合物共混体系的动力学表现出独特的特征。我们进一步说明了如何通过软光刻施加一种简单而新颖的外部对称性破坏扰动来对相分离的AuPS纳米颗粒的形状、大小和位置进行图案对齐。具体来说，亚微米尺寸的地形图案弹性体约束被引入到动力学控制的远程有序域，具有致密但分散良好的非结晶纳米颗粒分布。这种控制纳米颗粒组装的新方法的简单性、多功能性和卷对卷的适应性，将有助于为各种功能材料和应用创建理想的图案纳米颗粒域。
The controlled organization of nanoparticle (NP) constituents into superstructures of well-defined shape, composition and connectivity represents a continuing challenge in the development of novel hybrid materials for many technological applications. We show that the phase separation of polymer-tethered nanoparticles immersed in a chemically different polymer matrix provides an effective and scalable method for fabricating defined submicron-sized amorphous NP domains in melt polymer thin films. We investigate this phenomenon with a view towards understanding and controlling the phase separation process through directed nanoparticle assembly. In particular, we consider isothermally annealed thin films of polystyrene-grafted gold nanoparticles (AuPS) dispersed in a poly(methyl methacrylate) (PMMA) matrix. Classic binary polymer blend phase separation related morphology transitions, from discrete AuPS domains to bicontinuous to inverse domain structure with increasing nanoparticle composition is observed, yet the kinetics of the AuPS/PMMA polymer blends system exhibit unique features compared to the parent PS/PMMA homopolymer blend. We further illustrate how to pattern-align the phase-separated AuPS nanoparticle domain shape, size and location through the imposition of a simple and novel external symmetry-breaking perturbation via soft-lithography. Specifically, submicron-sized topographically patterned elastomer confinement is introduced to direct the nanoparticles into kinetically controlled long-range ordered domains, having a dense yet well-dispersed distribution of non-crystallizing nanoparticles. The simplicity, versatility and roll-to-roll adaptability of this novel method for controlled nanoparticle assembly should make it useful in creating desirable patterned nanoparticle domains for a variety of functional materials and applications.