Nanoparticle Assembly in High Polymer Concentration Solutions Increases Superlattice Stability
Nanoparticle Assembly in High Polymer Concentration Solutions Increases Superlattice Stability
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DOI：
10.1002/smll.202102107
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发表时间：
2021-07-28
期刊：
影响因子：
13.3
通讯作者：
Macfarlane, Robert J.
中科院分区：
文献类型：
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作者：
Lee, Margaret S.;Alexander-Katz, Alfredo;Macfarlane, Robert J.
聚合物纳米复合材料是通过将纳米级填料与聚合物基体结合而制成的，其中聚合物颗粒的相互作用可以增强基体的性能，并引入不同于任何组分的行为。在复合材料中操纵粒子组织可以更好地控制聚合物-粒子的相互作用，并且有序阵列的形成可以引入在随机复合材料中没有观察到的新特性。然而，有序粒子阵列的自组装通常需要弱的粒子间相互作用来防止动力学陷阱，这使得这些组装与大多数传统的加工技术不兼容。因此，需要进行更基础的研究，寻找在不破坏这些晶格内部组织的情况下为其提供额外稳定性的方法。作者表明，在组装溶液中加入自由聚合物链是提高纳米粒子超晶格抗热解离稳定性的一种简单方法。通过在纳米粒子超晶格中加入高浓度（50 mg mL -1）的自由聚合物，可以显著提高纳米粒子的热稳定性，而不会对有序性产生不利影响。此外，聚合物的拓扑结构、分子量和浓度也可以作为独立的设计处理来调整这种行为。总的来说，这项工作为生产未来的纳米复合材料提供了更广泛的加工条件，可以完全控制材料内的颗粒组织。
Polymer nanocomposites are made by combining a nanoscale filler with a polymer matrix, where polymer-particle interactions can enhance matrix properties and introduce behaviors distinct from either component. Manipulating particle organization within a composite potentially allows for better control over polymer-particle interactions, and the formation of ordered arrays can introduce new, emergent properties not observed in random composites. However, self-assembly of ordered particle arrays typically requires weak interparticle interactions to prevent kinetic traps, making these assemblies incompatible with most conventional processing techniques. As a result, more fundamental investigations are needed into methods to provide additional stability to these lattices without disrupting their internal organization. The authors show that the addition of free polymer chains to the assembly solution is a simple means to increase the stability of nanoparticle superlattices against thermal dissociation. By adding high concentrations (>50 mg mL(-1)) of free polymer to nanoparticle superlattices, it is possible to significantly elevate their thermal stability without adversely affecting ordering. Moreover, polymer topology, molecular weight, and concentration can also be used as independent design handles to tune this behavior. Collectively, this work allows for a wider range of processing conditions for generating future nanocomposites with complete control over particle organization within the material.