The ordering of nanoparticles into predetermined configurations is of importance to the design of advanced technologies. Here, we balance the interfacial energy of nanoparticles against the elastic energy of cholesteric liquid crystals to dynamically shape nanoparticle assemblies at a fluid interface. By adjusting the concentration of surfactant that plays the dual role of tuning the degree of nanoparticle hydrophobicity and altering the molecular anchoring of liquid crystals, we pattern nanoparticles at the interface of cholesteric liquid crystal emulsions. In this system, interfacial assembly is tempered by elastic patterns that arise from the geometric frustration of confined cholesterics. Patterns are tunable by varying both surfactant and chiral dopant concentrations. Adjusting the particle hydrophobicity more finely by regulating the surfactant concentration and solution pH further modifies the rigidity of assemblies, giving rise to surprising assembly dynamics dictated by the underlying elasticity of the cholesteric. Because particle assembly occurs at the interface with the desired structures exposed to the surrounding water solution, we demonstrate that particles can be readily cross-linked and manipulated, forming structures that retain their shape under external perturbations. This study serves as a foundation for better understanding inter-nanoparticle interactions at interfaces by tempering their assembly with elasticity and for creating materials with chemical heterogeneity and linear, periodic structures, essential for optical and energy applications.

中文翻译：

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在胆甾型液滴的界面处形成纳米颗粒指纹。

将纳米颗粒排列成预定构型对于先进技术的设计很重要。在这里，我们平衡了纳米粒子的界面能与胆甾型液晶的弹性能之间的关系，以动态地塑造流体界面处的纳米粒子组件。通过调节表面活性剂的浓度，该浓度起着调节纳米颗粒疏水性和改变液晶分子锚定的双重作用，我们在胆甾醇型液晶乳剂的界面上对纳米颗粒进行了图案化。在该系统中，界面约束通过由受限胆甾醇的几何受挫产生的弹性图案来调节。可以通过改变表面活性剂和手性掺杂剂的浓度来调整图案。通过调节表面活性剂的浓度和溶液的pH值，可以更精细地调节颗粒的疏水性，从而进一步改善组件的刚度，从而产生令人惊讶的组件动态，这些动态由胆甾型化合物的基本弹性决定。因为粒子组装发生在与暴露于周围水溶液的所需结构的界面处，所以我们证明了粒子可以很容易地交联和操纵，形成在外部扰动下保持其形状的结构。这项研究为更好地了解界面处的纳米粒子之间的相互作用（通过调节其组装弹性）以及创建具有化学异质性和线性，周期性结构的材料（对于光学和能量应用必不可少）提供了基础。