We report a general strategy to fabricate highly concentrated, viscoplastic and stable suspensions by designing the particle surface structure to control the interparticle attractive forces. Unlike conventional methods, where the choice of solvent is critical in balancing interparticle interactions, suspensions showing excellent stability and viscoplastic properties were made using various solvents. We demonstrated this approach using highly sparse agglomerates of carbon nanotubes (CNTs) as the particles. Our results revealed that the essential feature of the CNT agglomerate to fabricate these suspensions was high porosity with a spacing size much smaller than the overall size, which was only possible using long single-walled carbon nanotubes (SWNTs). In this way, the agglomerate surface was characterized by fine network of CNT bundles. These suspensions exhibited solid-like behavior at rest (characterized by a high yield stress of c.a. 100 Pa) and a liquid-like behavior when subjected to a stress (characterized by a significant drop of an apparent viscosity to 1 Pa·s at a shear rate of 1000 s-1). Furthermore, in contrast to conventionally fabricated suspensions, these "CNT pastes" exhibited exceptional stability at rest, under flow, and at extremely high concentrations during the drying process, with only a weakly observable dependence on solvent type. As a result, highly uniform micrometer-thick SWNT films were successfully fabricated by dried blade-coated films of these pastes. Finally, we developed a simple, semiempirical model and clarified the importance of the CNT agglomerate microstructure (the ratio of spacing size/particle size and porosity) on tailoring the cohesive forces between particles to fabricate stable viscoplastic suspensions.

中文翻译：

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基于调节粒子间相互作用的结构方法制备高浓度粘塑性悬浮液的新通用策略

我们报告了通过设计颗粒表面结构来控制颗粒间吸引力来制造高浓度、粘塑性和稳定悬浮液的一般策略。与传统方法不同，溶剂的选择对于平衡颗粒间相互作用至关重要，使用各种溶剂制备具有优异稳定性和粘塑性的悬浮液。我们使用高度稀疏的碳纳米管 (CNT) 团聚体作为颗粒来演示这种方法。我们的结果表明，用于制造这些悬浮液的 CNT 附聚物的基本特征是高孔隙率，其间距尺寸远小于整体尺寸，这只能使用长单壁碳纳米管 (SWNT)。通过这种方式，团聚体表面的特征是 CNT 束的精细网络。这些悬浮液在静止状态下表现出类似固体的行为（以约 100 Pa 的高屈服应力为特征），在受到应力时表现出类似液体的行为（特征为在剪切力下表观粘度显着下降至 1 Pa·s 1000 s-1 的速率）。此外，与传统制造的悬浮液相比，这些“CNT 糊状物”在静止、流动和干燥过程中的极高浓度下表现出非凡的稳定性，对溶剂类型的依赖性很小。结果，通过这些浆料的干燥刮刀涂层薄膜成功地制造了高度均匀的微米厚 SWNT 薄膜。最后，我们开发了一个简单的，