通过表面粗糙度和物理化学相互作用调节悬浮液的剪切增稠性
Tuning the shear-thickening of suspensions through surface roughness and physico-chemical interactions
AI总结：
通过调节颗粒表面粗糙度和化学性质，研究了悬浮液剪切增稠行为，发现氢键对不连续剪切增稠至关重要，并展示了如何通过混合不同表面化学的颗粒实现对剪切增稠响应的精细控制。
摘要：
剪切增稠是指在外部剪切作用下，刚性颗粒悬浮液的粘度可逆性增加。这种普遍现象已在多种多相颗粒系统中被记录，而其微观起源相继被归因于流体动力学相互作用和颗粒之间的摩擦性接触。这两种现象对剪切增稠幅度的相对贡献仍存在高度争议，我们在此报告了一项使用模型剪切增稠悬浮液的区分性实验研究，该悬浮液允许独立调节颗粒的表面化学和表面粗糙度。我们显示，这两个属性在连续剪切增稠（CST）中都很重要，且颗粒之间氢键的存在对于通过增强紧密接触颗粒之间的固态摩擦来实现不连续剪切增稠（DST）是至关重要的。此外，一个简单的论点使我们能够预测CST的起始，对于这些非常粗糙的颗粒，其起始体积分数远低于文献中 previously reported 的值。最后，我们展示了如何通过具有相反表面化学性质的颗粒混合物，使在固定体积分数下悬浮液的剪切增稠响应能够精细调节，为在工程应用中实现剪切增稠过渡的精细控制铺平了道路。
英文摘要：
Shear thickening denotes the reversible increase in viscosity of a suspension of rigid particles under external shear. This ubiquitous phenomenon has been documented in a broad variety of multiphase particulate systems, while its microscopic origin has been successively attributed to hydrodynamic interactions and frictional contact between particles. The relative contribution of these two phenomena to the magnitude of shear thickening is still highly debated and we report here a discriminating experimental study using a model shear-thickening suspension that allows us to tune independently both the surface chemistry and the surface roughness of the particles. We show here that both properties matter when it comes to continuous shear thickening (CST) and that the presence of hydrogen bonds between the particles is essential to achieve discontinuous shear thickening (DST) by enhancing solid friction between closely contacting particles. Moreover, a simple argument allows us to predict the onset of CST, which for these very rough particles occurs at a critical volume fraction much lower than that previously reported in the literature. Finally, we demonstrate how mixtures of particles with opposing surface chemistry make it possible to finely tune the shear-thickening response of the suspension at a fixed volume fraction, paving the way for a fine control of the shear-thickening transition in engineering applications.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
