标题： 在剪切增稠纳米颗粒悬浮液中添加微米尺寸的入侵物 显示英文标题

标题： On the addition of micron-size intruders in a shear-thickening suspension of nanoparticles

摘要： 本研究调查了在添加称为颗粒的大侵入物后，由不同类型的纳米颗粒制成的剪切增稠悬浮液的流变行为。 尺寸比范围从20到120。 我们考察了颗粒尺寸、体积分数和表面特性对剪切增稠特性的影响。 从一种不加颗粒时表现出不连续剪切增稠（DST）的气相二氧化硅悬浮液开始，不同体积分数的颗粒添加会将增稠的起始点转移到较低的剪切速率。 同时，增稠强度（通过增稠指数量化）降低，从DST转变为连续剪切增稠（CST）。 与纳米二氧化硅球体的悬浮液相比，显示出类似趋势，表明在不同系统中具有普遍性。 然而，这些结果与基于玉米淀粉的悬浮液相反，在后者中颗粒的添加增强了增稠效果。 这种差异归因于此处研究的较大尺寸比：当颗粒远大于间隙悬浮液中的颗粒时，颗粒会在局部剪切速率上引入分散性，并破坏颗粒形成力链扩展结构的能力。 这些发现突显了颗粒尺寸比在决定复杂悬浮液流变性中的关键作用，为工业和科学应用中定制材料特性铺平了道路。 显示英文摘要

摘要： This study investigates the rheological behavior of shear-thickening suspensions made of different types of nanoparticles upon the addition of large intruders referred to as granules. The size ratio ranges from 20 to 120. We examine the effects of granule size, volume fraction, and surface properties on shear-thickening characteristics. Starting with a fumed silica suspension exhibiting discontinuous shear thickening (DST) without granules, the addition of granules at different volume fractions, shifts the onset of thickening to lower shear rates. Concomitantly, the strength of the thickening, quantified by the thickening index, decreases, transitioning from DST to continuous shear thickening (CST). Comparison with suspensions of nanosilica spheres reveals a similar trend, suggesting generality across different systems. However, these results contrast with cornstarch-based suspensions, where granule addition enhances thickening. This difference is attributed to the large size ratio studied here: When the granules are much larger than the particles in the interstitial suspension, the granules introduce a spread in the local shear rate and disrupt the particles' ability to form an extended fabric of force chains. The findings highlight the critical role of particle size ratio in determining the rheology of complex suspensions, paving the way for tailoring material properties in industrial and scientific applications.