For the nanoparticle-filled polymers, weak attractive interactions between nanoparticles lead to agglomeration and even formation of a network of nanoparticles in the polymer matrix. Both the agglomeration and the deagglomeration (breakdown) of the particle network are affected by the shear flow, resulting in shear-induced liquid-solid (L-S) transition and shear-induced solid-liquid (S-L) transition, respectively. In this study, we quantify the percolation threshold of both transitions under shear-induced agglomeration and shear-induced breakdown processes. Both the present shear condition and the preshear condition affect the percolation threshold, which turns to only shear rate dependence under steady shear condition, indicating no shear hysteresis. A scaling relation is suggested to describe the percolation threshold at low shear rate. The critical strains at both S-L and L-S transitions are inversely proportional to the distance of the particle concentration to the percolation concentration under steady shear. The apparent phase boundary under shear, represented by the shear rate and shear history-dependent percolation threshold, is further conceptually converted to the space of structural parameter, from which the possible transitions pathway under steady shear are discussed.

中文翻译：

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纳米颗粒填充的聚合物中的剪切诱导的分解和团聚：相界和动力学的变化

对于纳米颗粒填充的聚合物，纳米颗粒之间的弱吸引力相互作用导致团聚，甚至在聚合物基质中形成纳米颗粒网络。剪切流影响颗粒网络的团聚和解聚（分解），分别导致剪切诱导的液-固（LS）转变和剪切诱导的固-液（SL）转变。在这项研究中，我们量化了在剪切诱导的团聚和剪切诱导的分解过程中两个过渡的渗滤阈值。当前的剪切条件和预剪切条件都会影响渗流阈值，在稳定的剪切条件下，它仅取决于剪切速率，表明没有剪切滞后。建议使用比例关系来描述低剪切速率下的渗滤阈值。在SL和LS跃迁下的临界应变与稳定剪切下颗粒浓度与渗滤浓度的距离成反比。由剪切速率和与剪切历史相关的渗流阈值表示的剪切下的表观相界在概念上进一步转化为结构参数空间，从中讨论了稳态剪切下可能的跃迁路径。