We present an integrated theoretical study of the structure, thermodynamic properties, dynamic localization, and glassy shear modulus of melt polymer nanocomposites (PNCs) that spans the three microstructural regimes of entropic depletion induced nanoparticle (NP) clustering, discrete adsorbed layer driven NP dispersion, and polymer-mediated bridging network. The evolution of equilibrium and dynamic properties with NP loading, total packing fraction, and strength of interfacial attraction is systematically studied based on a minimalist model. Structural predictions of polymer reference interaction site model integral equation theory are employed to establish the rich behavior of the interfacial cohesive force density, surface excess, and a measure of free volume as a function of PNC variables. The glassy dynamic shear modulus is predicted to be softened, reinforced, or hardly changed relative to the pure polymer melt depending on system parameters, as a result of the competing and qualitatively different influences of interfacial cohesion (physical bonding), free volume, and entropic depletion on dynamic localization and shear elasticity. The localization of polymer segments is the dominant factor in determining bulk PNC softening and reinforcement effects for moderate to strong interfacial attractions, respectively. While in the athermal entropy-dominated regime, the primary origin of mechanical reinforcement is the stress stored in the aggregated NP subsystem. The PNC shear modulus is often qualitatively correlated with the segment localization length but with notable exceptions. The present work provides the foundation for developing a theory of segmental relaxation, T_g changes, and collective NP dynamics in PNCs based on a self-consistent treatment of the cooperative activated motions of segments and NPs.

中文翻译：

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依赖于微结构的玻璃态剪切弹性和熔融聚合物纳米复合材料中动态局部化的理论。

我们目前对熔融聚合物纳米复合材料（PNC）的结构，热力学性质，动态局部化和玻璃态剪切模量进行了综合的理论研究，该研究涵盖了熵耗竭诱导纳米颗粒（NP）团聚，离散吸附层驱动的NP分散体的三种微观结构状态，和聚合物介导的桥接网络。基于极简模型，系统地研究了随着NP含量，总堆积分数和界面吸引强度而变化的平衡和动态特性。聚合物参考相互作用位点模型积分方程理论的结构预测被用来建立界面内聚力密度，表面过剩和自由体积的量度作为PNC变量的函数的丰富行为。由于界面内聚力（物理键合），自由体积和熵的竞争和质的不同，玻璃质动态剪切模量相对于纯聚合物熔体预计会相对于纯聚合物熔体软化，增强或几乎不变。动态局部化和剪切弹性的耗竭。聚合物链段的定位分别是决定整体PNC软化和增强作用的主要因素，中等至强界面吸引力。在非热熵主导的状态下，机械增强的主要来源是聚集在NP子系统中的应力。PNC的剪切模量通常在质量上与链段定位长度相关，但有明显的例外。T _g的变化以及基于段和NP协同激活运动的自洽处理的PNC中的NP集体动力学。