In this study, we investigate the motion of polymer segments in polymer/nanoparticle composites by varying nanoparticle (NP) volume fractions. By studying the probability distribution of segment displacement, segment trajectory, and the square displacement of segment, we find the intermittent motion of segments, accompanied with the coexistence of slow and fast segments in polymer nanocomposites (PNCs). The displacement distribution of segments exhibits an exponential tail, rather than a Gaussian form. The intermittent dynamics of chain segments is comprised of a long-range jump motion and a short-range localized motion, which is mediated by the weakly attractive interaction between NP and chain segment and the strong confinement induced by NPs. Meanwhile, the intermittent motion of chain segments can be described by the adsorption-desorption transition at low particle loading and confinement effect at high particle loading. These findings may provide important information for understanding the anomalous motion of polymer chains in the presence of NPs.

在这项研究中，我们通过改变纳米粒子（NP）的体积分数来研究聚合物/纳米粒子复合物中聚合物链段的运动。通过研究节段位移，节段轨迹和节段的平方位移的概率分布，我们发现节段的间歇运动，以及聚合物纳米复合材料（PNC）中慢节段和快节段的共存。段的位移分布表现出指数尾巴，而不是高斯形式。链段的间歇动力学包括一个长距离跳跃运动和一个短程局部运动，这是由NP与链段之间的弱吸引相互作用和NPs引起的强约束作用所介导的。同时，链段的间歇运动可以通过低颗粒负荷下的吸附-解吸转变和高颗粒负荷下的约束作用来描述。这些发现可能为了解NP存在时聚合物链的异常运动提供重要信息。