We conducted a dissipative particle dynamics simulation on the motion of polymer-grafted nanoparticles in entangled polymer melts. Three regimes for the mean square displacement of the nanoparticles were discovered at different time scales. The nanoparticles undergo Brownian diffusion at short and long time scales and exhibit subdiffusive behavior at intermediate time scales. The short-time diffusion can be approximated as the motion of bare nanoparticles, while the long-time diffusion is associated with the entire polymer-grafted nanoparticle. The long-time Brownian diffusion was found to be non-Gaussian, which originates from the hopping diffusion of polymer-grafted nanoparticles in entangled polymer melts. The results nicely support the experimental findings and provide a comprehensive insight into the anomalous dynamics of polymer-grafted nanoparticles in polymer melts.

中文翻译：

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纠缠的聚合物熔体中聚合物接枝的纳米颗粒的纳米级扩散。

我们对缠结的聚合物熔体中聚合物接枝的纳米粒子的运动进行了耗散粒子动力学模拟。在不同的时间尺度上发现了三种纳米颗粒的均方位移方案。纳米粒子在短时间和长时间尺度上经历布朗扩散，并在中间时间尺度上表现出亚扩散行为。短时扩散可以近似为裸露的纳米粒子的运动，而长时扩散与整个聚合物接枝的纳米粒子相关。发现长时间的布朗扩散是非高斯的，这是由于聚合物接枝的纳米粒子在纠缠的聚合物熔体中的跳跃扩散所致。