Coupling of Nanoparticle Dynamics to Polymer Center-of-Mass Motion in Semidilute Polymer Solutions
Coupling of Nanoparticle Dynamics to Polymer Center-of-Mass Motion in Semidilute Polymer Solutions
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DOI：
10.1021/acs.macromol.7b02441
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发表时间：
2017-11
期刊：
影响因子：
5.5
通讯作者：
Ren-peng Chen;R. Poling-Skutvik;A. Nikoubashman;Michael P. Howard;J. Conrad;J. Palmer
中科院分区：
文献类型：
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作者：
Ren-peng Chen;R. Poling-Skutvik;A. Nikoubashman;Michael P. Howard;J. Conrad;J. Palmer
我们研究了半稀释聚合物溶液中的纳米粒子的动力学时，纳米粒子的大小的聚合物线圈使用显式和隐式溶剂模拟方法。纳米粒子的动力学是subdiffusive在短时间尺度上，然后过渡到扩散运动在长时间尺度上。长时间的扩散率的规模根据理论预测的基础上充分动态耦合的聚合物链段松弛。然而，与我们最近的实验相一致，我们观察到纳米颗粒的亚扩散指数在很宽的聚合物浓度范围内明显大于耦合理论预测的。我们把这种差异的subdiffusive制度之间的纳米粒子的动力学和聚合物的质心运动，这不同于控制长时间扩散的聚合物弛豫的额外的耦合机制的存在。这种耦合即使在没有多体流体动力学干扰的情况下也能保持。
We investigate the dynamics of nanoparticles in semidilute polymer solutions when the nanoparticles are comparably sized to the polymer coils using explicit- and implicit-solvent simulation methods. The nanoparticle dynamics are subdiffusive on short time scales before transitioning to diffusive motion on long time scales. The long-time diffusivities scale according to theoretical predictions based on full dynamic coupling to the polymer segmental relaxations. In agreement with our recent experiments, however, we observe that the nanoparticle subdiffusive exponents are significantly larger than predicted by the coupling theory over a broad range of polymer concentrations. We attribute this discrepancy in the subdiffusive regime to the presence of an additional coupling mechanism between the nanoparticle dynamics and the polymer center-of-mass motion, which differs from the polymer relaxations that control the long-time diffusion. This coupling is retained even in the absence of many-body hydrodynamic inte...