Department of Physics, Indian Institute of Science, Bangalore, 560 012, India.
Soft Matter. 2018 Jul 25;14(29):6076-6082. doi: 10.1039/c8sm01072b.
Controlling and understanding the flow properties of polymer nanocomposites (PNC) is very important in realising their potential for various applications. In this study we report molecular dynamics simulation studies of slip between a rotating polymer-grafted nanoparticle and the surrounding free linear matrix chains. By varying the interface wettability between the nanoparticle and matrix chains defined by the parameter f, the ratio of the graft to the matrix chain length, or the graft chain density, Σ, we were able to tune the interface slip, δ, significantly. Both f and Σ alter the interface wettability by changing the matrix chain penetration depth, λ, into the graft chain layer. We observed a large value of δ at smaller f or Σ which reduces with an increasing value of the respective parameters. Since interface slip is also likely to affect other properies of PNCs, like viscosity and the glass transition, we suggest that these parameters could become useful tools to control the flow and mechanical properties of PNCs made with grafted nanoparticles.
控制和理解聚合物纳米复合材料（PNC）的流动性能对于实现其在各种应用中的潜力非常重要。在这项研究中，我们报告了旋转聚合物接枝纳米粒子与周围自由线性基质链之间滑动的分子动力学模拟研究。通过改变由参数 f 定义的纳米粒子与基质链之间的界面润湿性、接枝与基质链长度的比值或接枝链密度Σ，可以显著调节界面滑动δ。f 和 Σ 通过改变基质链进入接枝链层的穿透深度λ来改变界面润湿性。我们观察到较小的 f 或 Σ 值对应较大的δ，而随着相应参数的增加，δ 值减小。由于界面滑动也可能影响 PNC 的其他性能，如粘度和玻璃化转变温度，因此我们建议这些参数可能成为控制使用接枝纳米粒子制备的 PNC 流动和力学性能的有用工具。
