Nanoparticle Brush Architecture Controls Polymer Diffusion in Nanocomposites
Nanoparticle Brush Architecture Controls Polymer Diffusion in Nanocomposites
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DOI：
10.1021/ma500235v
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发表时间：
2014-04-08
期刊：
影响因子：
5.5
通讯作者：
Composto, Russell J.
中科院分区：
文献类型：
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作者：
Choi, Jihoon;Hore, Michael J. A.;Composto, Russell J.
我们发现聚合物纳米复合材料(PNC)中的聚合物扩散是由接枝到硬质球形纳米颗粒(NPs)上的聚合物刷的结构控制的。在高接枝密度时，扩散链被排除在聚合物刷之外，导致更大的限制。但是，在较低的接枝密度下，与相同的NP含量相比，这些链条穿透刷子，扩散类似于硬NP的情况。我们利用自洽场理论，通过模拟聚合物对接枝刷子的渗透来计算有效粒子间距。当根据限制参数(IDef/2R(G)，其中R-g是扩散聚合物的旋转半径)绘制时，减少的扩散系数(D/D-o)落在独立于画笔体系结构的主曲线上。这些发现表明，刷子结构为控制PNC的聚合物动力学和粘弹性提供了一条新的途径。
We show that polymer diffusion in polymer nanocomposites (PNCs) is controlled by the architecture of polymer brushes grafted to hard spherical nanoparticles (NPs). At high grafting density, diffusing chains are excluded from the polymer brush leading to greater confinement. However, at lower grafting density, these chains penetrate the brush and diffusion is similar to the hard NP case, compared at the same NP loading. We calculate the effective interparticle spacing (IDeff) by modeling polymer penetration into the grafted brush using self-consistent field theory. When plotted against a confinement parameter (IDeff/2R(g), where R-g is the radius of gyration of the diffusing polymer), reduced diffusion coefficients (D/D-o) fall on a master curve independent of brush architecture. These findings show that brush architecture provides a new route toward controlling polymer dynamics and viscoelasticity of PNCs.