Simulation of interphase percolation and gradients in polymer nanocomposites
Simulation of interphase percolation and gradients in polymer nanocomposites
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DOI：
10.1016/j.compscitech.2008.11.022
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发表时间：
2009-03-01
影响因子：
9.1
通讯作者：
Brinson, L. Catherine
中科院分区：
文献类型：
--
作者：
Qiao, Rui;Brinson, L. Catherine
实验数据表明，在聚合物基体中分散良好的纳米颗粒会在每个纳米颗粒周围形成一个明显的聚合物迁移率改变的间相区，从而导致复合材料内部形成一个渗透的间相网络。为了研究这一概念和界面的性质，建立了一个二维有限元模型来研究界面区域对复合材料整体性能的影响。在基体中随机分布着30个不重叠的相同圆形夹杂物，夹杂物周围有层间相。模拟结果清楚地表明，复合材料的损耗模量随几何渗流界面网络的存在或不存在而变宽或位移。我们的数值研究结果与实验数据相吻合，表明非功能化复合材料的损耗峰变宽，功能化纳米管聚合物复合材料的损耗模量有很大的变化。此外，我们的研究结果表明，界面层的性质存在梯度，并且将这种梯度纳入模型对于反映聚合物纳米复合材料的行为至关重要。(C) 2008 Elsevier Ltd版权所有。
Experimental data suggests that well dispersed nanoparticles within a polymer matrix induce a significant interphase zone of altered polymer mobility surrounding each nanoparticle, which can lead to a percolating interphase network inside of the composite. To investigate this concept and the nature of the interphase, a two-dimensional finite element model is developed to study the impact of interphase zones on the overall properties of the composite. Thirty non-overlapping identical circular inclusions are randomly distributed in the matrix with layers of interphase surrounding the inclusions. The simulation results clearly show that the loss moduli of composites are either broadened or shifted corresponding to the absence or presence of a geometrically percolating interphase network. Our numerical study correlates well with experimental data showing broadening of loss peaks for unfunctionalized composites and a large shift of the loss modulus for functionalized nanotube polymer composites. Further, our results indicate the existence of a gradient in properties of the interphase layer and that incorporating this gradient into modeling is critical to reflect the behavior of polymer nanocomposites. (C) 2008 Elsevier Ltd. All rights reserved.