Impact of an Emergent Hierarchical Filler Network on Nanocomposite Dynamics
Impact of an Emergent Hierarchical Filler Network on Nanocomposite Dynamics
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DOI：
10.1021/acs.macromol.8b01510
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发表时间：
2018-10
期刊：
影响因子：
5.5
通讯作者：
Kabir Rishi;G. Beaucage;V. Kuppa;Andrew Mulderig;Vishak Narayanan;Alex McGlasson;M. Rackaitis;J. Ilavsky
中科院分区：
文献类型：
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作者：
Kabir Rishi;G. Beaucage;V. Kuppa;Andrew Mulderig;Vishak Narayanan;Alex McGlasson;M. Rackaitis;J. Ilavsky
聚集的聚合物填料，如炭黑和二氧化硅，在高于逾渗阈值的浓度下形成不混溶体系中的涌现结构，即分层填料网络，其中分散由累积的应变驱动。有人提出，分层填料网络是由一个主要的纳米级网络，局部膨胀在105%（体积）的聚集体，在低应变下的动态光谱的变化，和一个次要的微米级网络，全球膨胀在1020%（体积）与佩恩效应和电导率。提出了一个模型，弹性体占主导地位的动态响应所描述的Einstein-Smallwood行为在高频率和小尺寸和填料网络占主导地位的响应在低频率和大尺寸。纳米级网格尺寸与低应变动态响应中的这种转变相关。微米级网络在非常低的频率下显示出凝胶状的动态响应和相应的凝胶状响应.
Aggregated polymer fillers, such as carbon black and silica, at concentrations above the percolation threshold form an emergent structure, the hierarchical filler network, in immiscible systems where dispersion is driven by accumulated strain. It is proposed that the hierarchical filler network is composed of a primary nanoscale network that locally percolates at ∼5 vol % of aggregates, associated with changes in the dynamic spectrum at low strain, and a secondary micrometer-scale network that globally percolates at ∼20 vol % associated with the Payne effect and electrical conductivity. A model is proposed with an elastomer dominated dynamic response described by Einstein–Smallwood behavior at high frequencies and small sizes and a filler network dominated response at low frequencies and large sizes. The nanoscale mesh size correlates with this transition in low strain dynamic response. The micrometer-scale network displays a gel-like dynamic response at very low frequencies and a corresponding gel-like s...