Controlled Structure Evolution of Graphene Networks in Polymer Composites
Controlled Structure Evolution of Graphene Networks in Polymer Composites
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DOI：
10.1021/acs.chemmater.7b04343
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发表时间：
2018-02
影响因子：
8.6
通讯作者：
Stephen C Boothroyd;David W. Johnson;M. Weir;C. Reynolds;J. M. Hart;Andrew J. Smith;N. Clarke;R. Thompson;K. S. Coleman
中科院分区：
文献类型：
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作者：
Stephen C Boothroyd;David W. Johnson;M. Weir;C. Reynolds;J. M. Hart;Andrew J. Smith;N. Clarke;R. Thompson;K. S. Coleman
由于石墨烯构象和分散性难以控制，在聚合物复合材料中利用石墨烯优异的物理性能是一项重大挑战。因此，难以实现具有均匀一致性能的石墨烯聚合物复合材料的可靠加工。我们展示了形态和纳米复合材料特性的独特机制，这可以通过系统控制剪切速率和剪切历史来实现。观察到石墨烯纳米片 (GNP) 复合材料特有的电阻抗显着变化。 ≤0.1 s–1 的低剪切速率会破坏石墨烯复合材料中典型的 GNP 团聚体，将 GNP 部分剥离为几层石墨烯，并减少取向，从而增强复合材料的导电性，而在较高剪切速率下，随着石墨烯填料网络的破坏，GNP 取向增加，电导率降低四个数量级。复合材料的结构不断发展，...
Exploiting graphene’s exceptional physical properties in polymer composites is a significant challenge because of the difficulty in controlling the graphene conformation and dispersion. Reliable processing of graphene polymer composites with uniform and consistent properties can therefore be difficult to achieve. We demonstrate distinctive regimes in morphology and nanocomposite properties, achievable through systematic control of shear rate and shear history. Remarkable changes in electrical impedance unique to composites of graphene nanoplatelets (GNPs) are observed. Low shear rates ≤0.1 s–1 break up the typical GNP agglomerates found in graphene composites, partially exfoliate the GNPs to few-layer graphene, and reduce orientation, enhancing electrical conductivity in the composite materials, whereas at higher shear rates GNP orientation increases and the conductivity reduces by four orders of magnitude, as the graphene filler network is broken down. The structure of the composite continues to evolve, ...