Investigations on the quality of dispersion of nanofillers in poly(methyl methacrylate) composites by creep-recovery experiments
Investigations on the quality of dispersion of nanofillers in poly(methyl methacrylate) composites by creep-recovery experiments
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DOI：
10.1122/1.3314291
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发表时间：
2010-03-01
影响因子：
3.3
通讯作者：
Muenstedt, Helmut
中科院分区：
文献类型：
--
作者：
Triebel, Christian;Katsikis, Nikolaos;Muenstedt, Helmut
纳米复合材料与聚（甲基丙烯酸甲酯）作为基体和三种不同类型的填料，即，纳米粘土，纳米二氧化硅，和多壁碳纳米管，使用各种方法制备的特定填料的分散体。使用光学和透射电子显微镜分析形态。复合材料的蠕变恢复实验进行了研究，除了传统的动态力学测量。虽然储能模量G（“）的变化对于低填料浓度不是非常明显，但通过蠕变恢复实验测量的可恢复柔度的差异变得显著。分散的质量越好，可恢复的顺应性越高。这一发现可以通过大分子与颗粒表面的相互作用来解释，对于分散良好的颗粒，这种相互作用更为明显，因为它们提供了更大的表面积。因此，蠕变恢复测量可以非常灵敏地用于确定分散体的质量。这种流变学方法集成了整个样品的状态，而透射电子显微镜只分析了其中的一小部分。
Nanocomposites with poly(methyl methacrylate) as the matrix and three different types of fillers, namely, nanoclay, nanosilica, and multiwalled carbon nanotubes, were prepared using various methods for the dispersion of the particular fillers. The morphology was analyzed using light and transmission electron microscopy. The composites were investigated by creep-recovery experiments, in addition to conventional dynamic-mechanical measurements. While the changes of the storage modulus G(') are not very distinctive for low filler concentrations, the differences in the recoverable compliance measured by creep-recovery experiments become significant. The better the quality of dispersion, the higher is the recoverable compliance. This finding is explained by an interaction of macromolecules with the particle surface which is more pronounced for well dispersed particles as they offer a larger surface area. Therefore, creep-recovery measurements can very sensitively be used for the determination of the quality of dispersion. This rheological method integrates over the state of the whole sample, whereas transmission electron microscopy analyses only a tiny part of it.