Impact of ultrasonication on carbon nanotube demixing and damage in polymer nanocomposites |
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| Authors: | Jayadurga Iyer Ganapathi Stephanie S. Lee Dilhan M. Kalyon Frank T. Fisher |
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| Affiliation: | 1. Department of Mechanical Engineering, Stevens Institute of Technology, Hoboken, New Jersey, USA;2. Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, New Jersey, USA |
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| Abstract: | While ultrasonication is universally employed for dispersion and distribution of carbon nanotubes (CNTs) in a solvent or polymer solution, the current work focuses on the underlying mechanisms of CNT demixing and CNT damage that can occur during processing. Here, multi-walled CNTs were dispersed in a polycaprolactone polymer matrix using an established solution processing technique. Electrical, rheological, and mechanical characterization results suggest that once nanocomposite property enhancements reach an optimal level, further sonication leads to a decrease in the corresponding properties due to a combination of CNT damage and demixing mechanisms. Evidence of CNT damage from transmission electron microscopy, poor CNT distribution from optical image analysis and shear-induced crystallization results, and reagglomeration observed from ultraviolet–visible results, taken together, suggest that mechanisms of demixing and damage of the CNTs coexist for excessive sonication times. |
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| Keywords: | mechanical properties structure–property relationships synthesis and processing techniques |
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