- Description of the effort: This effort seeks to develop a fundamental understanding of the role of nanoscale constituents and their large surface-to-volume ratio in modulating damping properties in polymer based nanocomposites. The two main directions of this research are benefiting from the interfacial friction between nanoscale constituents and matrix to achieve tunable frictional energy dissipation, and coupling thermal energy to matter (matrix) as a means to actively, controllably and reversibly modulate the damping of nanocomposites. This work hinges upon developing innovative architectures of CNT assemblies in polymer matrices to promote desired damping mechanisms in expense of others.
Figure: Top Left: PS-CNT nanocomposite with highly aligned CNTs processed to promote interfacial sliding and damping in rotor crafts (Top Right). Bottom: Above a strain threshold, the interface is reversibly broken, providing an opportunity for energy dissipation. This work addresses the need of the US Army to dissipate undesired vibrations via exploiting the inherent material properties.
- Main findings so far:
- Below the interfacial slip strain threshold, damping scales monotonically with CNT content which indicates the prevalence of CNT-CNT friction dissipation mechanisms within agglomerates,
- Above the interfacial slip strain threshold, interfacial slip contributes to energy dissipation. The slip interaction is reversible at time scales of 1-10 Hz, suggesting the nature of these interactions are mainly mechanical interlocking.
- The percolated network of CNTs within the polymer matrix can be used to substantially enhance the damping properties of the composite by coupling thermoelectric energy to matter, with minimal reduction in stiffness.
- Funded by ARL
- Senior personnel involved: Dr. M. Naraghi (Single PI)
- References
- Gardea F., Glaz B., Riddick J., Lagoudas D., and Naraghi M., “Thermally Activated Energy Dissipation in Semi-crystalline Polymer Nanocomposites” Composites Science and Technology, 134, 275-286 (2016).
- Gardea F., Glaz B., Riddick J., Lagoudas D., and Naraghi M., “Identification of Energy Dissipation Mechanisms in CNT Reinforced Nanocomposites” Nanotechnology, 27(10), 105707 (2016).
- Gardea F., Glaz B., Riddick J., Lagoudas D., and Naraghi M., “Energy Dissipation due to Interfacial Slip in Nanocomposites Reinforced with Aligned Carbon Nanotubes” ACS Applied Materials and Interfaces, 7, 9725-9735 (2015).
- Gardea, F., M. Naraghi, and D. Lagoudas, “Effect of Thermal Interface on Heat Flow in Carbon Nanofiber Composites”. Acs Applied Materials & Interfaces, 6(2): p. 1061-1072. (2014)