<I>In-Situ</I> Raman Spectra of Single-Walled Carbon Nanotube/Epoxy Nanocomposite Film Under Strain

Abstract

In-situ Raman spectra under continuous strain have been carried out to follow the load transfer efficiency in a single-walled carbon nanotube/epoxy nanocomposite film, which was fabricated by a facile and filter-free infiltration method using directly synthesized SWNT film as skeleton. It was found that in the low elastic range of 1%, with the increase of applied strain, the G- and G+ Raman bands downshift nearly lineally with corresponding ultrahigh rates up to -12 and -17 cm(-1)/% strain, respectively. As the applied strain decrease, these Raman bands upshift to their original frequencies with almost the same rates. These precise relationships between the Raman band shift and the applied strain enable this nanocomposite film promising stress or stain sensors. Furthermore, some Raman radial breathing modes (RBMs) disappear (appear) under larger strain (1.6%) and recover (vanish) when the strain is released, also verify the effective deformation of micro SWNTs induced by extra macro strain applied on the nanocomposite film. More interestingly, these frequency shifts and intensity vibrations are recoverable and repeatable, indicating the high elasticity of deformation in this strain region of 2%.