Noncovalent functionalization of carbon nanotubes by polyaniline molecules: Raman analysis

Polyaniline/single-walled carbon nanotube composite (PANI4@SWCNT) has been studied theoretically by means of Raman spectroscopy calculations. We evidence that the structural organization of the nanohybrid systems depends on the diameter of carbon nanotubes. To study the stability of PANI4 molecules encapsulated in the cavity of the SWCNTs, the optimum configurations of PANI4 inside carbon nanotubes are derived from minimum energy calculations using a convenient Lennard-Jones expression. We discussed also two important Raman features of SWCNTs before and after encapsulation of PANI4 including the G-band and the radial breathing mode (RBM) taking into account its metallic or semiconducting character. The G-band shift suggests a significant charge transfer between the PANI4 and the nanotubes.