Raman study of graphene nanoribbon analogs confined in single-walled carbon nanotubes and their high-pressure transformations

摘要

Single wall carbon nanotubes with a diameter distribution from 1.30 to 1.55nm filled with perylene molecules were synthesized via a vapor-phase encapsulation method. The perylene molecules formed short-chain nanoribbon analogs inside the tubes by polymerization. The polymerization of perylene molecules is found to be dependent on the annealing temperature and thus the length of the formed nanoribbons. High-pressure transformation of the formed hybrid nanostructure has been studied by means of Raman spectroscopy combined with theoretical simulation. It is found that the encapsulated nanoribbon analogs can act as a probe for identifying the structural transitions of the host nanotubes. In comparison to empty carbon nanotube, filling with nanoribbon analogs into the nanotubes decreases the collapse pressure of the nanotubes, which can be explained in terms of their inhomogeneous interactions between the fillers and carbon nanotubes. Our theoretical calculation gives further insight into the experimental observations. Copyright (c) 2017 John Wiley & Sons, Ltd.