New Strategies for the Chemical Characterization of Multi-Walled Carbon Nanotubes and their Derivatives

Abstract

Industrially relevant characterization of multi-walled carbon nanotubes (MWCNT) is still remaining a challenging task. The aim of this work is to show novel and fast concepts for the chemical characterization of CNTs by combination of different analytical techniques. While the informations obtained by individual analytical tools like Fourier transform infrared spectroscopy (FTIR), attenuated total reflection infrared spectroscopy (ATR-FTIR), and Raman spectroscopy are not giving a full picture of the functionalisation of the MWCNTs, the combination of analytical tools such as FTIR or mass spectrometry with thermo gravimetric analysis are proven to be very useful methods for the chemical characterisation. Another focus of this contribution is put on sample preparation for FTIR and Raman spectroscopy, as this parameter shows a major influence on the obtained results. Suggestions for the sample preparation leading to results with high reproducibility are given. The measurements have been carried out on typical CNT samples such as commercially available pristine, carboxylated and amine functionalized MWCNTs, but also polystyrene (PS)-grafted MWCNTs. The results may serve as a guidance for the qualitative and quantitative characterization of CNT.