Infrared spectrometric evaluation of carbon nanotube sulfonation

In present study, wet chemical functionalization process of carbon nanotubes (CNT) is studied for evaluation of the structural and chemical changes in CNT. An aim of this research was to study the sulfonation process by a spectroscopic-chemometrics method. Purified multi wall carbon nanotubes (MWCNT) were activated being prepared via reaction with LiAlH4 reducing agent, for nucleophilic attack by chlorosulfonic acid. In the next step, sulfonation was conducted by reflux. Fabricated samples were characterized by scanning electron microscope (SEM), thermo gravimetric analysis (TGA), Raman and Fourier transform infrared (FTIR) spectroscopy. In order to evaluate the reaction evolution trend, diffuse reflectance mid IR spectroscopy was employed to obtain data along the reaction period and spectral data were processed by multivariate curve resolution alternating least squares (MCR-ALS) chemometrics techniques.