Functional groups in carbon black by FTIR spectroscopy

Results of the application of Fourier transform infrared (FTIR) spectroscopy to determine the type and amount of surface functional groups in carbon black are reported. Surface functional groups in carbon black have been identified and analyzed using carbon black dispersions in KBr. At low dilutions less than 0.10% (wt/wt), Beer's law is followed. Absorbance at 1720 cm−1 can be assigned to carboxylic acid, while the assignment of the strong band at 1600 cm−1 is uncertain. Semi-quantitative analysis of band shapes indicates that there is a distribution of electronic environments in the carbon blacks. The magnitude of the absorbances (0.02–0.10) correspond to carboxylic or quinone groups in the amount of ~0.1–1.8 meq/g. Further developments of the technique could lead to a quantitative method for the determination of functional groups in carbon black.