Studies on the electrochemical properties of lignin/polyaniline composite

In this study, we have synthesized a lignin/polyaniline composite using a typical conductive polymer as a high value-added biomaterial. Further, the morphological characteristics as well as the chemical and electrochemical properties of the lignin/polyaniline composite were evaluated. The morphological analysis of the composite denoted that polyaniline particles, smaller than the lignin particles, formed near the surface of the lignin particles. In addition. FT-IR (Fourier-transform infrared spectroscopy) analysis of the composite revealed that the intrinsic peaks corresponding to lignin considerably reduced or even disappeared and that the lignin/polyaniline interaction occurred because of the shifting of the main polyaniline peaks. Although the electrochemical properties of lignin were considerably poor, the composite exhibited good characteristics. In particular, the capacitance of lignin, lignin/polyaniline composite, and pure polyaniline were 1.52, 131.75, and 214.44 mF-cm-2, i.e., the capacitance of the composite was lower than that of pure polyaniline but considerably higher than that of lignin. Because the lignin content in the composite was approximately 55%, the resulting capacitance was considered to be good.