Thermal stability of several polyaniline/rare earth oxide composites
Polyaniline/rare earth oxide composites (PANI/La2O3 and PANI/Sm2O3) were synthesized by in situ polymerization at the presence of sulfosalicylic acid (as dopant). The composites obtained were characterized by Fourier transform infrared spectra (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The thermal stability of the composites was investigated by thermogravimetry (TG) and derivative thermogravimetry (DTG). The electrochemical performance of the composites was investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results of FTIR, XRD, SEM, CV, and EIS show that the structure of composite has changed greatly when rare earth oxide content is >0.7 g (PANI/La2O3[w/w(92.7/7.3)] and PANI/Sm2O3[w/w(96.2/3.8)]) and the PANI in the composite has transformed into pernigraniline base (non-conducting state) from emeraldine base (conducting state). TG-DTG analysis indicates that the thermal stability of composite was higher than pure PANI, which is attributed to the interaction between PANI and rare earth oxide.
KeywordsPANI/La2O3 composite PANI/Sm2O3 composite Thermal stability TG-DTG Electrochemical performance
The authors are gratefully acknowledged the National Natural Science Foundation of China under the Grant No. 20903017, the Science and Technology Foundation of Dalian under the Grant No. 2010J21DW010, and China Environmental Protection Foundation No. CEPF2010-123-2-17 for financial support to this study.