Papers by Keyword: Polyaniline (PANI)

Abstract: SiO2 doped by polyaniline for application in electrorheological (ER) fluid was prepared by using a simple one-pot interfacial synthesis method. Scanning electron microscopy (SEM) image shows that the morphologies of SiO2 may be changed from spherical to fibroid structure by changing the molar ratio of tetraethyl orthosilicate(TEOS) and aniline. X-ray diffraction (XRD) proves that polyaniline does not change the crystallinity of SiO2. The ER behaviors of SiO2 doped by polyaniline in silicone oil are investigated with different doping degrees under different shear rate, and the results show that properly doping polyaniline improves electrorheological behavior of SiO2.

Abstract: In this study a solution-blend method is adopted to prepare conductive polyvinyl alcohol (PVA) and polyaniline doped with dodecyl benzene sulfonic acid (PVA/PANI-DBSA) blend films. Emeraldine base (EB)-type polyaniline (PANI) is dissolved in N-methyl-2-pyrrolidinone (NMP) and then blended with PVA/dodecyl benzene sulfonic acid (DBSA) solution by various amounts. The morphological structures and characterized of the films were observed via scanning electronic microscopy (SEM), thermogravimetric analysis (TGA) and X-ray powder diffraction (XRD). Electrical properties of the blends were characterized by means of electrical conductivity measurements. It is found that the electrical conductivity and the thermal degradation onset temperature of the PVA/PANI-DBSA blend film are increased as the amount of PANI-DBSA is increased.

Abstract: Composite nanofibers of polyaniline doped with dodecylbenzene sulfonic acid (PANI-DBSA) and polyacrylonitrile (PAN) were prepared via an electrospinning process. The surface morphology of PANI-DBSA/PAN nanofibers was characterized using scanning electron microscopy (SEM). Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) were used to investigate the hydrogen bonding and miscibility behavior of the blend. It was found that the average fiber diameter of composites nanofiber was increased with the increase of PANI-DBSA content. The formation of the hydrogen bonding between PAN and PANI-DBSA was identified by the FTIR spectra

Abstract: Conductive polyaniline/cerium dioxide (PANI/CeO2) composites have been synthesized by in-situ polymerization of aniline in the presence of CeO2 nanoparticles. The structure and thermal stability of obtained composites were characterized by Fourier-transform infrared spectra (FTIR), Fourier-transform Raman spectra (FT-Raman), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The results showed that PANI and CeO2 nanoparticles were not simply blended, and a strong interaction existed at the interface of CeO2 and PANI. In the PANI/CeO2 composite, the degree crystallinity of PANI increased and diffraction pattern of CeO2 was amorphous. And that the composites were more thermally stable than that of the pure PANI. Electrical conductivity measurements indicated that the conductivity of PANI/CeO2 composites was much higher than that of the pure PANI and the maximum conductivity obtained was 11.68 S/cm at 17.5 wt% of CeO2.

Abstract: A chemical oxidative polymerization of aniline sulfosalicylic acid (ANISSA) and aniline sulfate acid (ANIH2SO4) was performed in an aqueous solution. A co-doped polyaniline (PANI) was thus obtained, a higher conductivity than the insoluble H2SO4-doped PANI compressed pellet, and much higher conductivity than that prepared from pure ANISSA. The PANI doped with SSA and H2SO4 was characterized using Fourier-transform infrared spectra (FTIR), Fourier-transform Raman spectra (FT-Raman), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The investigation reveals that SSA and H2SO4 as dopant not only enhances crystallinity of polyaniline but also stability of polyaniline.

Abstract: X-ray photoelectron spectroscopy (XPS) has been employed to investigate the protonation degree of polyaniline doped with sulfosalicylic acid (PAni-SSA) obtained by different synthetic methods. The protonation degree has been compared to electrical conductivity. Prepared PAni-SSA through the redoping process in an agate mortar displays conductivity values within the range of 1S/cm. Protonation degree of synthesized PAni-SSA by aqueous dispersion polymerization of aniline in the presence of SSA is higher than 50 %, indicating that a substantial portion of amine units have also been protonated. The C/N and S/N molar ratios obtained by XPS analysis indicate that the polyaniline chains obtained by aqueous dispersion polymerization are protonated by both sulfate anions.

Abstract: Polyaniline(PANI) nanofibers were firstly prepared by rapid mixture method, EP/PANI nanocomposite was obtained by in-situ adding the PANI nanofibers to epoxy resin(EP). Scanning electron microscopy(SEM) proves that the type of doped acids has a little effect on the morphologies of PANI, and the PANI doped by different acids present nanofiber structures with the diameter of about 50 nm. The thermal behaviour of EP/PANI nanocomposites were investigated in detail by using a dynamic rate mode of thermogravimetric analyser (TGA) in inert atmosphere, and the results show that the PANI nanofibers obviously improve thermal stability of pure EP. Compared with EP/PANI doped by nitric acid or sulfuric acid, EP/PANI doped by phosphoric acid has best thermal stability.

Abstract: The rod-shaped polyaniline (PANI)-barium ferrite nanocomposites were synthesized by in situ polymerization of aniline in the presence of BaFe12O19 nanoparticles with diameters of 60-80 nm. The composites obtained were characterized by infrared spectra (IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The thermal stability and the composition of the composites were investigated by TG-DTG analysis. The results indicate that the thermal stability of the composites is higher than that of the pure PANI which can be attributed to the interactions existed between PANI chains and ferrite particles.

Abstract: The ordered polyaniline nanoarrays had dispersed homogeneously on the graphene oxide or reduced graphene oxide sheets without agglomeratation in isopropanol media. The composites were characterized by field emission scanning electron microscopy, transmission electron microscopy, infrared spectroscopy, Raman spectroscopy and electrochemical tests. The electrochemical performance of the electrode material had been dramatically improved with the highest specific capacitance of 1351 F/g.

Abstract: A graphene oxide/polyaniline composite was synthesized by an in situ polymerization process. This product was simply prepared in an ethylene glycol medium, using ammonium persulfate as oxidant in ice bath. The composite was characterized by field emission scanning electron microscopy, transmission electron microscopy, X-Ray photoelectron spectroscopy, Raman spectroscopy and electrochemical test. The composite material showed a good electrochemical performance.