Polyaniline–calcium titanate perovskite hybrid composites: Structural, morphological, dielectric and electric modulus analysis

Abstract

This paper reports hybrid composites based on polyaniline (PANI) and calcium titanate (CaTiO3) perovskite as a nanofiller synthesized by in-situ polymerization technique. Their structure and morphology were investigated by X-ray diffraction analysis and scanning electron microscopy. The XRD analysis shows that the addition of CaTiO3 in polyaniline reduced the amorphous structure of polyaniline transforming it into semi-crystalline nature, which agrees well with the higher conductivity. Scanning electron microscopy of composites showed a more compact and homogenous structure with uniform distribution of CaTiO3 in the polymer matrix. Dielectric parameters such as dielectric constant, loss factor, and dielectric loss, real and imaginary parts of electric modulus were measured and evaluated as a function of frequency and temperature as well. The variation of dielectric properties and ac conductivity reveals that the dispersion is due to the Maxwell-Wagner type of interfacial polarization. The observed ac conductivity behavior of polyaniline in the presence of calcium titanate was discussed in the framework of Jonscher’s power law. The result showed that ac conductivity increases with the rise of the frequency of applied field and temperature analogous to the semiconducting behavior of composites. Temperature-dependent behavior of frequency exponent seems to obey correlated barrier hopping conduction mechanism. The relaxation behavior of the synthesized samples was analyzed by the electric field modulus and was found to decrease with temperature and CaTiO3 content and increase with frequency.

Study of methylene blue dye elimination from water using polyaniline (PANI) and PANI/SiO2 composite

“…The application of PANI as adsorbent for water purification is due to the large amounts of amine and imine functional groups, which are expected to have interactions with inorganic and organic molecules, such as Hg(II), Cr(VI) and methylene blue. [5][6][7][8][9][10] Recently, a great work has been made to combine conjugated polyaniline with conventional organic and inorganic adsorbents to form composites or hybrid adsorbents such as PANI-graphene oxide, 11 doped polyaniline-potash alum, 12 polyaniline-polystyrene (PANI-PS), 13 PANI-cellulose, 14 PANI-cellulose fiber, 15 polyaniline-polyethylene glycol (PANI-PEG), 16 polyaniline-magnetite, 17 PANI-chitosan, 18 PANI-sawdust, 19 polyaniline-multiwalled carbon nanotubes (PANI-MWCNT), 20 PANI-chitin, 21 PANI-nickel ferrite. 22 These functional materials are combined with PANI to generate PANI-related composites to improve its surface area and change its surface morphology and have been studied like adsorbents for removing dyes, heavy metals and ions from aqueous solutions [23][24][25][26][27][28][29][30][31][32] and demonstrate an important attention because of their excellent adsorption performance.…”