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Solid‐state synthesis of a new core–shell nanocomposite of polyaniline and silica via oxidation of aniline hydrochloride by FeCl 3 .6H 2 O
Author(s) -
Koosheh Hajar Bagheri,
ModarresiAlam Ali Reza
Publication year - 2016
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/pat.3766
Subject(s) - polyaniline , materials science , polymerization , nanocomposite , dopant , aniline , thermogravimetric analysis , chemical engineering , in situ polymerization , fourier transform infrared spectroscopy , polymer chemistry , composite material , organic chemistry , polymer , doping , chemistry , engineering , optoelectronics
Among the different oxidants used for the preparation of polyaniline in the solid‐state, iron (III) chloride (FeCl 3 .6H 2 O) can act as both oxidant and dopant. This work reports the synthesis and characterization of novel composite of polyaniline/silica. The polymerization was performed by oxidative polymerization of aniline hydrochloride in the presence of silica and FeCl 3 .6H 2 O under solid‐state (solvent‐free) condition. The FeCl 3 .6H 2 O has been chemically supported on silica and generated silica‐supported FeCl 3 ( SSFe ), which plays three important roles simultaneously (a) oxidant, (b) primary dopant, and (c) secondary dopant (Lewis acid). Furthermore, the existence of silica is important for proceeding of polymerization in solid state. In the other words, the surface polymerization and green chemistry in solid state have been coupled. The characterization and doping process are verified by ultraviolet‐visible, Fourier transform infrared, atomic absorption spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and elemental analysis (CHNS). From atomic absorption spectroscopy the ratio of Fe/N in the composite obtained about 1, which confirms the formation of delocalized polarons by SSFe in the composites. The conductivity is in the range of semi‐conductive. Furthermore, contact resistance was determined by circular‐transmission line measurement. According to scanning electron microscopy images silica particles have been thoroughly coated by polyaniline within the range of 0.2 to 1 µm. However, transition electron microscopy images depict the uniform solid nanospheres (no hollow spheres or fibers), and their mean diameters are under of 50 nm. It confirms nanocomposite of core–shell PANI‐SSFe. Copyright © 2016 John Wiley & Sons, Ltd.