Synthesis and Characterization of Self-Assembled Polyaniline Nanotubes/Silica Nanocomposites

Abstract

Self-assembled semiconducting, paramagnetic polyaniline nanotubes have been synthesized by the oxidative polymerization of aniline with ammonium peroxydisulfate in aqueous medium in the presence of colloidal silica particles of an average diameter approximately 12 nm, without added acid. The electrical conductivity of polyaniline nanotubes/silica nanocomposites is in the range (3.3-4.0)x10(-3) S cm(-1). The presence of paramagnetic polaronic emeraldine salt form of polyaniline and phenazine units in nanocomposites was proved by FTIR, Raman, and EPR spectroscopies. The influence of the initial silica/aniline weight ratio on the morphology of polyaniline/silica nanocomposites was studied by scanning and transmission electron microscopies. Nanocomposites synthesized by using the initial weight ratio silica/aniline<or=0.2 contain polyaniline nanotubes which have a typical outer diameter of 100-250 nm and an inner diameter of 10-80 nm, and nanorods with a diameter of 60-100 nm, accompanied with polyaniline/silica nanogranules, while the nanocomposite synthesized at weight ratio silica/aniline approximately 2 contains polyaniline/silica nanogranules with an average diameter of 35-70 nm. The evolution of molecular and supramolecular structure of polyaniline in the presence of colloidal silica is discussed.

Effect of reduced graphene oxide–silica composite in polyaniline: electrode material for high-performance supercapacitor

“…Major peaks of PANI obtained are close to those of characteristic peaks of reported polyaniline salt [12], peak at 3445 cm −1 (N-H str. ), 3260 cm −1 (NH + -indicative of doping, i.e., salt formation), 1560 cm −1 (C=C str., quinonoid ring), 1475 cm −1 (C=C str., benzenoid ring), 1295 cm −1 (C-N str., quinonoid ring), 1240 cm −1 (C-N str., benzenoid ring), IR spectrum of pure rGOS shows a peak at 3425 cm −1 corresponding to O-H group of graphene, peaks at 2875 and 2925 cm −1 corresponding to aromatic sp 2 C-H stretching of graphene [13], 1090 and 810 cm −1 corresponding to Si-O-Si asymmetric and symmetric stretching, respectively, [14]. On careful examination of IR spectrum of rGOSP20 sample, major peaks obtained at 3450, 2920, 1560, 1475, 1295, 1240, 1105, and 800 cm −1 are very similar to the IR spectrum of PANI and peaks due to rGOS is not visible in the spectrum.…”

One-dimensional nitrogen-containing carbon nanostructures

“…Ru NPs were conveniently immobilized on NCNTs via microwave-assisted ethylene glycol reduction [163,486]. NCNTs/silica nanocomposites [490]. Composites consisting of Fe-or Fe 3 C-containing…”

Electroactive Polymers and Coatings

“…Being a more stable approach than chemical synthesis of an EAP, it also yields EAPs with less variation in molecular mass as a result of the exothermic reaction during chemical oxidation of the monomer, with temperature fl uctuations impacting the polymer chain length [ 63 ]. The process implicates dissolution of the monomer in an appropriate solvent together with a selected anionic doping salt; this is followed by oxidation of the monomer at the anode.…”