Exceptionally crystalline and conducting acid doped polyaniline films by level surface assisted solution casting approach

Abstract

Emeraldine salt form of polyaniline (PANI) was synthesized by chemical oxidative polymerisation method using ammonium persulfate as oxidant. Resultant emeraldine salt form of PANI was dedoped using ammonia solution and then re-doped with camphor sulphonic acid (CSA), naphthaline sulphonic acid (NSA), hydrochloric acid (HCl), and m-cresol. Thin films of these doped PANI samples were deposited on glass substrates using solution casting method with m-cresol as solvent. A level surface was employed to get homogeneous thin films of uniform thickness. Detailed X-ray diffraction studies have shown that the films are exceptionally crystalline. The crystalline peaks observed in the XRD spectra can be indexed to simple monoclinic structure. FTIR and Raman spectroscopy studies provide convincing explanation for the exceptional crystallinity observed in these polymer films. FESEM and AFM images give better details of surface morphology of doped PANI films. The DC electrical conductivity of the samples was measured using four point probe technique. It is seen that the samples also exhibit quite high DC electrical conductivity, about 287 S/cm for CSA doped PANI, 67 S/cm for NSA doped PANI 65 S/cm for HCl doped PANI, and just below 1 S/cm for m-cresol doped PANI. Effect of using the level surface for solution casting is studied and correlated with the observed crystallinity.

Room-temperature Magnetism in Carbon Dots and Enhanced Ferromagnetism in Carbon Dots-Polyaniline Nanocomposite

“…Figure 3d shows two strong Raman features around 1380 and 1570 cm −1 in the CDs spectrum, accounting for sp 3 -hybridized (D) and sp 2 -hybridized (G) carbon-carbon vibrations, respectively 12 . Differently, Mat-PANI shows a Raman feature around 1557 cm −1 , attributed to the C = N stretching vibration in quinomoid ring (Q) 27 , 28 whereas Raman features around 1393 and 1610 cm −1 had been ascribed to C-N + vibration of delocalized polaronic structures (protonation band PB and B) 29 , 30 and C-C stretching of benzenoid ring 31 , 32 , respectively. Raman bands appearing in the range of 700–900 cm −1 in the Mat-PANI spectrum (particularly 832 cm −1 in Fig.…”

Silk and its composites for humidity and gas sensing applications

“…The reduced resistance in PANI-functioned CNTA on exposure to HCl vapor is a result of the protonic acid doping activity of PANI, leading to a decline in resistance in PANI ( Puthirath et al, 2016 ). Here the fibroin solution is mainly used to hold the CNTs together and ease their removal from the SiO 2 substrate.…”