Evolution and Interdependence of Structure and Properties of Nanocomposites of Multiwall Carbon Nanotubes with Polyaniline

Abstract

Structure–property relationships of nanocomposites of multiwall carbon nanotubes (MWCNTs) and polyaniline (PANI) doped with dodecylbenzenesulfonic acid (DBSA) are studied and discussed in terms of contribution of the PANI phase properties. Two phases of PANI-DBSA with different properties, such as a shell-wrapping carbon nanotube and separate neat PANI-DBSA domains, are revealed for the first time in the nanocomposites with a high or medium PANI-DBSA content. In the nanocomposites with lower PANI-DBSA contents (<40 wt %), only a core–shell morphology with ∼3 nm or lower thickness PANI shell on the nanotubes is observed. Under this condition, the degree of crystallinity of the PANI-DBSA shell increases almost 2-fold, and thermal stability of the nanocomposite grows sharply. As compared with the neat PANI-DBSA, this special PANI shell phase has more perfect molecular structure and is characterized by a reduced amount of DBSA. It is found that the latter is caused by a competition between the processes of doping of the formed PANI in the shell by the protonic acid and p-doping caused by the MWCNT surface. The nanocomposites demonstrate ppm/ppb range sensitivity to ammonia/methylamine gases with response times, which inversely depend on the PANI-DBSA contents and thickness of the shell.

Development of whey protein isolate/polyaniline smart packaging: Morphological, structural, thermal, and electrical properties

“…The band at 1323 cm −1 is associated with the elongation of the C‐N + bonds, which suggests the polymer protonation and evidences its conducting state. Finally, the band at 1569 cm −1 is related to the elongation of the C=C bond …”

Reactive Template Synthesis of Inorganic/Organic VO2@Polyaniline Coaxial Nanobelts for High‐Performance Supercapacitors

“…The weak bands at 262, 395, 682, and 1010 cm −1 are characteristic of VO 2 , which are identified as, in order, the bending vibrations of V=O and bridging V−O−V, the stretching modes of doubly coordinated V 2 ‐O entity and terminal V=O bond . With regard to the pure PANi and VO 2 @PANi, all the visible peaks at 415, 524 (the C−N−C out‐of‐plane torsions), 574, 607 (the deformations of amine and benzenoid ring), 1162 (the C−H in‐plane bending vibration), 1228, 1336 (the stretching modes of C−N and C−N .+ ), 1387 (the cross‐linked phenazine units), 1459 and 1586 cm −1 (the C=N and C=C stretching species) can be attributed to the PANi phase . It should be noted that the intensity of the peak at 607 cm −1 is much higher than that at 574 cm −1 for PANi, while an opposite case is detected for VO 2 @PANi, which is in agreement with Wan's analysis, indicating the imperfect structure of polymer chain in the obtained PANi.…”

On the importance of interface interactions in core-shell nanocomposites of intrinsically conducting polymers

“…Structure differences between the conducting polymer in pure and composite states were confirmed for different (nano)composites [16,17,19,23,25,26,29,[30][31][32][33]. For example, from the XRD-spectra of doped polyaniline and its nanostructured composite with polycarbonate (PC), we found that its degree of crystallinity in the pure state was about 3 times lower, and 6.…”

“…6b) and also polypyrrole (Fig. 6b) an increased crystallinity of ICP in the nanocomposite, especially at its low contents, was observed [29,35].…”

“…For example, from the XRD-spectra of doped polyaniline and its nanostructured composite with polycarbonate (PC), we found that its degree of crystallinity in the pure state was about 3 times lower, and 6. XRD evidences of the structure differences between the conducting polymers in pure and composite states (core-shell composites): a) the degree of crystallinity and size of crystallites of the doped PANI in pure state and in the shells on the surface of the PC particles (adapted from [25]); the crystallinity changes in doped PANI (b) or PPy (c) phases in nanocomposites with MWCNT (adapted from [29,35]). the average crystallite size was 3 times higher than that in the composite (Fig.…”