Structure/Property Relationships for Poly(Vinylidene Fluoride)/Doped Polyaniline Blends

Abstract

Poly(vinylidene fluoride) (PVDF) and its blends with polyaniline (PANI) doped with dodecylbenzene sulfonic acid (DBSA) were characterized by electrical conductivity, differential scanning calorimetry (DSC) and X-ray scattering techniques.The onset of an infinite cluster (InC) of conducting, highly anisometric PANI/ DBSA particles in PVDF/(PANI/DBSA) blends was observed at the percolation threshold as low as w à % 3.5 wt.%. The small angle X-ray scattering (SAXS) data confirmed the expected spatial organization of PANI/DBSA needles into fractal-like structures above w à . A slight decrease of both the DSC and the wide-angle X-ray scattering (WAXS) degrees of crystallinity of PVDF with the PANI/DBSA mass content w was explained by strong interactions at the PVDF/(PANI/DBSA) interface resulting in the loss of crystallizability of a fraction of sterically immobilized chains of PVDF in boundary layers around PANI/DBSA particles. The available data suggest that the conductive paths within InC of PANI/DBSA in PVDF/(PANI/DBSA) blends were formed primarily by the end-to-end contacts of PANI/DBSA fibrils.

Ammonia/amine electronic gas sensors based on hybrid polyaniline–TiO2 nanocomposites. The effects of titania and the surface active doping acid

“…4). The similarity of observed intensity decays at q < 0.14 A À1 suggests the absence of both large-scale and lower-scale structural heterogeneities in PANI nanocomposites, 44 whereas the well-resolved SAXS reections near q ¼ 0.204 A À1 (PANI/DBSA) and 0.180 A À1 (PANI/LSA) corresponding to mean interchain distances of d ¼ 2p/q z 3.1 nm and 3.5 nm respectively can be seen. Summarizing the above, we suggest a specic non-structured polymer condition in the composites due to small thickness of the layers (shells) covering TiO 2 nanoparticles.…”

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.…”