Comparison between inorganic geomimetic chrysotile and multiwalled carbon nanotubes in the preparation of one-dimensional conducting polymer nanocomposites

Abstract

The aim of this study was to examine the role of the nanofillers spatial arrangement in the electrical properties of hybrid organic-inorganic fibers. In this paper, we have presented experimental results for preparation of fibers with a nanometric diameter based on a polyaniline/poly(ethylene oxide) doped blend and geomimetic chrysotile nanotubes. The nanostructured material was prepared using electrospinning techniques. Electrospun fibers made by pristine polymers and by the same blend loaded with carbon nanotubes were used as reference materials to compare the structural, and electrical properties of the novel organic-inorganic material. Generally, electrical properties were improved by the addition of materials that have high conductivity. Electrospun fibers filled with a traditional insulator like chrysotile have shown higher electrical conductivity than the pristine materials. In order to fully understand how structural variations impact upon the electrical conductivity the materials were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy (RS), differential scanning calorimetry (DSC) and four-point probe method. The results suggest that the occurred electrical conductivity gain could be attributed to parallel orientation of the chrysotile nanotubes and higher crystallinity induced by the one-dimensional nanostructured filler materials. The obtained results bring us one step closer to using intrinsically conducting polymers (ICPs) in the creation of functionalized polymeric nanocomposites for nanotechnology.

Electrospun Polyaniline-Based Composite Nanofibers: Tuning the Electrical Conductivity by Tailoring the Structure of Thiol-Protected Metal Nanoparticles

“…Furthermore, three weak peaks are visible in this region. The patterns show a very broad signal centred at around 2 = 23 ∘ , which is ascribable to the amorphous structure of polyaniline [7,8]. The neat polymer and composite mats showed similar patterns, without any additional peaks, which proves that the presence of embedded nanoparticles does not induce the formation of defects.…”

“…Since it is well known that the presence of metal nanofillers within the polymer matrix can change the material crystallinity (and, in turn, the final material electrical properties) [36], we focused on the influence of nanoparticles upon the polymer chain conformation. As shown in Figure 8, all the electrospun samples showed the typical peaks associated with the electrospun polymer blend in their XRD patterns [7]. In XRD diffractograms, two typical peaks at 2 = 19.…”

“…The starting polymer blend and polymer composite solutions were prepared according to an already standardized method [7]. The concentration of nanoparticles in the polymer solutions was previously optimized for the production of nanocomposites with the largest possible amount of nanofillers, which does not cause any nanofiber structural defect.…”

“…The electrical conductivity of the electrospun mats was investigated by our routine method based on a four-point probe system [7,8]. The analyzed samples were prepared by collecting around 50 mg of polymer blend/composite nanofibers on the glass slides placed onto the metal collector during the electrospinning process.…”

“…Furthermore, electrospinning leads to the fabrication of nanofibers with a favorable hierarchical structure for the development of advanced electronic devices, thanks to the stretching and alignment of polymer chains along the fiber axis [6], creating a preferential and more effective path for the charge transport into the material [7]. Unfortunately, intrinsically conductive polymer (ICP) solutions have an insufficient viscosity for the successful formation of nanofibers during the electrospinning process.…”