Remarkable change in the broadband electrical behavior of poly(vinylidene fluoride)–multiwalled carbon nanotube nanocomposites with the use of different processing routes

Abstract

Poly(vinylidene fluoride) (PVDF) nanocomposites have plenty of applications in the electronic realm. In this study, we produced nanocomposites based on PVDF and multiwalled carbon nanotubes (MWCNTs), with various MWCNT loadings, using three different processing routes: solution mixing, melt mixing, and electrospinning. The broadband electrical behavior of these nanocomposites was studied and compared via impedance spectroscopy. The morphologies of the nanocomposites were characterized by transmission electron microscopy and scanning electron microscopy. The results reveal that the electrical behaviors of the samples were completely different according to the processing route used. Solution mixing was the most suitable method for producing nanocomposites with the highest conductivities, at low MWCNT loadings, whereas electrospinning was the most suitable method for producing nanocomposites with the lowest dielectric permittivity. These differences were attributed to the different arrangements of the MWCNTs caused by the different processes. Although the solution‐mixed samples exhibited long and twisted MWCNTs, the melt‐mixed samples had shorter MWCNTs, and the electrospun samples had MWCNTs embedded and aligned inside the insulating polymer nanofibers. Thus, these results project a vast horizon for tailoring the structure and thereby the broadband electrical behavior of PVDF–MWCNT nanocomposites for different types of applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47409.

Improving the dispersion of MWCNT and MMT in PVDF melts employing controlled extensional flows

“…The sample of neat PVDF had a single melting peak, where melting temperature (T m ) 170 C, which was ascribed to the melting of α phase crystals. 1 The same behavior was observed for PVDF-el, PVDF/MWCNT and PVDF/MWCNT-el. T m was 170 C for all these samples.…”

“…It is known that structure and properties of PVDF nanocomposites can be dramatically changed under different processing approaches or flow fields. In a previous work, 27 we showed that electrical properties of PVDF/ MWCNT nanocomposites were completely different depending upon the processing method used. While melt and solution mixing led to the dispersion of MWCNT through the whole PVDF matrix yielding conductive nanocomposites, the process of electrospinning promoted high degrees of MWCNT alignment through the PVDF yielding highly insulators nanocomposites.…”

“…Owing to their unique combination of properties, such as piezoelectric activity, ferroelectricity, ease processability, chemical and thermal resistance, poly (vinylidene fluoride) (PVDF) have been employed to obtain polymer nanocomposites for a wide range of applications such as energy storage, 1 sensing devices, 2 electrolyte membranes, 3 ultra membranes for desalination, 4 among others. In general, Multiwalled carbon nanotubes (MWCNT) and montmorillonites (MMT) stands out as some of the most used nanofillers in synergism with PVDF.…”

Melt-mixed nanocomposites of SIS/MWCNT: rheological, electrical and structural behavior

“…The following MWCNT concentrations were used for this study: 0.1, 1.0, 3.0 and 5.0 vol.% MWCNT. These filler loadings were selected based on previous works [1,20,21] , which pointed out a value of 0.31vol.% MWCNT for the theoretical percolation threshold of a generic polymer matrix filled with the MWCNT NC7000 from Nanocyl [1,3,22] . After melt mixing, films of the resulting nanocomposites were produced by compression molding at 190ºC under 8 MPa of pressure using a hot press.…”

“…The use of multiwall carbon nanotubes (MWCNT) in polymeric matrixes to produce conductive nanocomposites has been widely studied [1,2] . Among the broad range of polymer matrixes, the thermoplastic elastomers have the advantage of behaving as elastomers at room temperature, but being able to be processed as thermoplastics [3] .…”