The influence of self-assembly behavior of nanoparticles on the dielectric polymer composites

Abstract

To clearify the influence of the distribution of the conductive nanoparticles on the dielectric properties of the corresponding polymer composites, the microstructure and dielectric character of the composites based on the oleic acid modified ferroferric oxide and polyvinylidene fluoride (PVDF) polymer have been studied experimentally. It is found that these composites exhibit a normal percolative phase transition over the filler content from insulator to conductor, consistent with the classical percolation theory. However, when the percentage of fillers is at a certain value which is below the percolation threshold, these nanoparticles can assemble into a special porous structure in the PVDF matrix, associated with the enhancement of dielectric constant at low frequency. In addition, the controllable dispersion of conducting nanoparticles in a polymer matrix can prevent premature agglomeration at low filling fractions and avoid the appearance of anomalously early percolation. Therefore, the self-assembly behavior of nanoparticles can be beneficial to preparation of the high dielectric constant and low loss composites for the application of electric energy storage.

Enhanced dielectric properties of polyvinylidene fluoride with addition of SnO2 nanoparticles

“…a, a′, b and b′). However, when the volume fraction of SnO 2 nanoparticles is 0.159, the nanoparticles begin to link and connect to form a conductive network, which is in agreement with the normal percolation behavior .…”

“…S1c of the Supporting Information, the conductivity of the nanocomposites is in range of 10 –7 –10 –5 S/m. Compared with other percolative nanocomposites , the lower conductivity should relate to the wide band‐gap of SnO 2 , leading to steadily decreased breakdown field. Besides, the interfaces created by nanosized SnO 2 particles and polymer matrix can bring effective electron scatterers and trapping centers, which would also prevent quick decrease of breakdown field .…”

Interface Optimization of Metal Quantum Dots/Polymer Nanocomposites and their Properties: Studies of Multi-Functional Organic/Inorganic Hybrid

“…The presence of the F atom as a strong electron acceptor can also promote free electrons in the polyaniline layer to tunnel the interface of PANI/PVDF. According to the conductive mechanism of nanomaterials/polymer nanocomposite [88][89][90][91][92], the Pt/PVDF nanocomposite comprises an intricate network of conducting and insulating components, and its electrical conduction in composite systems is determined by two mechanisms, i.e., percolation in a continuous conducting channel and tunneling between isolated conducting Pt nanodots. The thickness of the PVDF layer of nanocomposite is the critical parameter to carrier transfer [88][89][90][91][92][93].…”

High power density at low electric fields in dopamine modified barium titanate based poly(arylene ether nitrile) based composites

“…At present, one way to improve the energy density of materials is to introduce high permittivity fillers into the polymer matrix, such as ceramic particles, ceramic nanowires, and so on. [ 4–6 ] It is expected that the materials with high permittivity can be uniformly dispersed in a suitable proportion, so the properties of high permittivity ( ε r ) and high breakdown strength can be obtained at the same time, and the polymer matrix composites with high energy storage properties can be obtained.…”