Polystyrene/MWCNT/Graphite Nanoplate Nanocomposites: Efficient Electromagnetic Interference Shielding Material through Graphite Nanoplate–MWCNT–Graphite Nanoplate Networking

Abstract

Today, we stand at the edge of exploring carbon nanotube (CNT) and graphene based polymer nanocomposites as next generation multifunctional materials. However, irrespective of the methods of composite preparation, development of electrical conductivity with high electromagnetic interference (EMI) value at very low loading of CNT and (or) graphene is limited due to poor dispersion of these nanofillers in polymer matrix. Here, we demonstrate a novel technique that involves in-situ polymerization of styrene/multiwalled carbon nanotubes (MWCNTs) in the presence of suspension polymerized polystyrene (PS)/graphite nanoplate (GNP) microbeads, for the preparation of electrically conducting PS/MWCNT/GNP nanocomposites with very high (~20.2 dB) EMI shielding value at extremely low loading of MWCNTs (~2 wt %) and GNP (~1.5 wt %). Finally, through optimizing the ratio of PS-GNP bead and MWCNTs in the nanocomposites, an electrical conductivity of ~9.47 × 10(-3) S cm(-1) was achieved at GNP and MWCNTs loading of 0.29 and 0.3 wt %, respectively. The random distribution of the GNPs and MWCNTs with GNP-GNP interconnection through MWCNT in the PS matrix was the key factor in achieving high electrical conductivity and very high EMI shielding value at this low MWCNT and GNP loadings in PS/MWCNT/GNP nanocomposites. With this technique, the formation of continuous conductive network structure of CNT-GNP-CNT and the development of spatial arrangement for strong π-π interaction among the electron rich phenyl rings of PS, GNP, and MWCNT could be possible throughout the matrix phase in the nanocomposites, as evident from the field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) studies.

AC electrical conductivity, shielding effectiveness and viscoelastic characteristics of nanocomposites based on RTV silicon rubber and nano graphite sheets/carbon black hybrid system

“…Shielding materials attenuate the incident EM waves by means of reflection R, multiple reflections M, and absorption (A) [6]: SET = SEA + SER + SEM (4) Figure 6 demonstrates the EMI SE of binary and ternary composites contained 3, 5 and 8 wt% of conductive fillers over the frequency range 8-12 GHz (X-band frequency range). It is obvious that composites based on 8 wt% filler show higher SE, which is attributed to higher concentration and more conductive paths within the polymer matrix that could interact with incident EM waves.…”

“…At a critical volume fraction of conductive filler, electrical conductivity of polymer shows a the transition from insulating to known as percolation threshold concentration (φc) [2]. Recently, composites based on hybridized filler systems comprising fillers with different dimensions and aspect ratio have great attention to the preparation of the electrically conductive polymer composites with low percolation threshold and the potential for manufacturing of electromagnetic interference(EMI) shielding materials [6]. In present work, nanocomposites based on a hybrid system comprising, conductive Carbon black (CB) and Graphite nanoplates (GNP), and silicon rubber matrix were prepared.…”

Carbon nanohorn and graphene nanoplate based polystyrene nanocomposites for superior electromagnetic interference shielding applications

“…Moreover, Khatua et al 41 reported that the p-p interaction between the nanofiller and polymer facilitates electron transport in the nanocomposites. In our case, the p-p interaction among the CNH, GNP, and phenyl rings of PS can be operative to improve the EMI SE value of the.…”

Electromagnetic Shielding Performance of Nickel Plated Expanded Graphite/Wood Fiber Composite

“…However, there has not been much research about wood-based electromagnetic shielding composites made with the EG. Moreover, microholes in EG result in a situation where incident EM waves are repeatedly reflected at different directions on its surface or in the holes, which make it conducive to attenuation for electromagnetic waves (Maiti et al 2013). Furthermore, its vermicular shape (appears to be a fiber shape) can contribute to mixing with other components uniformly (Kratochvíla et al 2013).…”