Electromagnetic shielding properties of MWCNT/PMMA composites in Ka‐band

Abstract

A novel lightweight multi-wall carbon nanotubes (MWCNT) based polymethylmetacrylate (PMMA) composite is shown to present high electromagnetic (EM) shielding. EM shielding effectiveness (SE) was investigated in the frequency range 26-37 GHz (Ka-band). It was found that SE of the given composites strongly depends on MWCNT content. The highest EM attenuation reaching À37 dB at 28 GHz was observed for polymer film comprising 10 wt.% of MWCNT. Data on SE correlates well with the electrical conductivity measured by four-probe technique and by broadband dielectric spectroscopy (20 Hz-1 MHz). Both microwave and low-frequency analysis demonstrate low percolation threshold (lower than 1 wt.%) for the produced MWCNT/PMMA composites. At the same time significant electromagnetic interference absorbance demonstrates the contribution of the absorbance mechanisms specific for carbon nanostructures different of the main conductance mechanism.

Carbon nanostructure composite for electromagnetic interference shielding

“…Pristine and NH 2 functionalized MWCNT forms interconnected structure of PMMA in polystyrene matrix upon annealing. Similar work was reported by other researchers [81][82][83].…”

Filler reaggregation and network formation time scale in extruded high‐density polyethylene/multiwalled carbon nanotube composites

“…Much research has focused on the use of single and multiwalled carbon nanotubes (SWNTs and MWNTs, respectively) as fillers in polymer composites to create materials with unique mechanical and electrical properties [ 2, 4–6]. Electrically conductive polymer nanocomposites have gained popularity in applications such as electrostatic discharge shielding (EDS) and electromagnetic interference shielding (EIS) because they are lightweight, flexible and resistant to corrosion [ 7–10].…”

Microwave absorption properties of pyrolytic carbon nanofilm

“…As it has been shown in [11], the DC conductivity of multiwalled CNT in poly(methyl methacrylate) (PMMA) increases with the carbon mass fraction, showing typical percolation behavior, and EMI SE reaches 5 dB only for 10 wt.% of raw CNT loading at 5 GHz. At room temperature, the high-frequency conductivity of multiwalled CNTs embedded into PMMA in small content (up to 2 wt.%) [17] also turns out to be lower than that of PyC films; only when the concentration reaches 5 wt.% of CNTs in 1-mm-thick PMMA, it provides EMI SE due to absorption at the level of 35%, compatible with that for 25-nm-thick PyC film. Within 1-mm-thick epoxy resin, 0.5 wt.% of single- and multiwalled CNTs gave 2.5 to 2.8 dB of EM attenuation at 30 GHz [18].…”