Electromagnetic Interference Shielding Foams Based on Poly(vinylidene fluoride)/Carbon Nanotubes Composite

Abstract

Polymeric electromagnetic interference (EMI) shielding foaming materials are found and applied in many frontier fields such as aerospace, transportation, and portable electronics. In this paper, a foam based on a composite system of poly(vinylidene fluoride) (PVDF) filled with carbon nanotubes (CNTs) is prepared for EMI shielding properties by using a solid‐state supercritical CO2 foaming strategy. PVDF is chosen as the matrix because of its excellent chemical resistance, thermal stability, and flame retardancy. The inclusion of CNTs renders this composite system enhanced complex viscosity and storage modulus by about two orders of magnitude. The electrical conductivity and EMI specific shielding effectiveness of obtained foams can be adjusted and reached the optimum value of 0.024 S m−1 and 29.1 dB cm3 g−1, respectively, originating from the gradual development of interconnected CNTs and conductive CNTs network as well as the introduction of cell structure in PVDF matrix. Interestingly, the reorientation of CNTs caused by foaming process results in electrical conductivity percolation threshold of PVDF/CNTs foams markedly decreases, in comparison to their unfoamed samples. This study provides a facile, efficient, green, and economic route for the preparation of EMI shielding foams consisted of fluorinated polymers and carbonaceous fillers.

Improved electromagnetic interference shielding properties of poly (vinylidene fluoride) composites based on carbon nanotubes and graphene nanoplatelets

“…[ 45 ] Finally, the special 2D GNPs and abundant interior surface could result in multiple reflection of incident microwave and lessening escape possibility of EM waves. [ 14 ] In summary, based on aforementioned results, the synergistic effect between GNPs and CNTs improved the EMI shielding properties of PVDF/CNTs/GNPs composite.…”

“…Considering those unique properties, PVDF is an ideal material for EMI applications. [ 14 ] In our previous studies, the electrical and EMI shielding properties of PVDF could be improved by the incorporation of CNTs. The corresponding percolation threshold was approximate 2 wt% of CNTs.…”

“…The corresponding percolation threshold was approximate 2 wt% of CNTs. [14] Based on our previous research, a new idea was proposed aiming at preparing PVDF samples with the improved electrical conductivity and EMI shielding effectiveness (EMI SE) through incorporating both CNTs and GNPs in this study. The effect of hybrid fillers content on the crystallization, melting and rheological behavior, electrical performance as well as EMI shielding property of PVDF was investigated in detail.…”

Facial Preparation of Segregated Poly(butylene succinate)/Carbon Nanotubes Composite Foams with Superior Conductive Properties via Synergistic Effect of High Pressure Solid Phase Molding and Supercritical Fluid Foaming

“…In recent years, many researchers have used supercritical CO 2 (scCO 2 ) foaming technology to prepare CPC foams with improved conductivity. [30][31][32][33][34] For example, Zhi et al prepared high-performance PC/CNT CPC foams by using scCO 2 batch foaming. [25] Specifically, the conductivity of PC/CNT composite foam reached 7.7 S m −1 under 2.0 vol% CNT content.…”

“…In recent years, many researchers have used supercritical CO 2 (scCO 2 ) foaming technology to prepare CPC foams with improved conductivity. [ 30–34 ] For example, Zhi et al. prepared high‐performance PC/CNT CPC foams by using scCO 2 batch foaming.…”