Microstructure Design of Lightweight, Flexible, and High Electromagnetic Shielding Porous Multiwalled Carbon Nanotube/Polymer Composites

Abstract

Multiwalled carbon nanotube/polymer composites with aligned and isotropic micropores are constructed by a facile ice-templated freeze-drying method in a wide density range, with controllable types and contents of the nanoscale building blocks, in order to tune the shielding performance together with the considerable mechanical and electrical properties. Under the mutual promotion of the frame and porous structure, the lightweight high-performance shielding is achieved: a 2.3 mm thick sample can reach 46.7 and 21.7 dB in the microwave X-band while the density is merely 32.3 and 9.0 mg cm , respectively. The lowest density corresponds to a value of shielding effectiveness divided by both the density and thickness up to 10 dB cm g , far beyond the conductive polymer composites with other fillers ever reported. The shielding mechanism of the flexible porous materials is further demonstrated by an in situ compression experiment.

Retracted Article: The influence of gradient and porous configurations on the microwave absorbing performance of multilayered graphene/thermoplastic polyurethane composite foams

“…Aerwards, graphene/TPU composite foams were obtained by thermally induced phase separation (TIPS) process. [58][59][60][61][62][63][64][65][66][67] The prepared graphene/TPU composites were dissolved in 1,4-dioxane and stirred for 5 h at 60 C. The dispersed solution was poured into an undeled metal mold with a length and width of 200 mm and then placed it in a low temperature test chamber at a constant temperature of À60 C for 1 h. The frozen mixture was then transferred into a vacuum freeze dryer (LGJ-10FD, Yaxing Instrument Science and Technology Development Co., Ltd.) for 36 h at 0 C. The resultant single-layer graphene/TPU composite foams were then dried at 80 C for 24 h to remove the residual 1,4-dioxane. The gradient graphene content multilayer graphene/TPU composite foams were obtained by bonding a plurality of single-layer samples of different graphene content with commercial glue.…”

Ultrathin MXene/Calcium Alginate Aerogel Film for High‐Performance Electromagnetic Interference Shielding

“…Carbon‐based materials, like graphene and carbon nanotubes, have attracted much attention as promising effective EMI shielding materials due to their high conductivity, relatively low density, and corrosion resistance. Incorporating conductive fillers with polymer matrix has been developed as a feasible alternative solution for EMI shielding materials due to its tunable structure, good processability, and mechanical properties .…”

Economical synthesis of composites of FeNi alloy nanoparticles evenly dispersed in two-dimensional reduced graphene oxide as thin and effective electromagnetic wave absorbers

“…[12][13][14][15] As is well known, the EM wave absorption performance of a material is determined by complex permittivity, complex permeability and impedance matching, which are affected by its components, microstructure, size and so on. 16,17 Hence, by rational cooperation of the magnetic components (Fe 3 26 carbon ber, 27 graphene, 28 porous carbon materials 29 ) within the magnetic/carbon-based hybrids, competent EM wave absorbers can be achieved.…”