Superhigh Electromagnetic Interference Shielding of Ultrathin Aligned Pristine Graphene Nanosheets Film

Abstract

Ultrathin, lightweight, high‐strength, and thermally conductive electromagnetic interference (EMI) shielding materials with high shielding effectiveness (SE) are highly desired for next‐generation portable and wearable electronics. Pristine graphene (PG) has a great potential to meet all the above requirements, but the poor processability of PG nanosheets hinders its applications. Here, efficient synthesis of highly aligned laminated PG films and nacre‐like PG/polymer composites with a superhigh PG loading up to 90 wt% by a scanning centrifugal casting method is reported. Due to the PG‐nanosheets‐alignment‐induced high electrical conductivity and multiple internal reflections, such films show superhigh EMI SE comparable to the reported best synthetic material, MXene films, at an ultralow thickness. An EMI SE of 93 dB is obtained for the PG film at a thickness of ≈100 µm, and 63 dB is achieved for the PG/polyimide composite film at a thickness of ≈60 µm. Furthermore, such PG‐nanosheets‐based films show much higher mechanical strength (up to 145 MPa) and thermal conductivity (up to 190 W m−1 K−1) than those of their MXene counterparts. These excellent comprehensive properties, along with ease of mass production, pave the way for practical applications of PG nanosheets in EMI shielding.

Multifunctional Graphene Composites for Electromagnetic Shielding and Thermal Management at Elevated Temperatures

“…The MXene fillers and films exhibit high shielding efficiencies but prone to formation of oxide layers and reveal poor thermal conductivity making them unsuitable for high-temperature EMI shielding applications. [76,[94][95][96]112] Figure 5. Total EMI shielding efficiency of the epoxy with a) 11.4 vol%, b) 13.4 vol%, and c) 17.1 vol% of graphene fillers as a function of temperature in the X-band frequency range.…”

“…Although the polymer‐metal composites alleviate the problems associated with corrosion and oxidation, they suffer from heavy weight and degraded efficiency at elevated temperatures. [ 31,32 ] Ceramics, [ 33–40 ] carbon fibers, [ 41–48 ] carbon black, [ 49,50 ] carbon nanotubes, [ 51–57 ] graphite, [ 58–60 ] reduced graphene oxide, [ 5,8,61–71 ] graphene, [ 72–76 ] ferromagnetic materials, [ 77–80 ] and combinations of carbon allotropes with metallic and nonmetallic fillers [ 69,71,72,74,81–86 ] have been tested as potential fillers for EMI shielding applications. Ceramic fillers have demonstrated a promise for high‐temperature applications owing to their excellent thermal stability and relatively high thermal conductivity at high temperatures.…”

“…Although the polymer-metal composites alleviate the problems associated with corrosion and oxidation, they suffer from heavy weight and degraded efficiency at elevated temperatures. [31,32] Ceramics, [33][34][35][36][37][38][39][40] carbon fibers, [41][42][43][44][45][46][47][48] carbon black, [49,50] carbon nanotubes, [51][52][53][54][55][56][57] graphite, [58][59][60] reduced graphene oxide, [5,8,[61][62][63][64][65][66][67][68][69][70][71] graphene, [72][73][74][75][76] ferromagnetic materials, [77][78]…”

Vertically Aligned Graphene for Thermal Interface Materials

“…Flexible graphene paper/film assembled from graphene sheets has been fabricated by solution-based methods, such as direct evaporation, [95] vacuum filtration, [53] direct electro-spray deposition, [96] and scanning centrifugal casting. [97] Planar graphene paper has been commonly used as an in-plane thermal spreading material, due to its excellent in-plane thermal conductivity. [98,99] Recently, some research effort has been devoted to explore the vertical thermal conductivity of graphene paper.…”

Flexible, stretchable and magnetic Fe3O4@Ti3C2Tx/elastomer with supramolecular interfacial crosslinking for enhancing mechanical and electromagnetic interference shielding performance

“…Metal-based materials are widely used for EMI shielding, while their easy-tocorrode nature, high density and low flexibility restrict their applications in emerging flexible wearable devices [4,5]. Over the past decades, researchers have focused on the carbon-based conductive fillers (carbon nanotubes [6,7], graphene [8,9], etc.) and soft polymer matrices (cellulose [10,11], elastomer [12,13], etc.)…”