High Electromagnetic Interference Shielding Effectiveness of Carbon Nanotube–Cellulose Composite Films with Layered Structures

Abstract

Flexible and electrically conductive carbon nanotube (CNT)–cellulose composite films are fabricated by a green route based on sodium hydroxide/urea aqueous solution. Both single‐walled carbon nanotubes (SWCNTs) and multi‐walled carbon nanotubes (MWCNTs) are investigated as conductive fillers. The microstructure and physical properties of the films are characterized extensively. It is observed that CNTs form layered conductive networks in the cellulose matrices during the drying process. The electromagnetic interference (EMI) shielding effectiveness (SE) of these composite films is also investigated. The results exhibit that the EMI SE of the materials is in accordance with electrical conductivity, which is highly dependent on the CNT loadings. Compared to MWCNT–cellulose composite films, the films with SWCNT show more effectiveness as EMI materials in the frequency range of 12–18 GHz. With SWCNT loading of 10 wt%, the EMI SE can reach 32.5–40 dB. Considering the thickness and density of the material, furthermore, the SWCNT–cellulose film possesses an extremely high specific EMI SE value of about 7678 dB cm2 g−1, which is due to the unique layered structures of CNTs. Thus, these flexible conductive composite films have the potential to be used as high‐efficiency shielding materials against electromagnetic radiation in advanced application fields.

Mechanical, Thermal, Electrical Characteristics and EMI Absorption Shielding Effectiveness of Rubber Composites Based on Ferrite and Carbon Fillers

“…The preparation and investigation of polymer composite shields by the application of ferrites and carbon-based fillers into various polymer matrices has been the interest of many experimental studies [18][19][20][21][22][23][24][25]. The results have demonstrated that composites filled with those fillers can effectively shield EMI.…”

Recent Advances in Design and Fabrication of Nanocomposites for Electromagnetic Wave Shielding and Absorbing

“…The high aspect ratio, high electrical conductivity, and excellent mechanical properties of CNTs make them the perfect choice for fabricating conductive composites for EMI shielding [65]. In addition, the few defects of SWCNTs lead to higher conductivity compared to MWCNTs [47]. The large aspect ratio of CNTs facilitates them to form a conductive network in a polymer matrix.…”

“…It is worth noting that although EMI SE increased significantly after annealing, the long-SWCNTs composites without annealing performed much better, which verified that the EMI SE is more closely related to the aspect ratio other than wall integrity. 1D carbonaceous materials CNT/cellulose Film Dielectric loss, multiple reflection [47] Cds-CNT Core-shell nanowire Dielectric loss, interfacial polarization [48] ZnO@MWCNT Hybrid…”

A novel cellulose‐derived carbon aerogel@Na2Ti3O7 composite for efficient photocatalytic degradation of methylene blue

“…Among these carbon aerogels, cellulose‐based porous carbon aerogel with environmentally friendly and low‐cost properties have aroused widespread research interest 35–40 . Cellulose possesses biodegradability, non‐toxicity, renewable and rich in carbon, so it is an ideal raw material for preparing carbon materials 41–44 . Due to 3D network structure, high porosity, and large specific surface area, cellulose carbon aerogel makes up for the defects of Na 2 Ti 3 O 7 nanomaterials that are difficult to recycle, easy to damage and agglomerate.…”