3D Printed Integrated Gradient-Conductive MXene/CNT/Polyimide Aerogel Frames for Electromagnetic Interference Shielding with Ultra-Low Reflection

Abstract

Construction of advanced electromagnetic interference (EMI) shielding materials with miniaturized, programmable structure and low reflection are promising but challenging. Herein, an integrated transition-metal carbides/carbon nanotube/polyimide (gradient-conductive MXene/CNT/PI, GCMCP) aerogel frame with hierarchical porous structure and gradient-conductivity has been constructed to achieve EMI shielding with ultra-low reflection. The gradient-conductive structures are obtained by continuous 3D printing of MXene/CNT/poly (amic acid) inks with different CNT contents, where the slightly conductive top layer serves as EM absorption layer and the highly conductive bottom layer as reflection layer. In addition, the hierarchical porous structure could extend the EM dissipation path and dissipate EM by multiple reflections. Consequently, the GCMCP aerogel frames exhibit an excellent average EMI shielding efficiency (68.2 dB) and low reflection (R = 0.23). Furthermore, the GCMCP aerogel frames with miniaturized and programmable structures can be used as EMI shielding gaskets and effectively block wireless power transmission, which shows a prosperous application prospect in defense industry and aerospace.

Conductivity-Controlled Polyvinylidene Fluoride Nanofiber Stack for Absorption-Dominant Electromagnetic Interference Shielding Materials

“…This can be attributed to the layered NF conductivity gradient structure, which allows for more efficient heat transfer within the layer parallel to the surface, and the thermal conductivity of gradient PVDF-PEDOT was relatively higher than those of other polymers . Finally, to assess the performance of the NF EMI shielding material with the L-to-H conductivity gradient developed herein, a comparison was made with other state-of-the-art composite-based EMI shielding materials, as shown in Figure f,g. − The NF EMI shielding material with the L-to-H conductivity gradient structure exhibited excellent EMI SE and absolute EMI SE with lower reflectivity than other materials employing a similar method.…”

Research Progress with Membrane Shielding Materials for Electromagnetic/Radiation Contamination

“…Most polymer substrates are polymers, such as polyurethane [ 66 , 67 ] and nanofibers [ 54 , 68 , 69 , 70 ]. Nanofillers include composite shielding materials such as metal-based materials [ 71 , 72 ], MXene-based materials [ 73 , 74 , 75 , 76 ], carbon-based materials [ 77 , 78 , 79 , 80 ], and so forth. They have different forms so that they can are suitable for different fields.…”

Universal passive radiative cooling behavior of aerogels

“…Aerogel, a type of porous solid material featuring extremely low density, low thermal conductivity, high porosity, and large specic surface area (SSA), has attracted increasing attention from both academia and industry, not only because of its exceptional properties but also due to numerous components that can be fabricated into the aerogel. [1][2][3][4] To name a few, inorganic oxides (such as SiO 2 , Al 2 O 3 , ZrO 2 , and TiO 2 ), [5][6][7][8][9][10] metals (such as Ag and Au), [11][12][13] carbon (carbon nanotube and graphene oxide), [14][15][16] polymers (such as polyimide, cyclodextrin, polyvinyl alcohol, and Kevlar), [17][18][19][20] and natural products (such as cellulose, wood, and chitosan) [21][22][23][24][25] have been used to synthesize aerogels with resistance to extremely low temperature and ultrahigh temperature. 26,27 Thus, aerogels nd wide applications in the eld of thermal insulation, 28,29 environment, 30,31 aerospace, 32 catalysts, 33,34 energy, 35 and biomedicine.…”