Journal Article

Efficient Electromagnetic Wave Absorption and Thermal Infrared Stealth in PVTMS@MWCNT Nano-Aerogel via Abundant Nano-Sized Cavities and Attenuation Interfaces

Li, Guangxian, Gong, Pengjian, Ma, Haoyu, Park, Chul B, Liu, Yingjun, Fashandi, Maryam, Ming, Xin, Rejeb, Zeineb Ben

2024

Overview

HighlightsPVTMS@MWCNT nano-aerogel with nano-pore size and abundant heterogeneous interface was fabricated via radical polymerization, sol–gel transition and CO2 drying.The nano-aerogel shows superior electromagnetic wave absorption property (RLmin = −36.1 dB and cover all Ku-band) and thermal infrared stealth property (ΔT reached 60.7 °C).Layered nano-aerogel/graphene film with high EMI shielding and absorption properties was obtained;Pre-polymerized vinyl trimethoxy silane (PVTMS)@MWCNT nano-aerogel system was constructed via radical polymerization, sol–gel transition and supercritical CO2 drying. The fabricated organic–inorganic hybrid PVTMS@MWCNT aerogel structure shows nano-pore size (30–40 nm), high specific surface area (559 m2 g−1), high void fraction (91.7%) and enhanced mechanical property: (1) the nano-pore size is beneficial for efficiently blocking thermal conduction and thermal convection via Knudsen effect (beneficial for infrared (IR) stealth); (2) the heterogeneous interface was beneficial for IR reflection (beneficial for IR stealth) and MWCNT polarization loss (beneficial for electromagnetic wave (EMW) attenuation); (3) the high void fraction was beneficial for enhancing thermal insulation (beneficial for IR stealth) and EMW impedance match (beneficial for EMW attenuation). Guided by the above theoretical design strategy, PVTMS@MWCNT nano-aerogel shows superior EMW absorption property (cover all Ku-band) and thermal IR stealth property (ΔT reached 60.7 °C). Followed by a facial combination of the above nano-aerogel with graphene film of high electrical conductivity, an extremely high electromagnetic interference shielding material (66.5 dB, 2.06 mm thickness) with superior absorption performance of an average absorption-to-reflection (A/R) coefficient ratio of 25.4 and a low reflection bandwidth of 4.1 GHz (A/R ratio more than 10) was experimentally obtained in this work.

• Publisher: Springer Nature B.V
• Subject: Absorption / Aerogels / Carbon dioxide / Drying / Electrical resistivity / Electromagnetic interference / Electromagnetic radiation / Electromagnetic shielding / Free convection / Graphene / Polymerization / Pore size / Sol-gel processes / Stealth technology / Superhigh frequencies / Thermal insulation / Void fraction / Wave attenuation