Flexible Sandwich-Structured Silicone Rubber/MXene/Fe₃O₄ Composites for Tunable Electromagnetic Interference Shielding

Abstract

There is a pressing demand for efficient electromagnetic interference (EMI) shielding materials with strong electromagnetic wave absorption and low reflection for the protection of next-generation communication technologies and wearable electronic devices. In this work, silicone rubber/MXene/Fe3O4 (SRMF) composites with a sandwich-like structure were fabricated using vacuum-assisted dipping and curing. The top and bottom layers of the SRMF composites are magnetic layers containing Fe3O4 particles and silicone rubber (SR), while the middle layer is a 3D conductive network of MXene aerogel film and SR. This sandwich-like structure enables the composites to effectively shield incident electromagnetic waves and improve the absorption of electromagnetic waves through a mechanism of “absorption–reflection–reabsorption”. The electromagnetic shielding performance of a sandwich-structured SR composite containing 1.2 wt % MXene and 20 wt % Fe3O4 reached 55.5 dB, which was higher than that of a blended SRM1.2F20b composite containing the same proportion of MXene and Fe3O4 (23.1 dB), while the power coefficient of reflectivity was 0.65. The SRMF composites also retained their EMI shielding performance after 1000 bending cycles and displayed good tensile strength. These flexible SRMF composites have broad application prospects in the field of electromagnetic protection of wearable devices.

Magnetically driven hierarchically ordered carbonyl iron@SiO2/Ni@Ag/silicone rubber composite film for enhanced electromagnetic interference shielding with ultralow reflection

“…5h. 20–22,50–63 The CSNA film prepared in this work exhibited a higher SE and a lower R value than them, indicating outstanding EMI shielding and a significant reduction in EMW secondary pollution.…”

“…[17][18][19] Inspired by this, SRMs prepared with various conductive fillers and absorbents (e.g., CNT, graphene, and Fe 3 O 4 ) have achieved effective EMW absorption, yet sufficient EMI SE is fairly difficult to achieve due to their low intrinsic conductivity. [20][21][22] Therefore, it is demanding to develop novel SRMs to achieve absorption-dominated EMI shielding and maintain effective performances under large tensile strain.…”

Electromagnetic Absorption by Magnetic Oxide Nanomaterials: A Review

“…A third method involves preparing Fe 3 O 4 /MXene composite fabric (HFMs) by layering multiple hollow magnetic Fe 3 O 4 nanospheres on a flexible nonwoven fabric. 115 This fabric has low chip resistance, super hydrophobicity, self-cleaning, and good electromagnetic wave shielding performance. The electromagnetic wave shielding efficiency is 33.28 dB, and its electromagnetic wave shielding mechanism can be adjusted according to the loading of the active material.…”

“…The composite film with a thickness of 52 μm achieves an electromagnetic shielding of 49 dB SE in both the X- and Ku-bands. A third method involves preparing Fe 3 O 4 /MXene composite fabric (HFMs) by layering multiple hollow magnetic Fe 3 O 4 nanospheres on a flexible nonwoven fabric . This fabric has low chip resistance, super hydrophobicity, self-cleaning, and good electromagnetic wave shielding performance.…”

Composites of Non-Woven Poly p-Phenylene Terephthalamide and Fe3O4-Decorated Ti3C2Tx MXene Nanosheets Coated with Ag Nanoparticles for Electromagnetic Interference Shielding

“…Ferromagnetic materials have been used along with conductive fillers to improve the EM wave absorption ability of polymer composites. − The introduction of magnetic nanoparticles can promote EMI SE by providing hysteresis loss and reduce the reflection of EM waves by adjusting the impedance matching between the material surface and the free space. , Fe 3 O 4 nanoparticles, which have the advantages of high magnetic loss, suitable saturation magnetization, strong spin polarization, and low cost, are increasingly being used in EMI shielding. ,, …”