Ti₃C₂T_x MXene- and Sulfuric Acid-Treated Double-Network Hydrogel with Ultralow Conductive Filler Content for Stretchable Electromagnetic Interference Shielding

Abstract

Hydrogels are emerging as stretchable electromagnetic interference (EMI) shielding materials because of their tissue-like mechanical properties and water-rich porous cellular structures. However, achieving high-performance hydrogel shields remains a challenge because enhancing conductivity often results in a compromise in deformation adoptability. This work proposes a treatment strategy involving sulfuric acid/titanium carbide MXene, which can simultaneously enhance the conductivity and stretchability of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PE-DOT:PSS)/poly(vinyl alcohol) (PVA) double-network hydrogels. Multiple spectroscopic characterizations reveal that sulfuric acid promotes the linear conformation transition of the PEDOT molecular chain, while MXene increases charge delocalization and hydrogen bond cross-linking sites. The hydrogels, synthesized with a combined content of 0.6 wt % of MXene and PEDOT:PSS, exhibit an average X-band EMI SE of 41 dB. This performance is sustained at 94.5%, even following stretching and release at a strain of 200%. Interestingly, the EMI SE is found to linearly increase, reaching a value of 99 dB as the frequency is increased to 26.5 GHz. This increase is attributed to the enhanced water molecular polarization process, as supported by theoretical calculations of the impedance and attenuation constant. This work introduces a post-treatment technique that optimizes double-network hydrogels, providing deep insights into their EMI shielding mechanism and enabling high-performance EMI shielding with an ultralow conductive filler content.

High green index electromagnetic interference shields with semiconducting Bi2S3 fillers in a PEDOT:PSS matrix

“…Each semicircle in this plot signifies a Debye relaxation process, and the presence of multiple semicircles indicates a process involving multiple relaxation. 31 The Cole–Cole plot of the pristine BS sample displays only scattered points, suggesting a lack of electromagnetic wave absorption capability (Fig. S8(d), ESI†) as expected.…”

Recent Advances in Functional Hydrogels for Treating Dental Hard Tissue and Endodontic Diseases

“…A hydrogel is a kind of porous material with a 3D network structure and shows huge application potential in the biomedical field. − By introducing hydrogen bonding or dynamic ion interactions, the strength and adhesion of hydrogels can be effectively improved. − In addition, due to adjustable water content and drug loading/releasing, functional hydrogels have potential applications in oral disease treatment, − such as mucosa healing, oral ulcers, periodontitis treatment, etc. (Figure ).…”

Ti3C2Tx MXene/Fe3O4/Carbon Fiber Fabric/Water Polyurethane Composite Fabrics for Electromagnetic Interference Shielding and Thermal Management

“…The emerging MXene, a two-dimensional transition metal carbide/nitride, has garnered considerable interest in the realm of EMI shielding owing to its exceptional conductivity and distinctive layered structure. − By selectively etching the Al atomic layers of the MAX precursor, − large-sized MXene nanosheets with an abundance of polar functional groups were prepared. The inherent defects and surface chemical interactions of MXene promote the amplification of polarization loss, and the carbon vacancies in MXene contribute to its outstanding conductivity and flexibility, as shown by density functional theory (DFT) simulations, resulting in outstanding EMI shielding performance. − For example, Zhao et al used a one-step vacuum-assisted filtration method to fabricate liquid metals reinforced cellulose nanofiber (CNF)/MXene (LMs-CNF/MXene) composite films due to the excellent conductivity of MXene, and the shielding effectiveness of the composite films can reach 51.9 dB at ∼27 μm. However, the EMI shielding performance of MXene-based composite materials is primarily contingent upon a substantial loading of MXene, typically exceeding 50 wt %. ,, Increasing the filler content in composite materials can often lead to a compromise in the mechanical properties.…”