Synergistic Interfacial Engineering of Small Molecule-Modified 1T-Phase MoS2 for Robust Electromagnetic Interference Shielding Composites Hydrogel

Abstract

The impact of high-frequency electromagnetic environments on the data accuracy of wearable smart devices necessitates the development of flexible, multifunctional, integrated electromagnetic interference (EMI) shielding materials. In this work, we demonstrate a flexible and multifunctional EMI shielding material fabricated from few-layer MoS₂, which has been functionalized with carboxylic acid-containing small-molecules (SF-MoS₂). This composite is embedded within a dual-network hydrogel matrix comprising polyvinyl alcohol (PVA) and sodium alginate (SA), which was called PS/SF-MoS₂. The elevated 1T phase content of MoS₂ (65.5%) provided superior conductivity. Supramolecular interactions between polar functional groups facilitated the formation of both the polymer scaffold and a 2D conductive network, synergistically enhancing EMI shielding through multiphase interfaces and conductive fillers. Consequently, PS/SF-MoS₂ achieved a maximum electromagnetic shielding effectiveness (SE_T) of 53.7 dB in the Ku band, coupled with an exceptional tensile strength of 450 kPa. The hydrogel also demonstrated rapid response/recovery times (38/39.9 ms) and sustained stable sensing functionality over 200 cycles. Critically, the SF-MoS₂ conductive filler simplifies processing complexity by eliminating the need for multi-material composite structural design, as required by traditional materials for similar functionalities, thus providing a new paradigm for the development of high-performance anti-electromagnetic interference wearable smart electronic devices.