Synergistic Interfacial Engineering of Small Molecule‐Modified 1T‐Phase MoS 2 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 MoS 2 , which has been functionalized with carboxylic acid‐containing small‐molecules (SF‐MoS 2 ). This composite is embedded within a dual‐network hydrogel matrix comprising polyvinyl alcohol (PVA) and sodium alginate (SA), which was called PS/SF‐MoS 2 . The elevated 1T phase content of MoS 2 (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‐MoS 2 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‐MoS 2 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.