Preparation of dual-network MXene hydrogels and their electromagnetic and UV shielding properties

MXenes show unique advantages in electromagnetic shielding materials due to their high electrical conductivity, abundant active sites (such as —OH, —F, —O), electrochemical behavior, and excellent hydrophilicity. However, hydrogels with both excellent mechanical strength and high electromagnetic shielding efficiency remain to be further studied. Meanwhile, transparent hydrogels often lack the ability to filter ultraviolet light, which greatly limits the application of hydrogel materials. In this work, PAAm-PHEMA/PAA-Fe³⁺-MXene hydrogels with double shielding mechanism were prepared by using acrylamide (AAm) copolymer hydroxyethyl methacrylate (HEMA) chemical cross-linking as the first network, and polyacrylic acid (PAA)-Fe³⁺ metal ion complexation as the second network, and two-dimensional MXene as conductive nanofillers. The presence of MXene and Fe³⁺ makes the hydrogel possess both electromagnetic and UV shielding properties. The structure and three-dimensional network of the composite hydrogel were confirmed by FTIR, SEM and EDS. The as-prepared double-network hydrogel exhibits high mechanical strength (320.1 kPa), high stretchability (1786%), and good electrical conductivity (3.8 S/m). In addition, the composite hydrogel also exhibits excellent UV shielding ability, with transmittances of 0% and 79.2% at characteristic wavelengths of 365 and 550 nm, respectively. At the same time, the composite hydrogel can obtain excellent electromagnetic-interference (EMI) shielding effect of more than 36 dB in the X-band, strong adhesion to various substrates, rapid self-healing performance and high shape adaptability. This work provides a flexible and highly tunable dual-shielding mechanism hydrogel network design and large-scale facile fabrication of new ideas, showing great application prospects in flexible wearable materials.