Sodium alginate-assisted dispersion of MXene in vulcanization-free natural rubber for efficacy photothermal conversion and electromagnetic shielding

High-performance photothermal conversion composites with excellent mechanical properties hold great potential for applications in energy harvesting, thermal management, and sensing. In this work, vulcanization-free natural rubber (NR) composites with outstanding mechanical strength and photothermal conversion efficiency were fabricated by incorporating Ti 3 C 2 T x MXene nanosheets as photothermal agents and sodium alginate (SA) as a dispersion aid. SA effectively prevented MXene restacking in the NR matrix, ensuring uniform distribution and enhancing interfacial interactions. As a result, the NR/SA/MXene composites reached peak surface temperatures of 88 °C and a photothermal conversion efficiency of 75.89% under 300 s Xe lamp irradiation and maintained this performance over 10 heating–cooling cycles. NR/SA/MXene-8 further achieved an EMI shielding effectiveness of 50.07 dB, while maintaining a tensile strength of 3.68 MPa, elongation at break above 400%, and stable structural integrity. This work offers a scalable approach for designing multifunctional MXene-based elastomers with synergistic photothermal and EMI shielding capabilities, without the need for vulcanization.