Silicone-Coated MXene/Cellulose Nanofiber\nAerogel Films with Photothermal and Joule Heating Performances for\nElectromagnetic Interference Shielding

Abstract

Aerogels with a larger\nspecific surface\narea and lightweight property have aroused tremendous attention in\nrecent years. Functional aerogel materials have shown applications\nin the fields of industry, environment, biomedicine, and so forth.\nHerein, multifunctional composite aerogels of cellulose nanofibers\n(CNFs), MXenes, and silicone have been achieved <i>via</i> a simple freeze-drying and post-coating process. CNFs with a one-dimensional\nnanostructure are employed for assisting the construction of three-dimensional\nframeworks to overcome the weak interlayer bonding force of MXene\nnanosheets. The resultant aerogel exhibits an electrical conductivity\nof ∼65.6 S m^–1 and an EMI shielding of 39.5\ndB. Meanwhile, the silicone coating makes MXene/CNF aerogel membranes\nhydrophobic, displaying an outstanding water-repellent feature, which\nis significant for maintaining a satisfactory lightweight of the aerogel\nin a wet environment. Especially, the silicone-coated MXene/CNF aerogel\nfilm also exhibits excellent Joule heating and photothermal performances.\nIn particular, the aerogel shows a fast thermal response and a higher\ntemperature range (30.2–141.4 °C in Joule heating and\n30–91 °C in photothermal performance). Considering the\ncharacteristics of hydrophobicity, high EMI shielding efficiency,\nand superior Joule heating and photothermal performances, multifunctional\nsilicone–MXene/CNF aerogel films will have promising applications\nin intelligent garments and EMI shielding fields.