Mechanically Robust Nanocellulose/MXene Aerogels with Synergistic Thermal Insulation and Antibacterial Performance for Extreme Environments

Aerogels exhibit considerable potential as thermal insulation materials for high-temperature and cryogenic applications. Nevertheless, their widespread application is hindered by insufficient mechanical stability and limited functional adaptability. In this study, a novel methodology was developed to integrate oxidized nanocellulose (ONC) with polyethylenimine (PEI) using ethylene glycol diglycol ether (EGDE), followed by directional drying to fabricate an elastic aerogel designated as CP-D. Subsequently, MXene nanosheets were incorporated into the aerogel matrix to construct an ONC/PEI/MXene composite aerogel (CP@MXene-D), thereby endowing it with enhanced thermal insulation and antibacterial capabilities. The improved thermal insulation performance can be attributed to two synergistic effects: the ordered pore structure suppresses heat conduction, while MXene nanosheets mitigate radiative heat transfer. Compared to CP-D, CP@MXene-D achieves approximately 30 °C greater temperature difference when placed on a hot plate maintained at 100 °C. Additionally, it demonstrates exceptional flame-retardant properties, principally resulting from the layered architecture and physical barrier effect provided by the MXene nanosheets. Furthermore, it demonstrates a 99% antibacterial efficacy against <i>Escherichia</i> <i>coli</i> and <i>Staphylococcus aureus</i>, attributable to the incorporation of MXene nanosheets. As a multifunctional material, CP@MXene-D integrates elasticity, thermal insulation, and antibacterial activity, presenting potential for applications in the field of personal thermal management.