Intelligent bamboo: A splendid flame retardant, fire warning and photothermal sterilization nanocoating via low-temperature evaporation induced self-assembly

Abstract

The application of bamboo to assist carbon neutral strategy has attracted worldwide attention due to its naturally carbon-negative property. However, the inherent defects of flammable and mildewed make bamboo encounter a bottleneck in its application. Hence, an intelligent bamboo (IB) with integrated performances of stable connection, high-temperature resistance, reliable fire warning and splendid photothermal sterilization properties was constructed via low-temperature evaporation induced self-assembly strategy. The hydrogen bonding, coordination complexes, van der Waals forces, and electrostatic forces can be formed between Ti3C2Tx (MXene) and pre-treated bamboo substrate (TB). The optimized bamboo-based fire alarm sensor (AM@TB) exhibits significant improvement in flame retardant properties, e.g., the limiting oxygen index (LOI) value of AM@TB8-2 was 61.4%, surpassing TB by an impressive margin of 65.8% and the vertical burning test reach the UL94 V-0 rating. Besides the PHRR (heat release rate) of AM@TB8-2 was decreased 80.3% compared to TB. The residual mass of AM@TB8-2 is 34.5%, which is 1.6 times higher than TB. Additionally, the AM@TB8-2 presents a sensitive fire warning response (∼2 s) and reliable repeatability. Furthermore, based on the outstanding photothermal conversion performance of MXene, AM@TB8-2 demonstrates predominant sterilization efficacy after a near-infrared laser (NIRL) illumination. Therefore, this work provides inspiration for the design and fabrication of high-performance IB that combine fire safety and antimicrobial properties.