Multifunctional bacterial cellulose photothermal aerogels with multi-bonded network assisted by carbon nanotube

As one of the important ways to utilize solar energy, it is of great significance to construct composite photothermal materials with high photothermal conversion and multifunctionality for in-depth investigation of their application performance. The nanofiber network and the reactivity of a large number of hydroxyl groups on the surface of environmentally friendly bacterial cellulose (BC) provide a prerequisite for its use as an excellent matrix material. Here, we use bacterial cellulose nanofibers (BCNFs) as the matrix, methyltrimethoxysilane (MTMS) as the crosslinking agent and hydroxylated multi-walled carbon nanotubes (MCNT − OH) as the photothermal absorber and conductive substrate to construct a multifunctional BC photothermal aerogel with multi-bonded network structure. Multiple chemical bond and physical bond interactions are formed between BCNF, MTMS and CNT, and fiber entanglement is combined to make CNT uniformly dispersed. This optimal photothermal aerogel has rich network structure with high hydrophobicity of 147°, compressive strength of 17.62 kPa and high elasticity. It also shows high light absorption of 93.5%, eminent photothermal conversion of 80.4 °C and photothermal stability under 1 kW m−2 irradiation with a low CNT content of 27.1%. Therefore, the photothermal aerogel shows potential of multi-scenario applications in the field of solar-driven high-viscosity crude oil recovery and piezoresistive strain sensors.