Multifunctional magnetic cellulose aerogel nanopaper made from nanofibrillated bamboo pulp fiber as templates

Elastic or ductile networks derived from plant cellulose nanofibrils are suitable for use as nanostructured biofunctional materials with tunable mechanical properties. However, the non-destructive processing of functional guest nanoparticles into macroscopic cellulose nanofibril aerogel nanocomposites with enriched architecture and functionality through conventional nanotechniques maintains a challenge. Here, we developed cellulose nanofibril aerogels that can be used as a versatile template for the nonagglomerative in situ growth of nanoparticles and processed ferromagnetic cobalt ferrite nanoparticles into lightweight and porous magnetic aerogels through their unique network architecture, which were subsequently piezo-controlled into flexible magnetic nanopapers. It optimizes the tensile strength, resistance to ultrasonic decomposition, and ultra-foldable conductivity of flexible magnetic cellulose nanopaper. This flexible magnetic cellulose aerogel nanopaper (CANP) have excellent mechanical strength, with a high tensile modulus of 761.95 ± 10.2 MPa and exceptional foldability without misconfiguration damage after 10,000 repetitions of folding, as well as flexural fatigue resistance. Simultaneously, the highly flexible magnetic CANP exhibits large coercivity and moderately strong saturation magnetization strength. Due to optimized impedance matching of the dielectric/magnetic components with cellulose aerogel, the highly flexible magnetic CANP doped with cobalt ferrite nanoparticles has good effective absorption bandwidth (13.28 GHz) with a minimum reflection loss values of - 58.24 dB. Moreover, it had large coercivities, high saturation magnetization, and a minimum value of reflection. • Freeze-dried cellulose nanofibril aerogel for the nonagglomerative. • Processed ferromagnetic cobalt ferrite nanoparticles into aerogels. • CANP exhibit exceptional mechanical strength and outstanding foldability. • CANP has good effective absorption bandwidth and minimum reflection. • CANP exhibits strong saturation magnetization strength.