Flexible and strong Fe3O4/cellulose composite film as magnetic and UV sensor

Abstract

Flexible and strong Fe3O4/cellulose composite films were prepared successfully by co-dispersing homemade Fe3O4 particles and cellulose in aqueous solvent followed by regeneration. The Fe3O4 particles were immobilized in the cellulose matrix via coordinate bonding with hydroxyl of cellulose, and formed clusters with diameter of several hundreds of nanometers which embedded in the cellulose matrix, endowing the composite films with excellent mechanical property and thermal stability. The composite films were thermally stable below approximately 290 °C, and can be folded and bended without fracture, which guarantees the wide application as sensors and devices. Due to the incorporation of Fe3O4, the composite film presented an excellent saturated magnetization, superparamagnetic property, as well as strong UV shielding property. It is noted that the composite films exhibited two extraordinary sensing capabilities against both UV exposure and magnetic field, with fast responsiveness and excellent reproducibility. The present work not only supplies a simple pathway to prepare sensors with excellent properties, but also utilizes the renewable resources, demonstrating both sustainability and great potentials.