Magnetic cellulose nanocrystal nanocomposites for the development of green functional materials

A magnetic cellulosic material composed of cellulose nanocrystals (CNC) and cobalt ferrite (CoFe₂O₄) nanoparticles was developed through evaporation-induced self-assembly (EISA). Nanoparticles demonstrated good dispersibility within the cellulose nanocrystal template. The addition of glucose to CNC network allows the development of homogeneous crack-free CNC-based films and does no modify neither the morphology nor the optical properties. In contrast, the introduction of CoFe₂O₄ nanoparticles produces a marked decrease in the amount of the transmitted light. 20wt.% of CoFe₂O₄ nanoparticles inside the CNC matrix induced a maximum magnetization value of 12.96emug^-1, increased the real part of the dielectric constant (permittivity) from 10 (pure CNC film) to 12 and improved the thermostability of the nanocomposite as evidenced by the increase of the onset temperature from 165.1 to 220.4°C. Those features obtained in a non-petroleum-based composite provide insight into the development of the next generation of functional materials from natural origin.