WEB Nanocomposites based on cellulose and SrFe12O19 nanoparticles as novel magnetic nanopapersTuesday (22.09.2020) 10:40 - 10:55 P: Processing and Synthesis 1 Part of:
Nanostructured biocompatible cellulose nanofibrils (CNF) show attractive properties such as made from renewable resources, lightweight, thermal stability, and excellent mechanical properties. These prerequisites make the combinations of magnetic nanoparticles and CNF a promising precursor for the design of bio-inspired flexible magnetic templates. This hybrid material provides a promising magnetic composite material for flexible, electrical and electromechanical devices, catalysis, data storage, water purification, biomedical applications, loudspeakers, etc..
We combined negatively charged CNF (1360 µmol/g) colloids with stable magnetic colloids based on positively charged disc-like hard magnetic hexaferrite particles for the preparation of thin films. Spray deposition was used for the fabrication of the magnetic composite material for a novel magnetic nanopaper. We used a unique type of stable magnetic colloids based on hard magnetic hexaferrite nanoparticles (SrFe12O19, SHNP), stabilized by electrical charge and dispersed in water. The colloidal single-crystalline particles possess plate-like shapes with a mean average lateral size of about 50 nm and a thickness of 4 nm. Each particle carries a large permanent magnetic moment oriented perpendicularly to the plate surface and exhibits the highest intrinsic coercivity field of about Hc = 4500 Oe (Ms = 50 emus/g).
As a result of the interaction of positively charged SHNPs particles with a negatively charged surface of the CNF fibrils, a hierarchically ordered magnetic composite material in the form of a thin film is obtained. The nano- and microstructure formation of the nanoscale composites was studied by a combination of atomic force microscopy (AFM) and scanning electron microscopy (SEM) imaging, as well as grazing-incidence small- and wide-angle X-ray scattering (GISAXS/GIWAXS). The microstructure was related to their magnetic properties by SQUID magnetic techniques. The results of the experiments on the fabrication and structural studies showed a uniform distribution of single SHNPs in a cellulose matrix, as well as the presence of preferential orientation of SHNPs platelets parallel to the plane of the substrate. The SQUID technique demonstrates the presence of a large coercive force in the magnetic composite inherent to individual magnetic nanoparticles.
We show a facile route of creating new ferromagnetic cellulose-based nanocomposite by spray deposition for with large-scale applicability.
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