(528e) Fabrication and Characterization of Superparamagnetic Hybrid Cellulose Nanocrystals (CNC)/Iron Oxide (Fe3O4) Nanoparticles
AIChE Annual Meeting
2019
2019 AIChE Annual Meeting
Particle Technology Forum
Fundamentals of Nanoparticle Coatings and Nanocoatings on Particles
Wednesday, November 13, 2019 - 1:50pm to 2:10pm
Each CNC was then coated with Fe3O4 by in-situ co-precipitation of FeCl2 and FeCl3 in the presence of ammonium hydroxide. The reactions were done with theoretical mass compositions of CNC/Fe3O4 and BCNC/Fe3O4 of 1:1, 1:2, and 1:4. The resultant magnetic cellulose nanocrystals (MagCNC) were found to have moderate dispersibility in water and can be easily recovered by a magnetic field. Transmission Electron Microscopy (TEM), Thermal Gravimetric Analysis (TGA), and Fourier Transform Infrared (FTIR) spectroscopy experiments confirmed the successful assembly of CNC with magnetite. TEM images showed that increasing the magnetite concentration increased the coated area of CNC and apparently more aggregation between the hybrid MagCNC. The actual amounts of CNC and Fe3O4 in MagCNC were calculated by TGA. The actual amounts of CNC in the MagCNC were lower than the theoretical values due to some loss of CNC not attached to magnetite during the purification steps. Increasing the magnetite concentration decreased the loss of CNC indicating a greater number of coated CNC. The FTIR spectroscopy results indicated the interaction of magnetite nanoparticles with the hydroxyl group of CNC surface. Moreover, the colloidal stability of MagCNC in water was tested by Dynamic Light Scattering (DLS), UV-Vis spectroscopy and zeta potential measurements. The UV-vis spectroscopy data suggest that particles with higher ratios of Fe3O4/CNC are less colloidally stable than neat CNC at neutral pH. The hydrodynamic radius of neat CNC, neat Fe3O4, and MagCNC were determined by DLS. Increasing the magnetite composition in the MagCNC increased the hydrodynamic radius, providing additional evidence for aggregation among the particles. Zeta potential measurements showed that MagCNCs were moderately stable in water from pH 5 to pH 9 (zeta potential values â -30 mV). Furthermore, the magnetic properties of MagCNC were measured by Vibrating-Sample Magnetometer (VSM). The normalized saturation magnetizations of MagCNCs were 31.79 emu/g, 45.36 emu/g and 45.40 emu/g for CNC/Fe3O4-1:1, CNC/Fe3O4-1:2, CNC/Fe3O4-1:4, respectively while for neat Fe3O4 nanoparticles it was 77.37 emu/g.
Many papers reported various methods for the modification of CNC and their applications but only a few have been done with metal oxide particles. The prepared magnetic cellulose nanocrystals can be used to stabilize magnetically-controlled emulsions and foams for applications in drug delivery or low energy separations.