Deformation of Ferrogel Based on Carboxyl Methyl Cellulose (CMC)/Polyvinyl Alcohol (PVA) Hydrogel

Ferrogel is a smart material that combines the elastic properties of hydrogel and magnetic behavior from the filler of magnetic materials. In this work, ferrogel was fabricated through a freezing-thawing process with matrix materials of Carboxyl Methyl Cellulose (CMC)/Polyvinyl Alcohol (PVA) and a filler of magnetite. Magnetite nanoparticles were successfully synthesized by using a coprecipitation method at room temperature. The magnetite filler was investigated via X-ray Diffractometer (XRD) and Transmission Electron Microscopy (TEM), respectively, to analyze the structure and morphology of the magnetite. Based on the XRD analysis, the magnetite nanoparticle was matched by ICSD number of 9013529 and has an average particle size of about ∼ 9.67 nm. This result is well confirmed by the TEM characterization that showed an average particle size of 9.32 nm. Furthermore, ferrogel was explored by using a Vibrating Sample Magnetometer (VSM) and an electromagnetic instrument to measure the magnetic properties and deformation of ferrogel, respectively. The VSM analysis showed that CMC/PVA hydrogel-based ferrogel has a superparamagnetic behavior due to its magnetization remanent and field coercivity that is close to zero. Interestingly, the deflection of Fe₃O₄/CMC/PVA ferrogel under the effect of the external magnetic field exhibited a good response. The deformation of ferrogel significantly increased from 4.9 cm to 7.0 cm as the filler of magnetite in the ferrogel was increasing from 14 wt% to 22 wt%. This phenomenon could be improved and explored to change the ferrogel into an artificial muscle by engineering the concentration and magnetite response in the CMC/PVA hydrogel.