Complex dielectric-impedance spectroscopic studies of magnetite added chitin biopolymer

Abstract

We have successfully synthesized magnetic chitin (MCH) by incorporating iron oxide nanoparticles into biodegradable and abundantly naturally available chitin by the coprecipitation method. X-ray diffraction (XRD) characterization revealed formation of cubic inverse spinel structure of Fe3O4 nanoparticles. In addition to this, other characterization studies like energy dispersive X-ray analysis (EDX) and vibrating sample magnetometry (VSM) were also performed to have an insight into the compositional and functional nature of the structure. A detailed spectroscopic study of complex impedance and dielectric constant for a wide frequency range of ~1 Hz to 10 MHz at discrete temperatures ~300–400 K has been performed by us for the first time on MCH in order to understand various relaxation processes. From permittivity, we have estimated the height of the potential barrier to be ~95.8 ± 0.3 meV. Impedance measurements yielded an activation energy of ~35.85 meV. Thermogravimetric analysis (TGA) of the sample showed exceptionally high thermal stability of the sample with percentage of residual mass at 800 ℃ being ~73% in MCH, which is quite high in comparison to the pristine chitin. An S shaped curve obtained through VSM measurement confirmed the superparamagnetic nature of the nanocomposite. The study assumes significance in the present scenario of rising awareness about the environment and demand to explore alternative green materials with numerous biomedical/environmental applications ranging from drug delivery vehicles in COVID-19 treatment to food packaging.