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Rajeshwar Rai,
Anup Kumar Mishra,
Dhananjai Singh,
Rajnish Kumar Singh,
- Assistant Professor, Department of Chemistry, MIT Muzaffarpur, Department of Science, Technology and Technical Education, Bihar Engineering University, Patna, Bihar, India
- Assistant Professor, M.I.T Muzaffarpur, Department of Science, Technology and Technical Education, Bihar Engineering University, Patna, Bihar, India
- Assistant Professor, Department of Chemistry, Nalanda College of Engineering, Chandi, Nalanda, Bihar, India
- Lecturer, Department of Chemistry, Government Polytechnic Chapra, DSTTE, Bihar, India
Abstract
Magnetite/maghemite core/shell nanoparticles were prepared by alkaline co-precipitation of Fe(II) and Fe(III) precursors followed by controlled thermal oxidation at 350 °C and subsequently incorporated into chitosan at 1, 3, and 5 wt% loadings by solution casting. The resulting films were evaluated by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), high-resolution transmission electron microscopy (HR-TEM), vibrating-sample magnetometry (VSM), thermogravimetric analysis (TGA), and tensile testing. XRD showed the characteristic cubic spinel reflections at 2θ ≈ 30.15°, 35.48°, 43.12°, 53.45°, 57.02°, and 62.61°, with an apparent crystallite size of approximately 13.8 nm and a lattice parameter of 0.8362 nm. HR-TEM showed approximately spherical particles in the 12-16 nm range; contrast analysis gave a magnetite-rich inner region of about 9.5 nm and an oxidized outer region of about 2.2 nm, yielding an overall dimension consistent with the XRD-derived size. FT-IR bands shifted from approximately 3420 to 3385 cm⁻¹ and from 1592 to 1585 cm⁻¹ after filler incorporation, while an Fe-O vibration appeared near 582 cm⁻¹, supporting interfacial interaction between chitosan functional groups and the iron-oxide surface. At 300 K, the composite films displayed negligible remanence and coercivity under the reported measurement conditions, consistent with a highly reversible superparamagnetic-like response. The 5 wt% film exhibited the strongest combined property enhancement: tensile strength increased from 32.4 to 53.1 MPa (≈64%), Young’s modulus from 1.15 to 2.38 GPa, and the reported TGA degradation onset from 225 to 258 °C. These results support the use of low-loading Fe₃O₄@γ-Fe₂O₃/chitosan films as magnetically responsive, mechanically reinforced biopolymer composites for separation, adsorption, sensing, and related functional-material applications.
Keywords: Fe₃O₄@γ-Fe₂O₃; chitosan; core/shell nanoparticles; magnetic nanocomposites; interfacial interaction; superparamagnetic-like response; XRD; thermal stability
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Journal of Polymer & Composites
| Volume | 14 | |
| 04 | ||
| Received | 16/08/2026 | |
| Accepted | 08/09/2026 | |
| Published | 10/09/2026 | |
| Publication Time | 25 Days |