Nanoarchitectonics and Characterization of Hydroxypropyl Methylcellulose (HPMC)/Chitosan (CS) Nanocomposites Doped with NiFe₂O₄ Nanorods for Optoelectronics and Energy Storage

This study investigates the properties of nanocomposites prepared by incorporating nickel ferrite nanorods (NiFe₂O₄ NRs) into a hydroxypropyl methylcellulose (HPMC)/chitosan (CS) polymeric matrix using a casting method. The resulting HPMC/CS-NiFe₂O₄ nanocomposites were characterized for their optical, magnetic, electrical, and dielectric properties. X-ray diffraction (XRD) revealed a decrease in the crystallinity of the HPMC/CS matrix upon incorporation of NiFe₂O₄ NRs. Fourier-transform infrared (FT-IR) analysis confirmed interactions between the polymer matrix and the nanorods. UV-Vis spectroscopy indicated improved optical properties in the composites. Notably, the indirect optical bandgap decreased from 5.19 eV to 4.43 eV for blends containing 8 wt% NiFe₂O₄ NRs, suggesting potential applications in light absorption or manipulation. The AC conductivity of the nanocomposites increased compared to the pristine HPMC/CS blend. Furthermore, both dielectric permittivity and modulus displayed tunability with varying NiFe₂O₄ NR concentrations, making these materials promising candidates for applications requiring controlled dielectric responses. Magnetic measurements revealed enhanced coercive field and saturation magnetization compared to the pure HPMC/CS blend, suggesting potential applications in magnetic field sensing or data storage. An engineered HPMC/CS- NiFe₂O₄ nanocomposite capacitor exhibited improved storage capacity and controllable conductance characteristics. These findings suggest promising applications for these nanocomposites as bandgap tuners, optical sensors, permittivity-tunable dielectrics, and novel host matrices for solid polymer electrolytes. Overall, this study demonstrates the potential of these materials for the development of next-generation energy storage and conversion devices with superior performance.