Characterization of an Environmentally Responsive Organic–Inorganic Hybrid Fe₃O₄/SiO₂/PPy-c Core–Shell Nanocomposite with Magneto-Chromatic Ability for Synergistic Electrical Properties

Abstract

The aim of this study was to analyze the properties of a composite that incorporates carbon black and polypyrrole within an Fe 3 O 4 /SiO 2 core−shell structure, synthesized using the Stober method under high ultrasonic irradiation conditions (120 W) for Fe 3 O 4 /SiO 2 nanocomposite. The Fe 3 O 4 /SiO 2 core−shell indicates magnetochromatic behavior characterized by temperature-dependent coloration and magnetic alignment. Incorporating carbon black and polypyrrole at moderate temperature (5−15 °C) enhanced the electrical conductivity. The electrical resistivity ρ was 7.30 × 10 6 Ω•cm for Fe 3 O 4 , 3.19 × 10 8 Ω•cm for Fe 3 O 4 / SiO 2 , and 242.56 Ω•cm for Fe 3 O 4 /SiO 2 /PPy-c at room temperature. When it was performed at moderate temperature (5−15 °C), the ρ of the prepared Fe 3 O 4 /SiO 2 and Fe 3 O 4 /SiO 2 /PPy-c nanocomposite was 1.08 × 10 8 and 0.00799 Ω•cm, respectively. Current−voltage measurements revealed a linear relationship, with butterfly shaped curves in the forward-bias region for all samples. The Fe 3 O 4 / SiO 2 /PPy-c nanocomposite's tunable synergistic electrical properties at moderate temperatures make it useful for environmental applications, electrical wiring, and circuitry.