Impedance Spectroscopy and Antimicrobial Activity in <scp>ZnO</scp>–Cellulose/Chitosan@Cu²⁺ Wavy‐Like Nanocomposites Formed via Semi‐Dissolved Chitosan Templating

ABSTRACT In this study, an advanced approach to synthesizing wavy ZnO–cellulose/chitosan@Cu 2+ nanocomposites with improved functionality and conductivity was semi‐dissolving chitosan as a dual‐functionality template. The dual‐functionality template method uses chitosan to form semi‐porous structures and ethylene glycol as the solvent and crystallization agent for hybrid nanostructures. The wavy surface morphology, stability, and conductive nano‐nanostructures significantly improve the microstructural, electrical, and antimicrobial properties of Cu‐doped ZnO–cellulose/chitosan conductive nanostructures. The formed composite morphology and thermal properties are characterized by thermogravimetric analysis (TGA) and field emission scanning electron microscope (SEM–EDX). The conductivity properties of Cu‐doped ZnO–cellulose/chitosan revealed that the nanostructures exhibited a steady‐state plateau at low frequencies, which represents the DC conductivity, while the conductivity transferred to a frequency‐dependent increase at higher frequencies due to a hopping conduction mechanism, Ac conductivity. The impedance spectroscopy represented by the Cole–Cole analysis indicated non‐Debye relaxation processes. The equivalent circuit parameters estimated for different samples showed segmental capacitance (C1) and resistance (R1) values ranging from 4.5665 × 10 −11 F to 2.3882 × 10 −10 F and from 4.9 × 10 6 Ω to 5.244 × 10 5 Ω, as Cu 2+ concentration increased from zero (A0) to 4 mol%(A2), respectively. The antimicrobial activity of the nanostructures was estimated using the Well diffusion technique. The antimicrobial activity demonstrated inhibition zone diameters ranging from 19 to 31 mm against various microorganisms, including 30 mm for Aspergillus fumigatus and 28 mm for Escherichia coli for A3 (6 mol% Cu 2+ ). These findings suggest that the ZnO–cellulose/chitosan@Cu 2+ nanocomposites can be utilized in biomedical fields such as wound dressings, environmental conservation, food packaging, and coatings.