Investigation of the Synergistic Effect of Combined Antimicrobial Agents and Insect Repellent Microcapsules on Fabrics

The combined use of insect repellent (IR) and antimicrobial (AM) agents on textiles offers a promising approach to combating microbial and viral threats. This study presents a novel method for covalently bonding IR-containing microcapsules and AM agents onto hyperbranched polyethylenimine (PEI)-functionalized nylon-cotton (NyCo) fabric for prolonged protection. Geraniol essential oil, encapsulated in a gelatin/gum arabic shell, serves as the IR agent, while polyhexamethylene biguanide (PHMB) is covalently attached via a cyanuric chloride-based reactive dyeing method. Covalent attachment was confirmed using FTIR and ninhydrin assays, and morphological characterization was conducted via optical, fluorescent and scanning electron microscopy. A complete protection time assay and wash durability tests showed sustained IR efficacy (5–13 days), while direct-contact tests confirmed strong AM activity, achieving 99% bacterial reduction. Notably, both functionalities remained effective without adversely affecting each other. These findings highlight the potential of durable AM/IR-coated textiles for enhanced protective applications.