(274i) Investigation of the Synergistic Effect in Combined Antimicrobial Agents and Insect Repellent Microcapsules on Textiles

The application of insect repellent (IR) and antimicrobial agents (AM) onto textiles represents a promising solution in tackling global concerns regarding microbial and viral threats. However, methods to efficiently attach IR and AM agents to the fabrics remains a challenge. This study focuses on the development of a novel method to covalently bond IR containing microcapsules and AM agents on a hyperbranched polyethyleneimine (PEI) functionalized nylon-cotton 50:50 blended fabric (NyCo) to provide a solution towards prolonged protection against microbial and viral diseases. Geraniol essential oil is used as IR, and it is encapsulated in gelatin/gum arabic shell for longer retention and controlled release.The antimicrobial functionalization of NyCo was performed via a cyanuric chloride-based reactive dyeing treatment method. NyCo fabric was first treated with a dichloro-s-triazine-based colorless reactive dye. The reactive dyed fabrics were then treated with polyhexamethylene biguanide to covalently bind the antimicrobial agent onto NyCo. The modified NyCo was further functionalized with hyperbranched polyethylenimine to introduce amino groups to attach IR containing microcapsules. Morphological characterization of the microcapsules and coated fabrics were carried out using fluorescent microscope and SEM. IR testing was done using a simulated arm-in-cage experiment using IR/AM coated fabrics. The wash-durability of the IR/AM coating was also studied using four wash cycles and good results were obtained. Coated NyCo fabrics were tested for AM and IR activity. A series of direct-contact tests showed that the modified Nyco possessed potent antimicrobial activities against Staphylococcus aureus (gram-positive bacteria) and Pseudomonas aeruginosa (gram-negative bacteria) with at least 99% of bacterial reduction. Insect repellency lasting 7 to 15 days was observed depending on the amount of geraniol in the microcapsules. Results obtained will be presented and discussed.