(596d) Application and Characterization of Insect Repellent Containing Biopolymer Microcapsules As a Fabric Coating

Plant-based insect repellents are attractive because they offer a renewable and potentially safer method of preventing vector-borne diseases; however, they suffer from relatively short protection times and need to be frequently reapplied. In this work, the evaporation rate of a plant-based insect repellent is controlled using a biopolymer microcapsule as part of a fabric coating. Microcapsules are synthesized and evaluated for their morphology and insect repellent content. The optimized microcapsules are applied to a nylon-cotton fabric as a surface coating. The effects of coating parameters and structure, such as microcapsule loading, binder content and crosslinking, and presence of additional additives are studied. Coating morphology is determined using optical, as well as scanning electron microscopy (SEM). The air permeability and moisture vapor transport rates (MVTR) are determined using a dynamic moisture vapor permeability (DMPC) cell. The initial insect repellent loading and the evaporation rate over time are determined by storing the coated fabrics in a controlled temperature and humidity environment, with the repellent concentrations measured using HPLC. Finally, the effectiveness of the coated fabrics is demonstrated by exposing the fabrics to mosquitoes and recording the number of landings and probings on the fabrics over several weeks, as compared to unencapsulated insect repellent.

U21-408