Micro- and nano-encapsulation of limonene and permethrin for mosquito repellent finishing of cotton textiles

The aim of this study was to prepare mosquito repellent textiles. To compare bio-based and synthetic mosquito repellent agents, limonene and permethrin were encapsulated with ethyl cellulose shell. Coacervation was employed, which is a simple and reproducible method for the encapsulation with high production efficiency. Morphological assessment showed that the capsules had smooth surfaces and their shape was spherical. The homogenous size distribution of the capsules was supported by laser diffraction analysis. The capsules showed narrow size distribution and the mean particle size of the optimum formulations for limonene and permethrin was 1 and 1.3 μm, respectively. The size of the produced capsules was considered suitable for textile applications. The FTIR spectra revealed the similarity of the chemical structure of capsules with shell material. Cotton fabrics were treated separately with limonene and permethrin capsules by padding method. The presence of capsules on the fabrics was determined after 20 washing cycles. Insecticide activity was evaluated against common house mosquitoes ( Culex pipiens ), with respect to cone bioassay of World Health Organization (WHO). Mosquitoes were tended to stay away from treated fabrics, and mortality rates of mosquitos were noted as 41% and 54% for limonene and permethrin, respectively. Although efficacy of fabrics decreased with increasing washing, the fabrics still showed repellency after 20 washing cycles. This study showed that the developed product might be used as an alternative to the other products in the market for avoiding mosquito-borne diseases.