Mosquito repellent microcapsules of nepeta essential oil were prepared by electro-atomization complex coacervation

Microcapsules containing nepeta essential oil (NEO) are prepared by electro-atomization complex coacervation with sodium alginate and gelatin as wall materials. The effects of conditions such as sodium alginate solution concentration, core-to-wall ratio and emulsifier content on the release of essential oil and mosquito repellent properties of the microcapsules are studied. The microcapsules prepared under optimal preparation conditions have good performance and morphology, the encapsulation efficiency and loading capacity being 86.65% and 13.93%, respectively. The prepared microcapsules have adequate morphological characteristics observed using scanning electron microscopy. Fourier transform infrared spectra and thermogravimetric analysis show that NEO is successfully loaded in the microcapsules, and the thermal stability of NEO is improved. In addition, the results of release and repellent tests show that the NEO in the microcapsules could achieve stable release within 15 days and maintain an avoidance rate above 80% within 48 h, indicating the potential application of the microcapsules in the field of mosquito repellents. (C) 2023 Society of Industrial Chemistry.