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. © 2023 Society of Industrial Chemistry.

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Fosthiazate is a common insecticide for root‐knot nematode control, but it has a short shelf life and is prone to decomposition. In order to improve the stability and prolong the release time, this experiment used the ionic gel method to cross‐link chitosan with sodium tripolyphosphate and added nano‐silica sol to prepare microcapsules suspensions. The optimal preparation parameters for the preparation of chitosan/sodium tripolyphosphate@nano‐silica sol microcapsulated suspensions were optimized by single factor experiments and response surface analysis, and the encapsulation efficiency reached 61.3%. The highest control effect in greenhouse pots can reach 84.1%, and the optimal concentration was 2 g/m2 mixed with soil, which increased stem length, root length and fresh weight by 81.1%, 47.7% and 62.5%. The study showed that the microcapsules of chitosan cross‐linked with sodium tripolyphosphate and added with nano‐silica sol could significantly prolong the release of Fosthiazate, which also provided a positive effect on soybean cyst nematode control.