Highly Stable Cellulose-Based HIPPE Pesticide Delivery System: High Control Efficiency and Low Environmental Risk

Stimuli-responsive controlled-release formulations offer great potential for enhancing pesticide efficacy and reducing environmental impact, yet their stability under fluctuating field conditions remains challenging. This study developed a methacrylic-anhydride-functionalized cellulose nanocrystal-stabilized high internal phase Pickering emulsion (MCNCs-HIPPE) for pesticide delivery. MCNCs-HIPPE exhibit outstanding stability, which provides a reliable guarantee for its application in various complex environments. Subsequently, we evaluated the application performance of this delivery system by loading imidacloprid (IMI) onto the MCNCs-HIPPE (IMI@MCNCs-HIPPE). The research results show that IMI@MCNCs-HIPPE exhibited a greater cumulative release of IMI under cellulase-promoted conditions, thereby achieving intelligent responsive delivery. The release process also had a temperature dependence. Furthermore, compared with the commercial IMI formulation (EC) (Bisair), this formulation has better wetting properties, adhesion, and resistance to rain erosion. In the greenhouse pest control efficacy test, IMI@MCNCs-HIPPE demonstrated excellent control effects on the corn aphid (Rhopalosiphum maidis) over EC (15.981 mg/L vs 40.883 mg/L for LC50). The biological safety assessment indicated that compared with EC, IMI@MCNCs-HIPPE brought lower environmental risks. In summary, we developed an environmentally friendly, stimuli-responsive pesticide emulsion system that markedly improves pesticide utilization and reduces environmental risk, offering a promising strategy for reducing pesticide inputs, while enhancing efficacy in sustainable agriculture.