Cationic oligomer surfactant self-assembly modified halloysite nanotubes improves the spread and retention of chlorpyrifos on leaves

At present, it is very important to develop a nanoparticle drug delivery system that can spread and retain the leaf surface of plants at the same time, which can improve the loss of pesticide carriers on the leaf surface and improve the bioavailability of pesticides. The photosensitive pesticide chlorpyrifos was loaded with halloysite nanotubes. The coating of polydopamine (PDA) provided the interface adhesion ability for the pesticide carrier, and the assembly of cationic oligomeric surfactant provided the wetting and spreading ability for the pesticide carrier. The wettability and spreadability of pesticide carrier can be adjusted by changing the length of hydrophobic chain segment, and the contact angle of cotton leaf surface can reach 36.87°. The retention rate after simulated rain erosion can reach 83.65 %. The maximum release rate was 60.76 % after 60 hours of cumulative release, which showed sustained release performance. After 24 h of simulated solar illumination, the degradation rate of chlorpyrifos (CPF) was 62.76 %. Improving the adhesion and wetting spreading ability of inorganic nanopesticide carriers on leaf surface and reducing the loss and degradation of CPF of photosensitive pesticides play a positive role in improving the bioavailability of pesticides, so it has a wide range of significance in agricultural applications and environmental protection.