In this research the wetting behavior of agro-surfactant solutions (Triton X-100, SDS, DTAB) on wheat leaf surfaces have been investigated based on the surface free energy, surface tension, and the contact angle. The results show that the contact angle of those surfactant solutions keeps constant with low adsorption at interfaces below 1 × 10⁻⁵ mol L⁻¹. With the increase in concentration, the contact angles of Triton X-100 decrease sharply because the adsorption of molecules at solid–liquid interfaces (Γ_SL′) is several times greater than that at liquid–air interfaces (Γ_LV). With regards to SDS and DTAB, the contact angle also decreases but is even larger than 90° above the CMC, while the ratio of Γ_SL′ to Γ_LV is about 1.20, demonstrating that the Gibbs surface excess is related to the structure of surfactant molecules. Obviously, besides the properties of wheat leaf surfaces and surfactant solutions, the wetting behavior mainly depends on their noncovalent interactions. Among these, the hydrophobic interaction is the main force promoting molecules to adsorb on the surface, with the assistance of the Lifshitz–van der Waals interactions and the electrostatic interactions. According to the mechanism of their wetting behavior on plant surfaces, the recipe of pesticide formulation can be adjusted with better wettability to reduce its loss, consequently improving pesticide utilization and decreasing environmental contamination.

Mesoporous silica nanoparticles (MSNs) can be used as carriers to deliver pesticides into plants, which is considered to be one method of improving the efficacy of pesticide usage in agricultural production. In the present work, MSNs with an average diameter of 258.1 nm were synthesized and loaded with Fenoxanil. The structure of the nanocarriers was observed by scanning electron microscopy. The loading content of Fenoxanil-loaded MSNs was investigated. After rice plants in a hydroponic system were treated with loaded MSNs, the concentrations of Fenoxanil in different samples were determined using high-performance liquid chromatography–tandem mass spectrometry. The results suggested that rice plants can absorb MSNs from water through their roots, and the dosage has almost no effect on the distribution of Fenoxanil in rice plants. The application of pesticide-loaded nanoparticles in a hydroponic system poses a low risk of Fenoxanil accumulation in rice.

The deposition of pesticide liquid droplets on plant surfaces is of great importance in agricultural application. More than 50% of agrochemicals are lost and wasted during the spraying and wetting processes. Because the surfaces of plant leaves are negatively charged, we produced a kind of positive charge lambda-cyhalothrin loaded oil-in-water nanoemulsion in the system water/EL-80-Span 60/solvent 150# via the phase inversion composition (PIC) method with addition of Ionic Liquids (ILs). The electrostatic interaction between the negative charge surface and positive charge droplet would highly increase the wetting property. The results show that the positive zeta potential of nanoemulsion droplets gained along with the increase concentration of P₁₄₄₄₄Br, but with the increase concentration of P₄₄₄₄Br, the negative zeta potential of nanoemulsion droplets changed slightly and stayed around −17.8 mV (without any ILs). Besides, we explored the rheology characteristic of prepared nanoemulsions. Additionally, the contact angle experiments show that the positively charged nanoemulsions have a stronger adsorption on the negative surface and the contact angle decreased along with the increase of positive charge. Significantly, with addition of ILs, the nanoemulsions showed an excellent long-term stability due to electrostatic repulsion between droplets and homogeneous nanoscale droplet size. The highly stable pesticide nanoemulsions are of great importance in practical application and the nanoemulsions prepared with ILs offered a good potential as a carrier for drug delivery.