Assessing the transport potential of polymeric nanocapsules developed for crop protection

Nanotechnology is increasingly important in the agricultural sector, with novel products being developed to heighten crop yields and increase pesticide efficacy. Herein, the transport potential of different polymeric nanocapsules (nCAPs) developed as pesticide delivery vehicles was assessed in model soil systems. The nCAPs examined are (i) poly(acrylic acid)-based (nCAP1), (ii) poly(methacrylic acid)-ran-poly(ethyl acrylate) copolymer-based (nCAP2), (iii) poly(methacrylic acid-ran-styrene) copolymer-based (nCAP3), and (iv) poly(methacrylic acid-ran-butylmethacrylate)-based (nCAP4). nCAP mobility was examined in columns packed with agricultural loamy sand saturated with artificial porewater containing Ca2+ and Mg2+ cations (10 mM ionic strength, pH 6 and 8). Furthermore, the impact of (i) cation species, (ii) sand type, and (iii) ammonium polyphosphate fertilizer on the transport potential of a nanoformulation combining nCAP4 capsules and the pyrethroid bifenthrin (nCAP4-BIF) was examined and compared to a commercial bifenthrin formulation (Capture® LFR). Although nCAP4-BIF and Capture® LFR formulations were highly mobile in quartz sand saturated with 10 mM NaNO3 (≥95% elution), they were virtually immobile in the presence of 10% ammonium polyphosphate fertilizer. The presence of Ca2+ and Mg2+ did not hinder nCAP4-BIF elution in quartz sand saturated with 10 mM standard CIPAC D synthetic porewater; however, limited Capture® LFR transport (