(346e) Sustainable Agriculture Sprays: Cellulose Ester Aqueous Dispersions As Rainfast Biodegradable Foliar Formulations for Targeted Agrochemical Delivery
AIChE Annual Meeting
2022
2022 Annual Meeting
Sustainable Engineering Forum
The Food-Energy-Water Nexus
Tuesday, November 15, 2022 - 1:30pm to 1:45pm
The colloidal dispersions are synthesized through solvent evaporation process from a ternary mixture of cellulose ester (CE)/water/acetone. Fundamental insights in the phase behavior of the ternary system are analyzed via the Flory Huggins model wherein clear demarcation is observed in particle morphology and phase behavior through varying the ester linkages in the cellulose esters. Change in particle size and shape further effects the binding affinities with the model AI as is corroborated through Isothermal Titration Calorimetry (ITC) analysis and release assays. Our results demonstrate that tuning the particle morphology permits both weak and strong binding with the AI thus allowing achieving both slow and fast AI release as required. Contact angle and surface tension measurements of the dispersions on various model leaf surfaces revealed significantly lower values than water on the surface indicating enhanced wetting. Furthermore, we have verified the functional performance of the colloidal dispersions through simulated rain tests to validate rainfastness and anti-fungal assays to corroborate AI bioavailability. These results are further complimented with stability analysis, and surface interactions with model leaf surfaces.
The potential impact of rainfastness and controlled release formulations can be significant especially in tropical rainy climates where rain induced wash-off necessitates multiple sprays to achieve desired crop yields. This, in turn, increases operational costs in addition to causing environmental pollution, increased pathogen resistance and non-target exposure. CE dispersions as agrochemical formulations can be significant in reducing number of sprays required while maintaining the desired efficacy level. Our study goes the complete wheel starting from a fundamental thermodynamic system analysis of the CE particle formation process and the CE-AI binding interactions to demonstrating the superior rainfastness of the dispersions and the bio-availability of the loaded AI. With their functional performance verified through release and fungal assays, fundamental thermodynamic insights into the dispersion synthesis process and the particle-AI interactions open a window of opportunity allowing tuning particle size and the binding strength of the desired AI. This can allow tailoring of the dispersions to cater to a wide variety of AI, and crops. This âlab to leafâ approach demonstrates the potential of CE dispersions to achieve targeted AI delivering allowing higher efficacy at lower delivery rates.