Toward Sustainable Crop Protection: Aqueous Dispersions of Biodegradable Particles with Tunable Release and Rainfastness

Abstract

Fabrication of aqueous particulate dispersions of biodegradable cellulose esters (CEs) as efficient carriers of agrochemical active‐ingredients (AIs) for foliar applications, is reported. The use of different ester substituent groups on CE permits modulation of particle morphology and size, from irregular shapes (<350 nm) to spheres (≈1.1 µm diameter), while maintaining stability as supported by minimal change in zeta potential and particle size over one year. Rainfastness is tested by simulating >50 mm h−1 rainfall on coated banana and tomato leaves and silicon. Surface coverage loss as low as 9%, based on the nature of leaf and formulation, confirms the rainfastness of the formulations. Variation in the release kinetics of a model AI fluopyram from different CEs can be attributed to the particle morphology and the nature of binding between fluopyram and various CEs. Thermodynamic analysis demonstrates spontaneous binding between fluopyram and multiple sites of CEs, justifying its two‐step release from CE particles. System functionalities are corroborated via in‐vitro fungal inhibition assays demonstrating a 100% inhibition of the fungal growth. This “lab‐to‐leaf” approach of materials development involving fundamental insights and functional performance reveals CE dispersions are promising green agricultural formulations with the potential to impact a myriad of crops around the globe.

Preparation of Nano-PbWO4 Particles by Polymaleic Acid Modification: A Highly Filled Nonwoven Membrane Used To Improve the Wearing Comfort and Radiation Safety of γ-ray Protection Products

“…The stability of suspensions is enhanced by a significant magnitude of zeta potential. 43 The results suggest that suspensions of PWO@PMA particles exhibit improved stability across a wide range of pH levels, as evidenced by the findings. The laser particle size analysis depicted in Figure 4b indicates that the suspension of PWO particles has a Dx(90) value of 20.4 μm.…”

Cellulose Acetate-Stabilized Pickering Emulsions: Preparation, Rheology, and Incorporation of Agricultural Active Ingredients

“…Despite the aggregated network structure, the NP dispersion maintained a watery (fluid-like) consistency with little settling of particles, as was verified by visual observation (Figure 1b). We have previously reported 23 the formation of distinct, irregularly shaped CA NPs at a nonsolvent addition rate of 1 mL/min. Nanoprecipitation governed by the experimental conditions can yield NPs of varying shapes and morphology.…”

“…The emulsifying properties of CA NP can be attributed to the amphiphilic chemical structure of the CA polymer chains (Figure 1c), where the combination of hydrophilic hydroxyl groups (3.5% 23 ) and the hydrophobic acetate groups allows the NP to partition on the oil−water interphase providing effective stabilization. In Pickering emulsions, the contact angle (θ) of the particle at the biphasic fluid interphase plays a crucial role in determining the emulsion stability.…”

“…CA (Eastman, CA-398−10, degree of substitution of 2.4 with 39.8% acetyl content, M w = 40 000 g/mol, used as received) NP dispersion in water was synthesized as per our previously described protocol. 23 Briefly 2 wt % CA solution in acetone (Fisher Scientific S25120) was mixed with different weights of deionized (DI) water, which were added at an instantaneous rate of 30 mL/min controlled with a Metrohm dosing unit with continuous stirring at 1000 rpm. For instance, to prepare 1 wt % NP dispersion in water, we added twice the weight of water in the initial 2 wt % CA solution.…”

Water‐Dependent Upcycling of Eco‐Friendly Multifunctional Nanocompartmentalized Films

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of approximately 90%. [4,5] Given more than 4 million tons of pesticides were applied globally in 2018 to produce food, [6] and the human population will increase by about one billion by mid-2030, [7] the toxicity of the environment due to pesticides is likely to grow substantially, if nothing is done. [8] Large-scale production of safe and nutritious food for the global population is, therefore, one of humanity's most urgent needs.To address this challenge, the 21stcentury pest control system must adopt technological innovations combined with environmental management to provide the best global population growth.

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