Novel Synthesis, and Application of Carboxymethylated Cassia fistula‐Based Hydrogel for Extended‐Release of Dinotefuran

Abstract

The agricultural industry prioritizes minimizing crop yield losses caused by pests, making it essential to develop effective, safe and sustainable pesticide formulations. Hydrogels are promising carriers for pesticide delivery, due to their high surface area, large pore volume, and pore size. In this study, we synthesized Cassia fistula (CA‐g‐AA) and its derivative carboxymethylated Cassia fistula‐grafted polysodium acrylate hydrogel (CMCA‐g‐AA) using free radical polymerization, with N, N'‐methylene bisacrylamide (MBA) as a crosslinker, for the ex‐situ encapsulation of dinotefuran. Characterization was performed using FTIR, 13C CPMAS‐NMR, SEM, TGA, rheology, and XRD. The maximum swelling capacity of hydrogels was investigated in distilled water. CA‐g‐AA and CMCA‐g‐AA hydrogels exhibited a dinotefuran loading percentage of 37 and 39% and released dinotefuran for 26 and 29 h, respectively. The dinotefuran release kinetics was analyzed by using the Korsmeyer‐Peppas and Higuchi models. Under drought like conditions, CMCA‐g‐AA‐treated soil sustained plant growth for 7 days, compared to CA‐g‐AA (5 days) and untreated soil (3 days). The novel hydrogel CMCA‐g‐AA enhanced soil water absorption and retention along with highlighting its potential for extended pesticide release. Thus, the developed CMCA‐g‐AA hydrogel is an efficient strategy for sustainable agriculture.