Nanofibrous-substrate-based controlled herbicidal release systems: Atrazine/hydroxypropyl-β-cyclodextrin inclusion complex loaded PVA agro-augmenting electrospun mats

Abstract

The paper deals with the development of atrazine (ATZ)/hydroxypropyl-β-Cyclodextrin (H-βCD) inclusion complex (IC) loaded PVA-based sustainable electrospun mats (EM) as a structurally stable agro-augmenting assembly for controlled herbicide release system. The IC was prepared in a 1:1 stoichiometric ratio via the co-precipitation method. The thermal (DSC, TGA), morphological (FESEM), and microstructural (FTIR, XRD, and NMR) characterization revealed the successful encapsulation of ATZ into the cavity of H-βCD. Further, uniform and bead-free IC-loaded EM were fabricated by the incorporation of the synthesized IC into the PVA precursor solution. Microstructural analysis of IC-loaded PVA EM confirmed the presence of hydrogen bonding interactions between IC and PVA EM. The fabricated EM exhibited improvement in surface-hydrophobicity (contact angle ∼78.3º), swelling (∼260%), surface area ( ∼26 m2/g), pore volume (∼3.2 × 10−2 cc/g), and ATZ release efficacy in water (∼13.6%) and in soil (∼ 6.2%). The thermal and mechanical analysis indicated an increase in thermal stability (from ∼284 to ∼395 °C) with a simultaneous increment in the mechanical properties (from ∼24.3.7 to ∼27.4 MPa) for PVA-based EM upon the incorporation of IC at lower content. Furthermore, the herbicidal activities indicated that IC, as well as IC-loaded PVA EM, exhibited better herbicidal activity against L.sativa than free ATZ. Thus, the present study conceptually established an innovative and efficient method for designing fibrous mats with tunable ATZ-release and thermo-mechanical properties that can reinforce agrotechnology by optimally boosting both crop-yield and environmental sustainability via a substantial reduction in the excessive use of ATZ.