Value-added bio-products extracted from straw utilized as carriers for pesticide delivery: Innovative repurposing of agricultural waste

Straw serves as a significant biomass resource for the fabrication of cellulose nanocrystals (CNC) with a one-dimensional structure. The extraction of CNC from hemp stalks (HS), wheat straws (WS), and wheat husks (WH) was conducted to investigate their potential application as carriers for pesticide delivery. WH-CNC exhibited superior properties with the average particle length below 100 nm, the crystallinity up to 65.9 %, a Zeta potential value of –50.67 mV, and a silane-modified CNC (Si-CNC) grafting rate of 28.40 %. The inherent properties make it highly suitable for utilization as a dispersant in pesticide delivery systems (PDS). Consequently, an innovative PDS was constructed using electrospinning technology with avermectin (AVM) as the model pesticide, and incorporating CNC and Si-CNC as dispersants. The utilization of CNC and Si-CNC facilitated the dispersion of the PDS, thereby playing a significant role in controlling release and enhancing structural stability. The fabricated PDS exhibited a subspherically structured morphology with diameters ranging from 2 to 3 μm, enabling the formation of a stable colloidal suspension system that demonstrated obvious Tyndall effect. Moreover, both encapsulation efficiency and photostability of AVM were significantly enhanced. These improvements in performance can be attributed to the synergistic interaction between the different carrier materials. • WH-CNC was extracted from wheat husk and exhibited superior properties than other straw resources. • Silane modification on CNC (Si-CNC) was conducted to regulate hydrophobicity and dispersibility. • A novel pesticide delivery system (PDS) was constructed using electrospinning technology and innovative formulations. • Utilization of CNC and Si-CNC facilitated the dispersion of PDS, thereby exerting a significant role in controlling release.