Multi-Stimuli-Responsive, Topology-Regulated, and Lignin-Based Nano/Microcapsules from Pickering Emulsion Templates for Bidirectional Delivery of Pesticides.

The increasing demand for improving pesticide utilization efficiency has prompted the development of sustainable, targeted, and stimuli-responsive delivery systems. Herein, a multi-stimuli-responsive nano/microcapsule bidirectional delivery system loaded with pyraclostrobin (Pyr) is prepared through interfacial cross-linking from a lignin-based Pickering emulsion template. During this process, methacrylated alkali lignin nanoparticles (LNPs) are utilized as stabilizers for the tunable oil-water (O/W) Pickering emulsion. Subsequently, a thiol-ene radical reaction occurs with the acid-labile cross-linkers at the oil-water interface, leading to the formation of lignin nano/microcapsules (LNCs) with various topological shapes. Through the investigation of the polymerization process and the structure of LNC, it was found that the amphiphilicity-driven diffusion and distribution of cyclohexanone impact the topology of LNC. The obtained Pyr@LNC exhibits high encapsulation efficiency, tunable size, and excellent UV shielding to Pyr. Additionally, the flexible topology of the Pyr@LNC shell enhances the retention and adhesion of the foliar surface. Furthermore, Pyr@LNC exhibits pH/laccase-responsive targeting against Botrytis disease, enabling the intelligent release of Pyr. The in vivo fungicidal activity shows that efficacy of Pyr@LNC is 53% ± 2% at 14 days postspraying, whereas the effectiveness of Pyr suspension concentrate is only 29% ± 4%, and the acute toxicity of Pyr@LNC to zebrafish is reduced by more than 9-fold compared with that of Pyr technical. Moreover, confocal laser scanning microscopy shows that the LNCs can be bidirectionally translocated in plants. Therefore, the topology-regulated bidirectional delivery system LNC has great practical potential for sustainable agriculture.

3D, eco-friendly metal-organic frameworks@carbon nanotube aerogels composite materials for removal of pesticides in water.

To alleviate the secondary risks of using metal-organic frameworks (MOFs) nanoparticles as adsorbent, a novel method of loading two MOFs (ZIF-8 or UiO66-NH2) on the carbon nanotube aerogels (MPCA) by in situ nucleation and growth of MOFs nanoparticles onto carbon nanotubes were developed. The prepared MOFs@MPCA aerogels were well characterized via SEM, TEM, EDS, FT-IR, XRD and XPS to reveal the microstructure and formation mechanism of MOF@MPCA. Besides, the hydrophilia, mechanical property and thermostability of MOF@MPCA were investigated. The results showed that MOF@MPCA had good hydrophilia, compression resilience and thermostability. The study on the ability to adsorb herbicides (chipton and alachlor) showed that the adsorption capacity of MOF@MPCA was stronger compared with single MOFs nanoparticles, which indicated that there was a synergistic effect between MOFs and MPCA. The equilibrium adsorption capacity of chipton adsorbed by UiO66-NH2@MPCA was 227.3 mg/g, and can be expediently reused for 5 cycles without a significant decrease in adsorption performance. Moreover, the results of biosafety experiments showed that MPCA can reduce the risk of MOFs nanoparticles leakage into the environment and accumulation in organisms. This work can provide a new research idea, which has potential applications to remove pollutants effectively and safely from the environment.