Thermoresponsive lignin-based polyelectrolyte complexes for the preparation of spherical nanoparticles: Application in pesticide encapsulation

• Published in: International journal of biological macromolecules Vol. 288; p. 138623
• Main Authors: Yin, Yaqing, Qin, Shanjia, Deng, Shuai, Li, Zhili, Tang, Aixing, Li, Qunliang, Liao, Dankui, Liu, Youyan
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.02.2025
• Subjects: drugs; electrolytes; encapsulation; lignin; Lignin - chemistry; Lignin nanoparticles; Nano-pesticides; nanoparticles; Nanoparticles - chemistry; Nanoparticles - ultrastructure; Particle Size; pesticides; Pesticides - chemistry; Polyelectrolyte complexes; Polyelectrolytes - chemistry; porosity; Temperature; Thermally induced self-assembly; Viscoelastic effect; Viscoelastic effect; Thermally induced self-assembly; Nano-pesticides; Polyelectrolyte complexes; Lignin nanoparticles
• ISSN: 0141-8130; 1879-0003; 1879-0003
• DOI: 10.1016/j.ijbiomac.2024.138623

Lignin-based nanoparticles hold tremendous potential for various applications. This study proposes an innovative and straightforward method for the synthesis of spherical hybrid lignin nanoparticles (hy-LNPs) with a tunable pore structure. The approach involves blending lignin with 20 wt% polyamide-epichlorohydrin, resulting in the formation of thermoresponsive lignin-based polyelectrolyte complexes. Upon heating to 80 °C, the complexes undergo self-assembly into uniform spherical nanoparticles, achieving a minimum polydispersity index (PDI) as low as 0.08. The study reveals that nanoparticle formation involves simultaneous collapse and growth. During collapse, hy-LNPs become more compact, increasing their elastic behavior and inhibiting particle coalescence, which is critical for the formation of stable, low-dispersibility nanoparticles. Contrary to the expectation that collapse would reduce pore size, the average pore size of the hy-LNPs increases from 24.9 nm to 35.8 nm, likely due to the coalescence of smaller pores into larger ones. Furthermore, this straightforward method was applied to encapsulation β-cypermethrin, achieving an encapsulation efficiency of up to 95 % and reducing the release rate in an ethanol-water solution from 90.6 % to 63.1 % over 5 h. The thermoresponsive lignin-based polyelectrolyte complexes provide a new pathway for the controlled preparation of lignin-based nanoparticles. These nanoparticles demonstrate promising potential for applications such as drug encapsulation. [Display omitted] •Preparation of thermoresponsive lignin polyelectrolyte complexes by blending•Lignin-based nanoparticles prepared by thermally induced self-assembly at 80 °C•Spherical nanoparticles with a minimum PDI of 0.08 and tunable pore structure•Thermally induced interfacial deposition for β-cypermethrin encapsulation•Growth kinetics of nanoparticles subject to viscoelastic effects