1. Production of highly antioxidant lignin nanoparticles from a hardwood technical lignin.
- Author
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Pavaneli G, da Silva TA, Zawadzki SF, Sassaki GL, de Freitas RA, and Ramos LP
- Subjects
- Lignin chemistry, Solvents, Water, Antioxidants chemistry, Nanoparticles chemistry
- Abstract
Eucalypt kraft lignin isolated in a LignoBoost™ pilot plant was characterized by GC-MS, ICP-OES, DSC, HPSEC,
31 P NMR, and HSQC 2D-NMR to be used without any further processing to produce lignin nanoparticles (LNPs) by nanoprecipitation. Tetrahydrofuran (THF) was used as a solvent, and water as a non-solvent. Microscopic analysis (TEM) showed that LNPs were regularly spherical with some hollow particles dispersed in-between, and sizes were tunable by changing the solvent dripping rate onto the non-solvent. LNP particle sizes had a bimodal distribution, with the largest population having an average apparent hydrodynamic diameter ranging from 105.6 to 75.6 nm. Colloidal dispersions of LNPs in water presented good stability in different dilutions without significant size changes upon storage at pH close to neutral for as long as 45 days. Zeta potentials around -40 mV were obtained for LNP suspensions at pH ranging from 7 to 9. The high carbohydrate content (circa 10 % on a dry basis, mostly xylans) of the lignin precursor did not interfere in LNP formation, whose antioxidant activity was expressive as demonstrated by the ABTS assay at pH 7.4, with an EC50 of 4.04 μg mL-1 . Also, the Trolox® equivalent antioxidant capacity (TEAC) of LNPs reached 1.90 after 40 min reaction time., Competing Interests: Declaration of competing interest Luiz Pereira Ramos reports financial support was provided by National Council for Scientific and Technological Development. Giuliana Pavaneli reports financial support was provided by Coordination of Higher Education Personnel Improvement. Nothing to declare., (Copyright © 2023 Elsevier B.V. All rights reserved.)- Published
- 2024
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