Tunable electrical properties of lignin: morphology-dependent ionic conduction in Kraft and organosolv-derived materials

Lignin, a by-product of the pulp and paper industry and biomass processing, features a chemical structure rich in aromatic rings and functional groups such as ethers, alcohols, phenols and carboxyls, as well as electrical properties that can make it a promising material for various uses in a waste-t...

Full description

Saved in:
Bibliographic Details
Main Authors: Rosarita D’Orsi, Sebastiano De Stefano, Ofelia Durante, Marianna Ambrico, Domenico Aceto, Paolo Francesco Ambrico, Nadia Martucciello, Filippo Giubileo, Sandra Rivas, Alessandra Operamolla, Antonio Di Bartolomeo
Format: Article
Language:English
Published: IOP Publishing 2025-01-01
Series:JPhys Materials
Subjects:
Online Access:https://doi.org/10.1088/2515-7639/adf94c
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Lignin, a by-product of the pulp and paper industry and biomass processing, features a chemical structure rich in aromatic rings and functional groups such as ethers, alcohols, phenols and carboxyls, as well as electrical properties that can make it a promising material for various uses in a waste-to-application approach. This study investigates the composition, morphology, and DC electrical behavior of three distinct lignins: two derived from the Kraft extraction process and differing in their post-treatment ( L 1, L 2) and one ( L 3) extracted from Cynara cardunculus using an ethanolic organosolv process catalyzed by aqueous ammonia. Morphological analyses reveal that L 3 exhibits features intermediate between the smooth structure of L 1 and the fibrillar nanostructure of L 2. When used as the active layer in interdigitated devices, their I – V characteristics on a semilogarithmic plot exhibit butterfly-shaped curves, showing strong dependence on temperature and pressure. L 1 and L 3 are similar, while L 2 differs substantially, reflecting variations in functional group density and morphology. The low electrical conductivity, the dependence on morphology, and the hysteretic electrical behavior suggest that ionic conduction plays a significant role in the overall charge transport, with conductivity scaling as L 2 > L 3 > L 1 and increasing with pressure and temperature. Morphology-dependent adsorption of air molecules primarily enhances ionic conduction, and the good fit to the Arrhenius model suggests that charge transport occurs via carrier hopping across localized energy barriers. This study highlights the diverse electrical properties achievable with lignins with different extraction histories and their tunability through processing methods, enabling tailoring to specific applications and making lignin a versatile and sustainable material for electronic devices.
ISSN:2515-7639