Tuning the functional properties of lignocellulosic films by controlling the molecular and supramolecular structure of lignin

openaire: EC/H2020/720303/EU//Zelcor Funding Information: This work was funded by the Bio Based Industry Joint Undertaking under the European Union's Horizon 2020 research and innovation programme within the Zelcor project (under the grant number No 720303 ), part of the COFILI project (grant number D201550245 ) for AFM measurements funded by the Grand Est Region and the European FEDER Programme and the Lignoxyl project for EPR measurements supported by the Agence Nationale de la Recherche (ANR) through the Carnot Institutes 3BCAR ( www.3bcar.fr ) and Qualiment ( https://qualiment.fr/ ) (no. 3 no. 19-CARN-001-01 and no. 16-CARN 001-01). The EPR data in this manuscript were obtained using equipment supported jointly by the French National Ministry of Research (PPF IRPE), the “Fondation pour la Recherche Médicale” (FRM DGE20061007745), and the CNRS (Department of Chemistry and Life Sciences). The IJPB benefits from the support of the LabEx Saclay Plant Sciences-SPS (ANR-10-LABX-552 0040-SPS). Funding Information: This work was funded by the Bio Based Industry Joint Undertaking under the European Union's Horizon 2020 research and innovation programme within the Zelcor project (under the grant number No 720303), part of the COFILI project (grant number D201550245) for AFM measurements funded by the Grand Est Region and the European FEDER Programme and the Lignoxyl project for EPR measurements supported by the Agence Nationale de la Recherche (ANR) through the Carnot Institutes 3BCAR (www.3bcar.fr) and Qualiment (https://qualiment.fr/) (no. 3 no. 19-CARN-001-01 and no. 16-CARN 001-01). The EPR data in this manuscript were obtained using equipment supported jointly by the French National Ministry of Research (PPF IRPE), the ?Fondation pour la Recherche M?dicale? (FRM DGE20061007745), and the CNRS (Department of Chemistry and Life Sciences). The IJPB benefits from the support of the LabEx Saclay Plant Sciences-SPS (ANR-10-LABX-552 0040-SPS). Publisher Copyright: © 2021 The Authors Copyright: Copyright2021 Elsevier B.V., All rights reserved. This study investigated the relationships between lignin molecular and supramolecular structures and their functional properties within cellulose-based solid matrix, used as a model biodegradable polymer carrier. Two types of derivatives corresponding to distinct structuration levels were prepared from a single technical lignin sample (PB1000): phenol-enriched oligomer fractions and colloidal nanoparticles (CLP). The raw lignin and its derivatives were formulated with cellulose nanocrystals or nanofibrils to prepare films by chemical oxidation or pressure-assisted filtration. The films were tested for their water and lignin retention capacities, radical scavenging capacity (RSC) and antimicrobial properties. A structural investigation was performed by infrared, electron paramagnetic resonance spectroscopy and microscopy. The composite morphology and performance were controlled by both the composition and structuration level of lignin. Phenol-enriched oligomers were the compounds most likely to interact with cellulose, leading to the smoothest film surface. Their RSC in film was 4- to 6-fold higher than that of the other samples. The organization in CLP led to the lowest RSC but showed capacity to trap and stabilize phenoxy radicals. All films were effective against S. aureus (gram negative) whatever the lignin structure. The results show the possibility to tune the performances of these composites by exploiting lignin multi-scale structure.