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

Int J Biol Macromol. 2021 Jun 30:181:136-149. doi: 10.1016/j.ijbiomac.2021.03.081. Epub 2021 Mar 23.

Abstract

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.

Keywords: Antioxidant and antibacterial properties; Cellulose nanocomposite; Colloid lignin particles (CLP); Electron paramagnetic resonance; Phenoxy radicals; Protobind 1000.

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Antioxidants / pharmacology
  • Escherichia coli / drug effects
  • Free Radical Scavengers / chemistry
  • Intercellular Signaling Peptides and Proteins / metabolism
  • Lignin / chemistry*
  • Microbial Sensitivity Tests
  • Microscopy, Atomic Force
  • Nanoparticles / chemistry
  • Nanoparticles / ultrastructure
  • Phenols / chemistry
  • Spectroscopy, Fourier Transform Infrared
  • Staphylococcus aureus / drug effects
  • Suspensions
  • Water / chemistry

Substances

  • Anti-Bacterial Agents
  • Antioxidants
  • Free Radical Scavengers
  • Intercellular Signaling Peptides and Proteins
  • Phenols
  • Suspensions
  • Water
  • lignocellulose
  • phenoxy radical
  • Lignin