Advanced Materials Interfaces (Feb 2024)

Polyelectrolyte Complexation of Chitosan and WS2 Nanotubes

  • Eimear Magee,
  • Fengwei Xie,
  • Stefano Farris,
  • Andrea Dsouza,
  • Chrystala Constantinidou,
  • Alla Zak,
  • Reshef Tenne,
  • Tony McNally

DOI
https://doi.org/10.1002/admi.202300501
Journal volume & issue
Vol. 11, no. 6
pp. n/a – n/a

Abstract

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Abstract The inclusion of tungsten disulphide nanotubes (WS2 NTs) in chitosan, plasticized with glycerol, facilitates the formation of a polyelectrolyte complex. The glycerol interrupts the intramolecular hydrogen bonding between chitosan chains allowing positively charged protonated amines of chitosan to form a complex with negatively charged oxygen ions chemisorbed to the tungsten atoms in defects. These interactions, with the unique mechanical and chemical properties of WS2 NTs, result in a chitosan film with superior properties relative to unfilled chitosan. Even at low WS2 NT loadings (≤1 wt%), the Young's modulus (E) increases by 59%, tensile strength (σ) by 40% and tensile toughness by 74%, compared to neat chitosan, without sacrificing ductility. Addition of highly dispersed WS2 NTs significantly improves the gas barrier properties of chitosan, with a 50% reduction in oxygen permeability, while the addition of both glycerol and WS2 NTs to chitosan effectively reduces the carbon dioxide permeability by 80% and the water vapor transmission rate by 90%. The intrinsic antimicrobial efficacy of chitosan against both Gram‐positive and Gram‐negative bacteria is enhanced on inclusion of WS2 NTs. Polyelectrolyte complexation of WS2 NTs and glycerol‐plasticized chitosan provides a cost‐effective, sustainable route to biodegradable films with desirable mechanical, gas barrier properties, and antimicrobial efficacy suitable for food packaging applications.

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