Nanoclay reinforced chitosan nanocomposites—state-of-the-art and technological imprints

Abstract

Nanoclays (layered silicates) have been applied as effective reinforcements for polymeric matrices. Chitosan has gained much research interest owing to its remarkable physical features and applications. It is an important amino-polysaccharide formed from deacetylated chitin. The processability, properties, and applicability of chitosan have been enhanced in the form of nanoclay nanocomposites/hybrids. The ensuing high-performance chitosan/nanoclay nanocomposites have been observed in high-tech applications of engineering to biomedical fields. This state-of-the-art comprehensive overview debates the potential of chitosan/nanoclay nanocomposites. In this regard, numerous design combinations of the chitosan, modified chitosan, and chitosan blends have been observed with nanoclays (montmorillonite, bentonite, laponite, cloisite, halloysite nanoclay). Chitosan/nanoclay nanocomposites have been investigated for toxic ions/dyes/biological pollutants removal, flame retardancy, packaging, and antimicrobial/biomedical applications. Consequently, chitosan blends with laolinite nanoclay revealed thermal stability of 400–600 °C and around 80% degradation. Modified chitosan blends filled with organo-modified montmorillonite had non-flammability properties according to V-0 rating and a decrease in total peak heat release and heat release rate. Chitosan nanocomposites with montmorillonite or cloisite nanoclay have been tested for Pb²⁺, Cr⁶⁺, Cu ²⁺, Zn²⁺, etc. ions and adsorption capacity >100–300 mg/g was observed. Moreover, chitosan/montmorillonite nanocomposites had an adsorption capacity of 80–500 mg/g for methylene blue and rhodamin-6 dyes. For antimicrobial packaging application, chitosan/halloysite depicted antibacterial efficiency of > 80% against E. coli and S. aureus bacterial strains. Enhanced characteristics rely on chitosan-nanoclay interactions, interface formation, synergistic effects, and structure-property relationships. The future of these nanomaterials in the technical field depends on new designs, facile fabrication, and overcoming underlying challenges toward nanoclay nanomaterials.

GRAPHICAL ABSTRACT

Keywords:

• Nanoclay
• chitosan
• nanocomposite
• flame retardancy
• packaging
• water purification
• biomedical

Disclosure statement

No potential conflict of interest was reported by the author(s).