Multilayer photonic films based on interlocked chiral-nematic cellulose nanocrystals in starch/chitosan

• Published in: Carbohydrate polymers 2022-01, Vol.275, p.118709-118709, Article 118709
• Main Authors: Babaei-Ghazvini, Amin, Acharya, Bishnu, Korber, Darren R.
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Carbohydrate Conformation; Carbohydrate films; Cellulose - chemistry; Cellulose - pharmacology; Cellulose nanocrystals; Chitosan; Chitosan - chemistry; Chitosan - pharmacology; Escherichia coli - drug effects; Microbial Sensitivity Tests; Nanoparticles - chemistry; Photonic biodegradable materials; Photons; Pseudomonas aeruginosa - drug effects; Salmonella enteritidis - drug effects; Staphylococcus aureus - drug effects; Starch; Starch - chemistry; Starch - pharmacology
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2021.118709

In this study, a new approach to employ and control cellulose nanocrystal (CNC) chiral nematic structure as a biodegradable, intelligent material was investigated. Tuned CNC self-assembled films were interlocked between two layers of citric acid, cross-linked starch/chitosan (1:1) films through the solvent casting process. This method increased the mechanical properties of produced films and created a selective reflection band from UV to near-IR depending on the helical pitch of the chiral nematic CNC layer. The features of these intelligent films have potential for different applications, from UV protective packaging to biomedical uses. The water vapor permeability (WVP) of the produced films decreased considerably by adding a CNC layer into the cross-linked starch/chitosan structure. Also, the WVP was different for the different helical pitches of the CNC layer. The starch/chitosan (outer layer) also showed a remarkable antibacterial property against E. coli, P. fluorescens, S. Enteritidis, and S. aureus which could be useful for biomedical applications or antibacterial packaging. [Display omitted] •A new approach to employ and control cellulose nanocrystal (CNC) chiral nematic structure is investigated.•The films showed different light reflection specially in the UV range that can be used as a UV protecting films.•Better mechanical properties and lower WVP with CNC layer have been obtained.•The films demonstrated remarkable antibacterial properties.