Co‐Assembly of Cellulose Nanocrystals and Silk Fibroin into Photonic Cholesteric Films
Name
adsu.202000272.pdf
Description
Published version
Size
1.92 MB
Format
Adobe PDF
Checksum (MD5)
411ded1e4e66d99123af1b5fab4b2256
Author(s)
Guidetti, Giulia
Sun, Hui
Ivanova, Alesja
Marelli, Benedetto
Frka‐Petesic, Bruno
Date Issued
March 2021
Journal
Advanced Sustainable Systems
Publisher
Wiley
Citation
Guidetti, G., Sun, H., Ivanova, A., Marelli, B., Frka-Petesic, B., Co-Assembly of Cellulose Nanocrystals and Silk Fibroin into Photonic Cholesteric Films. Adv. Sustainable Syst. 2021, 5, 2000272.
Version
Final published version
Abstract
Controlled self-assembly of bio-sourced nanocolloids is of high importance for the development of sustainable and low-cost functional materials but controlling nanocomposite fabrication with both satisfactory optical properties and composition remains challenging. Silk fibroin (SF) and cellulose nanocrystals (CNCs) have independently demonstrated their ability to produce high-quality photonic materials, in part due to their low absorbance and their transparency in the visible range. While SF is able to replicate inverse structures by high-resolution nano-templating, CNCs can spontaneously assemble into cholesteric liquid crystalline structures that are retained upon solvent evaporation, yielding photonic films. In this work, the conditions of successful co-assembly of regenerated SF, extracted from silkworm silk, with CNCs extracted from cotton, are investigated. Their co-assembly is investigated for various relative concentration ratios and pH, combining polarized optical microscopy and spectroscopy, SEM, and other characterization techniques (XRD, ATR-FTIR, TGA). The appearance of photonic properties is observed when CNC and SF are assembled at pH ≥ 4.15, highlighting the importance of suppressing attractive electrostatic interactions between the two species for an organized structure to emerge. Beyond its fundamental motivations for colloidal co-assembly with structural proteins, this work is relevant to design sustainable optical materials compatible with food packaging coatings and edible coloring pigments.
MIT Department
Massachusetts Institute of Technology. Department of Civil and Environmental Engineering
Terms of Use
Creative Commons Attribution 4.0 International license
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1002/ADSU.202000272
