Biodegradable and Insoluble Cellulose Photonic Crystals and Metasurfaces

• Published in: ACS nano Vol. 14; no. 8; pp. 9502 - 9511
• Main Authors: Caligiuri, Vincenzo, Tedeschi, Giacomo, Palei, Milan, Miscuglio, Mario, Martin-Garcia, Beatriz, Guzman-Puyol, Susana, Hedayati, Mehdi Keshavarz, Kristensen, Anders, Athanassiou, Athanassia, Cingolani, Roberto, Sorger, Volker J, Salerno, Marco, Bonaccorso, Francesco, Krahne, Roman, Heredia-Guerrero, José Alejandro
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 25.08.2020
• Subjects: Cellulose; Glass; Optics and Photonics; Photons; Spectrum Analysis, Raman; biodegradability; cellulose; SERS; cocoa agro-waste; plasmonic colors; water insolubility photonic crystals; meta-structures
• ISSN: 1936-0851; 1936-086X
• DOI: 10.1021/acsnano.0c03224

The replacement of plastic with eco-friendly and biodegradable materials is one of the most stringent environmental challenges. In this respect, cellulose stands out as a biodegradable polymer. However, a significant challenge is to obtain biodegradable materials for high-end photonics that are robust in humid environments. Here, we demonstrate the fabrication of high-quality micro- and nanoscale photonic and plasmonic structures via replica molding using pure cellulose and a blended version with nonedible agro-wastes. Both materials are biodegradable in soil and seawater according to the ISO 17556 standard. The pure cellulose films are transparent in the vis–NIR spectrum, having a refractive index similar to glass. The microstructured photonic crystals show high-quality diffractive properties that are maintained under extended exposure to water. Nanostructuring the cellulose transforms it to a biodegradable metasurface manifesting bright structural colors. A subsequent deposition of Ag endowed the metasurface with plasmonic properties used to produce plasmonic colors and for surface-enhanced Raman scattering.