Building a biodegradable rainbow

An easy way to pattern the surface of cellulose so that it forms a colourful photonic crystal has been developed.

As society looks for sustainable and eco-friendly alternatives to common plastics, cellulose is attracting increasing interest. The planet’s most abundant biopolymer, cellulose is readily available, cheap and biodegradable. It can also be processed into cellulose nanoparticles, which have many applications.

Although cellulose typically scatters light diffusely — the property that makes paper white — nanocellulose can incorporate microstructural features that interact with light to give it colour. Structural colour also gives some butterfly wings their iridescence, for example.

Researchers from the Spanish National Research Council (ICMAB-CSIC) have shown that a technology called soft nanoimprinting lithography can easily create these features in a cellulose derivative. The team could stamp a submicrometre scale pattern onto a hot hydroxypropyl cellulose surface, forming free-standing photonic crystals that produce a rainbow of colours.

The crystals could be used for various photonic and plasmonic applications.

© Wolfgang Kaehler/Getty

Hydroxypropyl cellulose photonic architectures by soft nanoimprinting lithography

Nature Photonics 12, 343–348 (2018). DOI: 10.1038/s41566-018-0152-1

Other articles highlighted in Nature Index

Phonon Engineering in Twinning Superlattice Nanowires

Nano Letters. DOI: 10.1021/acs.nanolett.9b01775

Stability and nature of the volume collapse of ε-FeO under extreme conditions

Nature Communications. DOI: 10.1038/s41467-018-06966-9

Giant topological Hall effect in correlated oxide thin films

Nature Physics. DOI: 10.1038/s41567-018-0307-5

Influence of the magnetic field on the stability of the multiferroic conical spin arrangement of Mn0.80Co0.20WO4

Physical Review B. DOI: 10.1103/physrevb.98.134430

More information:

https://www.natureindex.com/article/10.1038/s41566-018-0152-1#highlight