Mind the Microgap in Iridescent Cellulose Nanocrystal Films

Susete N Fernandes; Pedro L Almeida; Nuno Monge; Luis E Aguirre; Dennys Reis; Cristiano L P de Oliveira; António M F Neto; Pawel Pieranski; Maria H Godinho

doi:10.1002/adma.201603560

Mind the Microgap in Iridescent Cellulose Nanocrystal Films

Adv Mater. 2017 Jan;29(2). doi: 10.1002/adma.201603560. Epub 2016 Nov 9.

Authors

Susete N Fernandes¹, Pedro L Almeida^{1

2}, Nuno Monge^{1

3

4}, Luis E Aguirre¹, Dennys Reis⁵, Cristiano L P de Oliveira⁵, António M F Neto⁵, Pawel Pieranski⁶, Maria H Godinho¹

Affiliations

¹ i3N/CENIMAT, Department of Materials Science, Faculty of Science and Technology, Universidade NOVA de Lisboa, Campus de Caparica, 2829-516, Caparica, Portugal.
² Área Departamental de Física, Instituto Superior de Engenharia de Lisboa, Instituto Politécnico de Lisboa, 1959-007, Lisbon, Portugal.
³ CIAUD, Faculty of Architecture, University of Lisbon, Rua Sá Nogueira, Pólo Universitário, Alto da Ajuda, 1349-055, Lisbon, Portugal.
⁴ CIED, Lisbon School of Education, Polytechnic Institute of Lisbon, Campus de Benfica do IPL, 1549-003, Lisbon, Portugal.
⁵ Instituto de Física, Universidade de São Paulo, Rua do Matão, 1371, 05508-090, São Paulo, SP, Brazil.
⁶ Laboratoire de Physique des Solides, UMR 8502, Université Paris-Sud, Bât. 510, 91405, Orsay, France.

PMID: 27862372
DOI: 10.1002/adma.201603560

Abstract

A new photonic structure is produced from cellulose nanocrystal iridescent films reflecting both right and left circularly polarized light. Micrometer-scale planar gaps perpendicular to the films' cross-section between two different left-handed films' cholesteric domains are impregnated with a nematic liquid crystal. This photonic feature is reversibly tuned by the application of an electric field or a temperature variation.

Keywords: cellulose nanocrystals; liquid crystals; mimicking Plusiotis resplendens cuticles; photonics.