Cellulose Based Photonic Materials Displaying Direction Modulated Photoluminescence

Molíria V Santos; Fernando E Maturi; Édison Pecoraro; Hernane S Barud; Laís R Lima; Rute A S Ferreira; Luís D Carlos; Sidney J L Ribeiro

doi:10.3389/fbioe.2021.617328

Cellulose Based Photonic Materials Displaying Direction Modulated Photoluminescence

Front Bioeng Biotechnol. 2021 Mar 30:9:617328. doi: 10.3389/fbioe.2021.617328. eCollection 2021.

Authors

Molíria V Santos^{1

2}, Fernando E Maturi^{1

2}, Édison Pecoraro¹, Hernane S Barud³, Laís R Lima¹, Rute A S Ferreira², Luís D Carlos², Sidney J L Ribeiro¹

Affiliations

¹ Institute of Chemistry, São Paulo State University (UNESP), Araraquara, Brazil.
² Department of Physics, CICECO - Aveiro Institute of Materials, University of Aveiro, Aveiro, Portugal.
³ Biopolymers and Biomaterials Laboratory, University of Araraquara, Araraquara, Brazil.

Abstract

Photonic materials featuring simultaneous iridescence and light emission are an attractive alternative for designing novel optical devices. The luminescence study of a new optical material that integrates light emission and iridescence through liquid crystal self-assembly of cellulose nanocrystal-template silica approach is herein presented. These materials containing Rhodamine 6G were obtained as freestanding composite films with a chiral nematic organization. The scanning electron microscopy confirms that the cellulose nanocrystal film structure comprises multi-domain Bragg reflectors and the optical properties of these films can be tuned through changes in the relative content of silica/cellulose nanocrystals. Moreover, the incorporation of the light-emitting compound allows a complementary control of the optical properties. Overall, such findings demonstrated that the photonic structure plays the role of direction-dependent inner-filter, causing selective suppression of the light emitted with angle-dependent detection.

Keywords: bacterial cellulose nanocrystals; chiral nematic liquid crystal; iridescence; luminescence; modulated light emission; photonic materials; rhodamine 6G.