Redox‐Modulated Circularly Polarized Luminescence in Chiral Photonic Films Derived from Cellulose Nanocrystals and Polyoxometalate

Abstract

Achieving smart circularly polarized luminescence (CPL) materials with large luminescence dissymmetry factor (glum) is in high demand for potential technological applications in the chiroptical fields. Herein, a series of chiral photonic crystals (CPCs) derived from cellulose nanocrystals (CNCs) and photosensitive inorganic polyoxometalates (POMs) through an evaporation‐induced self‐assembly strategy are reported. The photonic bandgaps (PBGs) of CPC films are well regulated by controlling the amount of doped POMs, yielding the tunable right‐handed CPL emission with tailored glum. By locating the maximum emission peak of POMs at the center of the PBG of CPC films, the composite shows remarkable CPL performance with a |glum| value up to 0.53. Furthermore, the CPL can be reversibly switched on/off through a fluorescence resonance energy transfer (FRET) process controlled by alternate UV irradiation reduction and air oxidation. The CPC films hold the great promise as next‐generation chiroptical memory devices.

Design Strategies for Creating Cellulose-Based Nanomaterials with Tailored Optical Functionality

“…Chiroptical difference through (b 8 ) an L-CP and (b 11 ) an R-CP. Reproduced with permission from ref . Copyright 2016 Wiley-VCH.…”

“…Beside the nanoparticles, inorganic materials are also a practical candidate for creating nanocellulose composite films. Zhang et al 112 evaluate the circularly polarized luminescence of an inorganic polyoxometalates/CNCs composite film (Figure 10b). They confirmed that the photonic bandgaps of the composite films can be well regulated by controlling the amount of polyoxometalate filler, yielding tunable right-handed circularly polarized luminescence emission with tailored dissymmetry factor.…”

Achiral substituent- and stoichiometry-controlled inversion of supramolecular chirality and circularly polarized luminescence in ternary co-assemblies

“…10–15 This can be achieved by various external stimuli such as temperature, 16 solvents, 17 light, 18 metal ions, 19 pH, 20 and redox. 21 However, most of the reported supramolecular chirality inversions have focused on single-component self-assembled systems, 22–25 and both basic and application research studies of multiple-component co-assemblies with controllable chirality are still limited. The study of supramolecular chirality inversion in multicomponent systems not only benefits simulation of complicated biosystems, but also provides considerable meaning to the rational design and manufacture of advanced chiroptical materials.…”