fig4

Figure 4. (A) Advanced anti-counterfeiting materials with reflective color, fluorescence, and CPL signals, each having three reversible states; insets show photographs under natural and 365 nm light using glasses with R-CPF and L-CPF filters; (B) Advanced information encryption/decryption utilizing fluorescence, reflective color, and CPL, demonstrating dynamic variations. Reproduced with permission from^[49]. Copyright 2022, Wiley-VCH. GmbH; (C) Hierarchical assembly for macroscopic, bio-inspired, chiral emissive CNC-SP nanostructures; (D) Chiral patterning via chemical treatment for controlling CPL handedness and chiral emission wavelength, facilitating enhanced security optical labeling through the utilization of quantum dot codes imprinted onto chiral emissive CNC-SP film via photochemical printing. Reproduced with permission from^[50]. Copyright 2021, Wiley-VCH. GmbH. CPL: Circularly polarized luminescence; CPF: circular polarized filter; CNC: cellulose nanocrystal; SP: spiropyran.