Figure 1.

Schematic depiction of the presented work. (a) Illustration of the composite nanocellulose films with thermochromic pigment as the filler for CNF and CNC matrices. The CNF matrix is composed of highly entangled nanofibrils, whereas the CNC matrix is composed of short rod-like crystalline particles. (b) Depiction of the optical characterization of the sample films using a laser light source. Laser intensity was varied to generate a thermochromic transition in the films, rendering them transparent when locally heated above 31 °C via a laser. The shift in optical properties upon the thermochromic transition was studied in terms of transmission, forward and backward scattering, haze, and attenuation. (c) Description of the visible laser light interaction with the sample film and optical parameters measured in the current study.