Synthetic Plant Cuticle Coating as a Biomimetic Moisture Barrier Membrane for Structurally Colored Cellulose Films

• DOI: 10.1002/admi.202202112
• Publication Date: 2023-01-21T03:30:17Z
• Authors: Prasaanth Ravi An...; Shuvra Singha; Debashree Banerjee; Magnus P Jonsson; Mikael S. Hedenqvist; Anna J. Svagan
• Keywords: Permeance; Colored; Cuticle (hair); Structural Coloration; Gloss (optics)

Abstract Photonic films based on cellulose nanocrystals (CNCs) are sustainable candidates for sensors, structurally colored radiative cooling, and iridescent coatings. Such CNC‐based possess a helicoidal nanoarchitecture, which gives selective reflection with the polarization of incident light. However, due to hygroscopic nature CNCs, structural material changes may be irreversibly damaged at high relative humidity. Thus, moisture protection is essential in such settings. In this work, protected bioinspired synthetic plant cuticle; strategy already adopted by real plants. The protective cuticle layers altered reflected colors some extent, but more importantly, they significantly reduced water vapor permeance than two orders magnitude, from 2.1 × 10 7 (pristine CNC/GLU film) 12.3 4 g µm m −2 day −1 atm (protected film). This expands time window operation