Self-Healable, Solvent Response Cellulose Nanocrystal/Waterborne Polyurethane Nanocomposites with Encryption Capability

Authors：Xue, Rui; Zhao, Hui^*; An, Ze-Wei; Wu, Wei; Jiang, Yan; Li, Peng; Huang, Chong-Xing; Shi, Dean; Li, Robert K. Y.; Hu, Guo-Hua; Wang, Shuang-Fei

Source：ACS Nano, 2023, 17(6): 5653-5662.

DOI：10.1021/acsnano.2c11809

• cellulose nanocrystal
• waterborne polyurethane
• chiral nematic
• self-healing
• flexible photonic materials
• solvents response
• anticounterfeiting

Cellulose nanocrystal (CNC)-based chiral nematic structure is widely used in stimulus response and sensing. A popular area of research is enhancing the mechanical characteristics and environmental adaptability of chiral nematic materials. In this paper, a flexible photonic film with selfhealing ability (FPFS) was prepared by combining waterborne polyurethane containing dynamic covalent disulfide bonds (SSWPU) with CNC. The results found that the FPFS showed excellent toughness under the action of stretching, bending, twisting, and folding. The FPFS exhibited an amazing selfhealing efficiency, which can be self-healed within 2 h at room temperature. Moreover, the FPFS could respond immediately and produce reversible color change when it was soaked in typical solvents. In addition, when ethanol was used as ink to paint on the FPFS, a visible pattern only under polarized light was formed. This study offers fresh perspectives in the areas of self-healing, biological anticounterfeiting, solvent response, and flexible photonic materials.

• Institution
  GuangXi University