Title:Recent Progress on Photonic Cellulose Nanocrystal Films for Sensing Applications
Volume: 22
Issue: 2
Author(s): Zhijie Deng, Tao Tao, Jianzhong Yuan and Caichao Wan*
Affiliation:
- College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, PR China
Keywords:
Nanocellulose, cellulose nanocrystals, cholesteric liquid crystal, structural color, film, sensing.
Abstract: Cellulose nanocrystals (CNCs) have triggered considerable research interest in the
last few years owing to their unique optical, biodegradation, and mechanical behavior. Herein,
recent progress on the sensing application of photonic CNC films is summarized and discussed
based on the analyses of the latest studies. We briefly introduce the three approaches for preparing
CNCs: mechanical treatment, acid hydrolysis, and enzymatic hydrolysis, recapitulating
their differences in preparation and properties. Then, when the aqueous suspension of cellulose
nanocrystals (CNCs) reaches a specific concentration, it will self-assemble to form a lefthanded
nematic liquid crystal structure, and this structure can be maintained in films after
water evaporation, which has strong photonic crystal properties. The periodic layered structure
in the film interferes and diffracts with light, showing a rainbow color. Photonic CNC composites
that combine CNCs and functional materials have good properties and broad prospects.
Finally, we highlight the advanced applications of photonic CNC films, including mechanical
sensing, thermal sensing, and humidity sensing. The prospects and ongoing challenges of photonic
CNC films were summarized.
