Lateral Gradient Ambidextrous Optical Reflection in Self-Organized Left-Handed Chiral Nematic Cellulose Nanocrystals Films

Micro assembly strategies for enhancing solid-state emission of cellulose nanocrystals and application in photoluminescent inks

Crystalline cellulose exhibits photoluminescent properties, making it ideal for solid-state emission through properly assembling crystal arrays. However, assembling in water or other polar solvents poses structural integrity issues. To address this, a micro-assembly method is proposed. Cellulose nanocrystals (CNCs) are organized within a sub-micrometer-sized ZIF-8 metal-organic framework and coated with TiO2. Notably, the assembly within ZIF-8 improves the CNCs' emission quantum yield to 37.8 %. The bonding between ZIF-8 and CNCs relies on electrostatic interactions and hydrogen bonds, which are sensitive to polar solvents. Yet, the sturdy coordination bonds between TiO2 and ZIF-8 enhance resistance. Solvent-resistance tests confirm that TiO2 prevents CNC assembly breakdown, resulting in only an 8.0 % drop in photoluminescent intensity in an alkaline solution after 24 h, compared to 33 % without the coating. For anti-counterfeiting purposes, TiO2@ZIF-8@CNC is combined with a polymer matrix, allowing information to be revealed under specific wavelengths using screen-printed labels.

Nature-Inspired Chiral Structures: Fabrication Methods and Multifaceted Applications

Diverse chiral structures observed in nature find applications across various domains, including engineering, chemistry, and medicine. Particularly notable is the optical activity inherent in chiral structures, which has emerged prominently in the field of optics. This phenomenon has led to a wide range of applications, encompassing optical components, catalysts, sensors, and therapeutic interventions. This review summarizes the imitations and applications of naturally occurring chiral structures. Methods for replicating chiral architectures found in nature have evolved with specific research goals. This review primarily focuses on a top-down approach and provides a summary of recent research advancements. In the latter part of this review, we will engage in discussions regarding the diverse array of applications resulting from imitating chiral structures, from the optical activity in photonic crystals to applications spanning light-emitting devices. Furthermore, we will delve into the applications of biorecognition and therapeutic methodologies, comprehensively examining and deliberating upon the multifaceted utility of chiral structures.

Synthesis, Properties, Applications, and Future Prospective of Cellulose Nanocrystals

The exploration of nanocellulose has been aided by rapid nanotechnology and material science breakthroughs, resulting in their emergence as desired biomaterials. Nanocellulose has been thoroughly studied in various disciplines, including renewable energy, electronics, environment, food production, biomedicine, healthcare, and so on. Cellulose nanocrystal (CNC) is a part of the organic crystallization of macromolecular compounds found in bacteria's capsular polysaccharides and plant fibers. Owing to numerous reactive chemical groups on its surface, physical adsorption, surface grating, and chemical vapor deposition can all be used to increase its performance, which is the key reason for its wide range of applications. Cellulose nanocrystals (CNCs) have much potential as suitable matrices and advanced materials, and they have been utilized so far, both in terms of modifying and inventing uses for them. This work reviews CNC's synthesis, properties and various industrial applications. This review has also discussed the widespread applications of CNC as sensor, acoustic insulator, and fire retardant material.

Cellulose Nanocrystal Films with NIR-II Circularly Polarized Light for Cancer Detection Applications

Near-infrared circularly polarized light is attractive for wide-ranging applications. However, high-performance near-infrared circularly polarized light is challenging to realize. Here, we show that left-handed chiral photonic cellulose nanocrystal (CNC) films produced from ultrasonicated suspensions enable right-handed circularly polarized luminescence with a dissymmetry factor of -0.330 in the second near-infrared window (NIR-II). We present a theoretical analysis of the adverse effect of structural defects and luminescence intensity heterogeneity on the right-handed circularly polarized luminescence g_lum inside the bandgap and the occurrence of left-handed circularly polarized luminescence at the band edges. We demonstrate the potential of the chiral photonic CNC films with NIR-II circularly polarized light for cancer cell discrimination. The present work identifies key scientific questions in CNC-based circularly polarized luminescence materials research.