1. What is structural color?

Structural color is a color formed by the interference, reflection and scattering of light by In nature, the gorgeous colors such as peacock feathers, butterfly wings, beetle shells, etc. originate from structural colors. the material's micro-nano structure , and does not rely on traditional dyes.
Compared with traditional pigments, nanocellulose structural colors have the advantages of high brightness, non-fading, environmental protection and sustainability , and have become a hot topic in materials science in recent years.

2. The relationship between nanocellulose and structural color

Nanocellulose is a green and environmentally friendly material derived from natural cellulose, with a diameter of only 3–50 nm , and has high strength, light weight and self-assembly properties. When they are concentrated and arranged under appropriate conditions, a chiral nematic liquid crystal structure ( Chiral Nematic Phase ) can be formed. 。
This spiral arrangement will produce Bragg reflections on visible light , thus presenting colors of different wavelengths. By regulating nanocellulose structural color preparation methods (such as changing concentration, ionic strength, drying rate), gradient colors from blue to red can be obtained.

3. Advantages of nanocellulose structural color

Green and environmentally friendly : Nanocellulose is a natural source of environmentally friendly material , does not rely on chemical dyes, and is in line with the trend of sustainable development.

Color Stable : Compared to traditional dyes, nanocellulose structural colors do not fade due to light or time.

Strong controllability : By adjusting the pitch, humidity or additives of the liquid crystal, the color can be flexibly controlled.

Lightweight and transparent : Suitable for the preparation of films, clear coatings or composites.

Excellent biocompatibility : suitable for use in food, cosmetics, and medical materials.

4. Application fields of nanocellulose structural color

Anti-counterfeiting and encryption : Based on the anti-counterfeiting characteristics of nanocellulose , it can be used in currency, anti-counterfeiting labels and high-end packaging, and is difficult to imitate.

Green coatings and pigments : Use nanocellulose pigments to replace chemical dyes and are used in automotive coatings, building decorations, and environmentally friendly inks.

Optics and Sensors : Preparation of nanocellulose photonic materials , used in optical filters, humidity sensors and pH monitoring.

Food and cosmetics : As a replacement for nanocellulose natural pigment , it is used in lipstick, eyeshadow and food packaging, safe and environmentally friendly.

Intelligent coating : Through nanocellulose structural color coating , the intelligent function of color visible with the change of the environment is achieved.

5. Future development and challenges

Although nanocellulose structural colors show great potential, there are still some challenges:

Preparation consistency : The stability of liquid crystal orientation must be ensured during large-scale production.

Environmental sensitivity : Humidity and temperature may affect color stability.

Industrialization breakthrough : In the future, it is expected to combine polymers, graphene and other materials to develop high-performance nanocellulose coatings and composite materials.