Angular-Independent Structural Colors of Clay Dispersions
Nobuyoshi Miyamoto1, Shinya Yamamoto1
1Department of Life, Environment, and Applied Chemistry, Fukuoka Institute of Technology, 3-30-1, Wajiro-Higashi, Higashi-ku, Fukuoka 811-0295, Japan.
ACS Omega
|February 28, 2022
Summary
Clay mineral nanosheets create structural colors independent of viewing angle after removing salts. Color is tunable by adjusting nanosheet size and concentration, offering a low-cost, eco-friendly material for diverse applications.
Area of Science:
- Materials Science
- Colloid Science
- Nanotechnology
Background:
- Structural color arises from light interference in periodic nanostructures.
- Clay mineral nanosheets offer potential for creating tunable optical materials.
- Existing structural color systems often exhibit significant angular dependence.
Purpose of the Study:
- To investigate the structural color properties of clay mineral nanosheet colloids.
- To explore the tunability of color based on nanosheet characteristics.
- To demonstrate the angular-independent nature of the observed structural color.
Main Methods:
- Preparation of clay mineral nanosheet colloids.
- Desalting process to induce structural color.
- Naked-eye observation for color assessment.
- UV-visible reflectance spectroscopy for quantitative analysis.
- Systematic variation of nanosheet size and concentration.
Main Results:
- Clay mineral nanosheet colloids exhibited distinct structural colors upon desalting.
- The structural color was tunable by altering average nanosheet size and concentration.
- A low angular dependence of the structural color was observed and confirmed.
- This represents the first reported instance of angular-independent structural color in a nanosheet system.
Conclusions:
- Desalted clay mineral nanosheet colloids provide an environmentally benign and cost-effective source of structural color.
- The tunable and angular-independent nature of the color makes them suitable for various applications.
- This work opens new avenues for developing advanced optical materials from abundant clay minerals.
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