Multicolor Fluorescent Hydrogels Based on CaZnOS Phosphors for Anticounterfeiting Applications.

Area of Science:

• Materials Science
• Inorganic Chemistry
• Polymer Science

Background:

• Calcium zinc oxysulfide (CaZnOS) is an inorganic phosphor with efficient and stable luminescence, suitable for lighting, display, and information encryption.
• CaZnOS's unique excitation and emission properties, coupled with its hydrophilicity and water resistance, make it ideal for integration into hydrogel systems.

Purpose of the Study:

• To develop a strategy for creating fluorescent hydrogels by combining CaZnOS inorganic phosphors with hydrogel materials.
• To demonstrate the tunable luminescence of these hydrogels by adjusting doping concentrations for anticounterfeiting applications.

Main Methods:

• Utilized poly(vinyl alcohol) (PVA) as a matrix to stabilize CaZnOS phosphors.
• Incorporated Mn²⁺ and Bi³⁺ dopants into CaZnOS hosts to control luminescence color.
• Prepared fluorescent hydrogels with adjustable color ranges (orange, red, dark red, blue).

Main Results:

• Successfully prepared fluorescent hydrogels by embedding stabilized CaZnOS phosphors within a PVA matrix.
• Demonstrated that doping concentrations of Mn²⁺ and Bi³⁺ precisely control the hydrogel's emission color.
• Showcased the potential for creating custom shapes and arrays of these hydrogels for encrypted information display.

Conclusions:

• The developed fluorescent hydrogels offer a versatile platform for anticounterfeiting and information encryption.
• This strategy enables the creation of diverse fluorescent hydrogels with enhanced security features.
• The tunable luminescence and customizable formats position these materials for high-performance anti-counterfeiting solutions.