Mechanical tough and multicolor aggregation-induced emissive polymeric hydrogels for fluorescent patterning.

Area of Science:

• Materials Science
• Polymer Chemistry
• Supramolecular Chemistry

Background:

• Aggregation-induced emissive fluorogens (AIEgens) are crucial for fluorescent polymeric hydrogels (FPHs).
• Existing AIE-active FPHs often exhibit single-color fluorescence and lack mechanical robustness.
• Developing multicolor and mechanically strong AIE-active hydrogels remains a significant challenge.

Purpose of the Study:

• To synthesize a novel AIE-active monomer for creating mechanically tough and multicolor FPHs.
• To investigate the mechanism of tunable multicolor emission in the hydrogel matrix.
• To demonstrate the potential applications of these advanced hydrogels.

Main Methods:

• Synthesis of a methyl picolinate-substituted 1,8-naphthalimide (MP-NI) AIE monomer.
• Incorporation of MP-NI into a dually cross-linked alginate polymer network.
• Utilizing lanthanide ions (Eu³⁺ and Tb³⁺) for sensitization of red and green fluorescence via antenna effect.

Main Results:

• The synthesized MP-NI monomer exhibits intense aggregation-induced blue emission due to its propeller-shaped conformation.
• The resulting hydrogels display tunable multicolor fluorescence (blue, green, red) by incorporating MP-NI and lanthanide ions.
• The fabricated hydrogels demonstrate high mechanical strength, sustaining stress up to 1 MPa.
• Arbitrary multicolor fluorescent patterns were successfully written using the hydrogels, showcasing their potential for display and encryption.

Conclusions:

• Novel AIE-active monomer enables the fabrication of mechanically robust, multicolor fluorescent polymeric hydrogels.
• The synergistic combination of AIEgens and lanthanide ions provides a versatile platform for tunable fluorescence.
• These advanced hydrogels hold promise for applications in smart displays, information encryption, and beyond.