In Situ Hofmeister Effect in Polymer Solution by Hydrophobic I₃^- for Multifunctional Hydrogel

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Multifunctional hydrogels are crucial for advanced applications like flexible electronics, energy devices, and sensors.
• Conventional synthesis of these hydrogels is often complex, time-consuming, and limits practical use.

Purpose of the Study:

• To develop a simple, rapid synthesis method for a quadruple-functional hydrogel.
• To achieve high reconstructability, self-healability, ultra-extension, and redox-activity in a single hydrogel system.

Main Methods:

• Introduced hydrophobic triiodide (I3-) into a polymer solution to trigger the Hofmeister effect in situ.
• Eliminated conventional steps like cooling-induced shaping and prolonged immersion.
• Synthesized a hydrogel with quadruple functionality: reconstructability, self-healability, ultra-extension, and redox-activity.

Main Results:

• The synthesized hydrogel demonstrated complete reconstructability over 6 cycles and self-healability over 100 cycles.
• The material exhibited ultra-extension capabilities, retaining over 150-fold biaxial extension after reconstruction or self-healing.
• Capacitive sensors and self-powered sensor systems fabricated with this hydrogel maintained original performance after rebuilding and self-healing.

Conclusions:

• A facile and efficient strategy for synthesizing multifunctional hydrogels was demonstrated.
• The developed hydrogel's properties pave the way for practical and delicate applications in flexible electronics and sensing.
• This rapid synthesis approach overcomes limitations of traditional methods, enabling broader use of advanced hydrogels.