A salt-triggered multifunctional smart window derived from a dynamic polyampholyte hydrogel

Area of Science:

• Materials Science
• Polymer Chemistry
• Smart Materials

Background:

• Hydrogel smart windows offer light modulation via thermo-, humidity-, or electrochromic effects.
• Existing technologies face limitations in active control, complex assembly, energy input, and susceptibility to damage.
• Thermo- and humidity-triggered windows are passive, while electrochromic ones require intricate setups and power.

Purpose of the Study:

• To develop a novel hydrogel smart window with active and facile actuation.
• To introduce self-healing capabilities to hydrogel smart windows.
• To explore information input/storage and encryption functionalities in smart windows.

Main Methods:

• Development of a salt-triggered polyampholyte hydrogel (PAH).
• Utilizing dynamic ionic bonds in PAH for reversible disassociation and reformation in aqueous sodium chloride solution (NaCl(aq.)) and water (H2O).
• Patterning PAH via localized NaCl(aq.) treatment for information inscription.

Main Results:

• PAH demonstrates reversible transparency-shifting and efficient light transmittance modulation.
• Patterning enables one-time information input/storage, with visibility linked to transparency changes.
• The dynamic ionic bonds provide self-healing and automatic damage-repairing abilities without compromising light modulation.

Conclusions:

• Salt-triggered PAH offers a new approach for actively controlled hydrogel smart windows.
• The developed material exhibits multifunctionality, including self-healing and information storage.
• This technology presents a promising alternative to existing smart window systems, enhancing durability and user interaction.