Mass Diffusion-Dominated Phase Separation Enabling On-Demand and Repeatable Lifetime Programming of Room-Temperature...

Area of Science:

• Materials Science
• Polymer Chemistry
• Photophysics

Background:

• Current luminescent polymer hydrogels primarily offer tunable emission intensity and color.
• Achieving room-temperature phosphorescence (RTP) hydrogels with programmable lifetimes has been a long-standing challenge.
• Programmable RTP hydrogels could significantly expand the utility of stimuli-responsive materials.

Purpose of the Study:

• To develop the first RTP polymer hydrogels with on-demand programmable lifetimes.
• To investigate the mechanism behind lifetime programming in RTP hydrogels.
• To demonstrate a novel application for these programmable RTP hydrogels.

Main Methods:

• Utilized a mass diffusion-dominated phase separation strategy.
• Induced phase separation and rubbery-to-glassy transition via heating (90 °C).
• Programmed RTP lifetimes by controlling heating duration and utilized natural cooling (25 °C) for reversibility.

Main Results:

• Successfully developed the first RTP polymer hydrogels with continuously programmable lifetimes ranging from 9.1 to 130.8 ms.
• Demonstrated that RTP performance is dominated by phase-separation kinetics, not heat transport.
• Achieved a 154-fold enhancement in Young's modulus through controlled phase separation.
• Showcased repeatable RTP lifetime programming via thermal cycling.
• Demonstrated a rewritable spatiotemporal-resolved information decryption platform with time-dependent security.

Conclusions:

• This study presents a novel method for creating RTP polymer hydrogels with unprecedented lifetime-programming capabilities.
• The findings open new avenues for RTP hydrogels and enhance the intelligence of luminescent materials.
• The developed hydrogels offer a new dimension for stimuli-responsive materials, enabling advanced applications like secure information decryption.