High-entropy thermal-stiffening hydrogels with fast switching dynamics
Li Li1, Baohu Wu2, Shengtong Sun1
1State Key Laboratory of Advanced Fiber Materials, College of Chemistry and Chemical Engineering & Center for Advanced Low-Dimension Materials, Donghua University, Shanghai 201620, China.
National Science Review
|March 24, 2025
Summary
Researchers developed a high-entropy design to accelerate the cooling recovery of thermal-stiffening hydrogels. This innovation significantly reduces recovery time from over 30 minutes to just 28 seconds, enabling faster self-protection and shape memory applications.
Area of Science:
- Materials Science
- Polymer Chemistry
- Soft Matter Physics
Background:
- Thermal-stiffening hydrogels offer temperature-triggered transitions for self-protection and shape memory functions.
- Current limitations include slow recovery (>30 min) due to diffusion and dissolution kinetics.
Purpose of the Study:
- To design a novel strategy for accelerating the recovery dynamics of thermal-stiffening hydrogels.
- To investigate the impact of high-entropy phase separation on hydrogel recovery speed.
Main Methods:
- Developed a high-entropy phase separation design using a poly(calcium acrylate)-based copolymer hydrogel.
- Incorporated hydrophilic units into the hydrogel to disrupt cluster packing and create a high-entropy structure.
- Characterized the thermal-stiffening response and recovery dynamics.
Main Results:
- Achieved a 760-fold increase in storage modulus, maintaining the thermal-stiffening effect.
- Reduced the characteristic recovery time to 28 seconds, a significant acceleration.
- Demonstrated that hydrophilic units facilitate rapid mass diffusion via a low energy barrier.
Conclusions:
- The high-entropy phase separation design effectively accelerates hydrogel recovery dynamics.
- This strategy offers a promising approach for developing modulus-adaptive materials with fast switching capabilities.
- The findings are broadly applicable to advanced material design for responsive applications.
