Strong Acid Enabled Comprehensive Training of Poly (Sodium Acrylate) Hydrogel Networks

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Hydrogel networks are crucial for various applications.
• Conventional poly (sodium acrylate) hydrogels have limitations in performance.
• Improving hydrogel mechanical properties and functionality is an ongoing challenge.

Purpose of the Study:

• To develop a general strategy for enhancing poly (sodium acrylate) hydrogel networks.
• To investigate the effects of acid-assisted training on hydrogel properties.
• To achieve significant improvements in mechanical performance, anti-swelling, and self-healing.

Main Methods:

• Preparation of hydrophobic homogeneous crosslinked poly (sodium acrylate) hydrogels.
• Immersion of hydrogels in sulfuric acid solutions for surface transformation.
• Cyclic stretch/release training with acid infiltration for internal network transformation.
• Reversible recovery using NaOH neutralization.

Main Results:

• Acid treatment transforms poly (sodium acrylate) to poly (acrylic acid), tightening the network via hydrogen bonding.
• Trained hydrogels exhibit enhanced anti-swelling, self-healing, and mechanical properties.
• Young's modulus, stress, and toughness increased by 187.6, 35.6, and 5.4 times, respectively.
• Fully-trained hydrogels maintain isotropic networks with 8.6 stretchability.

Conclusions:

• Acid-assisted training is a general and effective strategy for improving poly (sodium acrylate) hydrogels.
• The method imparts desirable properties like enhanced mechanics and self-healing.
• This approach offers a pathway for designing high-performance hydrogels for diverse applications.