Nanoclay Reinforced Self‐Cross‐Linking Poly(N‐Hydroxyethyl Acrylamide) Hydrogels with Integrated High Performances

• Published in: Macromolecular materials and engineering Vol. 303; no. 9
• Main Authors: Yu, Xianqiang, Li, Yu, Yang, Jia, Chen, Feng, Tang, Ziqing, Zhu, Lin, Qin, Gang, Dai, Yahui, Chen, Qiang
• Format: Journal Article
• Language: English
• Published: Weinheim John Wiley & Sons, Inc 01-09-2018
• Subjects: Acrylamide; Gels; Healing; high strength; high toughness; Hydrogels; nanocomposite hydrogels; Nanocomposites; Recoverability; Recovery; self‐healing; self‐recovery; Stiffness; Stretchability; Toughness
• ISSN: 1438-7492; 1439-2054
• DOI: 10.1002/mame.201800295

Despite recent significant progress in fabricating tough hydrogels, it is still a challenge to realize high strength, large stretchability, high toughness, rapid recoverability, and good self‐healing simultaneously in a single hydrogel. Herein, Laponite reinforced self‐cross‐linking poly(N‐hydroxyethyl acrylamide) (PHEAA) hydrogels (i.e., PHEAA/Laponite nanocomposite [NC] gels) with dual physically cross‐linked network structures, where PHEAA chains can be self‐cross‐linked by themselves and also cross‐linked by Laponite nanoplatelets, demonstrate integrated high performances. At optimal conditions, PHEAA/Laponite NC gels exhibit high tensile strength of 1.31 MPa, ultrahigh tensile strain of 52.23 mm mm−1, high toughness of 2238 J m−2, rapid self‐recoverability (toughness recovery of 79% and stiffness recovery of 74% at room temperature for 2 min recovery without any external stimuli), and good self‐healing properties (strain healing efficiency of 42%). The work provides a promising and simple strategy for the fabrication of dual physically cross‐linked NC gels with integrated high performances, and helps to expand the fundamentals and applications of NC gels.
Poly(N‐hydroxyethyl acrylamide)/Laponite nanocomposite gels with dual cross‐linking network structures demonstrate integrated high tensile strength, ultrahigh elongation, high toughness, rapid self‐recoverability, and good self‐healing property.