title: Dual Physically Cross-Linked Double Network Hydrogels with High Mechanical Strength, Fatigue Resistance, Notch-Insensitivity, and Self-Healing Properties.
abstract: Double-network (DN) hydrogels with high strength and toughness have been developed as promising materials. Herein, we explored a dual physically cross-linked polyacrylamide/xanthan gum (PAM/XG) DN hydrogel. The nonchemically cross-linked PAM/XG DN hydrogels exhibited fracture stresses as high as 3.64 MPa (13 times higher than the pure PAM single network hydrogel) and compressive stresses at 99% strain of more than 50 MPa. The hydrogels could restore their original shapes after continuously loading-unloading tensile and compressive cyclic tests. In addition, the PAM/XG DN hydrogels demonstrated excellent fatigue resistance, notch-insensitivity, high stability in different harsh environments, and remarkable self-healing properties, which might result from their distinctive physical-cross-linking structures. The attenuated total reflectance infrared spectroscopy (ATR-IR) and dynamic thermogravimetric analysis (TGA) results indicated that there were no chemical bonds (only hydrogen bonds) between the XG and PAM networks. The PAM/XG DN hydrogel synthesis offers a new avenue for the design and construction of DN systems, broadening current research and applications of hydrogels with excellent mechanical properties.
authors.affiliation: Department of Materials Science and Engineering, College of Science and Engineering, Jinan University , Guangzhou 510632, P. R. China.
authors.forename: Ningxiao
authors.initials: N
authors.lastname: Yuan
authors.affiliation: Department of Materials Science and Engineering, College of Science and Engineering, Jinan University , Guangzhou 510632, P. R. China.
authors.forename: Lu
authors.initials: L
authors.lastname: Xu
authors.affiliation: Department of Materials Science and Engineering, College of Science and Engineering, Jinan University , Guangzhou 510632, P. R. China.
authors.forename: Hualiang
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Materials Science and Engineering, College of Science and Engineering, Jinan University , Guangzhou 510632, P. R. China.
authors.forename: Youpeng
authors.initials: Y
authors.lastname: Fu
authors.affiliation: Department of Materials Science and Engineering, College of Science and Engineering, Jinan University , Guangzhou 510632, P. R. China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Materials Science and Engineering, College of Science and Engineering, Jinan University , Guangzhou 510632, P. R. China.
authors.forename: Lan
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Materials Science and Engineering, College of Science and Engineering, Jinan University , Guangzhou 510632, P. R. China.
authors.forename: Cuiling
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Materials Science and Engineering, College of Science and Engineering, Jinan University , Guangzhou 510632, P. R. China.
authors.forename: Jianhao
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Department of Materials Science and Engineering, College of Science and Engineering, Jinan University , Guangzhou 510632, P. R. China.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Rong
keywords: double network hydrogels; fatigue resistance; high mechanical strength; notch-insensitivity; self-healing