3D Printing of Dual-Physical Cross-linking Hydrogel with Ultrahigh Strength and Toughness
- Pan JiangPan JiangState Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, ChinaCenter of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100039, ChinaMore by Pan Jiang,
- Peng LinPeng LinSchool of Chemistry and Chemical Engineering, Anhui University of Technology, Ma’anshan 243032, ChinaMore by Peng Lin,
- Chang YangChang YangHubei Key Laboratory of Hydroelectric Machinery Design & Maintenance, China Three Gorges University, Yichang 443000, ChinaMore by Chang Yang,
- Hongling QinHongling QinHubei Key Laboratory of Hydroelectric Machinery Design & Maintenance, China Three Gorges University, Yichang 443000, ChinaMore by Hongling Qin,
- Xiaolong Wang*Xiaolong Wang*Email: [email protected]State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, ChinaMore by Xiaolong Wang, and
- Feng ZhouFeng ZhouState Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, ChinaMore by Feng Zhou
Abstract

3D printing of hydrogels with high intrinsic mechanical performance has significant applications in many fields yet has been proven to be a fundamental challenge. Here, 3D printing of ultrahigh strength hydrogels is achieved by constructing cross-linkingDPC networks based on poly(vinyl alcohol) (PVA) and chitosan (CS). The hybrid ink with moderate rheology for direct ink writing is employed to manufacture complex hydrogel structures, first. Then, the cyclic freezing–thawing followed by sodium citrate solution soaking realize the first network of PVA crystallization and the second one of CS ionic interaction between amino and carboxyl groups. The optimized DPC hydrogel displays a tensile strength of 12.71 ± 1.32 MPa at a strain of 302.27 ± 15.70%, Young’s modulus of 14.01 ± 1.35 MPa, and work of extension at fracture Wext of 22.10 ± 2.36 MJ m–3 because of the dominant energy dissipation of the stiff CS ionic network. Moreover, the tearing test supports that this DPC hydrogel possesses a high toughness of 9.92 ± 1.05 kJ m–2. This protocol can readily realize not only the hydrogel lattice, honeycomb, and spring, but also secondary-shaping hydrogel objects including whale, octopus, and butterfly via a local DPC strategy. Integrating the advanced 3D-printing technique with high-performance hydrogels uncovers a feasible strategy to broad practical applications in engineering, intelligent machine, and soft robotics.




