High-strength and high-toughness sodium alginate/polyacrylamide double physically crosslinked network hydrogel with superior self-healing and self-recovery properties prepared by a one-pot method

Double-network hydrogels have become a research hotspot in the field of hydrogels because of their high strength and toughness. Here, we prepared PAM/SA-Fe dual physically crosslinked hydrogels formed by hydrophobic association and ionic coordination. The fracture stress, elastic modulus and toughness of the PAM/SAFe hydrogel are 1.39 MPa, 122.12 kPa and 7320.83 kJ/m(3) respectively. The hydrogel also has excellent self-recovery, puncture resistance, fatigue resistance and self-healing performance. In addition, swelling and thermogravimetric analysis tests confirmed that the hydrogel has pH sensitivity and good thermal stability. Finally, we observed the chemical composition and internal microstructure of the hydrogel by SEM and FITR. The PAM/SA-Fe hydrogel provides a new design method for double-network hydrogels and has broad application prospects in electronic skin, sensors and medicine.