Design of mechanically strong and tough alginate hydrogels based on a soft-brittle transition

This study reveals the water-induced mechanical transition of alginate hydrogels and the corresponding mechanism, through which, mechanically strong and tough hydrogels are fabricated. It is found that in the water content (CW, wt%) range of 62 < CW < 93, the alginate hydrogels exhibit soft material properties with low modulus and fracture stress, but high extendability. However, within range of 19 < CW < 48, ultrahigh modulus and fracture...