Hence, r2 hydrogel samples were cast and cured in the mold under humid atmosphere for 1, 3, and 7 days at room temperature and measured at each time point by a rheological amplitude sweep at 1 Hz oscillation frequency while varying the strain from 0.1 to 100 % at room temperature. The storage moduli at 1 % strain, which is within the linear region for all samples, was compared to find out the time required for complete gelation.