Figure 5.

Experiment showing autonomous programming of homogeneous “molding and casting” of the hydrogel of 1 (2 mg/mL) involving the following initial conditions: [urease] = 0.2 mg/mL, [urea] = 0.02 M, volume of methyl formate = 100 μL. An initially formed gel inside a syringe (a) was immediately extruded after 30 s of preparation (b). With time, the gel progressively converted to a homogeneous solution and acquired the shape of the container (c–e). Photographs were taken after 1 min (c), 2 min (d), and 5 min (e) of extrusion. Then the system was left undisturbed for 16 h (f). (g)–(i) represent photographs of the molded gel obtained after the experiment. The white structures in the gel are air bubbles, not precipitation. Solvent is 20/80 DMSO/water (v/v).