Autocatalytic Reaction Networks: A Pathway to Spatial Temporal Mastery in Dynamic Materials

Autocatalytic reaction present a significant opportunity for the precise spatial and temporal control of dynamic materials, mimicking the characteristics of living matter within autonomous chemical systems. Herein, we have crafted an autocatalytic chemical reaction network (CRN) designed to be incorporated into a dynamic system, allowing for efficient control of both sol(I)-gel and gel-sol(II) transitions through autocatalytic fronts. The CRN incorporates two autocatalytic reactions. The first reaction promotes the formation of disulfide crosslinks while increasing the local pH through base product generation, catalyzing further disulfide bond formation and initiating a polymerization front that transforms the liquid phase into a gel. A subsequent, slower reaction triggered at the gel/air interface, resulted in the breakage of disulfide crosslinks, transforming the gel back into a liquid state through accelerating fronts. The dynamics of these autocatalytic fronts are accurately predicted by a reaction-diffusion model, providing a theoretical framework for system preprogramming. Moreover, our results show that the reversible sol-gel transition can be reliably repeated multiple times. This approach not only enhances our understanding of autocatalytic CRNs but also pioneers a new approach for developing dynamic materials with life-like properties, significantly impacting material science and bioengineering.