Temporal Control of Gelation and Mechanical Properties by Electrolyte Gelators Applicable to Heterogeneous Reservoirs

Kinetically dormant chemical systems during hydrogel formation have engineering applications in various areas. Herein, we have designed an approach to tune hydrogel formation by controlling the topologies of ionic gelators. The spatial connectivity between ionic gelators and the polymer precursor determined the gelation time of the hydrogels. The nucleophilic attack of carboxylates along the polymer backbone to cyclic sulfonium motifs tethered to end-linkable gelators accounted for the covalent bridges within the hydrogels. The modulation of gelation time can be adjusted from hours to weeks, depending upon gelator topologies, which further determined the mechanical properties of formed hydrogels. We demonstrated simultaneous control of the gelation and mechanical properties of the hydrogels triggered by thermal stimuli. Moreover, the topological crosslinker-based in situ gels had excellent plugging efficiency against water flow, providing a viable approach for water management of heterogeneous reservoirs. Chemical handles were imbued with a fluorescent function without compromising mechanical integrity for additional applications.