Hydrogels with dynamic linkers have garnered intense interest for applications that require flow, including injectable delivery vehicles and 3D bioprinting inks. However, to fully enable these applications, there remains a need to understand how linking chemistry affects gelation and nonlinear rheological properties. To probe this relationship, we developed synthetic multi-arm polyethylene glycol (PEG) gels linked with dynamic covalent bonds.

• Dynamic covalent hydrogels exhibit non-monotonic flow curves under steady shear, with shear thickening behavior that depends on exchange kinetics of linkers.
• Transient shear measurements indicate chain stretching is responsible for shear thickening.
• These results will guide hydrogel design for injectable gels and 3D bioprinting inks.
• This work supports the IRG goals of developing strategies for dynamic polymeric depletants and materials with rheo-adaptive behavior.

UT Austin MRSEC

DMR-1720595/2308817