Gel architecture controls dissipation in fibrous double networks

We use coarse-grained molecular dynamics simulations to investigate how the architecture of double-network gels affects energy dissipation during shear loading/unloading cycles. We establish a link between macroscopic hysteresis and the microstructures characterized via network topology and spatial distributions of local stresses. Our microscopic analysis reveals that the architecture of the double networks (demixed or intertwined) determines the inter-species sacrificial bonds that promote yielding. Moreover, the hysteresis area increases with a power law as a function of the maximum strain during a cycle and the power-law exponent is architecture dependent. Thus, we propose that experiments can glean information on double-network architectures by measuring how the hysteresis area changes with approaching the yield strain during a cycle.