Design of Double Network Gels Using Molecular Dynamics Simulations

Multi-component gels are common in biology and display striking material properties. Indeed, the extra-cellular matrix features a combination of various proteins and sugars, including collagen, elastin, and glycosaminoglycans, and engineered double network (DN) hydrogels exhibit remarkable toughness. Understanding and controlling the properties of these networks at a molecular level requires knowledge of the way in which inter-species and intra-species interactions affect morphology and rheology of the combined gel. In order to predict properties of DNs, we designed a series of rheological tests performed on in-silico self-assembled colloidal gels. The computational model includes two-body interactions, which drive self-assembly, and three-body terms that create filamentous networks. We systematically changed the strength of inter-species two-body and three-body interactions and explored the remarkable variety of topologies and mechanical responses generated by parameter exploration. Our results underscore the richness of DN gels, illustrate how to control their properties, and set the stage for comparison with experiments.