Interplay between structure and mechanical performances of multi-component colloidal gels.

We present a detailed numerical study of composite colloidal gels obtained by arrested phase separation. Under deformation, we show that increasing the complexity in our gels, by adding multiple same gel components that are repulsive with each other, leads to softer solids that can accommodate progressively larger strains before yielding compared to mono-gels. The simulations highlight how this is the direct consequence of the steric repulsion between different components, that prevents compactification of the network and allows multi-gels to exhibit collective reorganization to resist deformations. Our work suggests new strategies of tuning the mechanics of soft composite materials by controlling the inter-gel interactions and may open the road to the design of new materials of great use in soft robotics, batteries and stretchable electronics.