Many-body interactions in amorphous materials

Amorphous materials lack structural order at any scale, as their constituent elements are trapped in disordered configurations. This leads to a complex free energy landscape with many different local minima. Plasticity happens by local rearrangements of elements or particles as they overcome the energy barriers created by their neighbors. Therefore, the macroscopic properties of amorphous materials highly depend on the energy landscape and the many-body interactions between the particles. In this work, we employ classical density functional theory to model the free energy of solvent-free polymer-grafted nanoparticles at the molecular scale. The absence of a solvent in this model system forces the grafted polymers to fill the void space between the cores, leading to a soft glassy material with many-body interactions and intrinsic disorder. We present the effect of many-body interactions on the equilibrium structure and compare it to a system with pair-wise potential. Additionally, we demonstrate how the many-body interactions evolve as the number of particles in the system changes. These insights are fundamental in understanding the role of many-body interactions in amorphous materials. This work offers a physics-based framework to explore the energy landscape of amorphous materials without relying on an estimate based on classical pair-wise potentials.