To make membrane separations a more attractive option for carbon capture, recent research has focused on discovering materials capable of surpassing the Robeson bound, thereby enhancing membrane separation performance. One prominent approach to overcoming this challenge involves developing composite materials, in which fillers are embedded within a polymer matrix to create heterogeneous membranes known as mixed matrix membranes (MMMs). In MMMs, the polymer serves as a host matrix, offering the necessary processability to shape the composite into a membrane, while the enhanced perm-selectivity and permeability are derived from the properties of the filler material.