Methods include producing tunable carbon structures and combining carbon structures with a polymer to form a composite material. Carbon structures include crinkled graphene. Methods also include functionalizing the carbon structures, either in-situ, within the plasma reactor, or in a liquid collection facility. The plasma reactor has a first control for tuning the specific surface area (SSA) of the resulting tuned carbon structures as well as a second, independent control for tuning the SSA of the tuned carbon structures. The composite materials that result from mixing the tuned carbon structures with a polymer results in composite materials that exhibit exceptional favorable mechanical and/or other properties. Mechanisms that operate between the carbon structures and the polymer yield composite materials that exhibit these exceptional mechanical properties are also examined.