Interface and mechanical properties of 1D and 1D-2D carbon nanomaterials in copper matrix

Low-dimensional carbon nanomaterials have unique electron density distributions which warrant their classification as 1D and 2D, and they are useful for a wide variety of nanocomposite applications. This group includes 1D carbyne, which has high stiffness, and a 1D-2D hybrid composed of carbyne and a highly elastic cyclo[18]carbon ring (2D). We use density functional theory and molecular dynamics methods to study the interface properties of carbyne and the hybrid on Cu (111) surface and determine the mechanical properties of nanocomposites comprised of the nanomaterials as a fiber in Cu matrix at varying temperatures. We predict that on Cu (111) surface, the hybrid case has a higher adsorption energy than carbyne. During tensile loading, we find the elastic moduli of Cu-carbyne and Cu-hybrid nanocomposites are dependent on the Cu-C interface and nanomaterial dimension (1D or 1D-2D). We observe that high adsorption energy at the Cu-C interface contributes to higher elastic moduli for a Cu-hybrid nanocomposite than a Cu-carbyne nanocomposite at 300K. Above 300K, strain from thermal expansion coefficient mismatch between the 1D and 2D components of the hybrid cause Cu-hybrid elastic modulus to decrease. The thermal strain and volumetric strain of the Cu FCC lattice are affected by the dimension of the nanomaterial, and causes Cu-carbyne elastic moduli to be higher than Cu-hybrid for temperatures 600K. We also find high nanomaterial density causes Cu lattice distortion, leading to low elastic moduli at all temperatures. We conclude that carbyne and the hybrid are promising nanomaterials for Cu nanocomposites.