Modeling nanoscale heat transfer on dissimilar interfaces using Molecular Dynamics

Enhancing thermal transport mechanisms in nanostructures and nanomaterials are important factors for their use in energy applications. The behaviors and reliability of nanoscale devices strongly depend on the way the systems dissipate heat. Solid-liquid interface thermal resistance is well known as the Kapitza length. Silicon with a diamond crystal lattice structure and copper, silver, gold, and platinum with face-centered cubic (FCC) crystal lattice structure were chosen as the solid materials due to their extensive applications in nanotechnology. Temperature jumps at such solid-liquid interfaces are due to thermal transport between the dissimilar materials, resulting in an interface thermal resistance.

In addition to that, a series of molecular dynamics simulations will be introduced to investigate Kapitza length at the interface of liquid water and nano-composite surfaces of graphene-coated-Cu(1 1 1). We found that Kapitza length gradually increased and converged to the value measured on pure graphite surface with the increase of the number of graphene layers inserted on the Cu surface. Different than the earlier hypothesis on the “transparency of graphene,” the Kapitza length at the interface of mono-layer graphene coated Cu and water was found to be 2.5 times larger than the value of bare Cu surface. Also, this talk presents that when the continuum description is subjected to the proper treatment of the interface effects via modified boundary conditions, the so-called continuum-based modified-analytical solutions, they can adequately predict nanoscale transport phenomena.