Analytical modeling of effect of interlayer on effective moduli of layered graphene-polymer nanocomposites

Nanocomposites enhanced with two-dimensional, layered graphene fillers are a new class of engineering materials that exhibit superior properties and characteristics to composites with conventional fillers. However, the roles of “interlayers” in layered graphene fillers have yet to be fully explored. This paper examines the effect of interlayers on mechanical properties of layered graphene polymer composites. As an effective filler, the fundamental properties (in-plane Young's modulus E_L1, out-of-plane Young's modulus E_L2; shear modulus G_L12, major Poisson's ratio ν_L12) of the layered graphene were computed by using the Arridge's lamellar model. The effects of interlayers on effective moduli of layered graphene epoxy composites were examined through the Tandon-Weng model. The properties of the interlayer show noticeable impact on elastic properties of the composites, particular the out-of-plane properties (Young's modulus E₂ and shear modulus G₁₂). The interlayer spacing is seen to have much great influence on properties of the composites. As the interlayer spacing increases from 0.34 nm to 2 nm, all elastic properties of the composites have been greatly decreased.