Rheological modeling and forming process simulation of CNT nanocomposites

This paper is concerned with the rheological modelling of untreated Carbon Nanotubes (CNTs) suspended within an epoxy resin and its application in nanocomposites forming processes. The untreated CNT suspensions exhibited significant steady shear-thinning and contained optically resolvable aggregate structures. A simple orientation model, based on a Fokker-Planck advection–diffusion description, failed to capture the experimentally observed rheological responses for untreated CNT suspensions. A new model named the “Aggregation/Orientation” (AO) model has been developed to describe the experimental findings. The model integrated elements of both a standard orientation model and aggregation modelling concepts within the Fokker-Planck formalism. However, the proposed model has different weakness; the most important concerns the affine orientation of tubes with the fluid deformation independently of the state of aggregation. This mechanism seems to be in opposition to the experimental observations. In this paper we propose an alternative rheological model that is then employed for simulating film processing by employing spin coating.