Anisotropy and Heterogeneity of Nematic Polymer Nano-composite Film Properties

Nematic polymer nanocomposites (NPNCs) are comprised of large aspect ratio rod-like or platelet macromolecules in a polymeric matrix. Anisotropy and heterogeneity in the effective properties of NPNC films are predicted in this article. To do so, we combine results on the flow-processing of thin films of nematic polymers in a planar Couette cell, together with homogenization results for the effective conductivity tensor of spheroidal inclusions in the low volume fraction limit. The orientational probability distribution function (PDF) of the inclusions is the central object of DoiHess-Marrucci-Greco theory for flowing nematic polymers. From recent simulations, the PDF for a variety of anisotropic, heterogeneous thin films is applied to the homogenization formula for effective conductivity. The principal values and principal axes of the effective conductivity tensor are thereby generated for various film processing conditions. Dynamic fluctuations in film properties are predicted for the significant parameter regime where the nematic polymer spatial structure is unsteady, even though the processing conditions are steady.