The dynamic behaviors of diblock copolymeranorod mixtures under equilibrium and nonequilibrium conditions

摘要

Cylindrical diblock copolymer/anisotropic nanorod composites under equilibrium and nonquilibrium conditions, have been modeled and simulated using dissipative particle dynamics. The aim of our present study is to understand how the anisotropic NRs affect the equilibrium self-assembled structure of diblock copolymers (DBCPs) melts and how the shear flow induces the dynamic behaviors of DBCPs/NRs composites, especially the orientation and distribution of NRs in diblock matrix. We consider two different shear directions categorized with respect to the flow velocity parallel or perpendicular to the orientation of initial structures, which are defined as z-axis shear flow and x-axis shear flow, respectively. Our results show the shear flow not only aligns the orientation of DBCPs template and the dispersed NRs toward the flow direction, but also regulates the orientational and positional order of NRs. The final self-assembly behaviors of DBCPs/NRs nanocomposites is determined by the interplay between shear-induced polymer thinning and NRs dispersion. This work provides us a viable strategy for creating polymer nanocomposites with tunable and enhanced processing properties.