Effect of nanorods on the mesophase structure of diblock copolymers

Mixtures of symmetric diblock copolymers and rigid nanorods (NRs) that are preferentially wetted by one of the blocks (A) are systematically investigated via dissipative particle dynamics simulations. The morphology of such composites depends not only on the characteristics of the copolymers, but also on the physical or chemical features of the NRs, such as NR volume fraction, size, and polymer-NR interaction. We find that the presence of NRs influences the phase behavior of copolymers and the phase-separated domains of copolymers in turn confine the NRs spatial distribution and positional orientation. The morphologies and phase transitions of hybrids and the corresponding NRs distributed and oriented regularities can be rationalized on the basis of the relative enthalpic and entropic effects involving all of the species, A and B blocks, and NRs. These results suggest that by choosing appropriate parameters, our model systems may provide a prediction to control and design the high-performance composites.