A molecular simulation approach to the prediction of the morphology of self-assembled nanoparticles in diblock copolymers

Mixing microphase-separating diblock copolymers and nanoparticles can lead to the self-assembly of organic/inorganic hybrid materials that are spatially organized on the nanometre scale. Controlling particle location and patterns within the polymeric matrix domains remains, however, an unmet need. Computer simulation of such systems constitutes an interesting challenge since an appropriate technique would require the capturing of both the formation of the diblock mesophases and the copolymer-particle and particle-particle interactions, which can affect the ultimate structure of the material. In this work we discuss the application of Dissipative Particle Dynamics ( DPD) to the study of the distribution of nanoparticles with different degree of functionality and volume fraction in a lamellar microsegregated copolymer template. The DPD parameters of the systems were calculated according to a multi-step modelling approach, i.e., from lower scale (atomistic) simulations. The results show that positioning and ordering of the nanoparticles, as well as the dimensions of the block domains depend on covering extent and volume fraction, in full agreement with experiments. The overall results provide molecular-level information for the rational, a priori design of new polymer-particle nanocomposites with ad hoc, tailored properties.