Mixing-Demixing Transition in Polymer-Grafted Spherical Nanoparticles

Polymer-grafted nanoparticles can provide property profiles than cannot be obtained individually by polymers or nanoparticles. Here, we have studied the mixing–demixing transition of symmetric copolymer melts of polymer-grafted spherical nanoparticles by means of coarse-grained molecular dynamics
simulation and a theoretical mean-field model. We find that a larger size of nanoparticles leads to higher stability for given number of grafted chains and chain length reaching a point where demixing is not possible. Most importantly, our results suggest that there is a nontrivial dependence on the grafting
density in the case of intermediate particle size, where the steric interactions of the core particles are shielded by a growing effective attractive core of the tethered polymer chains. Our study elucidates the phase behaviour of polymer-grafted NPs anticipating that it will open new doors in the understanding
of these systems with implications in materials science and medicine.