Structural Changes in Hairy Nanoparticles-Insights from Molecular Simulations

Coarse-grained molecular dynamics simulations are used to study the reorganization of mobile ligands pinned to isolated nanospheres. Three types of ligands are considered: (i) freely jointed homogeneous attractive chains (H); (ii) flexible diblock copolymers composed of inert linkers and the attractive end-groups (D1); and (iii) diblock copolymers built of inert flexible linkers and end-groups being attractive rigid-rods (D2). The impact of the type of ligands, their number, and the strength of interactions on the structure of hairy nanoparticles are discussed. It is shown that the properties of ligands determine the morphology of polymer corona. For the H-particles, the one-patchy and the core-shell particles are found, while for particles D1 and D2, the ligands aggregate into a few patches. As the number of ligands increases, more patches are formed. Rigidity of attractive groups favors the formation of higher number of patches. The ligands are regularly distributed in patches on the core surface. Two patches are almost symmetrically located on the core, three patches are placed nearly at the vertices of an equilateral triangle, and four patches lie at the vertices of a regular tetrahedron.