Self-Assembly of Giant Amphiphiles Based on Polymer-Tethered Nanoparticle in Selective Solvents

We study the self-assembly and formation process of vesicles of giant molecular shape amphiphiles in a selective solvent using the Brownian dynamics approach. Each amphiphile is composed of one hydrophilic nanoparticle tethered with one to five hydrophobic polymer tail(s), and the number of coarse-grained beads in each polymer tail is comparable to the number of repeating units in shape amphiphile used in the experiments. The effects of various parameters, such as the number of polymer tails, the length of each tail, the concentration of amphiphile beads, the size of the nanoparticle, and the temperature of the system on the self-assembled aggregate morphologies, are investigated. Morphological phase diagrams are constructed in different parameter spaces, and multiple morphological transitions are predicted and explained based on packing parameter. The formation pathways of vesicles are examined systematically, and mechanism II is identified for the first time in such shape amphiphilic systems. Transition between mechanism I and mechanism II can occur by varying several parameters, and principles controlling the different pathways are elucidated. The simulation results are compared with available experimental and simulation results of related systems