Shao-Gui WU
Beijing Computational Science Research Center
Abstract: In this talk, we present a DPD simulation of block copolymer self assembly in nanodroplets. The simulations are performed by relaxing disordered copolymer nanodroplets in solvent bath. Then microphase separation is carried out confined inside nanodroplets, which allows block copolymers self assemble into new morphologies differing from that in pure melt or in solution. These patterned structures are depended on the ratio of solvophilic/solvophobic blocks. As the increase of the ratio of solvophilic/solvophobic blocks, Plum Pudding microsphere, volleyball-like structure, multilamellar vesicles, cage-like structure, nanorods, and discrete micelles are formed in succession. The pathway of onion formation is described in detail. Energy analysis demonstrates that the structure optimization towards onion consumes very little energy while most of the energy is spent on the initial rapid microphase separation. Solvent cluster properties determination helps to getting more intuition about the dynamics of onion evolution. Density analysis is given to characterize the structure of onion. At high ratio of solvophilic/solvophobic blocks, block copolymers exhibit mainly solvophilicity and form swelled loose structures or small micelles suspending in solvent. The simulation results are qualitatively in agreement with experimental or theoretical results.
Date&Time: Mar 2, 2012
Location: 606 Conference Room