Dynamical process of coalescence of domains in a short chain-molecule system Original Research Article

As the fundamental process of structure formation for short chain molecules, the coalescence of two orientationally ordered domains are investigated by numerical simulation. Each domain consists of 61 chain molecules, each of which consists of 20 CH2 groups. One domain is tilted against another one with a certain angle. Then, the potential energy excited by tilting makes each domain rotate gradually. In this process, it is demonstrated that domains move collectively as if they were rigid bodies in spite of the non-bonded short-range interaction potential (Lennard-Jones potential) among chain molecules. From analysis of oscillation period of each potential well, it is concluded that the rigidity of domain derives its origin from the fact that the Lennard-Jones potential interaction of the unit hexagonal cell is strengthened to the order of the bonded interaction by packing.