Simulation of pseudopolyrotaxane formation and orientational order between pseudopolyrotaxanes

摘要

We have performed Brownian dynamics simulations in order to investigate the formation of apseudopolyrotaxane (PPRX) with cyclodextrins (CDs) and a polymer chain and the development oforientational order between PPRXs. The coarse-grained model is used to model the CDs and thepolymer chain. In our simulations, we observe the formation of a rodlike PPRX with up to six ringsfor 40 monomer chains. After the formation of the PPRX, the processes of inclusion and dissociationrepeat for the rings at the end of the chain. However, the PPRX has more than three rings andmaintains the rodlike shape. With regard to the motion of rings in the PPRX, we observe two kindsof motions—oscillating motion and shifting motion. In the oscillating motion, the rings movearound a particular position on the chain and display thermal fluctuation and collisions withneighboring rings. In the shifting motion, all rings shift to another location along the chain duringthe processes of inclusion and dissociation. In our simulations, we also observed that theorientational order between PPRXs develops at low temperatures.