Simulation of diffusion motion of ionomers using Monte Carlo algorithm

摘要

We present a simple model of ionomers, namely a single polymer chain in a series of fixed attractors. In analogy to ionized bead's claws of surrounding chains, the set of attractors can affectively slow down the diffusion motion of the target chain. The monomer mean-square displacement of ionomers is studied by using Monte Carlo algorithm, and compared with the prediction of the sticky Rouse model. The diffusion motion properties of ionomers are explored in three aspects, including the chain length of the polymer, the depth of the potential well and the number of ionic groups. The results show that a plateau appears in the monomer diffusion function due to the attraction of the attractors to the claws. However, comparative theoretical predictions and simulation results show that there exists some discrepancy between them. Therefore, the relaxation time distribution of polymer chain motion is explored. The simulation results confirm that the association lifetime is decreasing exponentially, and the expected values of the association lifetime satisfy the Boltzmann distribution as shown by the results. These results perfectly explain the deviation between the simulation data and the theoretical results.