Discretized model for diffusion of a chain in one dimension.
With the help of Monte Carlo simulations, the one-dimensional diffusion motion of a chain of N beads is studied to determine its diffusion coefficient and viscosity. We found that the end bead movements with respect to that of the central beads play a key role. There is no memory between bead hops but they become correlated as a consequence of the chain dynamics. This determines the scaling exponents and the relation connecting them. In particular, the scaling exponent for the viscosity can be smaller or greater than 3 but it must scale as N3 in the asymptotic regime (N--> infinity ). We analyze in detail the dynamics of a chain with three beads to explain why the expected relation between diffusivity and viscosity exponents is not satisfied.
Guidoni
S E
SE
Institute of Materials Science and Technology (INTEMA), Universidad Nacional de Mar del Plata-CONICET, Juan B. Justo 4302, 7600 Mar del Plata, Argentina.
Mártin
H O
HO
Aldao
C M
CM