ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
We study the diffusion of a linear polymer in the presence of permeable membranes without excluded volume interactions, using scaling theory and Monte Carlo simulations. We find that the average time it takes for a chain with polymerization index N to cross a single isolated membrane varies with N as N5/2, giving its permeability proportional to N2. When the membranes are stacked with uniform spacing d in the unit of the monomer size, the dynamics of a polymer is shown to have three different regimes. In the limit of small d(very-much-less-than)N1/2, the chain diffuses through reptation and D∼N−2. When d is comparable to N1/2 the diffusion coefficients parallel and perpendicular to the membranes become different from each other. While the diffusion becomes Rouse-like, i.e. D∼N−1, in the parallel direction, the motion in the perpendicular direction is still hindered by the two-dimensional networks. The diffusion eventually becomes isotropic and Rouse-like for large d(very-much-greater-than)N. © 1995 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.468857
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