SCALING BEHAVIOR OF DILUTE POLYMER-SOLUTIONS CONFINED BETWEEN PARALLEL PLATES

The average size and shape of a polymer coil confined in a slit between two parallel plates depends on the distance L between the plates. On the basis of numerical results, four different regimes can be distinguished. For large values of L the coil is essentially unconfined. For intermediate values the coil orientates without being squeezed considerably. For still smaller values the coil is squeezed with a corresponding decrease in the value of the radius of gyration. A further reduction in slit width is accompanied by a sharp increase in the value of the radius of gyration, signaling the onset of the transition from three- to two-dimensional behavior. L-Dependent scaling relations are supposed to be valid in the latter regime. Using Monte Carlo results for self-avoiding walks on a cubic lattice, scaling predictions for the parallel component of the radius of gyration and the end-to-end point distance as well as for the osmotic pressure and the number of segments at the wall are presented and verified.