MONTE-CARLO DYNAMICS OF A DENSE SYSTEM OF CHAIN MOLECULES CONSTRAINED TO LIE NEAR AN INTERFACE - A SIMPLIFIED MEMBRANE MODEL

The static and dynamic properties of a dense system of flexible lattice chain molecules, one of whose ends is constrained to lie near an impenetrable interface, have been studied by means of the dynamic Monte Carlo method. It is found that increasing the surface density of the chains in the layer increases the orientational order. The value of the order parameter of the chain segments decreases with increasing distance from the interface. The short time dynamics of the model chains are similar to those observed in polymer melts. Then, there is a time regime of strongly hindered collective motion at intermediate distance scales. Finally, for distances greater than the chain dimensions, free lateral diffusion of the chains is recovered. It is shown that the model exhibits many features of the real systems such as detergents on a surface and lipid bilayers. © 1990 American Institute of Physics.