LATTICE MONTE-CARLO SIMULATION OF POLYMER ADSORPTION AT AN INTERFACE,1 - MONODISPERSE POLYMER

Adsorption of a monodisperse polymer at a solid-liquid interface is co mprehensively studied by Monte Carlo simulation. The distributions of total segment density and different adsorption configurations includin g trains, loops and tails are obtained. Effects of seduced exchange in teraction energies <(epsilon)over tilde>, bulk concentrations phi, re duced adsorption energies <(epsilon)over tilde>(a) and chain lengths r on those distributions are studied. Comparisons with predictions of t he Scheutjens-Fleer (SF) theory are also provided. Generally, the chai n molecules are more easily adsorbed at an interface in non-solvents t han in good solvents. Longer chains are more likely to be adsorbed tha n shorter ones. The reduced adsorption energy and the bulk concentrati on have shown strong effects on the segment-density distributions. In addition, the thickness of the adsorption layer is mainly determined b y the extension of tails into the bulk solution, which are in turn det ermined by the chain length. The trains, loops and tails are overwhelm ingly short. On the other hand, the amounts of trains and loops are us ually much greater than that of tails. Though not perfect, satisfactor y agreement is found in comparison with the theoretical predictions of the SF theory.