Simulation Of Macromolecule Adsorptions On Solid-Liquid Interface

A Monte Carlo model was developed for simulating the adsorption behaviors of linear macromolecule chains on the solid-liquid interface. The simulations were performed on a simple cubic lattice, which was 50×50×50 sites in size. The concentration profiles of total segments, tails and loops in dilute solutions were used to analyze the influences of simulation parameters (body concentration, interaction energy between segments, adsorption energy of interface, and macromolecule chain length) on various adsorption configurations. Compared with the behavior of macromolecules in real solution system, the adsorption information in the Monte Carlo simulation system, such as adsorption isotherm, surface coverage, and bound fraction, was studied for discussing its relation to simulation parameters.Five-selection simple cubic lattice, self-avoiding walk, and nearest interaction model were used to construct the homopolymer adsorption model on the solid-liquid interface. Periodic boundary conditions were used to reduce the fixed error from limited cubic lattice in size. Body concentration, interaction energy between segments, adsorption energy of surface, and macromolecule chain length were used to affect the adsorption behavior of macromolecules. The simulation system was disturbed with end-rotation, L-inversion, crankshaft motion, snake motion, and configuration-bias Monte Carlo method. Macromolecule properties were obtained from the data sampled from the simulation system, when adsorption equilibrium had been reached.The absorption isotherm obtained from model showed the macromolecules adsorption had the Langmuir characters, which was proved by experiment results. The parameters in simulation could characterize macromolecules adsorption in real solution. Varieties of interaction energy between segments corresponded to different macromolecules. Varieties of adsorption energy of interface corresponded to different solid surfaces. The adsorption behaviors of simulation macromotecules in different conditions could be explained by the adsorption characters of real macromolecules incorresponding conditions. Above all, the adsorption characters of macromolecules in model were in agreement with those in real solution.