The Self-Consistent Field Study Of The Adsorption Of Homo-polymers Onto Nano Objects

The adsorption of polymer chains from solutions onto solid surfaces is a veryimportant phenomenon from both the theoretical and practical points of view. Theconformational properties of the adsorbed polymer chains directly affect many of themechanical properties of materials. Using the continuum self-consistent field theory(SCFT), the adsorption of homo-polymers onto the surfaces of nano-objects is studied.The main contents are as follow:1. The basic knowledge of polymer and polymer solutions, and also that of thedifferent conformations of adsorbed polymer chains are briefly introduced. A detailedderivation of the self-consistent field theory and several methods of solving theself-consistent field equations are presented in this part.2. Using the continuum self-consistent field theory (SCFT), the adsorption offlexible homo-polymers onto the surfaces of two identical cylinders immersed in aneutral polymer solution is studied. The effects of various system parameters on thebridging chain conformation and the total amount of the adsorbed chains areinvestigated. The efficient multigrid method is adopted to solve the modified diffusionequation. The “masking” technique is applied to deal with the interface between thecylinders and the polymer solution. Simulation results show that, all the differentsystem parameters has effects on the bridging chain conformation and the totalamount of the adsorption.3. The dependences of the loop and tail conformations are studied by using thesame method as that in part2. We find that, the relationship of total amount of theloop and tail conformations will be changed when the chain length or the intensity ofadsorption field are varied.4、Aiming at the polydisperse effect of polymer chains on the adsorption. Westudied the variation of polymer chain conformations for a polymer solution systemwhich is bi-disperse in the chain length distribution. And we focused on thecompetition between the two different chain lengths upon the adsorption. The resultsshow that the long chain dominates the absorption.