MODELS FOR THE SURFACE-ADSORPTION OF TRIBLOCK COPOLYMERS

Amphiphilic polymers are macromolecules that contain two types of segments: one that is compatible with a solvent and another that is solvent incompatible. In solution, the solvent incompatibility drives parts of the chain to adsorb onto the nearest surface or interface. Once bound to the surface, the presence of the polymer modifies the properties of the interface. However, the ability of these chains to adsorb onto a surface is complicated by the fact that the solvent-incompatible moieties will also associate with each other, causing the chains to self-assemble. Furthermore, chains attached to the surface can associate with free chains in solution. These interactions give rise to a complex microstructure in the interfacial region. In order to examine this microstructure, we develop computer simulations to model the adsorption of ABA triblock copolymers. Here, the A moieties are hydrophobic and the Β segment is hydrophilic. Using these models, we examine the conformations of the adsorbed chains. In addition, we investigate how surface coverage is affected by the length of the Β segment, polymer concentration, the energy of interaction between the Β segment and the surface, polydispersity, and reversible adsorption. © 1990, American Chemical Society. All rights reserved.