Optimal chain architectures for the molecular design of functional polymer surfaces

The Scheutjens-Fleer self-consistent mean-field theory is used to calculate the surface segregation of various chemical functional moieties located on functional polymers of different architectures. Our results demonstrate the importance of the number and location of functional groups and their surface preference relative to polymer backbone segments in determining surface segregation. In general, we conclude that adjacency of similar functional groups is the most effective means for enhancing surface segregation of functional groups and that having two functional groups of similar character is always preferable to having two functional groups of opposite character, the Pushmi-Pullyu architecture, where one group prefers the surface while the other is repelled from it. The calculations demonstrate that the optimal architecture for producing a low-energy release surface is a functional polymer with adjacent low-energy functional groups located at one chain end. In this situation, both enthalpic and entropic factors serve to drive chain ends to the surface. In contrast, high-energy adhesive surfaces are best obtained by placing adjacent high-energy functional groups at the center of the polymer chain. High-energy groups situated at the middle of the chain locate preferentially in the second lattice layer, from which they can migrate readily to the surface when it is contacted with any other high surface energy medium.