THE EFFECT OF POLYMER GEOMETRY ON POLYMER-SURFACTANT ASSOCIATION IN SOLUTION

We developed a Monte Carlo computer simulation to examine the effect of polymer architecture on polymer-polymer and polymer-surfactant association in solution. Initially, we compared the self-assembly of polymers containing four associating sites with the assembling behavior of polymers containing only two such "stickers," one at each end of the chain. This small difference in the number of stickers lead to marked differences in the properties exhibited by the two types of chains. At short times, the two-sticker polymers form a percolating network, which fragments into small clusters at long times. The four-sticker chains do not form such a network, but form relatively large, stable clusters. Surfactant molecules were then introduced into the system and we compared the polymer-surfactant association for both polymer architectures. The surfactants effectively break up the polymer clusters for the four-sticker architecture, while they enhance the cluster size found in the two-polymer solution. The implications of this behavior on the solution viscosity are discussed.