An effect of local mutual segment density on the complexing behavior of poly(propylene oxide) (PPO) and poly(dimethylaminoethyl methacrylate) (PDMAEMA) was found experimentally.[1] We investigated linear block-copolymers as well as miktoarm star polymers of the two components. A complexation of the PPO chain in the miktoarm stars was found for conditions under which the linear polymer is not complexed.
This architectural effect was investigated using a coarse grained bead spring model for the star polymer. The off-lattice Monte Carlo simulations involved star polymers of the type ABn (n: number of B arms) with a Lennard-Jones (L-J) potential between the beads of arm A and of arm B. The influence of the architecture is investigated for potentials ranging from 0 to 3.0 kJ/mol comparing star polymers ABn and linear polymers AB. End to end distances, radial distribution functions, numbers of next neighbors as well as the isotropic form factor were extracted. A significant effect of the architecture was found. Complex formation in the star polymers occurs for significantly weaker interaction potentials than in the linear block-copolymers.
