Journal of Polymer Science Part B: Polymer Physics, Vol.44, No.18, 2572-2588, 2006
Multiblock copolymers at selective liquid-liquid interfaces: Toward a block size chromatography
We report some very recent studies on the localization of hydrophobic-polar regular copolymers at a selective solvent-solvent interface with emphasis on the impact of block length M on their static properties and dynamics. A simple scaling theory is developed and its predictions are compared with extensive Monte Carlo simulations to provide an adequate description of copolymers behavior at such penetrable phase boundary. We have derived and verified the scaling of various quantities such as the components of the radius of gyration parallel and perpendicular to the interface, the lateral diffusion constant, as well as the characteristic relaxation times for the localization of the polymer coil in terms of chain length N and block size M for various strength of the interface. The copolymer dynamics is elucidated by a Rouse-mode analysis, which reveals a specific coupling of the modes once a copolymer is adsorbed at the selective interface. For the case of copolymer chains being dragged by an external field through the selective interface, we provide results, which suggest a possible application as a new type of chromatography designed to separate and purify complex mixtures with respect to the chain length and the block size of the individual macromolecules. (c) 2006 Wiley Periodicals, Inc.