Self-consistent treatment of copolymers with arbitrary sequences

Using the Gaussian Ansatz for the monomer-monomer correlation functions ae derive a set of the self-consistent equations for determination of the conf ormational state in the bead-and-spring copolymer model. The latter is base d on the Edwards-type effective free-energy functional with arbitrary two-b ody interaction matrix. The rate of conformational changes in kinetics may be expressed via the instantaneous gradients of the variational free-energy functional in the space of the averaged dynamical variables. We study the equilibrium and kinetics for some periodic and random aperiodic amphiphilic sequences in infinitely diluted solution. Typical equilibrium phase diagra ms are elucidated and the conformational structure of different states is d iscussed. The kinetics of compaction of an amphiphilic copolymer to the glo bular state proceeds through formation of locally frustrated non-equilibriu m structures. This leads to a rather complicated multistep kinetic process. We observe that even a small modification in the primary sequence of a cop olymer may significantly change its kinetic folding properties.