A.R. Khokhlov

Effect of twisting on the behavior of a double-stranded polymer chain: A Monte Carlo simulation

DNA and some proteins have a multistranded chain structure and exhibit characteristic tertiary structures due to twisting or anisotropic rigidity. We studied the effect of chain twisting on the behavior of a circular double-stranded polymer chain using a Monte Carlo simulation with bond fluctuation model. We found that there are two regimes for the chain conformation, depending on its twisting. In the first regime, with weak twisting, a circular chain behaves like a coiled linear chain. In the second regime, the chain shows scaling dependencies characterized by supercoiled structures.

Monte Carlo simulation of association of diphilic chains near the solvent critical region

By means of computer simulation the association process of diphilic chains with strongly attractive head links (stickers) in the vicinity of critical point of the solvent is studied. The calculations were carried out by means of Monte-Carlo simulation with bond-fluctuation model of polymer developed by us for the case of hexagonal-like lattice. It was found that the critical concentration of micelle formation and average aggregation number depend crucially not only on the attraction between stickers but on the quality and state of solvent.