QUANTITATIVE THEORY OF THE GLOBULE-TO-COIL TRANSITION .2. DENSITY DENSITY CORRELATION IN A GLOBULE AND THE HYDRODYNAMIC RADIUS OF A MACROMOLECULE

In this series of papers new results and a brief review of the current state of mean-field theories of the condensed globular state and of the globule-to-coil transition in the THETA-region for a linear, homogeneous, noncharged macromolecule are presented. As a basis of our consideration, we use both Lifshitz's theory and interpolation Flory-type theory. Complete quantitative theoretical results are obtained and compared with experimental data. In this paper (the second in this series) the macromolecule properties determined by the pair density-density correlation function are considered. This function for a polymer globule is calculated in the framework of mean-field Lifshitz's theory. Using the correlation function, the hydrodynamic radius of a macromolecule is found in the Kirkwood approximation. The value of fluctuations of the macromolecule radius of gyration is calculated in the region of the globule-to-coil transition, which is connected with a sharp change in the fluctuational regime. The existence of a maximum of fluctuations in the transition region is shown.