Analysis of the conformation of worm-like chains by small-angle scattering: Monte-Carlo simulations in comparison to analytical theory

Abstract

The analysis of the scattering intensity I0 (q) (q = (4 π/λ) sin (θ/2); λ: wavelength of radiation; θ: scattering angle) of dissolved linear polymers derived from static scattering experiments is considered. The determination of I0 (q) and possible sources of experimental uncertainties are discussed in detail. Moreover, a comprehensive overview of current analytical models for the calculation of I0 (q) of chains without excluded volume is given. These analytical theories are compared to Monte-Carlo simulations of semiflexible chains without excluded volume. It is shown that analytical expressions given by Pedersen and Schurtenberger (Macromolecules 29, 7602 (1996); method 2) provides the best description of the I0 (q) throughout the entire range of stiffness. Among the analytical theories the expression derived by Kholodenko (Macromolecules 26, 4179 (1993)) gives the best description of the scattering function of worm-like chains.