Persistence Length of Wormlike Polyelectrolyte Molecules

抄録

The persistence length of wormlike polyelectrolyte chains in the salt-free solutions is calculated on the following two assumptions: (i) the strong electrostatic repulsion of chain segments interrupts the mutual encounter of their monomers within a distance much larger than the monomer dimension, and (ii) the small-angle scattering intensity at zero scattering angle vanishes, or equivalently the osmotic compressibility of the solution is zero. The latter condition is expressed with the radial distribution function g₂(R) of the monomers on different polymers as,
N⁻¹n∫(1−g₂(R)) dR=1
where N is the total number of monomers in one polymer and n is the number concentration of monomers. The calculated persistence length is proportional to n^−1⁄2 in very high monomer concentration and to (n⁄N)^−1⁄3 in very low monomer concentration.