LIGHT-SCATTERING STUDY OF SEMIFLEXIBLE POLYMER-SOLUTIONS .2. APPLICATION OF AN INTEGRAL-EQUATION THEORY

The structure factor ($) over cap S(k) and the correlation length xi f or semiflexible polymer solutions were formulated using the generalize d Omstein-Zernike (GOZ) integral equation for the monomer-units pair c orrelation functions. The derived expression for ($) over cap S(k) con tained the Fourier transform C(k) of the direct correlation function C (r) involved in the GOZ equation. Taking advantage of the short range nature of C(r), we calculated C(k) from the scaled particle theory, wh ich was previously shown to successfully describe thermodynamic quanti ties of semiflexible polymer solutions. The present theoretical approa ch gave ($) over cap S(k) and xi which were favorably compared with th e previously obtained experimental results for dilute through semidilu te solutions of a semiflexible polymer poly(n-hexyl isocyanate) dissol ved in a good solvent dichrolomethane.