The scattering profiles of ionic polymer solutions were discussed in terms of highly distorted ordered arrangement. By using a three-dimensional paracrystal theory, the observed single broad peak was demonstrated to be due to paracrystalline distortion, limited size of the structure, and thermal motion of the lattice.The direct microscopic observation on latex particles substantiated the important contribution of the three factors. The Fourier transform of the micrographs of latex distribution gave scattering profiles, which provided a further support to the above interpretation. The localized non-space-filling ordering was concluded for simple ions, macroions, and latex particles by EXAFS, X-ray scattering and microscopy, respectively, proving the existence of an attraction between like-charged ionic species through the intermediary of counterions.

View full abstract