Colloidal structure of ionomer solutions in polar solvents

The structure of ionomer solutions in polar solvents which are not able to dissolve the neutral polymer analogue was investigated using small-angle X-ray and neutron scattering. The colloidal nature of these solutions is demonstrated for two different families of ionomers. The perfluorinated ionomers form rod-like particles. The value of the radius varies from 15 to 25 Angstrom depending on the nature of the ionomer and on the solvent. The polyethylene co-methacrylic acid partially neutralized ionomers form ellipsoidal particles. The semi-major axis and the semi-minor axis are, respectively, 125 Angstrom and 350 Angstrom. In both cases, no solvent penetrates the particles.