Neutron study of self-organization in solutions of ionomers based on sulfonated polystyrene

Processes of self-organization of ionomers based on sulfonated PS containing ionogenic groups in the salt form (SO3Na) in chloroform have been studied by small-angle neutron scattering. At a small content of ionogenic groups SO3Na (1.35 mol %), the conformation of PS chains changes from coil-like to globular due to electrostatic interactions between them. An increase in the share of ionogenic groups to 2.6 mol % brings about the assembly of ionomer chains into a hollow spherical structure with the solvent inside. In the shell of a micelle, polar groups are densely packed and shielded from the solvent by nonpolar fragments of adjoining chains. At a low content of ionogenic groups in ionomers, two-thirds of macromolecules in solution are not incorporated in any structures. With an increase in the content of polar groups to 2.6 mol %, almost all chains are organized to small clusters-the stable pairs of macromolecules.