Small-angle neutron scattering from sulfonate ionomers

Abstract

Small-angle neutron scattering experiments (SANS) have been performed on sulfonated polystyrene ionomers. Sulfonate concentrations were studied over the range 0-8.5 mol % . The radius of gyration of the polystyrene ionomers showed a regular increase with increasing sulfonate content. The radius of gyration was insensitive to thermal annealing and remained unchanged at temperatures well above the glass transition temperature.

Review and critical analysis of the morphology of random ionomers across many length scales

“…An overall change in conformation; however, can be probed using small-angle neutron scattering (SANS). A number of studies using SANS have explored whether ionic aggregation causes an expansion in chain dimensions in ionomer solids [64][65][66][67][68]. Overall, the picture that emerges is the following: SANS studies indicate that chain expansion, if it occurs, is slight ($10%).…”

Anomalous Concentration Effects of Zwitterionic Telechelic Polymer Solutions in Electric Fields

“…As seen for ionomers, this apparent increase in R g is associated with clustering of ionic groups. [86,87] Studies of 31 6 10 3 ZT-PS by Antonietti et al in toluene show there to be considerable aggregation, with between 3 and 8 chains per cluster even in dilute solutions with an associated R g value of 22 nm. [18] Although the absolute values of radius of gyration obtained by Antonietti et al are different from the values derived from the s values from the current work, this discrepancy is probably not significant since different solvents were used.…”

Neutron Scattering from Polymers: Five Decades of Developing Possibilities

“…At high salt content, they become polyelectrolyte materials, but at low levels-a few mole%-the salt groups form associations. Bill was interested in ionomers in the melt and glassy state, and we used SANS to elucidate how the salt clusters deformed the molecules and also gave rise to heterogeneous structure in the material (76)(77)(78). It was through Bill that I met Bob Weiss from the University of Connecticut, who also spent a sabbatical-in fact, two-at Imperial and with whom we collaborated on blends under shear, as mentioned earlier, and later on main-chain liquid crystal polymers.…”