Applications of magnetic resonance imaging to ion-exchange resins

Magnetic resonance imaging (MRI) was used to determine swollen resin morphology in cation–exchange beads. The study of the nonuuniformity of the swelling of cation–exchange beads [sulfonated styrene–divinylbenzene (SDVB) copolymers] is of interest because the exchange kinetics and other properties are expected to be strongly influenced by the swelling. MRI can replace current invasive and destructive methods for studying the morphology of these resins. Several types of ion–exchange resins were examined including beads which exhibit homogeneous swelling, heterogeneous swelling, and partially sulfonated beads. The variation in intensity observed is due to a variation in crosslink density, degree of sulfonation, composition, sulfone bridging, or a combination of these variables. Due to their small size, the beads were also imaged using a small coil insert. Results are compared to commercially available insert images in terms of signal‐to‐noise and experiment time. © 1995 John Wiley & Sons, Inc.