Many factors are known to affect the morphology and properties of ionomers, and the role that the cation local environment plays is not well understood. To better understand ionomer morphology, the cation environment in sulfonated and carboxylated ionomers was investigated using 23Na NMR. As many as three environments were seen in polydisperse sulfonated polystyrene (NaSPS): isolated sodium ions at 7 ppm, hydrated ions at 0 ppm, and aggregated ions at -12 to -23 ppm. In monodisperse NaSPS, a fourth peak at -2.7 ppm appeared at ionization levels above 1.2% and molecular weights of at least 35,000. The fraction of sodium ions held in isolated ion pairs decreased to zero while the fraction of ionic species in aggregates increased with increasing sulfonation. As the neutralization level increased, the aggregate peak shifted to higher frequency with incorporation of neutralizing NaOH. These peak positions and trends are explainable in terms of the magnetic and electric field properties of each Na+ environment.

As a spectroscopic method, Nuclear Magnetic Resonance (NMR) has seen spectacular growth over the past two decades, both as a technique and in its applications. Today the applications of NMR span a wide range of scientific disciplines, from physics to biology to medicine. Each volume of Nuclear Magnetic Resonance comprises a combination of annual and biennial reports which together provide comprehensive of the literature on this topic. This Specialist Periodical Report reflects the growing volume of published work involving NMR techniques and applications, in particular NMR of natural macromolecules which is covered in two reports: "NMR of Proteins and Acids" and "NMR of Carbohydrates, Lipids and Membranes". For those wanting to become rapidly acquainted with specific areas of NMR, this title provides unrivalled scope of coverage. Seasoned practitioners of NMR will find this an in valuable source of current methods and applications. Specialist Periodical Reports provide systematic and detailed review coverage in major areas of chemical research. Compiled by teams of leading authorities in the relevant subject areas, the series creates a unique service for the active research chemist, with regular, in-depth accounts of progress in particular fields of chemistry. Subject coverage within different volumes of a given title is similar and publication is on an annual or biennial basis.

Includes review and papers on the latest advances by acknowledged leaders and active researchers in nuclear magnetic resonance (NMR) spectroscopy

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