Quantitative Determination of Wax Contamination in Polystyrene HIPE Foam Using Solid-State NMR

Differences in molecular mobility between polystyrene foam and Brij-78 wax results in vast differences in the ¹H nuclear magnetic resonance (NMR) linewidth. This allows for the convenient determination of wax content in the polystyrene foam components of inertial confinement fusion targets via solid-state NMR. Contamination levels as low as 0.1% are easily recognized and quantified, and the detection limit is calculated to be 0.02% even when only 32 transients are recorded.