Diffusion coefficients by NMR-spin echo methods for the systems water-ammonium chloride, water-succinonitrile, and acetone-succinonitrile

Diffusion coefficients for the ammonium ion were obtained at 15-45 degrees C by nuclear magnetic resonance (N-15-NMR) spin-echo techniques in 72 and 8 6 wt% aqueous ammonium chloride 98% enriched with N-15. Diffusion coefficie nts for succinonitrile and water in a 9.4wt% aqueous mixture (25-45 degrees C) and for succinonitrile and acetone (35-55 degrees C) in a mixture with 8.8 wt% acetone were obtained similarly with H-1-NMR. The coefficients were compared with those from earlier studies of these systems, which are model s for the solidification of metals. (C) 2000 Elsevier Science B.V. All righ ts reserved.