Moment analysis of ion exchange kinetics: Particle diffusion control

✍ Scribed by Douglas M. Smith

• Publisher: Elsevier Science
• Year: 1985
• Tongue: English
• Weight: 438 KB
• Volume: 40
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(85)85141-1

✦ Synopsis

The rate that ion B will diffuse into an ion exchange particle and replace ion A depends upon the concentration, valance state and self diffusion coefficient of the two species. The self-diffusion coefficients, DA and DB, are usually determined by measuring isotopic exchange or from a complicated curve-fitting scheme which requires both forward and reverse exchange rate data. In this work, a moment analysis scheme is developed for the straightforward calculation of D, and D, when the ion exchange rate is controlled by particle diffusion. This moment analysis method requires a single uptake curve, and hence, avoids problems related to the assumption that D, and D, are the same for both forward and reverse exchange.