Ostwald Ripening in the Transient Regime: A Cryo-TEM Study

The evolution of the droplet size distribution of a tetradecane in water emulsion, stabilized by sodium dodecyl benzene sulfonate (SDBS) was followed by cryo-TEM during a 51 day period. As a reference for the initial distribution of a freshly prepared emulsion, the size distribution of a virtually nongrowing squalane in water emulsion was also monitored. It appears that the initial distribution is right skewed and close to log-normal with a broadness parameter of σ = 0.5. This distribution evolved rapidly to a more symmetrical one. At the end of the observation the average particle size increased by a factor of about 2.5, but the limiting left skewed distribution, predicted by the LSW (Lifshitz−Slyozov−Wagner) theory, was not obtained. The ripening rate estimated from the slope of a n 3 ( a n is the number averaged radius) as a function of time is in agreement with the prediction from the LSW theory.