Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8149556 | Journal of Crystal Growth | 2015 | 8 Pages |
Abstract
The precipitation of barium sulphate in a rapid mixing device (Y-mixer) coupled with an instantaneous sample freezing device was studied in order to accurately measure the nucleation rate. In this Shock-Freeze Cryo-TEM (SFCT) approach, a small volume of solution was removed from the stream directly into liquid ethane by means of a gravitational guillotine. Using different pipe lengths to measure various residence times, it was possible to determine the particle size, morphology, numbers of primary particles and thus nucleation rate. The nucleation rates were found to be a strong function of Reynolds number, up to Re=3Ã104 (Re being inversely related to the micromixing time). The measured nucleation rates ranged between 2.79Ã1014 and 3.81Ã1017 # mâ3Â sâ1 at supersaturations between 4Ã106 and 1Ã108. The measured particle sizes in this work (ranging from 62 to 320Â nm for supersaturation values between 4Ã106 and 1Ã108) were smaller than those measured by previous researchers, possibly because previous work did not quench the reaction sufficiently fast and thus allowed the particles a longer time to increase in size. In summary, this work successfully achieved a fast, accurate and reproducible nucleation rate measurement that could also give information about particle morphology.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
U. Hendricks, M. Rodriguez Pascual, J.F. Banfield, A.E. Lewis,