Crystallization promotion is a new and exciting field that offers the possibility of controlling crystallization to an even greater degree than previously imagined. Promotion has been observed for barium sulfate and calcium carbonate in the presence of organic molecules (for example, aspartic acid) and in the case of barium sulfate in the presence of inorganic cations of the alkaline earth metals. Inorganic anionic promoters of barium sulfate have yet to be reported, however, we will provide evidence here that such promoters exist.

 We show that, indeed, the presence of sodium sulfite and sodium dithionate promotes barium sulfate crystallization. Morphology experiments show that the impact appears to be dominant in the c axis and AFM experiments show that this is due to the promotion of 2D nucleation. Comparison is made with sodium oxalate, which is found to inhibit rather than promote crystallization.

 Finally, we discuss why this finding is curious and the possible mechanism by which this promotion may be occurring.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/28724 must be provided.

1. Jarosite crystallization in the presence of amino acids