Journal Article
Proceedings of the National Academy of Sciences, vol. 116, iss. 27, pp. 13221-13226, 2019
Authors
Ning Deng, Andrew G. Stack, Juliane Weber, Bo Cao, James J. De Yoreo, Yandi Hu
Abstract
Significance
The wide occurrence of Sr-rich marine barite in undersaturated seawater presents a paradox. Here, in undersaturated solution, we observe barite nucleation on organic films and show it is enabled by cation enrichment. In supersaturated solution, this enrichment generates nanometer-sized Sr-rich nuclei on organic films, while Sr-poor barite grows quickly to micrometer-sized crystals in bulk solutions. Theoretical solid-solution calculations explain the distinct Sr incorporation in barites on organic films and in bulk solutions. The findings resolve the barite paradox and provide insights into manipulating solid-solution nucleation and growth through the unique chemical environment near organic–mineral interfaces, which may revise our understanding of many biomineralization processes and allow strategies for tailoring material synthesis to achieve desired sizes and compositions.
