Organic additives frequently shape crystallisation in natural and industrial settings, yet their precise influence on nucleation remains poorly understood. Here, Baken et al. investigate how additives affect the crystallization of the industrially relevant minerals portlandite and gypsum. Using controlled titration coupled with in situ synchrotron monitoring, the team demonstrates that both minerals form via intermediate steps: portlandite gradually becomes more ordered as it develops, while gypsum switches abruptly from a disordered to an ordered state. The study reveals that additives influence these pathways prior to nucleation by altering the nature of prenucleation clusters. How strongly an additive interacts with these clusters depends on its chemical state, which is controlled by the pH conditions specific to each mineral. These findings offer a starting point for creating an industrial “toolbox” to help select more effective additives, and they advance our understanding of biomineralisation processes.
- Annet Baken
- Alejandro Fernandez-Martinez
- Alexander E. S. Van Driessche
