Supersaturation Research Paper

I.3.1. Nucleation and Crystallization
I.3.1.1. Supersaturation
Supersaturation, the fundamental driving force for the change of phase from solution to solid (i.e. when crystallization occurs), is the first and most essential step in the process of stone formation. On the other hand, Supersaturation means that the concentration of the ions that make up the stone forming salt exceed their solubility in the urine, causing the ions to interact and precipitate as a solid phase crystal.
The formation of renal stones is a consequence of increased urinary super saturation with subsequent formation of crystalline particles (Carvahlo and Nakagawa, 1999; Daudona and Jungers, 2004; Verdesca et al., 2011; Ouyang et al., 2012).
Among the most common expression

Crystallization starts with nucleation and the control of nucleation is critical for the control of the number, size, perfection, polymorphism, and other characteristics of crystalline materials (Shanthi et al., 2014).
Generally, the supersaturated solutions are not at equilibrium. In order to relieve the supersaturation and move towards equilibrium, the solution crystallizes. Once crystallization starts, the supersaturation can be relieved by a combination of nucleation and crystal growth. The supersaturation is the relation of the degree of nucleation to crystal growth that controls the product crystal size and size distribution. It is a crucial aspect of crystallization processes.
Supersaturated solutions exhibit a metastable zone in which nucleation is usually not spontaneous. When the supersaturation is increased, eventually a supersaturation will be reached at which nucleation occurs spontaneously. This is called the metastable limit. Fig. (I.3) described that a representation of the probable crystallization procedures that occur in urine as the degree of saturation changes from undersaturation to