Nucleationsstart

Nucleationsstart, sometimes written Nukleationsstart in German-language literature, denotes the onset of nucleation events in a system undergoing a phase transition or particle formation. It represents the moment when stable nuclei first appear within a supersaturated or undercooled medium and begin to grow, signaling the shift from a metastable state to a new, condensed phase.

Nucleation can proceed via homogeneous path, where nuclei form in the bulk, or via heterogeneous path, on surfaces, interfaces, or impurities. Classical nucleation theory describes the competition between the bulk driving force for phase change and the surface energy cost. A critical nucleus size exists, beyond which growth is favorable; smaller clusters dissolve.

The precise timing of the nucleationsstart depends on temperature or concentration, degree of supersaturation, impurities, and available surfaces. Detection methods include light scattering, calorimetry, and microscopy, which track the appearance of stable nuclei. In practice, nucleation start strongly influences subsequent growth, morphology, and material properties.

In materials science and chemistry, controlling the nucleationsstart is essential for crystallization control, pharmaceutical formulation, polymer processing, and mineral precipitation. In atmospheric science, the onset of droplet or ice nucleation governs cloud microphysics. Understanding and modeling the nucleationsstart helps optimize product quality and process efficiency.

Notes: the term is not universally standardized in English and is more common in German-language sources or in discussions of nucleation onset.