crystallisable

Crystallisable, sometimes spelled crystallizable in American English, is an adjective describing a substance that can form a crystalline solid under suitable conditions. A crystallisable material can arrange its molecules or ions into an ordered, repeating lattice, typically through processes such as crystallization from a solution, melting, or vapor deposition. Crystals are characterized by long-range order, a defined lattice structure, and often a sharp melting point and anisotropic properties.

Crystallisability depends on factors such as molecular symmetry, intermolecular or ionic interactions, and thermodynamic conditions. Substances with regular geometries and directional bonds tend to be crystallisable, while highly disordered, flexible, or crosslinked systems, including many polymers, may resist crystallization or form only partial crystallinity. Impurities, solvent effects, and the existence of polymorphs can also influence crystallization behavior and the ease with which crystals form.

In practice, assessing crystallisability involves experiments such as solvent screening, controlled crystallization from solution, or melt crystallization, followed by characterization using X-ray diffraction, thermal analysis, and microscopy. Crystallization kinetics, nucleation mechanisms (homogeneous versus heterogeneous), and crystal growth rates determine crystal size and quality. The concept is central in fields such as pharmaceuticals, where crystalline forms affect solubility and bioavailability, and materials science, where crystal structure governs mechanical, optical, and electronic properties.

See also: crystallization, crystalline, crystalline polymers, amorphous. Note on spelling: crystallisable is the British-English form; crystallizable is the American-English variant.