Partikelform

Partikelform, or particle form, is a term used to describe the external geometry and surface characteristics of individual particles. It encompasses the three-dimensional shape (for example spherical, ellipsoidal, rod-like, plate-like, needle-like, or fibrous) as well as quantitative descriptors such as aspect ratio, roundness, sphericity, and convexity. The form is influenced by material composition and by formation processes, including crystallization, precipitation, milling, grinding, spray drying, and agglomeration. In crystallography, the crystallization habit or crystal habit describes the typical shape a crystal form tends to take under given conditions.

Characterization of Partikelform combines microscopy (optical or electron), image analysis, and indirect methods such as dynamic light scattering or laser diffraction for size, complemented by specific surface area measurements. Shape descriptors are often used in conjunction with size distributions to model suspension stability, flowability, packing density, tabletability, and dissolution behavior.

Impact and applications: Partikelform strongly affects physical properties such as flow in powders, compressibility, and consolidation, as well as chemical properties like reaction rate and surface-related phenomena. In pharmaceuticals, controlling Partikelform can optimize dissolution rate and bioavailability; in catalysts, surface area and facet exposure matter; in pigments and ceramics, color, brightness, and packing are shape-dependent. Manufacturing steps such as crystallization conditions, solvents, temperature, and the use of additives can tailor the habit, while milling and spray drying can produce more equant or more elongated forms.