partikkelvolumfraksjonen

Partikkelvolum, or particle volume, refers to the physical volume occupied by a single particle. In solid, non-porous particles this is the actual solid material volume. For porous particles, the solid volume can be smaller than the apparent volume that the particle occupies, because void spaces contribute to the overall size without adding solid mass. The concept is used across disciplines such as materials science, pharmacology, and aerosol science to relate size, mass, and density of particles.

Measuring or estimating particle volume can be done in several ways. Direct methods include microscopy with image analysis, where particle dimensions are measured and a volume is calculated assuming a geometric shape (for example, sphere or ellipsoid). For irregular shapes, volumes can be approximated or determined by 3D imaging techniques. Density-based methods use the relationship volume = mass divided by true density; Archimedes’ principle can be employed to determine a particle’s immersed and dry masses to infer volume and density. For nanoscale particles, scattering or tomography techniques can provide volume estimates, often yielding an equivalent or effective volume.

Related quantities include the particle’s equivalent spherical diameter, derived from the volume via V = (π/6) d^3, and the concept of particle volume fraction (the ratio of total particle volume to the suspension or material volume). Porosity and specific volume are also connected, particularly for porous materials where porosity changes the relationship between solid volume and bulk volume.

Applications of particle volume measurements appear in powder technology, pharmaceutical formulation, catalysis, and environmental or aerosol studies, where volume data inform packing, flow, reactivity, and transport properties.