monodispersfördelning

Monodispersfördelning refers to a sample where all particles or entities are of essentially the same size. In contrast, polydispersity describes a sample with a range of particle sizes. Monodispersity is often a desirable characteristic in various scientific and industrial applications, as uniform particle size can lead to more predictable and reproducible behavior. For instance, in the synthesis of nanoparticles, achieving monodispersity is crucial for controlling their optical, electronic, or catalytic properties.

The term originates from the Greek words "mono" (one), "dispersos" (scattered), and "fördelning" (distribution). A perfectly monodisperse sample would have all particles with identical diameters. In reality, complete monodispersity is rarely achieved. Instead, a sample is considered monodisperse if the size distribution is very narrow, meaning the variation in particle sizes is minimal compared to the average size. This narrowness is often quantified using a polydispersity index (PDI). A PDI close to 1 indicates a monodisperse sample, while higher values signify increasing polydispersity.

Methods to achieve or characterize monodispersity include controlled synthesis techniques like seeded growth in colloidal chemistry, careful precipitation methods, or specific separation techniques. Characterization often involves techniques such as dynamic light scattering (DLS), electron microscopy (TEM/SEM), or size exclusion chromatography (SEC). The ability to produce and verify monodisperse samples is important for fields ranging from materials science and pharmaceuticals to inkjet printing and advanced diagnostics.