Partikelgrößenverteilung

Partikelgrößenverteilung refers to the range and proportion of different particle sizes within a sample of particulate matter. It is a fundamental property of powders, suspensions, emulsions, and other dispersed systems. Understanding and characterizing the particle size distribution is crucial in many scientific and industrial fields, as it significantly influences material properties and processing behavior.

The distribution can be described statistically, often using parameters like the mean particle size, median particle size, and the standard deviation or variance. Different mathematical models, such as the normal distribution, log-normal distribution, and Rosin-Rammler distribution, are used to represent these distributions depending on the nature of the material.

Methods for determining particle size distribution are broadly categorized into two types: sieving and sedimentation, which are considered "absolute" methods, and instrumental methods. Sieving uses a series of screens with decreasing mesh sizes to separate particles, while sedimentation relies on the settling velocity of particles in a fluid, which is related to their size. Instrumental methods include laser diffraction, dynamic light scattering, and image analysis. Laser diffraction is widely used due to its speed and versatility. Dynamic light scattering is suitable for very fine particles, typically in the nanometer range. Image analysis provides direct visualization and measurement of individual particles.

The particle size distribution impacts various applications. In pharmaceuticals, it affects drug dissolution rates and bioavailability. In the food industry, it influences texture and mouthfeel. In manufacturing, it plays a role in the flowability, compaction, and sintering of powders, as well as the stability of suspensions and emulsions. Control over particle size distribution is often a key aspect of product quality and process optimization.