Which particle properties change when size reduction is applied?

Size reduction is the process of reducing particle size, typically by using mechanical forces like cutting, milling, or grinding. This process is often conducted in various industries like food, pharmaceutical, mining, and more, where it can be useful to reduce the particle size of various materials for better processing.

Particle properties are the physical and chemical characteristics of particles that define their behavior in different environments. Some common particle properties include size, shape, surface area, density, porosity, and surface charge.

When size reduction is applied, the following particle properties change: 1. Size: As the name suggests, size reduction reduces the particle size. The particle size distribution can be narrowed down or shifted to smaller sizes, depending on the method used. 2. Surface area: As the size of particles decreases, the surface area per unit mass usually experiences a significant increase. This is important for various applications, such as controlling the reaction rate in chemical processes or improving the dissolution rate in pharmaceutical formulations. 3. Porosity: During size reduction, the porosity or void space between particles can also change. This can affect the properties of a porous material, such as its ability to absorb and hold moisture, as well as its mechanical strength. 4. Shape: The shape of particles can be altered during size reduction. For example, milling can cause particles to become more irregular in shape. Improved control on particle shapes can lead to better material properties and processability. It's important to note that some properties like density and surface charge may not necessarily change during size reduction. However, these properties can be affected by subsequent processing steps that depend on the initial size reduction process.