Definition From Wikipedia,
Microsphere is a term used for small spherical particles, with diameters in the micrometer range (typically 1?m to 1000?m (1mm)). Microspheres are sometimes referred to as microparticles.
Microspheres can be manufactured from various natural and synthetic materials. Glass microspheres, polymer microspheres and ceramic microspheres are commercially available. Solid and hollow microspheres vary a lot in density and, therefore, are used for different applications. Hollow microspheres are typically used as additives to lower the density of a material. Solid microspheres have numerous applications depending on what material they are constructed of and what size they are.
Polyethylene and polystyrene microspheres are two most common types of polymer microspheres.
Polystyrene microspheres are typically used in biomedical applications due to their ability to facilitate procedures such as cell sorting and immunio precipitation. Proteins and ligands absorb onto polystyrene readily and permanently, which makes polystyrene microspheres suitable for medical research and biological laboratory experiments.
Polyethylene Microspheres are commonly used as a permanent or temporary filler. Lower melting temperature enables polyethylene microspheres to create porous structures in ceramics and other materials. High sphericity of polyethylene microspheres, as well as availability of colored and fluorescent microspheres, makes them highly desirable for flow visualization and fluid flow analysis, microscopy techniques, health sciences, process troubleshooting and numerous research applications. Charged polyethylene microspheres are also used in electronic paper digital displays.
Glass microspheres are primarily used as a filler and volumizer for weight reduction, retro-reflector for highway safety, additive for cosmetics and adhesives, with limited applications in medical technology.
Ceramic microspheres are used primarily as grinding media.
Microspheres vary widely in quality, sphericity, uniformity, particle size and particle size distribution. The appropriate microsphere needs to be chosen for each unique application.
************ Comments? ************
We believe that microspheres are one of the least understood commercial products.? Most people associate microspheres with their use as a filler material in plastics and composites? (hollow glass microspheres).?? This is only one of many applications.
The second least understood use of microspheres is in cosmetics and the personal care industry.? Ceramic and polyethylene microspheres are used in cosmetics to create a soft silky texture, and to provide filler to diminish wrinkles on the skin.?? The personal care industry use polyethylene microspheres as exfoliating agents in shampoos and body washes (the suspended color objects).