Hollow Microsperes

• Published in: Chemical engineering & technology Vol. 27; no. 8; pp. 829 - 837
• Main Authors: Bertling, J., Blömer, J., Kümmel, R.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.08.2004; WILEY‐VCH Verlag
• Subjects: Microstructure; Modeling; Product properties; Spheres
• ISSN: 0930-7516; 1521-4125
• DOI: 10.1002/ceat.200406138

Hollow microspheres are spherically symmetrical particles consisting of at least two phases. Their sales are continuously increasing because of a large number of well‐known and new applications. While most of the current needs for hollow microspheres are met by inorganic byproducts of combustion processes (cenospheres), the fabrication of tailor‐made hollow sphere structures by processes like spray‐drying as well as dripping, emulsion and suspension techniques is gaining more and more interest. Surface phenomena play an important role as far as formation, properties and stability of hollow microspheres are concerned. Template techniques can be used to yield structures that have not been available so far. Modeling and simulation of the formation processes are useful tools to understand the formation mechanisms and to simplify the scaleup. Hollow microspheres are gas‐filled spherical particles with diameters between 1 and 1000 microns. They show a promising potential because of their advantageous properties like low effective density and high specific surface. The wall material consists of glass, oxide ceramics, mixed oxides, silicates, polymers, or metals. The fabrication of tailor‐made hollow microsphere strucures by processes like spray‐drying as well as dripping, emulsion and suspension techniques is becoming more popular.