1. Scientific Foundations Of Hollow Glass Microspheres one.1 Composition and Microstructure one.one.1 Chemical Composition: Borosilicate Dominance Hollow glass microspheres (HGMs) are mostly made up of borosilicate glass, a material renowned for its small thermal growth coefficient and chemical inertness. The chemical make-up normally contains silica (SiO₂, fifty-ninety%), alumina (Al... http://www.mysportsgo.com/profile/okok0972/action_id/1516637/show_comments/1