One. Scientific Foundations of Hollow Glass Microspheres one.1 Composition and Microstructure one.1.1 Chemical Composition: Borosilicate Dominance Hollow glass microspheres (HGMs) are mainly made up of borosilicate glass, a material renowned for its very low thermal expansion coefficient and chemical inertness. The chemical makeup typically incorporates silica (SiO₂, fifty-90%), alumi... http://myworldgo.com/profile/okok0972/action_id/3410077/show_comments/1