One. Scientific Foundations of Hollow Glass Microspheres one.1 Composition and Microstructure one.one.1 Chemical Composition: Borosilicate Dominance Hollow glass microspheres (HGMs) are primarily made up of borosilicate glass, a material renowned for its very low thermal expansion coefficient and chemical inertness. The chemical make-up usually includes silica (SiO₂, 50-ninety%), alum... https://go.bubbl.us/e9a4f6/c41b?/Elementary