One. 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 expansion coefficient and chemical inertness. The chemical make-up normally consists of silica (SiO₂, fifty-ninety%), alu... https://www.jointcorners.com/post/483681_elementary-substance-is-a-pure-chemical-substance-that-consists-of-atoms-belongi.html