1. Scientific Foundations of Hollow Glass Microspheres 1.1 Composition and Microstructure one.1.1 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 contains silica (SiO₂, fifty-ninety%), alumina (Al₂... https://friendstrs.com/post/167845_elementary-substance-is-a-pure-chemical-substance-that-consists-of-atoms-belongi.html