1. Scientific Foundations of Hollow Glass Microspheres one.1 Composition and Microstructure 1.1.1 Chemical Composition: Borosilicate Dominance Hollow glass microspheres (HGMs) are largely made up of borosilicate glass, a material renowned for its small thermal expansion coefficient and chemical inertness. The chemical makeup typically features silica (SiO₂, 50-90%), alumina (Al₂O₃, 10... https://www.scoop.it/topic/okok0972/p/4168399964/2025/10/14/exactly-what-is-calcium-stearate-powder