Microstructure of a Soda‐Lime Glass Surface

Electron micrographs were made of replicas of a weathered soda‐lime glass surface before and after various chemical and fire polishing treatments. These micrographs were compared with an electron micrograph of a replica of a fractured soda‐lime glass surface which was used as a typically smooth surface. Using this comparison, the smoothest surfaces were formed by dilute hydrofluoric acid, dilute phosphoric acid, sodium citrate solution, a solution of the disodium salt of ethylenediaminetetraacetic acid, and a fire polish‐water wash combination. On the other hand, alkaline solutions tended to roughen the glass surface and leave residues on it. Selected electron micrographs are shown to illustrate the effect of these treatments on soda‐lime‐type glass.