Structure and Function of Window Glass and Pyrex

TL;DR

This paper models the atomic structure of window glass and pyrex, explaining their thermal and mechanical properties through a unified nanoscopic framework, and suggests new research directions.

Contribution

It introduces a novel model for pyrex based on silica clusters with a ternary interface, extending previous work on window glass composition.

Findings

Model explains thermal expansivity contours of sodium borosilicates

Consistent with pyrex's resistance to shocks

Suggests new nanoscopic structural research directions

Abstract

Window glass is a ternary mixture, while pyrex (after window glass, the most common form of commercial glass) is a quaternary. Building on our previous success in deriving the composition of window glass (sodium calcium silicate) without adjustable parameters, and borrowing from known reconstructed crystalline surfaces, we model pyrex as silica clusters with a specific ternary interface. Our global model explains the thermal expansivity contours of ternary sodium borosilicates, and it is consistent with the optimized resistance of pyrex to mechanical and thermal shocks. It suggests new directions for studying the nanoscopic structure of these remarkable materials.