Formation temperature of ultra-stable glasses and application to ethylbenzene

Abstract

Ultra-stable thin glass films are obtained when they are deposited at a temperature Td below the glass transition temperature Tg. An enthalpy excess Δɛ×ΔHm is frozen during deposition inducing an isothermal liquid–glass transition temperature Tsg equal to Td and a liquid-to-liquid transition temperature Tgf above Tg depending on Δɛ. The enthalpy excess, the ultra-stable glass enthalpy saving, and the optimum deposition temperature Tsg leading to the maximum density, are predicted for ethylbenzene, knowing only the molar melting heat ΔHm of crystals, their melting temperature Tm, Tg, and the specific heat jump at Tg.