Origin of the Thermal Desorption Peeks of Gases in NaI above 180°C

Abstract

We analyze the origin of the water desorption peaks in NaI above the temperature stability range of the crystalline hydrate NaI•2H2O. The two water desorption peaks at t ≥180°C are shown to arise from the decomposition of aqua complexes based on hydroxyl groups. Such peaks in the pressure–temperature curve provide an effective and sensitive tool for detecting OH groups in raw materials. After prolonged room-temperature dehydration, no such peaks emerge. The dehydration process can be accelerated by microwave drying