The Low Temperature Phase Transition of Water on the Surface of Inorganic Powder Particles

Abstract

The cooling DSC technique was employed to measure the heat of freezing H of water present in the vicinity of the surface of ceramic powder particles. The powders used were α-Al₂O₃, ultrafine SiO₂, kaolin-clay and ZrO₂ being partially stabilized with Y₂O₃ (Y-PSZ). The thermodynamic stability of the vicinal water was in the order of ultrafine SiO₂>>kaolin clay>α-Al₂O₃≥Y-PSZ. The differences were also clearly seen in the relationship of H to T_r (freezing onset temperature) and to t (thickness of the water molecule layer on the surface)