Phase Transition of Water Confined in Saponites Using Positron Annihilation Spectroscopy
The temperature dependent Positron lifetime and Doppler broadening spectroscopy have been carried out to study the phase transition of water confined in interlamellar spaces of saponite clay in the temperature range 300K-200K. The change in slope/discontinuity in S-parameter and Ps lifetime as a function of temperature is an indication of phase transition. Two phase transition temperatures viz. above and below the bulk freezing temperature have been observed for water confined in saponite clay. This indicates the presence of two regimes of water confined in interlamellar spaces. The freezing-melting cycle is also marked by significant hysteresis.
Jozef Krištiak, Jan Kuriplach and Pradeep K. Pujari
P. Maheshwari et al., "Phase Transition of Water Confined in Saponites Using Positron Annihilation Spectroscopy", Materials Science Forum, Vol. 733, pp. 111-114, 2013