M. Sullivan, C. Harrison
Keywords: phase behavior, thermophoresis
Summary:We form vapor bubbles in a liquid using an electrically pulsed wire to locally heat and overcome the nucleation barrier. The heat relaxes quickly, allowing us to determine the equilibrium vapor phase stability by observing the subsequent behavior of the bubbles. By independently adjusting the system pressure and temperature we can measure a fluid phase diagram. We find good agreement between our measurements and those made using a conventional phase measurement apparatus. Surprisingly, we are even able to nucleate bubbles in some mixtures where a temperature increase is not expected to create a vapor phase. Evidence suggests that this is due to a thermophoretic enrichment of the more volatile components around the wire.