Fluorinert fluids

Lin et al. [16] conducted an experimental study on the bubble formatiOTi oti a line shaped polysilicon micro-resistor, which was immersed in the sub-cooled liquids such as Fluorinert fluids (inert and dielectric fluids from 3M Company), water, and methanol. Three different types of input currents were applied after initial nucleation. First, a bubble grew and departed when the input current was ccmstant or increased. Second, a bubble collapsed when the current was turned off abruptly. Third, the size of the bubble decreased and stayed on the top of the heater when the current was reduced gradually. Some important bubble formation phenomena such as Marangoni effects on a microscale, controllability of the size of the microbubbles, and bubble nucleation hysteresis were reported. 

Because structural phase transitions are often ferroelastic or coelastic in character it is essential to have a well-defined stress applied to the crystal at high pressures. In effect, this means that a hydrostatic pressure medium must be used to enclose the crystal. A 4 1 mixture by volume of methanol ethanol remains hydrostatic to just over 10 GPa (Eggert et al. 1992) and is convenient and suitable for many studies. If the sample dissolves in alcohols, then a mixture of pentane and iso-pentane which remains hydrostatic to 6 GPa (Nomura et al. 1982), or a solidified gas such as N2, He, or Ar can be employed. Water appears to remain hydrostatic to about 2.5 GPa at room temperature, just above the phase transition from ice-VI to ice-VII (Angel, unpublished data). The solid pressure media such as NaCl or KCl favoured by spectroscopists are very non-hydrostatic even at pressures below 1 GPa and have been shown to displace phase transitions by at least several kbar (e g. Sowerby and Ross 1996). Similarly, the fluorinert material used in many neutron diffraction experiments because of its low neutron scattering power becomes significantly non-hydrostatic at -1.3 GPa. Decker et al. (1979) showed that the ferroelastic phase transition that occurs at 1.8 GPa in lead phosphate under hydrostatic conditions is not observed up to 3.6 GPa when fluorinert was used as the pressure medium. At pressures in excess of the hydrostatic limit of the solidified gas and fluid... 

Displacement of tube contents was carried out with an Isco Model 185 density gradient analyzer. Each tube contained 14 mil of solution and was analyzed In about 20 minutes by Injecting ISCO s dense and water Immiscible "FluorInert displacement fluid Into the bottom of the tube at a flow rate of 0.75 m5./mln. 

Solvay Solexis HS-260 vapor phase reflow fluid. 3M Fluorinert 70 fluid. 

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