Melting depressing factor

A different melting point, and hence supercooling, is predicted for the strained sector. This is the basis for a different interpretation of the (200) growth rates a regime //// transition occurs on (110) but not on (200). This is despite the fact that the raw data [113] show a similar change in slope when plotted with respect to the equilibrium dissolution temperature (Fig. 3.15). It is questionable whether it is correct to extrapolate the melting point depression equation for finite crystals which is due to lattice strain caused by folds, to infinite crystal size while keeping the strain factor constant. 

Figure 9.24 shows temperature-reduced plots of 2d, Nc and 5 versus Tf + ATg. All the data conform well to a reduced curve like Figure 9.23. Interestingly, when the authors used both Tg and the melting temperature (Tm) [61] depressions to conduct superposition, they recognized that the reduced curve is nicely constructed but there is no significant difference compare with the case of Tf+ ATg. This indicates that Tg depression is important in optimizing foam processing conditions but Tm depression is not a significant factor for processing because the Tf range is still below Tm after C02 saturation.

Melting point also changes when a solute is added, but it is not related to the vapor pressure. Instead, it is a factor of crystallization. Impurities (the solute) interrupt the crystal lattice and lower the freezing point. Freezing point depression for an ideally dilute solution is given by the equation ... 

In Figures 2.7 - 2.9, the experimentally determined dependencies of the melting point depression of LiCl, NaCI, and KCI on composition, respectively, are compared with the theoretical course of liquidus curves for different values of the Storkenbeker s correction factor kst-... 

The relations which are found here will be best understood with the help of Fig. 72 In this figure, OB represents the sublimation curve of ice, and BC the vaporisation curve of water the curve for the solution must lie below this, and must cut the sublimation curve of ice at some temperature below the melting-point. The point of intersection A is the cryohydric point. If the solubility increases with rise of temperature, the increase of the vapour pressure due to the latter will be partially annulled. Since at first the effect of increase of temperature more than counteracts the depressing action of increase of concentration, the vapour pressure will increase on raising the temperature above the cryohydric point. If the elevation of temperature is continued, however, to the melting-point of the salt, the effect of increasing concentration makes itself more and more felt, so that the vapour-pressure curve of the solution falls more and more below that of the pure liquid, and the pressure will ultimately become equal to that of the pure salt that is to say, practically equal to zero. The curve will therefore be of the general form AMF shown in Fig. 72. If the solubility should diminish with rise of temperature, the two factors, temperature and concentration, will act in the same direction, and the vapour-pressure curve will rise relatively more rapidly than that of the pure liquid since, however, the pure salt is ultimately obtained, the vapour-pressure curve must in this case also finally approach the value zero.2... 

Rim and Runt discussed melting behaviour in blends in general. They pointed out that Tj depends on thermodynamic factors, melting-point depression and... 

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