Further studies of the supercooling of drops of some molecular liquids

Studies on the freezing of pure liquids I. Critical supercooling in molten alkali halides

“…The twinkling of individual particles or changes in bulk reflectivity are readily visible in the formation of ice clouds from water vapour (Cwilong 1945(Cwilong , 1947Sander & Damkoehler 1943;Schiff, Schiff & Gendron 1953). However, Thomas & Staveley (1952 and De Nordwall & Staveley (1954) who examined a number of molecular liquids in a cloud chamber, could in certain cases obtain no clear indication of changes in the nature of the cloud particles with changes of température. Thèse authors expressed doubts as to the reliability of using the appearance of twinkling to indicate the freezing threshold, suggesting, for example, that aggregation of crystalline particles might seriously impair their reflective properties, making them indistinguishable from droplets.…”

Comment on “Jump in the Rotational Mobility of Benzene Induced by the Clathrate Hydrate Formation”

“…Previous experiments have shown that even for the pseudospherical structure II large cage the 2 H NMR line width of deuterated guests is much larger. 5 To illustrate this, we have prepared a sample of benzene-d 6 hydrate with xenon as the small-cage guest and measured the 2 H line width at a temperatures of 270 K. As expected, the line width is close to 10 kHz ( Figure 1). This is due to the fact that the local symmetry of the structure II large cage is lower than that given by diffraction, which gives only the spaceaverage symmetry, and unless the motion of the water molecules in the hydrate lattice is fast enough to give time-averaging on an NMR time scale, the different H-bond configurations impose a distribution on the motional modes of the enclathrated guests and give rise to broad lines.…”

“…Recently it was observed that when a saturated solution of benzene in water was cooled below 253 K in glass capillaries, there were both a shift in the 2 H resonance frequency of the benzene-d 6 and a change in the spin-lattice relaxation time. 1 These changes were interpreted in terms of enclathration of benzene molecules in a clathrate hydrate lattice that caused an increase in motional mobility of the benzene molecules with respect to benzene in aqueous solution.…”

Crystallization and Melting in Glass-Forming Systems

“…The largest values tabulated in Table I are, in fact, not much above the lower limit of observability (about 1 cm-3 sec-I ). For comparison the nucleation frequency observed for a molten metal at a relative undercooling (ilT,) of 0.2 is about 1013 cm-3 sec-l , some 13 orders of magnitude larger than the expected value for Si02 at the same relative undercooling.…”