科研之友
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摘要
This work proposes a mechanism for the physical processes underlying the wide practical application of the unique properties of a substance in a critical state-critical fluid (CF)-in contemporary technologies. According to the fluctuation theory of phase transitions (FTPT), this mechanism may be due to the fluctuation and structural characteristics of a critical fluid, which determine its equilibrium and kinetic properties. Among such characteristics are the system correlation radius Rs, the number of order parameter fluctuations N (f) R (s) (-3) per mole of critical fluid, and the fluctuation component of the thermodynamic potential F*(f) = N (f) k T (c)/(P (c) V (c)) = C (0) R (s) (-3) . These structural characteristics are studied with the use of experimental gravity effect data, such as the altitude and temperature dependencies of the scattered light intensity I(z, t) in a heterogeneous substance (n-pentane) near the critical vaporization temperature. Using these results and the literature data on the formation of Al2O3 nanoparticles with the use of SC-H2O, the propagation velocity of substance molecules v (f) a parts per thousand 106 cm/s is estimated for the origination and decay of order parameter fluctuations. It has been concluded that just such high propagation velocities of substance molecules most likely cause the unique properties of a critical fluid during their practical application in a number of engineering processes.
- 出版日期2015-12
