Non-linear dielectric effect in critical and far pre-critical solutions of nitrotoluene

An apparent critical point in binary mixtures: Experimental and simulation study

“…At 321 K, in the concentration range of 0.5-0.7, the NDE increases in a way typical of far precritical effects. [1][2][3] In this range of concentrations the far-range fluctuations appear, which is manifested as an increase in NDE with decreasing temperature. In the vicinity of the concentration x 2 = 0.61 the highest NDE increase occurs, suggesting that this concentration can correspond to the hypothetical critical concentration of the system.…”

“…[1][2][3][4]27 An attempt has been made at interpreting the phenomena taking place in the two types of mixtures by assuming the same mechanism in both cases. The attempt was justified by the fact that for both types of mixtures, the temperature dependence of NDE related to critical fluctuations is described by a power law with the same values of the critical exponents.…”

“…[1][2][3][4][5][6][7]31 The melting point of these mixtures is higher than their critical point. Their critical point falls in the range of metastable states, and direct experimental determination of the critical point in such a systems is usually impossible because of the problem with reaching the desired overcooled state.…”

Far Precritical Effect in 1,3‐Dimethoxybenzene‐Alkane Mixtures Studied by Nonlinear Dielectric Effect

“…NDE of mixtures of 1,3-dimethoxybenzene with hexane, octane, dodecane, hexadecane and heptadecane was studied by a pulse method, which has been together with the measuring capacitor described in Ref. [15].…”

“…An attempt has been made at interpreting the phenomena taking place in the two types of mixtures by assuming the same mechanism in both cases. This attempt was justified bythe fact that for both types of mixtures the temperature dependence of NDE related to critical fluctuations is described by a power law with the same values of the critical exponents [13][14][15][16]. On the other hand, analyses of the phase diagrams (T,x)p showing the melting points as functions of concentration x of the m-nitrotoluene-alkane mixtures under atmospheric pressure, proved that in the con-centration range in which NDE anomalies are observed there exist two kinds of molecular compounds: the one richer and the other poorer in the polar component [17].…”