Dielectric Constant Anomaly of CO near its Liquid-Vapor Critical Point

Abstract

The first observation of the predicted anomaly in the static dielectric constant of a pure fluid near its critical point is reported. This anomaly, not observed to date in nonpolar fluids, is now seen in CO, a polar fluid. The anomalous increase in the dielectric constant, 6e/e ? reaches l x 10~3 for fluid with density very close to the critical value. The functional form of the anomaly is consistent with current theoretical predictions.

Dielectric Anomaly and the Vapor-Liquid Phase Transition in Mercury

“…This is in contrast to the behavior of nonmetallic fluids for which a comparatively moderate dielectric anomaly occurs very close to the critical point. 10 " 12 More physical insight is obtained when e x is plotted as a function of density N, as shown in Fig. 2.…”

Accurate High‐Pressure Measurements of Carbon Monoxide's Electrical Properties

“…this work 255.10 to 313.282.0 to 8.0 Pestak and Chan [25] 132.86 3.49 van Itterbeek and de Clippeleir [27] 273.2 to 372.9n/a van Itterbeek and Spaepen [28] 77.3 to 294.5 0.03 to 0.10…”

“…Review of the dielectricp ermittivity measurementsf or carbon monoxide.T he standard uncertainties in T, p and e r for this workw ere 0.02 K, 0.001MPa, and less than5 2ppm,r espectively.N ou ncertainties were reported for any of the literature data in Refs. [25][26][27][28][29][30]. Pestaka nd Chan [25] reported relative changes in the dielectric permittivity as well as one valuea tthe critical point.…”

“…[25][26][27][28][29][30]. Pestaka nd Chan [25] reported relative changes in the dielectric permittivity as well as one valuea tthe critical point.…”

“…The measured dielectric permittivities available in the literature [25][26][27][28][29][30] for pure CO are summarised in Table 1. No experimental values for the dielectric permittivity of CO could be found for pressures beyond0 .61 MPa, [26] except the value at the critical point (p cr = 3.49 MPa [31] )r eported by Pestak and Chan [25] (the authors investigated the relative changes in the dielectric permittivity in the critical region;n oa bsolute values were reported in their work, except for ad ielectric permittivity measurement at the critical point).…”