68
2 The Interaction of Electromagnetic Waves with Water
Fig. 2.7 Spectra of a the
imaginary part, , of the
dielectric constant (dielectric
loses), and b the dynamic
conductivity, σ , of water
(H 2 O), glycerol (C 3 H 8 O 3 ),
ethylammonium nitrate
(C 2 H 8 N 2 O 3 ), and quartz
(SiO 2 ). Experimental data
from [22, 23] and the
personal archive of the
author are used. The yellow
area shows the Debye
relaxation region, which is
not observed in the spectra of
normal dielectrics, such as
quartz (compare the gray
area). Black arrows show the
maxima of the dielectric
relaxation for different
substances
the other liquids are also manifested in the close activation energy of the relaxation
time and similar physical properties, yet the basic mechanisms underpinning their
dielectric properties were not fully analyzed in comparison.
2.4 The Static Dielectric Constant
2.4.1 Experimental Data
One of the most recognizable electrodynamic parameters of water is the static dielectric constant, which at 25
◦ C equals 78.4 and increases to 93.0 at –1
◦ C. This
value is relatively high for dielectrics, but yet not the highest (see Table 2.4). For
example, such ferroelectric materials as BaTiO 3 or SrTiO 3 have dielectric constants
of 4,000 and 300, respectively, while paraelectric SiO 2 , TiO 2 , and Teflon have dielectric constants of 4, 50, and 2, respectively. Despite the commonly accepted opinion, the dielectric constant is not always connected with the dipole moment of the
molecule. For example, the KCl molecule has dipole moment 6 D
7 (more than three
times higher than for the water molecule), while the dielectric constant of KCl crystal
is only about 5.
The (0) of water is important for various practical applications. It is used in
electronics, energy applications, communications, environmental sciences, analytical
chemistry, and electrochemistry. This parameter determines the characteristics of
the signal-transmission lines, indicates the phase transition and temperature change,
7 1 D (Debye) = 3.33 ·10 −30 C·m.
2 The Interaction of Electromagnetic Waves with Water
Fig. 2.7 Spectra of a the
imaginary part, , of the
dielectric constant (dielectric
loses), and b the dynamic
conductivity, σ , of water
(H 2 O), glycerol (C 3 H 8 O 3 ),
ethylammonium nitrate
(C 2 H 8 N 2 O 3 ), and quartz
(SiO 2 ). Experimental data
from [22, 23] and the
personal archive of the
author are used. The yellow
area shows the Debye
relaxation region, which is
not observed in the spectra of
normal dielectrics, such as
quartz (compare the gray
area). Black arrows show the
maxima of the dielectric
relaxation for different
substances
the other liquids are also manifested in the close activation energy of the relaxation
time and similar physical properties, yet the basic mechanisms underpinning their
dielectric properties were not fully analyzed in comparison.
2.4 The Static Dielectric Constant
2.4.1 Experimental Data
One of the most recognizable electrodynamic parameters of water is the static dielectric constant, which at 25
◦ C equals 78.4 and increases to 93.0 at –1
◦ C. This
value is relatively high for dielectrics, but yet not the highest (see Table 2.4). For
example, such ferroelectric materials as BaTiO 3 or SrTiO 3 have dielectric constants
of 4,000 and 300, respectively, while paraelectric SiO 2 , TiO 2 , and Teflon have dielectric constants of 4, 50, and 2, respectively. Despite the commonly accepted opinion, the dielectric constant is not always connected with the dipole moment of the
molecule. For example, the KCl molecule has dipole moment 6 D
7 (more than three
times higher than for the water molecule), while the dielectric constant of KCl crystal
is only about 5.
The (0) of water is important for various practical applications. It is used in
electronics, energy applications, communications, environmental sciences, analytical
chemistry, and electrochemistry. This parameter determines the characteristics of
the signal-transmission lines, indicates the phase transition and temperature change,
7 1 D (Debye) = 3.33 ·10 −30 C·m.