technique for dielectric property

(Permittivity, ?) measurement of polar-non polar mixture. The High Temperature

Probe measurement procedure consists of Rohde & Schwarz made ZNB-20 Vector

Network Analyzer, Dielectric Assessment Kit (DAK) and DAK Evaluation software

as shown in Fig. 1. The probe will be immersed into the polar-non polar mixture

sample. The resulting measured reflections (reflection coefficient, S11)

are then converted into dielectric properties values (permittivity, ?) via DAK

Evaluation software. Prior to usage, the high temperature dielectric probe kit

needs to be calibrated using three elements and the software. The elements are

air, a metallic shorting block and water.

Fig. 1. Network Analyzer Setup

III. THEORETICAL FORMULATIONS

A.

Estimation of ?jk and

µjk from ?ijk measurement

The straight

line equation in terms of, and are formed from

established equation 11:

(1) (1)

The slopes and

intercept of Eq. 1 for various wjk’s of solute at a given

frequency (f) of applied electric field were shown in Fig. 2.

Slopes of – wjk and – wjk curves in Fig. 3 & 4 are used to

calculate t 8. t’s are also calculated from the slope of of -straight line equation of Fig. 512.

All the t’s calculated from various above mentioned method along with the

most probable, measuredt,

symmetrical ts

and asymmetric tcs

are shown in TABLE I.

The c1

and c2 for relaxation time and can be

estimated using the relation 11, 6 as:

(2)

(3)

whereand provided >. All terms and symbols are depicted

elsewhere 13. All the systems show non-rigid behavior exhibiting double

relaxation times and respectively. The theoretical values of c1

and c2 are calculated from and of Frhlich’s equation:

(4)

(5)

c1

and c2 are also derived from

the plots of and against wjk

at wjk®0 as shown in Fig. 6 and termed as

experimental c1 and c2.

From Eq. 4,

after simplification one gets the dipole-moment µjk as:

(6)

where b=1/(1+w2tjk2)

is the dimensionless parameter and is the slope of

– wjk curve at as shown in

Fig. 2. All the µ’s are placed in TABLE III.

The free energy

of activation of dielectric relaxation DFt and viscous flow DF? has been calculated using

Eyring,s equation6

(7)

(8)

IV. RESULTS AND DISCUSSION

Double relaxation times and due to end over

end rotation as well as flexible part of the molecule are derived from straight

line Eq. 1 analytically. All systems exhibit reasonable values of and treated as

non-rigid systems. The graphs of