CHEM02200704003 Nilamadhab Pandhy - Homi Bhabha National ...

Chapter 3
equivalent circuit as shown in Fig.3.10a-b was used for uncoated, Ti, TiO2 and duplex Ti-TiO 2
coated specimens to study the effect top-surface coating on the polarization resistance, double
layer capacitance, coating capacitance and pore resistance in 1 M and 8 M nitric acid as compared
to uncoated specimen. Fig. 3.10a consisting of circuit elements such as R s as solution resistance,
CPE 2 as constant phase element characterized by double layer capacitance (Cdl 2 ) and Rct 2 as
charge transfer resistance respectively was used for uncoated specimens. Electrical equivalent
circuit as shown in Fig. 3.10b consisting of R s as solution resistance, CPE 1 as constant phase
element representing coating capacitance (Cdl 1 ), CPE 2 as constant phase element representing
double layer capacitance (Cdl 2 ), Rct 1 as coating resistance (pore resistance) and Rct 2 as interfacial
charge transfer resistance respectively was used for Ti, TiO 2 and duplex Ti-TiOTiO 2 coated specimen.
Fig. 3.10a-b: : Schematic of electrical equivalent circuit for (a) uncoated, and (b) Ti, TiO 2 and
duplex Ti-TiO 2 coated 304L SS [22].