Maruthamuthu, S. et al. - Teesside's Research Repository

FTIR was used for the analysis of the biochemical characteristics of the absorbed
products collected from the metal surface exposed to control and experimental systems.
The spectrum was taken in the mid IR region of 400–4000 cm -1 . The spectrum was
recorded using ATR (attenuated total reflectance) technique. The sample was directly
placed in the zinc selenide crystal and the spectrum was recorded in the transmittance
mode.
(b) X-ray diffraction (XRD) and Scanning electron microscopy (SEM)- Energy dispersive Xray
spectroscopy (EDX) studies
Cupronickel coupons of 5 x 1cm 2 size were machine polished to mirror finish, decreased with
trichloroethylene, washed with deionized water and dried. The coupons were immersed in
nitrogen-free broth with and without AG1 and AG3 for 20days and the coupons were
removed and the nature of oxides formed on the metal surface were estimated by XRD and
SEM-EDX. The specimen prepared as described above was analyzed by X’pert PRO PAN
analyzed X-ray diffractometer with Syn Master 793 software to identify the corrosion
product. The XRD pattern was recorded using computer controlled XRD-system, JEOL, and
Model: JPX-8030 with C α K radiation (Ni filtered = 13418 A o ) at the range of 40kV, 20A.
The ‘peak search’ and ‘search match’ program built in software (syn master 7935) was used
to identify the peak table and ultimately for the identification of XRD peak. The same
specimens were examined at different magnifications [500X, 1000X and 2000X] by scanning
electron microscope [Model – Hitachi – S 3000 H]. The elements were identified by Energy
dispersive X-ray spectroscopy (EDX) model: Naron system SIX (Thermo electron
corporation).
(c ) Atomic force microscope (AFM)
The cupronickel 90:10 specimens of size 2.0cm x 0.6cm × 0.06cm were machine and
cloth polished to mirror finish to give a homogeneous surface then washed with
trichloroethylene, followed by deionized water and dried. The specimens were immersed
in nitrogen-free medium in the presence and absence of bacteria at 30ºC for 5 days. The
specimens were removed on the 6 th day and picked. The corrosion product was removed
and dried at room temperature, and then characterized by atomic force microscopy,
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