Saeid Kakooei

Reviews on Corrosion Inhibitors: A Short View

A range of numerous corrosion inhibitors, viz. organic molecules with hetero atoms and π-electron clouds, inorganic salts and plant excerpts likewise their corresponding phytoconstituents were reported with success for metals in different corrosive media. Various literature reviews related to corrosion inhibitors have been reported by many authors based on their application, classification, and inhibition mechanism. A short view of all these reviews is summarized in this manuscript. Various aspects of corrosion inhibitors as well as their recent trends and advancement are also discussed.

Fabrication of nanogap electrodes via nano-oxidation mask by scanning probe microscopy nanolithography

In this study, a simple technique was introduced for the fabrication of nanogap electrodes by using nano-oxidation scanning probe microscopy lithography with a Cr/Pt coated silicon tip. Silicon electrodes with a gap of sub-31 nm were fabricated successfully by this technique. The current-voltage measurements (I-V) of the electrodes demonstrated excellent insulating characteristics. This technique is simple, controllable, inexpensive, and faster than common methods. The results showed that silicon electrodes have a great potential for the fabrication of single molecule transistors, single electron transistors, and other nanoelectronic devices.

Controlling the shape and gap width of silicon electrodes using local anodic oxidation and anisotropic TMAH wet etching

A simple method for fabricating silicon electrodes with various shapes and gap widths was designed using the special properties of anisotropic tetramethylammonium hydroxide (TMAH) wet etching and local anodic oxidation (LAO). A statistical system was used for the optimization of the parameters of the LAO process to facilitate a better understanding and precise analysis of the process. Analyses of the interaction effects among the significant factors of LAO showed that the relative humidity and applied voltage were interdependent. They had the strongest interaction effect on the dimensions of the oxide mask. TMAH with a concentration of 25% was used as an etchant solution in (1 0 0) silicon with a rectangular oxide mask. The observed undercutting at convex corners, tip shape of emitters and gap widths of electrodes were exactly consistent with theoretical studies. Combination of the LAO method and anisotropic TMAH wet etching was successfully used to fabricate Si nano-gap electrodes. This fabrication method of sharp and round tip emitters was simple, controllable and faster than common techniques. These results indicate that the method can be a new approach for studying the electrical properties of nano-gap electrodes.

Growth of Vertically Aligned ZnO Nanorods Arrays by Hydrothermal Method

Well-aligned ZnO nanorod arrays with different average diameters were grown on silicon (100) substrates by hydrothermal method via the precursors of zinc nitrate hexahydrate (Zn (NO3)2 .6H2O) and Hexamethylenetetramine (C6 H12N4) with equal molar concentration at 0.025 mol/l and 0.05 mol/l. The ZnO nanorods were characterized by X-ray diffraction (XRD) and field emission Scanning electron microscopy (FE-SEM). XRD results indicated that all the ZnO nanorods were preferentially grown along [000 direction (c-axis). field emission Scanning electron microscopy images showed that the well-faceted hexagonal ZnO nanorods were grown vertically from the silicon (100) substrates.

Nitriding of Duplex Stainless Steel for Reduction Corrosion and Wear

Duplex stainless steel (DSS) which has a dual nature of ferrite and austenite with nearly equal ratio has found a good application in oil and gas industries because of its excellent corrosion resistance, high yield strength, good weldability, and relative low life cycle costing from reduced operating cost. Dual phases of DSS or combination of two-phase existence to be more characterize with better mechanical properties than a single-phase metal of ferrite or austenite. Nitrogen is a good strengthening alloy for DSS because it forms a solid solution of (Fe, Cr)2N which is responsible for the hardness and wear resistance in DSS. Spontaneous formation of oxide or passivated layer is responsible for shield and direct exposure of surface of stainless steel to corrosive medium though is susceptible to depletion and deterioration in high chlorine water and low pH level in production environment. Total damage of passivated region on the surface of DSS prompts initiation of localized defect such as pit which grows over a time to form crack. Oil and gas environment is characterized with high H2S content which is a constraint in application of DSS in this environment because of its insignificant resistance to sulfide stress corrosion cracking (SSCC) and hydrogen-induced cracking (HIC).

Formation of Nano-Scale FeCO 3 Protective Corrosion Product in Carbon Dioxide-Saturated 3% Sodium Chloride Solution

Corrosion of carbon steel in CO2 saturated NaCl solution contains the formation of FeCO3, as a corrosion product. The protective property of the formed FeCO3 scale layer to corrosion in brine solutions containing CO2 was established as the possible cause of the corrosion rate decrease above 60 °C. In this study, formation of nanoscale FeCO3 film as a corrosion product of X52 carbon steel in CO2-Saturated 3% NaCl solution was investigated. Result showed that corrosion rate decreased after precipitation and formation of protective FeCO3 film in high temperature and high bulk solution pH.

Development of iridium oxide sensor for surface pH measurement of a corroding metal under deposit

1 Department of Physics, Shahid Beheshti University, Evin, Tehran 19839, Iran 2 Centre for Corrosion Research, Department of Mechanical Engineering, Universiti Teknologi PETRONAS, Tronoh31750, Malaysia 3 Centre of Nanoscience and Nanotechnology (NANO-SciTech Centre), Institute of Science, Universiti Teknologi MARA, Shah Alam, Selangor 40450, Malaysia * E-mail: skakooei59@hotmail.com, saeid.kakooei@utp.edu.my