Tapan Rout - Academia.edu (original) (raw)

Papers by Tapan Rout

A Treatise on Corrosion Science, Engineering and Technology

Journal of Research Updates in Polymer Science, Dec 31, 2013

This review paper summarizes the current state of the art of sol-gel technology for formulating a... more This review paper summarizes the current state of the art of sol-gel technology for formulating anti corrosive protective coating. A brief description of the mechanism of sol-gel reactions, various parameters that influence the property of the final product and the course of the sol-gel reaction has been given. Different types of metal precursors that are extensively used in sol preparation and the advantages and disadvantages have also been mentioned in brief. Surface chemistry of sol-gel matrix and various stabilizing and destabilizing forces that are active on the surface of colloidal particles have also been discussed. Problems related to obtaining good quality product with uniformly distributed concentrations have been outlined. Possible pathways for further improvement of anti-corrosive properties of the coating have been described, such as incorporation of various types of additives into the sol matrix prior to coating. As a whole the present study summarizes the superiority and benefits of organic-inorganic hybrid coatings using sol-gel technique and having good protective and anti-corrosive properties.

Journal of Sustainable Metallurgy, Nov 25, 2019

Aluminum is produced in chemical electrolysis by the Hall-Heroult process using carbon-based mate... more Aluminum is produced in chemical electrolysis by the Hall-Heroult process using carbon-based materials in electrodes (cathode and anode). The amorphous calcined petroleum coke is normally used as the carbon material. During the electrolysis of alumina, a voltage drop of about 0.15-0.25 V occurs due to the formation of gas bubbles at the anode which therefore reduces the electrolysis reaction kinetics. To improve the electrolysis efficiency, graphite material is partly used in both the cathode and anode. To further improve the efficiency of the electrolysis, the graphite may be replaced by graphene oxide (GO) and reduced graphene oxide (RGO) because of their outstanding electrical, mechanical and chemical properties. As the demand for graphene oxide and graphene is increasing daily, large-scale and economic processes should be developed to meet this challenge. This study was carried out to produce GO and RGO from natural high-purity graphite (HPG) by applying oxidation and reduction processes through chemical and mechanical exfoliation processes. In the chemical exfoliation process, multi-metal alloys of zinc, iron, aluminum and silicon are used as the reductant instead of using hazardous chemical materials. In the mechanical exfoliation process, a planetary ball mill is used to exfoliate the natural graphite by purging gaseous oxidants and reductants such as O 2 and H 2 for the oxidation of GO and the reduction of RGO, respectively. The morphology, structure and composition of HPG, GO and RGO have been characterized using different analytical techniques, such as X-ray diffraction, scanning electron microscopy, and transmission electron microscopy with selected area electron diffraction, micro-Raman spectroscopy and Fourier-transform infrared spectroscopy. The number of layers of the GO and RGO samples has been determined based on the characterization data and found to be four to five layers.

Pigment & Resin Technology, Jul 6, 2015

Purpose – This paper aims to investigate the potential of sol-gel coating as replacement for haza... more Purpose – This paper aims to investigate the potential of sol-gel coating as replacement for hazardous hexavalent chrome passivation treatment for galvanised iron (GI) sheet. Generally, corrosion resistance properties of the GI sheet are increased by hexavalent chrome passivation treatment. But hexavalent chrome is hazardous and not environment friendly. Design/methodology/approach – The aim of this study was to understand the effect of nano zinc oxide (ZnO) on corrosion behaviour of sol-gel coating prepared by hydrolysis of the 3-(Glycidoxy propyl) methyl diethoxy silane (GPTMS) and tetra-ethyl-orthosilicate (TEOS). The morphology of the film was characterised by a scanning electron microscope (SEM). The corrosion resistance of the coated samples was evaluated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarisation curve and salt spray test. Findings – From a different corrosion resistance study, it has been observed that sol-gel coating doped with 1 per cent nano ZnO rendered maximum corrosion protection. Beyond 1 per cent of nano ZnO, corrosion resistance property of coated galvanised steel sheet decreased drastically which may be due to agglomeration of nano ZnO and high water permeability of coated galvanised steel sheet. Research limitations/implications – The anti-corrosive property of the coating can be tested by means of atmospheric exposure which produces a real-time evaluation of the anti-corrosive nature of the coating under natural conditions rather than using an accelerated laboratory test. Practical implications – It may be useful for other metal industry like aluminium. The work can be used as a guiding chemistry for development of chrome-free passivation for aluminium. Social implications – It has the potential to replace hexavalent chrome passivation. Originality/value – The use of nano ZnO in sol-gel polymer matrix for the development of corrosion resistant chrome-free polymer coating for galvanised steel sheet and its corrosion resistance study (EIS curve fitting, capacitance value and water permeability) is a novel approach in this research.

Surface Engineering, Aug 8, 2016

Phosphate ion containing acidic polyphenol coating solutions were developed as to mitigate the de... more Phosphate ion containing acidic polyphenol coating solutions were developed as to mitigate the deleterious effect of corrosion on galvannealed iron surface. The influence of manganese sulphate, manganese phosphate and polyethylene wax in polyphenol coatings were investigated to reduce the powdering of complex-shaped galvannealed structures and corrosion effect. Moreover, the reactivity of coating at the surface was evaluated by glow discharge optical emission spectroscopy, scanning electron microscopy and energy dispersive spectroscopy. Low surface integration within 3.5% NaCl environment and frictional behaviour was achieved with 0.5% manganese phosphate in polyphenol coated coupon by electrochemical and mechanical testing respectively.

Progress in Organic Coatings, Dec 1, 2016

In this current study, epoxy-silane hybrid coatings were designed to investigate their anti-corro... more In this current study, epoxy-silane hybrid coatings were designed to investigate their anti-corrosion performance and adhesion on galvanized steel. Silanes with alkoxy group, epoxy group, amine group and thiol group were chosen to understand the role of functionalities in the performance of designed hybrid coatings. Moreover, the silanes were added at three different concentrations into epoxy polymer to asses the effect of concentration on anti-corrosion and adhesion properties of the coating films. From scanning electron microscopic (SEM) images, we observed a uniform coating without any agglomeration of coating particles over galvanized steel substrates. The corrosion performance of casted and cured films was evaluated by using potentiodynamic polarization and AC impedance spectroscopy method. The physical properties, such as, thermal behavior and thermo-mechanical behavior were studied using differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) respectively. The adhesion strength between coating films and galvanized steel substrate was checked by 'pull off' adhesion test. It was found that due to the grafting of sol-gel coatings onto organic polymer backbone, the adhesion property and anti-corrosive performance has improved remarkably as compared to non-grafted epoxy polymer. It was observed that amino silane showed superior performance compared to thiol silane. The poor performance of thiol silane grafted epoxy coating could be attributed to some chemical incompatibility of hydrophobic and non-polar sulfur silane moiety and hydrophilic and polar waterborne epoxy polymer backbone. Addition of silane by 1 wt% and 3 wt% into epoxy polymer backbone caused improvement in both anti corrosive property and adhesion strength but further increase of the silane concentration to 5 wt% led to deterioration of protective property of the films. This drop in performance can be attributed to excessive consumption of epoxide groups in epoxy resin by amino and thiol functionalities present in silane.

Indian Institute of Metals series, 2022

Theoretical Chemistry Accounts, Jun 24, 2022

Springer proceedings in energy, 2020

This paper describes the development of the dielectric-coated metal-integrated solar panel, which... more This paper describes the development of the dielectric-coated metal-integrated solar panel, which is lightweight and can be used as an alternative roofing material, which can harvest energy. The idea is to leverage the surface area of the roof and its exposure to the sun by generating distributed off-grid solar power. This type of structure can be used also for making solar energy-driven vehicle.

Anti-corrosion Methods and Materials, Oct 28, 2014

Purpose – The aim of this work was to study the effect of La(NO 3 ) 3 on the corrosion behavior o... more Purpose – The aim of this work was to study the effect of La(NO 3 ) 3 on the corrosion behavior of sol-gel coating prepared by hydrolysis of 3-glycidoxypropyl)methyldiethoxysilane and 3-aminopropyltriethoxysilane. Generally, galvanized steel is subjected to a hexavalent chromium passivation treatment. Hexavalent chromium passivation is not an environment friendly product and researchers are looking for a suitable alternative for chromium passivation treatment. Some of the potential alternatives are silicate conversion coating or the use of silane-based coatings. In this context, sol-gel coating was investigated as a potential replacement for hazardous hexavalent chromium passivation treatment. Design/methodology/approach – The sol-gel film was deposited on galvanized steel sheet by the dip coating method. The molecular vibration and chemical properties of sol-gel solution and coated films were obtained by infrared spectroscopy. Images from a scanning electron microscope were obtained to characterize the morphology of the film. The corrosion resistance of the coated samples was evaluated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization curves and salt spray tests. Findings – The results indicated that La(NO 3 ) 3 -doped coatings were more resistance to corrosion than undoped coating. The coating doped with 0.5 per cent La(NO 3 ) 3 offered improved corrosion protection due to the inhibitive action of the La3+ ion. Originality/value – This result can provide a reference for the development of chromium-free passivation for galvanized sheeting.

Journal of Coatings, Apr 3, 2014

Couple of high strength and flexible surface tolerant coatings were designed for oil contaminated... more Couple of high strength and flexible surface tolerant coatings were designed for oil contaminated, rusty, and minimally prepared steel surfaces. These coatings are to have strong interfacial adhesion due to low surface tension and sustain more than 5 MPa pull out force consistently. The effect of optimized concentration of zinc dust and micaceous iron oxide (MIO) as pigments is evaluated for these surface tolerant coating systems. It has been noticed that the presence of these two ingredients has enhanced corrosion resistance more than several times as compared to commercially available coating systems. The corrosion simulation test in 3.5 wt.% NaCl has evident for significant improvement in terms of delaying blistering and delamination. The high pore resistance () indicates the slow migration of ions and water into the substrate and coating interface, which could be the reason of the improvement in corrosion process.

Corrosion Science, Feb 1, 2007

ABSTRACT

The selection of precursors for silane-based anti-corrosive coatings to protect steel is challeng... more The selection of precursors for silane-based anti-corrosive coatings to protect steel is challenging to obtain in a few experiments as the protection performance varies with types of precursor molecule and surface of metal substrates. The coating performance of precursors was predicted through quantum chemical calculations (Density Functional Theory (DFT) where DFT parameters such as hardness (ƞ), dipole moment (µ), and the number of electrons transferred (∆N) to metal substrate enabling us to choose suitable silane coupling agents. DFT study and experimental validation reveals that precursor containing functional groups like -NH2, -SH, and -O- offers better protection against corrosion to galvanized IF steel compared to those without functional moiety. The order of corrosion inhibition is MPTMS (1M) ≈ APTES (1A) > GPTMS (1G) > TEOS(1T).

Materials Today: Proceedings, 2021

Iron oxide has various applications used in steel industry. In this work composites of graphene o... more Iron oxide has various applications used in steel industry. In this work composites of graphene oxide and iron oxide have been prepared by horizontal dry planetary ball milling technique. Graphene oxide (1, 2 wt%) is reinforced to iron oxide to develop composites with improved hardness. Compositions of iron oxide and graphene oxide were ball milled for 14 hrs followed by sintering. X-ray diffraction (XRD) analysis shows peaks of iron oxide and graphene oxide (GO). The agglomeration of phases were found in field emission scanning electron microscopy (FESEM) study. From microstructural analysis, graphene oxide is found to be randomly distributed in the grain of iron oxide. Micro hardness value of iron oxide and GO composite was found to increase significantly when 2% of GO is added to composite. The microstructure and hardness values of the composite of iron oxide-GO (2 wt%) can be considered as the suitable potential coating material for using on surface of conventional material like mild steel to improve its mechanical behavior and wear resistant property.

Materials Research Express, 2022

Phosphating is a widely used metal pre-treatment process due to its ability to improvise pitting ... more Phosphating is a widely used metal pre-treatment process due to its ability to improvise pitting corrosion resistance, wear-resistance, and adherence properties. In the present investigation, we report the manufacturing of spray grade powder of Fe-P metal ingot by mechanical hammering, milling and sieving process. The Fe-P powder and its blending with reduced graphene oxide (rGO) (2 and 4 vol %) were successfully coated over mild steel by thermal plasma spray method for the first time. Successful retention of rGO was observed even after thermal plasma spraying of Fe-P/rGO (2 vol % and 4 vol %), which was challenging and yet to be reported. The morphological investigation of the top-coat layer and cross-section was analysed using a field emission scanning electron microscope (FESEM). The presence of G, D and 2D bands at 1580 cm−1, 1350 cm−1, and 2700 cm−1, respectively in the Raman spectra were the straight forward demonstration of the retention of rGO. Hardness and air-jet erosion t...

SN Applied Sciences, 2021

WC–W2C composites of three different compositions have been synthesized from mixture of WC + W (0... more WC–W2C composites of three different compositions have been synthesized from mixture of WC + W (0, 5 and 16 wt% W) by thermal arc plasma melt-cast technique. Various grown phases observed in the composites consisting of major phases of WC and W2C and minor phases of unbound C (graphite) and tungsten (W) were confirmed by X-ray diffraction, selected area electron diffraction, X-ray photoelectron spectroscopy and Fourier transform infrared studies. Transmission electron microscopy and field emission scanning electron microscopy show polycrystalline nature of composites. Energy dispersive spectroscopy (of X-ray) infers the absence of any impurity in the composite. Almost porous free nature of composites were observed from X-ray micro computed tomography and BET analysis studies. WC–W2C composite (16 wt% W) shows 25% and 21% higher micro hardness (2535 VHN) and Young’s modulus (625 GPa) values than that of pure melt cast WC sample.

Materials Today: Proceedings, 2020

In this research work, we explored an idea to successfully prepare Si-graphene (0.5-1.5 wt%) comp... more In this research work, we explored an idea to successfully prepare Si-graphene (0.5-1.5 wt%) composites by an uniquely in-house designed planetary ball milling process. XRD of Si-graphene composites show major peak of Si (1 1 1) and C(0 0 2). With increasing addition of graphene, intensity of C(0 0 2) peak is found to be increased in the composites. Raman spectra show peaks of Si along with different peaks of carbon such as D, G and 2D peaks. Micro Raman and TEM characterizations indicate that graphene in the Si-graphene (1-1.5 wt%) composite is developed in bi-layer form. HRTEM of typical Si-graphene (1 wt%) composite confirms the formation of composite between graphene and silicon. XPS spectra of de-convoluted high resolution C 1s and Si 2p further confirm the formation of Si-graphene composites. XPS spectra of composites show that more amount of Si is converted into composite with graphene along with also presence of only free Si. When graphene (0.5-1.5 wt%) is added to Si, it is observed that the specific surface area is improved significantly from 87 to 304 m 2 g À1. In this work, it is found that the typical Si-graphene (1 wt%) composite exhibits 11% more electrical conductivity than pure Si.