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Article
Publication date: 27 September 2021

Joseph Raj Xavier

The purpose of this study is to use polybenzoxazine (Pbz) functionalized ZrO2 nanoparticles to synthesize polyurethane (PU)-PbZ/ZrO2 nanocomposite. The results derived…

Abstract

Purpose

The purpose of this study is to use polybenzoxazine (Pbz) functionalized ZrO2 nanoparticles to synthesize polyurethane (PU)-PbZ/ZrO2 nanocomposite. The results derived from the electrochemical impedance spectroscopy (EIS) and polarization studies indicated the superior anticorrosive activity of PU-Pbz/ZrO2 nanocomposite coatings compared to those of plain PU coatings. The decreased corrosion current was detected on the scratch of the PU-Pbz/ZrO2 nanocomposite-coated mild steel surface by scanning electrochemical microscopy (SECM) compared to other studied coatings. The superior anticorrosive and mechanical properties of the proposed nanocomposite coatings provide a new horizon in the development of high-performance anticorrosive coatings for various industries.

Design/methodology/approach

The Pbz functionalized ZrO2 nanoparticles were characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX) and thermogravimetric analysis (TGA) in terms of the structural, morphological and thermal properties of these coatings. A different formulation of coatings such as PU, PU-Pbz, PU-ZrO2 and PU-Pbz/ZrO2 were prepared and investigated for their corrosion protection performance on mild steel in natural seawater by electrochemical techniques. The surface morphological studies were done by SEM/EDX and XRD analysis.

Findings

The superior anticorrosive property of the proposed nanocomposite coatings provides a new horizon in the development of high-performance anticorrosive coatings for various industries. Addition of Pbz wrapped ZrO2 nanoparticles into the PU coating resulted in the blockage of charge transfer at the metal/electrolyte interface, which reduced the dissolution of mild steel. It was revealed from the SEM/EDX analysis that the formation of the corrosion products at the metal/electrolyte interface behaved as the passive layer which reduced the dissolution of steel.

Originality/value

The inclusion of polybenzoxazine functionalized ZrO2 nanoparticles to the polyurethane coating reinforces the barrier and mechanical properties of PU-Pbz/ZrO2 nanocomposite, which is due to the synergistic effect of ZrO2 and Pbz.

Details

Anti-Corrosion Methods and Materials, vol. 68 no. 6
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 2 January 2018

Joseph Raj Xavier

This paper aims to investigate the effect of introducing nano-ceria (CeO2) particles to the epoxy coatings on mild steel in natural seawater.

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Abstract

Purpose

This paper aims to investigate the effect of introducing nano-ceria (CeO2) particles to the epoxy coatings on mild steel in natural seawater.

Design/methodology/approach

The epoxy–ceria nanoparticles were coated with mild steel using a wire-wound draw-down bar method. The effects of ceria nanoparticles on the corrosion resistance of epoxy-coated samples were analyzed using scanning electrochemical microscopy (SECM) and electrochemical impedance spectroscopy (EIS).

Findings

Localized measurements such as oxygen consumption and iron dissolution were observed using SECM in natural seawater in the epoxy-coated sample. The increase in film resistance (Rf) and charge transfer resistance (Rct) values by the addition of nano-ceria particles in the epoxy coating was measured from EIS measurements after wet and dry cyclic corrosion test. Scanning electron microscope (SEM)/energy dispersive X-ray spectroscope (EDX) analysis showed that complex oxides of nano-ceria were enriched in corrosion products at a scratched area of the coated mild steel after corrosion testing. Focused ion beam-transmission electron microscope (FIB-TEM) analysis confirmed the presence of the nanoscale oxide layers of ceria in the rust of the steel.

Research limitations/implications

The tip current at −0.70 V for the epoxy–CeO2-coated sample decreased rapidly because of cathodic reduction of the dissolved oxygen. The increase in film resistance (Rf) and charge transfer resistance (Rct) values by the addition of nano-ceria particles in the epoxy coating were measured from EIS measurements after wet and dry cyclic corrosion test.

Practical implications

The presence of complex oxide layers of nano-ceria layers protects the coated steel from rusting.

Social implications

The use of this nano-ceria for corrosion protection is environment-friendly.

Originality/value

The results of this study indicated the significant effect of nano-ceria particles on the protective performance and corrosion resistance of the epoxy coating on mild steel. The dissolution of Fe2+ was lower in the epoxy–ceria nanoparticle-coated mild steel than that of the epoxy-coated mild steel resulting in a lower anodic current of steel. The increase in film resistance and the charge transfer resistance showed that the nano-ceria particles and the formation of complex oxides provide better barrier protection to the coating metal surfaces.

Details

Anti-Corrosion Methods and Materials, vol. 65 no. 1
Type: Research Article
ISSN: 0003-5599

Keywords

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Book part
Publication date: 13 May 2019

Abstract

Details

The Impact of Global Terrorism on Economic and Political Development
Type: Book
ISBN: 978-1-78769-919-9

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Book part
Publication date: 9 October 2020

Ali C. Akyol

Abstract

Details

Corporate Fraud Exposed
Type: Book
ISBN: 978-1-78973-418-8

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Article
Publication date: 28 May 2021

Alistair Anderson and Funmi Ojediran

The purpose of this paper is to review the literature on women’s entrepreneurship in emerging economies. This is a thematic review to identify patterns and trends to…

Abstract

Purpose

The purpose of this paper is to review the literature on women’s entrepreneurship in emerging economies. This is a thematic review to identify patterns and trends to better understand this literature. From the analysis, this study offers ideas for useful and theoretically informed research. In addition, this paper proposes the concept of restricted agency that helps to explain the practice.

Design/methodology/approach

This study identifies the nature, what is interesting, what it sees as important and considers what is neglected in this literature. The analysis sought important issues, interesting directions and the potential for useful future work. Thematic analysis is ideal for messy and unstructured material such as the literature used in this study as the data set. The process is qualitative, iterative and inductive but ontologically appropriate for the socially produced knowledge of the literature.

Findings

This paper finds the literature tends towards descriptive papers. Few papers make substantial contributions to theory. Many papers reported the barriers women to encounter, reporting general and typical processes of responding to obstacles and the implications for practice. Interestingly this study perceives overcoming and sometimes using, the cultural and physical restraints of gendered entrepreneurship. This paper proposes the concept of restricted agency explaining the gendering of entrepreneurs and explains what they can do. Moreover, the concept helps explain why and what. Most promising theoretically, is how the application of this agency is slowly and contextually differently changing the rules of the game.

Research limitations/implications

This study covers a large and extensive literature, so might have missed themes.

Originality/value

This paper starts with the notion of the “otherness” of women’s entrepreneurship. The literature is good at explaining both how and why women’s entrepreneurship is different and in effect, marginalised. This study conceptualises this gendering process as a restricted agency. Moreover, the concept helps explain why and what. Most promising theoretically, is how the application of this agency is slowly and contextually differently changing the rules of the game. It may be the mechanism for emancipation.

Details

Journal of Entrepreneurship in Emerging Economies, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2053-4604

Keywords

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