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Article
Publication date: 10 May 2021

María V. Puc-Oxté and Máximo A. Pech-Canul

This paper aims to prepare highly hydrophobic films on aluminum AA3003 using myristic acid (MA) and evaluate its corrosion protection efficiency in a low-chloride solution.

Abstract

Purpose

This paper aims to prepare highly hydrophobic films on aluminum AA3003 using myristic acid (MA) and evaluate its corrosion protection efficiency in a low-chloride solution.

Design/methodology/approach

The aluminum surface was initially treated with boiling water to develop a porous nanostructure, and then surface modification was carried out in ethanolic solutions with different concentrations of MA. The surface morphology, wetting behavior and film composition were first characterized, and then, the corrosion behavior was evaluated with electrochemical techniques.

Findings

The best hydrophobicity and corrosion resistance were obtained with 50 mM of MA. For such concentration, a water contact angle of 140° and protective efficiency of 96% were achieved. A multilayer structure was revealed by scanning electron microscope and X-ray photoelectron spectroscopy.

Originality/value

The results of this work shed light on the anticorrosion performance of fatty acid self-assembled multilayers on the surface of Al–Mn alloys.

Details

Anti-Corrosion Methods and Materials, vol. 68 no. 3
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 5 December 2016

David O. Obada, Muhammad Dauda, Fatai O. Anafi, Abdulkarim S. Ahmed and Olusegun A. Ajayi

A structural and textural characterization study has been performed to investigate the adherence of zeolite-based catalyst washcoated onto honey-comb-type cordierite…

Abstract

Purpose

A structural and textural characterization study has been performed to investigate the adherence of zeolite-based catalyst washcoated onto honey-comb-type cordierite monoliths. The supports were characterized by the scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS), X-ray diffraction (XRD) and Brunauer–Emmett–Teller (BET) techniques.

Design/methodology/approach

SEM/EDS provided quantitative estimate of the washcoated monolith as the elemental composition of catalyst coating. The XRD pattern deduced that the zeolite-based catalysts were successfully mounted on the cordierite support, showing the characteristic peaks of zeolites (Zeolite Socony Mobil–5; ZSM-5) at Braggs angles of 7.88°, 8.76°, 23.04°, 23.88° and 24.36°, whereas the characteristic peak of cordierite is seen at a Braggs angle of 10.44°.

Findings

The BET results proved that a monolayer of zeolite may serve the need for surface area and porosity. This was evident in the increase of surface area of washcoated support as against the bare support. The obtained isotherms were of Type IV, illustrating the presence of mesopores. The adsorption and desorption isotherm branches coincided over the interval 0 < P/P0 < 0.50 and 0 < P/P0 < 0.45, showing N2 reversible adsorption for the two samples, respectively.

Originality/value

It was concluded that the composite materials which are ZSM-5 (Si/Al = 25) and precursors of the transition salts of copper, zinc and ceria powders were deposited on the catalyst supports, establishing the success of the coating procedure relative to the adherence of the catalyst compositions on the ceramic support.

Details

World Journal of Engineering, vol. 13 no. 6
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 1 November 1988

Z.A. Foroulis Exxon Research and Engineering Company

Passivity and localized corrosion is discussed using iron, iron‐chromium, iron‐chromium‐nickel alloys and aluminium as examples. A brief description is given of the…

Abstract

Passivity and localized corrosion is discussed using iron, iron‐chromium, iron‐chromium‐nickel alloys and aluminium as examples. A brief description is given of the prevailing ideas regarding the nature of the passive film and the processes by which its protective properties are lost when breakdown of passivity and localized corrosion occurs.

Details

Anti-Corrosion Methods and Materials, vol. 35 no. 11
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 8 December 2020

Аleksandr Viktorovich Zaichuk, Аleksandra Andreevna Amelina, Yurii Sergeevich Hordieiev, Liliya Frolova and Viktoriia Dmitrievna Ivchenko

The purpose of this paper is to conduct the directed synthesis of blue-colour aluminate spinel pigments based on spent aluminium–cobalt–molybdenum (ACM) catalyst and to…

Abstract

Purpose

The purpose of this paper is to conduct the directed synthesis of blue-colour aluminate spinel pigments based on spent aluminium–cobalt–molybdenum (ACM) catalyst and to study peculiar features of mineral formation processes and changes in their colour indices depending on composition and firing temperature.

Design/methodology/approach

Aluminate spinel ceramic pigments with specified colour indices were synthesised by directed formation of their mineral composition and identification of the most rational technological parameters of production. Mineral composition of synthesised pigments was evaluated by X-ray phase analysis. The colour indices of pigments and pigment-containing glaze coatings were studied on the comparator colour. The chemical resistance of pigments was determined by loss of their weight loss after boiling in 1 N hydrochloric acid solution and 1 N sodium hydroxide solution.

Findings

Peculiar features of formation of the mineral composition of aluminate spinel pigments based on the ACM catalyst were studied. The expediency of using magnesium and zinc oxides in their composition has been proved. It is found that for the formation of stable pigments of intense blue colour, a concentration of cobalt (II) oxide in the amount of 0.5 mol is sufficient, which is 23.1 Wt.%. The colour of such pigments is determined by the ratios of cobalt, magnesium and zinc aluminates, which form a spinel solid solution.

Practical implications

The use of developed aluminate spinel pigments provides obtaining of high-quality glass coatings of blue colour, in particular, for ceramics.

Originality/value

Aluminium oxide in the spent ACM catalyst is predominantly in the active form (of amorphous aluminium hydroxide and y-Al2O3). This is a prerequisite for the use of this waste material as a complete substitute for chemically pure Al2O3 in the technology of aluminate spinel pigments and reduction of their firing temperature. Besides, spent ACM catalyst already contains 5 Wt.% of expensive cobalt (II) oxide in the form of stable colour-bearing phase CoAl2O4.

Details

Pigment & Resin Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 12 January 2010

I. Tsangaraki‐Kaplanoglou, A. Kanta, S. Theohari and V. Ninni

The purpose of this paper is to provide acid‐dyes, known for the dyeing of porous aluminum oxide films, as inhibitors of the corrosion of aluminum in neutral chloride solutions.

Abstract

Purpose

The purpose of this paper is to provide acid‐dyes, known for the dyeing of porous aluminum oxide films, as inhibitors of the corrosion of aluminum in neutral chloride solutions.

Design/methodology/approach

Potentiodynamic polarization plots are recorded on mechanically pretreated aluminum using a three‐electrode cell containing 0.01 M NaCl solution with or without 0.025 mM of the acid‐dyes monosulfonic methyl orange (MO), disulfonic chromotrop RR (CH), disulfonic alphazurine A (AZ) and trisulfonic light green SF yellowish (LG). The X‐ray fluorescence technique is used in certain cases for the estimation of sulfur net content of the surface of the probes and thus of the concentration of the adsorbed dye.

Findings

The inhibition efficiency of acid dyes on corrosion of mechanically pretreated aluminum seems to be related more to the presence of a following quinonoid structure which probably contributes more to the formation of mono‐ or bi‐dentate compounds with the aluminum cations in the substrate than to the number of sulfonic groups in their molecule. Thus, the triphenylmethane dyes LG and, to a greater extent AZ, having this quinonoid structure means they are more efficient as corrosion inhibitors in near‐neutral chloride solution than the azo dyes MO and CH, that do not have it.

Practical implications

Selected acid‐dyes such as triphenylmethane sulfonic‐dyes, which have found wide application in the dyeing industry, seem to protect aluminum against the corrosive action of chlorides.

Originality/value

This paper is intended to be the nucleus for the electrochemical studies of the effectiveness of acid dyes as corrosion inhibitors for aluminum.

Details

Anti-Corrosion Methods and Materials, vol. 57 no. 1
Type: Research Article
ISSN: 0003-5599

Keywords

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