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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

Keywords

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Article
Publication date: 29 June 2010

Z. Abdel Hamid and A. Abdel Aal

The purpose of this paper is to investigate the deposition of uniform, adherent and crack‐free Ni‐P thin films on carbon fibres using the electroless deposition technique.

Abstract

Purpose

The purpose of this paper is to investigate the deposition of uniform, adherent and crack‐free Ni‐P thin films on carbon fibres using the electroless deposition technique.

Design/methodology/approach

Before applying the electroless process, the carbon fibre surfaces must be subjected to several treatment processes to remove the organic binder, etching and surface metallization. The surface morphology of the Ni‐P coatings was assessed using a scanning electron microscope (SEM). The chemical compositions of Ni‐P layers were identified by energy dispersive X‐ray analysis (EDS). The bond strength of the coated layer was determined by measuring the electrical resistance at the fibre/coating interface. The magnetic properties of the fibres were estimated using a hysteresis diagram. The tensile performance of single fibres coated by Ni‐P has been investigated with respect to coating thickness.

Findings

Pre‐treatment processes are used to improve the adhesion of Ni‐P layers and to obtain homogeneous coatings. The influence of plating parameters (temperature, pH and time) on the coating thickness of the Ni‐P layer was investigated. It was found that the coating thickness increased as the pH value, plating time and the temperature of the bath increased. The results revealed that a complete and uniform Ni‐P coating on fibre could be obtained at optimum conditions 85°C, pH 6, for 60 min, and the results indicated that the P content in the electroless deposit is approximately 3.4 wt%. The tensile strength values are improved significantly after coating and increased by 3‐5 times with increasing of coating thickness from 0.3 to 2 μm.

Originality/value

The results presented in this work are an insight into understanding of the deposition and adherence of Ni‐P thin films on carbon fibre using the electroless technique and behaviour of the coated fibre.

Details

Anti-Corrosion Methods and Materials, vol. 57 no. 4
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 1 June 1961

N.A. Lockington and I.J. Tóth

A wide field of applications for vacuum coatings has been opened up by the development of techniques for producing thicker protective coatings and, in some cases…

Abstract

A wide field of applications for vacuum coatings has been opened up by the development of techniques for producing thicker protective coatings and, in some cases, aluminium coatings may replace nickel‐chromium plating. The coating process and basic equipment are discussed herein and an account given of the properties and applications of commercially produced aluminium and cadmium coatings.

Details

Anti-Corrosion Methods and Materials, vol. 8 no. 6
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 4 September 2017

Amita Rani, Niraj Bala and C.M. Gupta

Hot corrosion is the major degradation mechanism of failure of boiler and gas turbine components. The present work aims to investigate the hot corrosion resistance of…

Abstract

Purpose

Hot corrosion is the major degradation mechanism of failure of boiler and gas turbine components. The present work aims to investigate the hot corrosion resistance of detonation gun sprayed (D-gun) Cr2O3-75 per cent Al2O3 ceramic coating on ASTM-SA210-A1 boiler steel.

Design/methodology/approach

The coating exhibits nearly uniform, adherent and dense microstructure with porosity less than 0.8 per cent. Thermogravimetry technique is used to study the high temperature hot corrosion behavior of bare and coated boiler steel in molten salt environment (Na2SO4-60 per cent V2O5) at high temperature 900°C for 50 cycles. The corrosion products are analyzed by using X-ray diffraction, scanning electron microscopy (SEM) and field emission scanning electron microscope/energy-dispersive analysis (EDAX) to reveal their microstructural and compositional features for elucidating the corrosion mechanisms.

Findings

During investigations, it was found that the Cr2O3-75 per cent Al2O3 coating on Grade A-1 boiler steel is found to be very effective in decreasing the corrosion rate in the molten salt environment at 900°C. The coating has shown lesser weight gains along with better adhesiveness of the oxide scales with the substrate till the end of the experiment. Thus, coatings serve as an effective diffusion barrier to preclude the diffusion of oxygen from the environment into the substrate boiler steel.

Research limitations/implications

Therefore, it is concluded that the better hot corrosion resistance of the coating is due to the formation of desirable microstructural features such as very low porosity, uniform fine grains and the flat splat structures in the coating; as compared to the bare substrate under cyclic conditions.

Practical implications

This research is useful for coal-fired boilers and other power plant boilers.

Social implications

This research is useful for power generation plants.

Originality/value

There is no reported literature on hot corrosion behavior of Cr2O3-75 per cent Al2O3 coating deposited on the selected substrates by D-gun spray technique. The present work has been focused to study the influence of the Cr2O3-75 per cent Al2O3 coating developed with D-gun spraying technique on high temperature corrosion behavior of ASTM-SA210-A-1 boiler steel in an aggressive environment of Na2SO4-60 per cent V2O5 molten salt at 900°C under cyclic conditions.

Details

Anti-Corrosion Methods and Materials, vol. 64 no. 5
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 10 August 2018

Chao-Ching Chang, Feng-Hsi Huang and Liao-Ping Cheng

The purpose of this paper is to investigate the effects of dipentaerythritol hexaacrylate (DPHA) and 3-(trimethoxysilyl)propyl methacrylate-modified silica nanoparticles…

Abstract

Purpose

The purpose of this paper is to investigate the effects of dipentaerythritol hexaacrylate (DPHA) and 3-(trimethoxysilyl)propyl methacrylate-modified silica nanoparticles (MSiO2) contents on the performances of the Disperse Red 1 (DR1)-grafted-silica/poly(acrylate) color hard coatings.

Design/methodology/approach

The organic dye DR1 was silylated by reaction with the coupling agent 3-isocyanatopropyltriethoxysilane in methyl ethyl ketone. The silylated-DR1 thus obtained was grafted on MSiO2 to form dye-grafted silica (GSiO2). This hybrid dye was then UV-cured with the cross-linking agent, DPHA, to yield color coatings. Thermal durability of the coatings was evaluated based on their CIE (international commission on illumination) chromaticity coordinates and UV/Vis transmittances.

Findings

The results indicated that GSiO2-coatings could tolerate thermal attack better than pristine DR1-coatings or dye-absorbed silica (DSiO2)-coatings because of the fact that DR1 was more finely dispersed in the polymer binder when covalently bonded to the silica particles. Under optimal conditions, coatings with very small change of saturation and hue after high-temperature treatments were obtainable. These coatings appeared transparent, had 3H-6H pencil hardness and adhered perfectly onto the poly(methyl methacrylate) substrates.

Practical implications

Dye-grafted color coatings may find applications such as color filter photoresists for displays, microelectronics, printed circuit boards, etc.

Originality/value

The performances of the coatings were evaluated in terms of mechanical strength, adherence to the substrate, transmittance and color stability against heat treatments, which have not been disclosed. Also, using a newly developed triangular composition diagram, suitable ranges for preparing useful color coatings were accessed. The present method deserves further research studies on green and blue dyes.

Details

Pigment & Resin Technology, vol. 48 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 1 June 2002

M. Bajpai, Sunita Seth, A.K. Saxena and Ashok Ranjan

Some thermally stable epoxy coatings have been developed using functional aminosl.ilanes viz, N‐[3‐(trimethoxysilyl) propyl] ethylenediamine and copolymer of…

Abstract

Some thermally stable epoxy coatings have been developed using functional aminosl.ilanes viz, N‐[3‐(trimethoxysilyl) propyl] ethylenediamine and copolymer of aminopropylmethyl dimethylsiloxane in different ratio. It has been observed that use of silicon compounds invariably enhances the thermal stabililty, chemical resistance and corrosion resistance of epoxy coating. It has also been observed that silane bearing triethoxy group gave better adherence properities whereas silicone gave better thermal stability. The degradation kinetics showed that the reactions were of first order.

Details

Pigment & Resin Technology, vol. 31 no. 3
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 1 June 1991

Edgar S. Lower

Polyoxyethylated hydroxy benzyl oleamide has found use in lubricants to prevent adhesion in moulds during the production of vulcanizates of natural and of synthetic…

Abstract

Polyoxyethylated hydroxy benzyl oleamide has found use in lubricants to prevent adhesion in moulds during the production of vulcanizates of natural and of synthetic rubbers. Polyoxyethylated oleamide acts as a mould lubricant for synthetic rubbers, whilst polyglycol 400 dilaurate can be used to reduce the time and temperature necessary for the recovery of old vulcanizates using paraffin oil and bitumen. Anti‐fogging properties can be sustained in rubber hydrochloride films by the use of polyglycol 1500 dilaurate, and improved percentage elongation can be promoted in intimate blends of polystyrene and SBR rubbers by the inclusion of polyglycol 4000 monostearate. Polyoxyethylated sorbitan monostearate acts as an emulsifer in the emulsion polymerisation of styrene, butadiene and styrene/ butadiene copolymer rubbers, and it can perform as an anti‐static for the latter. Polyoxyethylated stearylamine can be incorporated into lubricants designed to prevent adhesion in moulds during production of vulcanizates of synthetic and of natural rubber, and rubber latexes and other aqueous dispersions of rubber can be rendered more stable by the employment of polyoxyethylated stearyl alcohol, and thus allow storage in untreated containers for long periods of time. Polyoxypropylated sorbitan monopalmitate will serve as a parting agent, releasing aid, for unvulcanized rubber and vulcanized rubber, without interfering with further bonding and coating of rubber.

Details

Pigment & Resin Technology, vol. 20 no. 6
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 1 May 1955

Leap forward in zinc‐rich paints. Corrosion Ltd. announce far‐reaching improvements in the whole of their range of Glopane zinc‐rich paints (otherwise known as ‘cold…

Abstract

Leap forward in zinc‐rich paints. Corrosion Ltd. announce far‐reaching improvements in the whole of their range of Glopane zinc‐rich paints (otherwise known as ‘cold galvanising’ materials), as a result of the replacement of the normal type of zinc dust used for pigmentation by ultra‐fine zinc dust and improvements in media.

Details

Anti-Corrosion Methods and Materials, vol. 2 no. 5
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 1 August 1954

Coating composition. A composition for use, e.g. in coating iron, etc., with a layer of metal with strong bonding consists of a low‐viscositysolution of chlorinated…

Abstract

Coating composition. A composition for use, e.g. in coating iron, etc., with a layer of metal with strong bonding consists of a low‐viscositysolution of chlorinated synthetic or natural rubber in an organic solvent mixed with a heavy metal powder (Pb, Ni) and including an osmic catalyst, e.g. potassium osmiate or osmic chloride, to the amount of 0.00025 to 0.001% of the total—Brit. Pat. 703,397, Goodcliffe‐Eecen Industries Pty. Ltd. and H. Goodman, April 3, 1950.

Details

Anti-Corrosion Methods and Materials, vol. 1 no. 8
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 1 April 1980

Americus

Specialty Maintenance Paints. Highly advanced technology presents numerous opportunities for specialized maintenance paints. Some of these which have been offered recently…

Abstract

Specialty Maintenance Paints. Highly advanced technology presents numerous opportunities for specialized maintenance paints. Some of these which have been offered recently will be described here.

Details

Pigment & Resin Technology, vol. 9 no. 4
Type: Research Article
ISSN: 0369-9420

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