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Article
Publication date: 13 September 2011

Peter Greenwood and Borje Gevert

The purpose of this paper is to study methods of reacting the surface of the particles of silica sols with silanes, primarily gamma‐glycidoxypropyltrimethoxysilane (GPTMS…

Abstract

Purpose

The purpose of this paper is to study methods of reacting the surface of the particles of silica sols with silanes, primarily gamma‐glycidoxypropyltrimethoxysilane (GPTMS) and study some basic properties of the modified sols and the nature and structure of the silane groups attached to the particle surface.

Design/methodology/approach

The surface of the silica particles was modified by reacting the silica sols with aqueous solutions of silanes, chiefly GPTMS. The presence and structure of silane groups on the particle surface were established by Si‐NMR and C‐NMR, respectively.

Findings

Several silanes were studied but silica sols could be readily modified only with GPTMS and glycidoxypropylmethoxydiethoxysilane (GPMDES), most readily if the silanes were pre‐hydrolysed in water. Higher degrees of silylation were preferably done by continuous addition of silane. Lower degrees of modification can be achieved at room temperature by the stepwise addition of the silane solution. The silylation of the silica surface with GPTMS significantly reduces the number of charged surface groups and silanol groups. GPTMS binds covalently to the silica surface and the epoxy ring opens and transforms into a diol. Silica sols modified with GPTMS and GPMDES are stable toward aggregation.

Research limitations/implications

Only organo‐reactive silanes were studied.

Originality/value

This is the first work to study the modification by silanes of silica aquasols with high concentrations of silica. The silane modification can extend the use of silica to areas of applications previously inaccessible to silica sols.

Details

Pigment & Resin Technology, vol. 40 no. 5
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 3 January 2017

Xiaochao Xian, Chenglong Nai, Lixin Li and Shuo Zhao

Immersion is one of the key steps during the preparation of silane-based hybrid films, which has important effects on the performance of films after curing. In this paper…

Abstract

Purpose

Immersion is one of the key steps during the preparation of silane-based hybrid films, which has important effects on the performance of films after curing. In this paper, the formation process of Zr-doped silane film (i.e. the adsorption of silane and deposition of zirconium compounds) on carbon steel immersed in Zr(NO3)4/silane mixed solutions was investigated.

Design/methodology/approach

The method of in situ monitoring the open circuit potential of a two-electrode system, consisting of carbon steel and saturated calomel electrode, was used. The effects of immersion conditions (i.e. the concentration of Zr(NO3)4 and pH of Zr(NO3)4/silane mixed solution) on the open circuit potential were investigated in detail. Furthermore, the surface coverage rate of different cured films (i.e. Zr cured film, silane cured film and Zr/silane composite cured film) after curing on carbon steel was calculated according to the results of polarization curves. Electrochemical impedance spectroscopy (EIS) was used to study the self-healing property of Zr-doped silane cured film.

Findings

The results indicate that in Zr(NO3)4/silane mixed solutions, most zirconium compounds deposit on the surface of carbon steel at the initial immersing stage, then the adsorption of silane on the residual surface of carbon steel dominates the following immersing stage. EIS results show that the Zr-doped cured film has improved self-healing property.

Originality/value

First, the method of in situ monitoring the open-circuit potential of two-electrode system was applied to investigate the deposition of Zr and the adsorption of silane on carbon steel immersed in Zr(NO3)4/silane mixed solutions. Second, the formation process of Zr-doped silane film was proposed.

Details

Anti-Corrosion Methods and Materials, vol. 64 no. 1
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 1 February 1994

K. Minten, K. Kitchens and J. Cisson

In the preceding three parts of this series, the authors have extensively reviewed and quantified the special processing sequences required for the ‘additive’ and…

Abstract

In the preceding three parts of this series, the authors have extensively reviewed and quantified the special processing sequences required for the ‘additive’ and ‘semi‐additive’ process strategies of PWB manufacture. In this, the fourth part of the series of five, they wish to present a series of full build processes which meet all the interconnect requirements of the 1990s while eliminating the drawbacks traditionally associated with additive processes.

Details

Circuit World, vol. 20 no. 3
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 8 November 2011

Mehran Rostami, Mohsen Mohseni and Zahra Ranjbar

The purpose of this paper is to investigate the effect of different PHS on the surface chemistry of fumed silica treated with aminopropyltrimethoxysilane (APTMS).

Abstract

Purpose

The purpose of this paper is to investigate the effect of different PHS on the surface chemistry of fumed silica treated with aminopropyltrimethoxysilane (APTMS).

Design/methodology/approach

The reaction conditions involved variation of pH ranging from acidic to alkaline. Different analytical techniques including FT‐IR spectroscopy, thermogravimetric analysis (TGA), CHN and Zeta potential analyses were employed to investigate the surface chemistry of treated particles. In addition, the stability of silanised silica dispersions were studied using turbidimetric and rheometric measurements.

Findings

It was revealed that in all conditions silica was more or less chemically grafted by the silane. When the pH of treating bath was adjusted to 1‐2 prior and during the reaction, 58 percent grafting was observed, as obtained by CHN and TGA analyses. At very alkaline conditions, however, the grafting content declined to 29 percent. The variations in grafting were dependent on the silane hydrolysis and its further condensation with the silica surface. Zeta potential measurements showed a drastic change from −7.1 mv to +18.01 mv (at pH 7) for the untreated particle and the one with the highest grafting, respectively. The dispersion stability of differently treated particles varied in solvents with different Hansen solubility parameters (HSP). Moreover, due to the variations of surface chemistry of particles, their rheological behaviours were significantly influenced.

Originality/value

The results obtained in this work showed that the surface chemistry of fume silica could be tuned with treating method. The highest content of grafting led to a better dispersion in solvents having greater hydrogen bonding component and to an inferior dispersion in solvents with higher polar component.

Details

Pigment & Resin Technology, vol. 40 no. 6
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 8 November 2011

Changrong Ran, Wenli Lu, Guo Song, Chao Ran and Shuo Zhao

In the industrial silylation process, the cost of production can be greatly reduced by reducing the frequency of the replacement of the silane solution. The purpose of…

Abstract

Purpose

In the industrial silylation process, the cost of production can be greatly reduced by reducing the frequency of the replacement of the silane solution. The purpose of this paper is to describe how a method of discontinuous addition of concentrated solution into the KH560 treatment bath was developed, to improve further the effective availability of the silane solution and reduce cost of production.

Design/methodology/approach

The preparation and addition of each incremental amount of concentrated KH560 was studied in detail.

Findings

The results indicate that adding concentrated silane solution is an effective method of maintaining the target bath concentration.

Originality/value

The paper describes how a method of adding concentrated KH560 was developed to prolong the working time of KH560 solution for silane coating production, and to improve the availability of the KH560 in solution. The results indicated that adding concentrated solution was an effective method of prolonging the working time of the silane solution. The mixture ratio of the concentrated solution, and the volume of each incremental amount, both affected the performance of the KH560 solution.

Details

Anti-Corrosion Methods and Materials, vol. 58 no. 6
Type: Research Article
ISSN: 0003-5599

Keywords

Content available
Article
Publication date: 4 January 2013

Peter Greenwood

Abstract

Details

Pigment & Resin Technology, vol. 42 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

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Article
Publication date: 4 November 2020

Tantan Shao, Xiaolong Chen and Lijun Chen

Silane cross-linkers have been used to strengthen the mechanical stabilities and friction resistance of plastic products. Therefore, the effect of silane cross-linkers on…

Abstract

Purpose

Silane cross-linkers have been used to strengthen the mechanical stabilities and friction resistance of plastic products. Therefore, the effect of silane cross-linkers on latex has been studied through preparing modified self-cross-linking long fluorocarbon polyacrylate latex. In this paper, nonionic surfactant alcohol ether glycoside (AEG1000) and anionic polymerizable surfactant 1-allyloxy-3-(4-nonylphenol)-2-propanol polyoxyethylene (10) ether ammonium sulfate (DNS-86) acted as mixed emulsifier and 3-(methacryloyloxy) propyltrimethoxysilane (KH-570) and bis (2-ethylhexyl) maleate (DOM) were used as functional monomers.

Design/methodology/approach

The modified acrylate polymer latex was synthesized through the semi-continuous seeded emulsion polymerization with methyl methacrylate (MMA), butyl acrylate (BA), dodecafluoroheptyl methacrylate (DFMA) and hydroxypropyl methacrylate (HPMA) as main monomers. Potassium persulfate (KPS) was applied to initiate polymerization reaction, nonionic surfactant AEG1000 and DNS-86 acted as emulsifier, KH-570 and DOM were used as functional monomers, respectively.

Findings

The optimum conditions of synthesizing the modified latex were the following. The mass ratio of monomers containing MMA, BA, DFMA, HPMA, KH-570 and DOM was 13.58:13.58:0.90:1.20:0.15:0.60, the usage of initiator KPS was 0.5% of the total weight of monomers and the amount of emulsifier was 7% of all monomers with AEG1000:DNS-86 = 1:1. The results indicated that the conversion of monomer was 99% and the coagulation was about 2.0%.

Originality/value

The resultant latex was modified silane cross-linker KH-570 and DOM, which positively affected the comprehensive properties of latex and its film. Apart from this, the novel mixed emulsifier was used to improve the size and distribution of latex particles and reduce environmental problems caused by the use of emulsifiers.

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: 7 September 2015

Rami Mohammad Suleiman

The purpose of this paper was to prepare a hybrid organic/inorganic coating with interesting barrier properties against the corrosion of plain carbon steel sheets in 3.5…

Abstract

Purpose

The purpose of this paper was to prepare a hybrid organic/inorganic coating with interesting barrier properties against the corrosion of plain carbon steel sheets in 3.5 per cent NaCl solution. The search for replacing chromates in protective coatings has led to the development of hybrid sol-gel anticorrosive coatings. Appropriate functionalization can dramatically enhance the chemical durability and mechanical strength of these coatings.

Design/methodology/approach

To prepare the targeted coating, 1,2-epoxybutane (EB) was mixed with 2 to 4 per cent aminoethylaminopropyl-methylsiloxane dimethylsiloxane (APDMS) copolymer and 1,6-diaminohexane. The above coating (EBAC) has been further mixed with three different corrosion inhibitors “Moly-white® 101-ED, Heucophos Zapp® and cerium ammonium nitrate”, yielding the coatings EBAC-M, EBAC-Z and EBAC-Ce, respectively. The corrosion characteristics of all coatings on the steel panels immersed in 3.5 per cent NaCl solution were obtained using different electrochemical methods such as electrochemical impedance spectroscopic and Tafel polarization measurements.

Findings

The newly prepared coatings showed interesting protection properties for protecting the steel substrate against corrosion in chloride-containing media.

Originality/value

The results provide a good approach for the modification of polydimethylsiloxane coatings using a simple organic modifier.

Details

Anti-Corrosion Methods and Materials, vol. 62 no. 5
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 28 October 2014

Rami Mohammad Suleiman

The purpose of this work was to prepare a hybrid organic/inorganic coating with interesting barrier properties against the corrosion of plain carbon steel sheets in 3.5…

Abstract

Purpose

The purpose of this work was to prepare a hybrid organic/inorganic coating with interesting barrier properties against the corrosion of plain carbon steel sheets in 3.5 per cent NaCl solution. The search for replacing chromates in protective coatings has led to the development of hybrid sol-gel anticorrosive coatings. Appropriate functionalization can dramatically enhance the chemical durability and mechanical strength of these coatings.

Design/methodology/approach

To prepare the targeted coating, 1,2-epoxybutane (EB) was mixed with 2-4 per cent aminoethylaminopropyl-methylsiloxane dimethylsiloxane copolymer and 1,6-diaminohexane. The above coating (EBAC) was further mixed with three different corrosion inhibitors “Moly-white® 101-ED, Hfucophos Zapp®” and Cerium Ammonium Nitrate, yielding the coatings (EBAC-M), (EBAC-Z) and (EABC-Ce), respectively. The corrosion characteristics of all coatings on carbon steel panels immersed in 3.5 per cent NaCl solution were obtained using different electrochemical methods such as electrochemical impedance spectroscopic and Tafel polarization measurements.

Findings

The newly prepared coatings showed interesting properties for protecting the steel substrate against corrosion in chloride containing media.

Originality/value

The results provide a good approach for the modification of polydimethylsiloxane coatings using a simple organic modifier.

Details

Anti-Corrosion Methods and Materials, vol. 61 no. 6
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 1 June 1995

Anthony Edwards

Enormous amounts of paint will be required in the coming decades to maintain the 570,000 bridges spanning the US rivers, canals and road‐ways and providing access to more…

Abstract

Enormous amounts of paint will be required in the coming decades to maintain the 570,000 bridges spanning the US rivers, canals and road‐ways and providing access to more than 3.5 million miles of US highways.

Details

Pigment & Resin Technology, vol. 24 no. 6
Type: Research Article
ISSN: 0369-9420

1 – 10 of 195