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Article
Publication date: 1 March 1965

MICHAEL BASSEY

PART V Organic chemistry textbooks. Twenty textbooks of organic chemistry are considered in this part of the review and the organic sections of the syllabuses of three GCE Boards…

Abstract

PART V Organic chemistry textbooks. Twenty textbooks of organic chemistry are considered in this part of the review and the organic sections of the syllabuses of three GCE Boards are analysed.

Details

Education + Training, vol. 7 no. 3
Type: Research Article
ISSN: 0040-0912

Article
Publication date: 1 December 2005

H.S. Awad and S. Abdel Gawad

To investigate the capability of a series of nitrogen‐based heterocyclic organic compounds in inhibiting corrosion of iron in HCl and elucidate the dominant active form of the…

Abstract

Purpose

To investigate the capability of a series of nitrogen‐based heterocyclic organic compounds in inhibiting corrosion of iron in HCl and elucidate the dominant active form of the applied compounds during the adsorption process to explore the mechanism of their action.

Design/methodology/approach

The tested compounds were pyrimidine containing compounds, which were selected, based on molecular structure considerations. Gravimetric method has been applied with various electrochemical techniques (polarisation resistance, polarisation curves and electrochemical impedance spectroscopy) to investigate inhibition efficiency and mechanism.

Findings

The inhibiting action of the investigated pyrimidine containing compounds depends primarily on their concentration and molecular structure. These compounds act as mixed type inhibitors and function via adsorption on the surface, which follows Frumkin adsorption isotherm. The inhibition by the tested pyrimidine derivatives could be attributed to their chemisorption on the metal surface forming donor/acceptor type of bond between the inhibitor molecules and the vacant d orbitals of the surface iron atoms. Contribution from electrostatic adsorption, via interaction between the protonated form of the inhibitor and the charged metal surface, is also possible.

Research limitations/implications

The applied inhibitors were tested in the presence of chloride ions as a corrosive medium. Whether these inhibitors will function well in the presence of other ions that are typically present in natural corrosive environment is unknown.

Originality/value

This paper provides useful information regarding inhibition effect of pyrimidine and series of its derivatives. The outcome of this work contributes to better understanding of the mechanism of inhibition by this class of N‐based heterocyclic organic compounds.

Details

Anti-Corrosion Methods and Materials, vol. 52 no. 6
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 1 April 1960

Brian A. Fox

In spite of the great advances made during the last thirty years or so in the understanding of organic chemistry, the teaching of the subject, at least at an elementary level, has…

1002

Abstract

In spite of the great advances made during the last thirty years or so in the understanding of organic chemistry, the teaching of the subject, at least at an elementary level, has remained more or less unchanged. It is not uncommon for teachers to adopt exactly the same approach to the subject as was used when they themselves were students and the somewhat dreary repetition of ‘preparations, properties and uses’ is still the most widely used teaching method. Many of the textbooks used have been current for three or more decades and are devoid of modern ideas; even the more recent ones are predominantly old‐fashioned in approach. Good textbooks are, of course, available and they are used to some extent, but unfortunately the old favourites still dominate the field.

Details

Education + Training, vol. 2 no. 4
Type: Research Article
ISSN: 0040-0912

Article
Publication date: 2 January 2018

Leighton Jones, Xujun Luo, Algy Kazlauciunas and Long Lin

This paper aims to synthesise and evaluate the properties of a novel smart material consisting of a metal-free organic black pigment with a unique chromophore for bifunctional…

Abstract

Purpose

This paper aims to synthesise and evaluate the properties of a novel smart material consisting of a metal-free organic black pigment with a unique chromophore for bifunctional applications in optoelectronics.

Design/methodology/approach

A robust and highly efficient organic reaction, namely, a double [2 + 2] cycloaddition, was deployed to transform a rod-like structure for charge-transfer applications to a strongly conjugated light-absorbing molecule for both optical and electronic applications.

Findings

The synthesis and characterisation of an air-stable metal-free black pigment is reported, which contains an unconventional donor–acceptor panchromatic chromophore with an absorption window spanning 600 nm; the compound was synthetically converted from an organic semiconducting molecular rod and retains strong charge-transfer properties. The chromophore comprises tetracyanoquinodimethane adduct on either side of a dithienothiophenyl core, capped with hexyl thiophenes that ensure solubility in common organic solvents. Its propensity to form excellent thin films on different substrates such as glass and paper, with a total opacity in organic solvent, gives it the potential for wide-ranging applications in organic optoelectronics.

Research limitations/implications

The synthetic chemistry and fundamental properties are investigated in the present study, with more detailed treatments and analysis to be soon developed. One leading smart material is presented, with further derivatives under investigation.

Practical implications

The work presented shows the possibility of converting structures from one application to another with relative ease, but how they retain properties for both, using well-known and facile conditions.

Originality/value

The structures are novel and an enhanced air-stable organic panchromatic chromophore is reported for processing in common organic solvents.

Details

Pigment & Resin Technology, vol. 47 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 26 August 2014

B.P. Markhali, R. Naderi, M. Sayebani and M. Mahdavian

The purpose of this paper is investigate the inhibition efficiency of three similar bi-cyclic organic compounds, namely, benzimidazole (BI), benzotriazole (BTAH) and benzothiazole…

Abstract

Purpose

The purpose of this paper is investigate the inhibition efficiency of three similar bi-cyclic organic compounds, namely, benzimidazole (BI), benzotriazole (BTAH) and benzothiazole (BTH) on carbon steel in 1 M hydrochloric acid (HCl) solution. Organic inhibitors are widely used to protect metals in acidic media. Among abundant suggestions for acid corrosion inhibitors, azole compounds have gained attention.

Design/methodology/approach

The inhibition efficiency of the three organic compounds was investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS).

Findings

Superiorities of BTH and BTAH corrosion inhibitors were shown by EIS data and polarization curves. Moreover, the results revealed that BTAH and BTH can function as effective mixed-type adsorptive inhibitors, whereas no inhibition behavior was observed for BI. Both BTAH and BTH obeyed Longmuir adsorption isotherm. The results obtained from this isotherm showed that both inhibitors adsorbed on the specimen surface physically and chemically. The difference in inhibition efficiencies of BTAH, BTH and BI was related to the presence of nitrogen and sulfur hetero atoms on their molecular structures.

Originality/value

This study evaluated inhibition efficiency of BI, BTAH and BTH using electrochemical methods. In addition, the study attempted to find inhibition mechanism of the inhibitors and to find modes of adsorption of the inhibitors, correlating effects of heteroatoms and inhibition efficiency.

Details

Anti-Corrosion Methods and Materials, vol. 61 no. 5
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 1 February 1978

Arthur Antony

The year 1977 was the first in the tenth collective period (1977‐1981) for Chemical Abstracts. Thus during that year the important and very voluminous Tenth Collective Index began…

Abstract

The year 1977 was the first in the tenth collective period (1977‐1981) for Chemical Abstracts. Thus during that year the important and very voluminous Tenth Collective Index began to appear on library shelves, but as this review is being written in 1978 there are still volumes of the formula and chemical substance indexes that have to be added. Librarians will have recently received two Index Guides: one as part of the Ninth Collective Index, and the other as the first Index Guide for the tenth collective period ‐ to be supplemented annually, and finally superseded by the Index Guide which appears as part of the Tenth Collective Index.

Details

Reference Services Review, vol. 6 no. 2
Type: Research Article
ISSN: 0090-7324

Article
Publication date: 1 March 2006

H.S. Awad

Zn‐Al alloys are widely used as coatings for corrosion protection of steel. These alloys provide long‐term protection to steel in several aqueous media; however, little attention…

Abstract

Purpose

Zn‐Al alloys are widely used as coatings for corrosion protection of steel. These alloys provide long‐term protection to steel in several aqueous media; however, little attention has been paid to their behaviour in acidic media. The aim of this investigation is to study the corrosion and inhibition of 90 per cent Zn‐10 per cent Al alloy in hydrochloric acid.

Design/methodology/approach

Pyridine and a number of its methyl‐containing derivatives were applied in controlling the corrosion of 90 per cent Zn‐10 per cent Al alloy. The inhibitive action and mechanism of these compounds were investigated by weight loss tests, linear polarisation resistance measurements, galvanostatic polarisation tests and electrochemical impedance spectroscopy.

Findings

It was found that the corrosion rate of this alloy was much higher than that of either Zn or Al alone. Pyridine and its derivatives exhibited good inhibition for the corrosion of 90 per cent Zn‐10 per cent Al alloy, their inhibition efficiency increased in the order: I < II < III < IV. Potentiodynamic polarisation studies revealed that the investigated pyridine derivatives were mixed‐type inhibitors and functioned by adsorption on reactive sites on the alloy surface through the influence of the nucleophilic nitrogen atom forming a good physical barrier to prevent access of aggressive ions to the alloy surface. This was supported by the impedance measurements which showed a change in the charge transfer resistance and double layer capacitance indicating adsorption on the alloy surface. It was shown that the introduction of the methyl group(s) into the pyridine ring enhanced the effectiveness of pyridine inhibition. The improvement was attributable to the electron‐donating tendency of this group that gives rise to the increase in the electron density at the adsorption site. All the investigated substituents showed negative values of the Hammett constant (σ), indicating their electron‐donating property. The negative value of this constant increased according to the order: I < II < III < IV, the greater the negative value of σ being consistent with the greater degree of corrosion inhibition. It also was revealed that the presence of these inhibitors increased the value of activation energy for corrosion with a ranking order that was consistent with that of their inhibition effectiveness.

Research limitations/implications

The evaluated inhibitors assured significant corrosion inhibition of the Zn‐Al alloy in HCl, however, their behaviour in different acid media was ambiguous.

Originality/value

This paper makes significant contibution to understanding the corrosion and inhibition of one of the widely apply coatings for steel protection in one of the most widely used aqueous mineral acids in industry.

Details

Anti-Corrosion Methods and Materials, vol. 53 no. 2
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 1 April 1965

MICHAEL BASSEY

PART VI Practical chemistry textbooks and miscellaneous books. Thirty‐nine practical chemistry textbooks were received from publishers for this part of the review and they have…

Abstract

PART VI Practical chemistry textbooks and miscellaneous books. Thirty‐nine practical chemistry textbooks were received from publishers for this part of the review and they have been briefly analyzed under the headings Physical, Inorganic, Organic, Quantitative analysis, and Other features, in Tables 1–4. It has not been possible to examine these in the same detail as the theory books previously considered. A number of other books which are used at ‘A/S’ level were also received and these have been tabulated: problem and calculation books in Table 5, and others in Table 6.

Details

Education + Training, vol. 7 no. 4
Type: Research Article
ISSN: 0040-0912

Article
Publication date: 1 March 1974

K. BHATTACHARYYA

This paper examines the implications of the findings of evaluative tests regarding the retrieval performance of natural language in various subject fields. It suggests parallel…

Abstract

This paper examines the implications of the findings of evaluative tests regarding the retrieval performance of natural language in various subject fields. It suggests parallel investigations into the structure of natural language, with particular reference to terminology, as used in the different branches of basic science. The criteria for defining the terminological consistency of a subject are formulated and a measure suggested for determining the degree of terminological consistency.

Details

Journal of Documentation, vol. 30 no. 3
Type: Research Article
ISSN: 0022-0418

Article
Publication date: 1 December 1998

Hans Mayer

An introduction to the topic of aqueous silicone resin coating systems for exterior masonry. Concentrates on applications in the construction industry.

1587

Abstract

An introduction to the topic of aqueous silicone resin coating systems for exterior masonry. Concentrates on applications in the construction industry.

Details

Pigment & Resin Technology, vol. 27 no. 6
Type: Research Article
ISSN: 0369-9420

Keywords

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