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Article
Publication date: 27 February 2009

Akif Kaynak and Eva Håkansson

The purpose of this paper is to investigate microwave reflection, transmission, and complex permittivity of p‐toluene‐2‐sulfonic acid doped conducting polypyrrole coated…

497

Abstract

Purpose

The purpose of this paper is to investigate microwave reflection, transmission, and complex permittivity of p‐toluene‐2‐sulfonic acid doped conducting polypyrrole coated nylon‐lycra textiles in the 1‐18 GHz frequency with a view to potential applications in the interaction of electromagnetic radiation with such coated fabrics.

Design/methodology/approach

The chemical polymerization of pyrrole is achieved by an oxidant, ferric chloride and doped with p‐toluene sulfonic acid (pTSA) to enhance the conductivity and improve stability. Permittivity of the conducting textile substrates is performed using a free space transmission method accompanied by a mathematical diffraction reduction method.

Findings

The real part of permittivity increases with polymerization time and dopant concentration, reaching a plateau at certain dopant concentration and polymerization time. The imaginary part of permittivity shows a frequency dependent change throughout the test range. All the samples have higher values of absorption than reflection. The total electromagnetic shielding effectiveness exceeds 80 percent for the highly pTSA doped samples coated for 3 h.

Originality/value

A non‐contact, non‐destructive free space method thin flexible specimens to be tested with high accuracy across large frequency range. The non‐destructive nature of the experiments enables investigation of the stability of the microwave transmission, reflection, absorption and complex permittivity values. Moreover, mathematical removal of the diffraction enables higher accuracy.

Details

International Journal of Clothing Science and Technology, vol. 21 no. 2/3
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 1 May 2010

Akif Kaynak and Richard Foitzik

Although conducting polymers have various potential applications, lack of solubility is an impediment in their direct application to material surfaces. Synthesis of alkyl pyrrole…

83

Abstract

Although conducting polymers have various potential applications, lack of solubility is an impediment in their direct application to material surfaces. Synthesis of alkyl pyrrole monomers and subsequent polymerization into soluble conducting polymers are aimed as alternatives to conventional methods of application of conducting polymers on substrates. Alkyl chains are attached to a pyrrole ring to produce solubility in the resulting conducting polypyrroles, which allow direct application of conductive polymer emulsions to any desired surface. Friedel-Crafts acylation of the tosyl-protected pyrrole provides high yields of the 3-acylated product. The conductivity values of poly-3- and 3, 4-substituted pyrroles are generally less than the unmodified polypyrrole. Increasingly bulkier groups attached to the pyrrole means lower conductivity of the resultant polymer. As the carbon chain length attached to the 3-position of pyrrole increases, the solubility also increases. However, the magnitude of change in conductivity of films and pellets of soluble conducting polypyrroles over the alkyl range is not significant.

Details

Research Journal of Textile and Apparel, vol. 14 no. 2
Type: Research Article
ISSN: 1560-6074

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Article
Publication date: 1 August 2007

Christopher James Hurren, Akif Kaynak and Xungai Wang

This study examines the resistance change in conductive polypyrrole-coated PET fabrics under the AS 2001.4.15 – 1994 laundering test conditions. The effects of individual…

81

Abstract

This study examines the resistance change in conductive polypyrrole-coated PET fabrics under the AS 2001.4.15 – 1994 laundering test conditions. The effects of individual detergent components of a standard detergent, including auxiliary chemicals, at four different temperatures were studied. When the coated fabric was washed under the AS 2001.4.15-1994 conditions, the ECE reference detergent and pure soap flakes (sodium sterate) both decreased the conductivity of the coating at a rate exponentially proportional to the laundering temperature. Detergent types had an influence over the rate of degradation; pH conditions had a large influence on the rate of polymer deterioration with the acidic nonionic detergent giving rise to significantly improved laundering conditions. The auxiliary chemicals, sodium carbonate and sodium perborate were seen to cause large degradation of polymers during laundering. Ethylene diamine tetra acetic acid was seen to have only a slight influence on the reduction of conductivity of polymers.

Details

Research Journal of Textile and Apparel, vol. 11 no. 3
Type: Research Article
ISSN: 1560-6074

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Article
Publication date: 1 May 2011

Akif Kaynak and Richard Foitzik

Soluble conducting alkyl polypyrrole polymers have been applied by either chemical polymerization of the 3-alkyl monomers or direct application of polymer emulsion to the surface…

192

Abstract

Soluble conducting alkyl polypyrrole polymers have been applied by either chemical polymerization of the 3-alkyl monomers or direct application of polymer emulsion to the surface. Solution, vapor and spray polymerization methods of coating poly(3-alkylpyrroles) to the surface of woven wool fabrics are explored. Conductive textile samples have also been prepared by applying emulsions of soluble prepolymerized 3-alkylpyrrole to the fabric surface. Direct applications of a conductive paint to the textile surface eliminate the exposure of the substrate to damaging oxidizing agents which allow the coating of more sensitive and delicate substrates. All textiles produced are tested for abrasion resistance and conductivity. For alkyl polypyrrole coated fabrics, the optimum carbon chain lengths are between n=10 and n=14, which result in optimum values of conductivity and solubility. The darkness of the tone is inversely related to the surface resistivity of the resulting conductive fabric. Therefore, deep black coatings have low resistivity whereas light gray coatings on a white fabric surface have higher surface resistivity. Longer alkyl chains result in higher surface resistivity in fabrics. The conductive coating of poly(3-decanylpyrrole) on the textile surface has a better abrasion resistance compared to that of an unsubstituted polypyrrole coating.

Details

Research Journal of Textile and Apparel, vol. 15 no. 2
Type: Research Article
ISSN: 1560-6074

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Book part
Publication date: 13 July 2023

Huriye Akpinar

Technologies that have developed for centuries have made people's lives easier. With new technologies, people have started to more easily and accurately do things that once used…

Abstract

Technologies that have developed for centuries have made people's lives easier. With new technologies, people have started to more easily and accurately do things that once used to take a lot of their time. Especially with the industrial revolution, everything has started to become automatic thanks to the machines that entered people's lives; and almost all work, including daily and professional work, was done by machines. Influencing the life of the society in many ways, it has also affected the businesses that serve the society and their stakeholders in many ways. Many changes in businesses affect the economies of countries, and in this way, the welfare and knowledge levels of societies. In this study, the positive aspects of technological developments (digitalization) on businesses and stakeholders are explained. The importance of developing and changing businesses with digitalization has been emphasized for countries.

Details

Two Faces of Digital Transformation
Type: Book
ISBN: 978-1-83753-096-0

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Book part
Publication date: 25 September 2023

Mehmet Bağış, Mehmet Nurullah Kurutkan and Liridon Kryeziu

This research aims to determine the contribution of publications in the context of Türkiye to the international entrepreneurship literature between 2005 and 2022. We examined 471…

Abstract

This research aims to determine the contribution of publications in the context of Türkiye to the international entrepreneurship literature between 2005 and 2022. We examined 471 articles published in international journals in the Web of Science (WoS) Core Collection database using bibliometric analysis techniques. We analyzed the data with the software Biblioshiny+Bibliometrix, SciMAT, and VOSViewer. We used performance, theme and evolution, co-authorship, and document analysis in data analysis. Performance analysis findings show that the most publications were made in 2021, the journal with the most publications was sustainability, and the author with the most publications was Bakır, C. Theme and evolution analysis revealed that the motor themes were corporate entrepreneurship, gender and entrepreneurial intentions in the first period (2005–2014), while institutional entrepreneurship stood out as the niche theme. In the second period (2015–2022), “corporate entrepreneurship” and “performance” emerged as the motor themes, while the niche themes in this period were “Syrian refugees” and “entrepreneurial intentions.” Document analysis findings show that the most studied entrepreneurship types are gender, family, corporate, social, and small business, respectively. In addition, immigrant/refugee entrepreneurship is emerging as a new topic, while indigenous entrepreneurship, informal entrepreneurship, sustainable entrepreneurship, and religion entrepreneurship are the most minor studied topics in entrepreneurship. Evidence-based decision-making inputs were obtained for those holding the resource allocation authority in Türkiye. Policymakers and funders, as well as individuals and institutions that want to design the future in terms of resources, can benefit from the findings and analysis of this chapter. Türkiye, which ranks 26th in the world regarding entrepreneurship, must develop a policy based on data.

Details

Entrepreneurship Development in the Balkans: Perspective from Diverse Contexts
Type: Book
ISBN: 978-1-83753-455-5

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Available. Content available
Book part
Publication date: 30 July 2018

Abstract

Details

Marketing Management in Turkey
Type: Book
ISBN: 978-1-78714-558-0

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