Polyimide Dielectric Layer on Filaments for Organic Field Effect Transistors: Choice of Solvent, Solution Composition and Dip-Coating Speed
1 Ghent University - Department of Textiles, Ghent, Belgium, Technologiepark 907, 9052 Zwijnaarde, tel +32 9 264 54 06, fax +32 9 264 58 31
2 Ghent University - Department of Inorganic and Physical Chemistry, Ghent, Belgium, Krijgslaan 281 S3, 9000 Ghent, tel. +32 9 264 44 47, fax +32 9 264 49 83
3 Ghent University - Electronics and Information Systems Department, Ghent, Belgium, Sint-Pietersnieuwstraat 41, 9000 Ghent, tel. +32 9 264 33 86, fax +32 9 264 35 94
4 Ghent University - Department of Textiles, Ghent, Belgium, Technologiepark 907, 9052 Zwijnaarde, tel +32 9 264 54 06, fax +32 9 264 58 31
Citation Information: Autex Research Journal. Volume 14, Issue 3, Pages 121–134, ISSN (Online) 2300-0929, DOI: 10.2478/aut-2014-0008, September 2014
In today’s research, smart textiles is an established topic in both electronics and the textile fields. The concept of producing microelectronics directly on a textile substrate is not a mere idea anymore and several research institutes are working on its realisation. Microelectronics like organic field effect transistor (OFET) can be manufactured with a layered architecture. The production techniques used for this purpose can also be applied on textile substrates. Besides gate, active and contact layers, the isolating or dielectric layer is of high importance in the OFET architecture. Therefore, generating a high quality dielectric layer that is of low roughness and insulating at the same time is one of the fundamental requirements in building microelectronics on textile surfaces. To evaluate its potential, we have studied polyimide as a dielectric layer, dip-coated onto copper-coated polyester filaments. Accordingly, the copper-coated polyester filament was dip-coated from a polyimide solution with two different solvents, 1-methyl-2-pyrrolidone (NMP) and dimethylformaldehyde. A variety of dip-coating speeds, solution concentrations and solvent-solute combinations have been tested. Their effect on the quality of the layer was analysed through microscopy, leak current measurements and atomic force microscopy (AFM). Polyimide dip-coating with polyimide resin dissolved in NMP at a concentration of 15w% in combination with a dip-coating speed of 50 mm/min led to the best results in electrical insulation and roughness. By optimising the dielectric layer’s properties, the way is paved for applying the subsequent semi-conductive layer. In further research, we will be working with the organic semiconductor material TIPS-Pentacene
Basic Comparison of the Properties of the Loop and Frotte Yarns, Woven and Knitted Fabrics
1 Lodz Technical University, faculty of material Technologies and Textile designs, Institute of Architecture of Textiles, 116 Żeromskiego Steet, 90-924 Łódź, Poland
2 Ghent University, Department of Textiles, 907 Technologiepark, 9052 Zwijnaard (Ghent), Belgium
Citation Information: Autex Research Journal. Volume 14, Issue 3, Pages 135–144, ISSN (Online) 2300-0929, DOI: 10.2478/aut-2014-0009, September 2014
Published Online: 2014-09-30
Both loop fancy yarns and frotte fancy yarns belong to the group of yarns with continuous effects. The difference between frotte and loop yarn relies on the fact that the loop yarn is constructed with two core yarns and the frotte yarn is constructed with only one core yarn. The differences are evident in the shape of these two types of fancy yarns. These shape differences are the functions of the tensions of component yarns during the twisting process. The shape and construction of the fancy yarn influence its properties. The properties of loop and frotte fancy yarns, woven and knitted fabrics are compared in this article in order to find out the optimal yarn’s and fabric’s production condition to satisfy the final user and maintain low production costs. In terms of economy aspects only, the frotte fancy yarns are believed to be cheaper in production due to lower quantity of components utilize for their production to compare with loop fancy yarns, under conditions of the same settings of ring twisting frame.
Drop Impact on Textile Material: Effect of Fabric Properties
1 Laboratory of Interfaces and Advanced Materials (L. A. M. I), faculty of sciences of Monastir - University of Monastir - Tunisia
2 Laboratory of thermal and energizing system studies, (L. E. S. T. E), National Engineering School of Monastir (E. N. I. M), University of Monastir - Tunisia, Avenue de l’Environnement 5019 Monastir Tunisie
Citation Information: Autex Research Journal. Volume 14, Issue 3, Pages 145–151, ISSN (Online) 2300-0929, DOI: 10.2478/aut-2014-0010, September 2014
Published Online: 2014-09-30
This paper presents an experimental study of impact of water drop on a surface in a spreading regime with no splashing. Three surfaces were studied: virgin glass, coating film and woven cotton fabric at different construction parameters. All experiments were carried out using water drop with the same free fall high. Digidrop with high-resolution camera is used to measure the different parameters characterising this phenomenon. Results show an important effect of the height of the free fall on the drop profile and the spreading behaviour. An important drop deformation at the surface impact was observed. Then, fabric construction as the weft count deeply affects the drop impact. For plain weave, an increase of weft count causes a decrease in penetration and increase in the spreading rate. The same result was obtained for coated fabric. Therefore, the impact energy was modified and the drop shape was affected, which directly influenced the spreading rate.
Surface Morphology of Polyimide Thin Film Dip-Coated on Polyester Filament for Dielectric Layer in Fibrous Organic Field Effect Transistor
1Ghent University - Department of Textiles, Ghent, Belgium, Technologiepark 907, 9052 Zwijnaarde, tel +32 9 264 54 06, fax +32 9 264 58 31
2Ghent University - Department of Inorganic and Physical Chemistry, Ghent, Belgium, Krijgslaan 281 S3, 9000 Ghent, tel. +32 9 264 44 47, fax +32 9 264 49 83
3Ghent University - Department of Inorganic and Physical Chemistry, Ghent, Belgium, Krijgslaan 281 S3, 9000 Ghent, tel. +32 9 264 44 47, fax +32 9 264 49 83
4Ghent University - Department of Textiles, Ghent, Belgium, Technologiepark 907, 9052 Zwijnaarde, tel +32 9 264 54 06, fax +32 9 264 58 31
The idea of wearable electronics automatically leads to the concept of integrating electronic functions on textile substrates. Since this substrate type implies certain challenges in comparison with their rigid electronic companions, it is of utmost importance to investigate the application of materials for generating the electronic functions on the textile substrate. Only when interaction of materials and textile substrate is fully understood, the electronic function can be generated on the textile without changing the textile’s properties, being flexible or stretchable. This research deals with the optimization of the dielectric layer in a fibrous organic field effect transistor (OFET). A transistor can act as an electrical switch in a circuit. In this work, the polyimide layer was dip-coated on a copper-coated polyester filament. After thoroughly investigating the process conditions, best results with minimal thickness and roughness at full insulation could be achieved at a dip-coating speed of 50 mm/min. The polyimide solution was optimal at 15w% and the choice for the solvent NMP was made. In this paper, details on the pre-treatment methods, choice of solvent and dip-coating speed and their effect on layer morphology and thickness, electrical properties and roughness are reported. Results show that the use of polyimide as a dielectric layer in the architecture of a fibrous OFET is promising. Further research deals with the application of the semiconductor layer within the mentioned architecture, to finally build an OFET on a filament for application in smart textiles.
Regressional Estimation of Cotton Sirospun Yarn Properties from Fibre Properties
1Ege University, Faculty of Engineering, Department of Textile Engineering, Izmir, 35100 Izmir, Turkey
Citation Information: Autex Research Journal. Volume 14, Issue 3, Pages 161–167, ISSN (Online) 2300-0929, DOI: 10.2478/aut-2014-0012, September 2014
In this paper, it is aimed at determining the equations and models for estimating the sirospun yarn quality characteristics from the yarn production parameters and cotton fibre properties, which are focused on fibre bundle measurements represented by HVI (high volume instrument). For this purpose, a total of 270 sirospun yarn samples were produced on the same ring spinning machine under the same conditions at Ege University, by using 11 different cotton blends and three different strand spacing settings, in four different yarn counts and in three different twist coefficients. The sirospun yarn and cotton fibre property interactions were investigated by correlation analysis. For the prediction of yarn quality characteristics, multivariate linear regression methods were performed. As a result of the study, equations were generated for the prediction of yarn tenacity, breaking elongation, unevenness and hairiness by using fibre and yarn properties. After the goodness of fit statistics, very large determination coefficients (R2 and adjusted R2) were observed.
A Wear Geometry Model of Plain Woven Fabric Composites
1College of Mechanical Engineering, Yanshan University, Qinhuangdao, Hebei, China
2Aviation Key Laboratory of Science and Technology on Generic Technology of Self-lubricating Spherical Plain Bearing, Yanshan University, Qinhuangdao, Hebei, China
Citation Information: Autex Research Journal. Volume 14, Issue 3, Pages 168–173, ISSN (Online) 2300-0929, DOI: 10.2478/aut-2014-0014, September 2014
Effect of Fabric Weave on Stick-Slip Properties of Woven Fabrics
1Erciyes University, Engineering Faculty, Department of Textile Engineering, 38039 Talas-Kayseri, Turkey Tel:+03524378737; Fax:+03524375784
Citation Information: Autex Research Journal. Volume 14, Issue 3, Pages 205–217, ISSN (Online) 2300-0929, DOI: 10.2478/aut-2014-0017, September 2014
The aim of this study was to understand the stick-slip properties of dry polyester plain, ribs and satin woven fabric weaves. It was found that the amount of stick-slip force was related to the number of interlacement points in the fabric, whereas the amount of accumulative retraction force was related to fabric structural response. Stick-slip force and accumulative retraction force depend on fabric weave, fabric density, the number of pulled ends in the fabric and fabric sample dimensions. The weft directional single and multiple yarn stick-slip and accumulative retraction forces of dry plain fabrics in fabric edge and centre regions were higher than those in the satin fabric due to fabric weave. In addition, the warp directional single and multiple yarn stick-slip and accumulative retraction forces in the meso-cell-1 to the meso-cell-6 of dry wide and long satin fabric in fabric edge were higher than those in the weft direction due to fabric density. Stick-slip and accumulative retraction forces of polyester fabric in the multiple yarn pull-out test were higher than those of the single yarn pull-out test.
The Efficiency of Non-Flammable Functional Underwear
1Technical University of Liberec, Faculty of Textile Engineering, Department of Clothing Technology, Liberec, Czech Republic, Studentska 1402/2, 461 17, Liberec, tel. +420 485 353 124, fax. +420 485 353 204
Citation Information: Autex Research Journal. Volume 14, Issue 3, Pages 174–178, ISSN (Online) 2300-0929, DOI: 10.2478/aut-2014-0018, September 2014
This study evaluates the efficiency of non-flammable functional underwear used as a secondary heat barrier in extreme conditions. Five groups of knitted fabrics were analysed for flame resistance and selected physiological properties (water vapour permeability, air permeability, thermal resistance and liquid moisture transport by moisture management transport). The results indicated similar levels of flame resistance for the materials tested but show important differences in terms of physiological characteristics, namely liquid moisture transport, which influences the safety and comfort of protective clothing.
The Influence of Pet Fibres Surface Enzymatic Modification on the Selected Properties
1Department of Material and Commodity Sciences and Textile Metrology, Lodz University of Technology, Żeromskiego 116, Poland
Citation Information: Autex Research Journal. Volume 14, Issue 3, Pages 179–186, ISSN (Online) 2300-0929, DOI: 10.2478/aut-2014-0020, September 2014
The effect of changes in the surface structure of glossy polyester filaments from poly(ethylene terephthalate) in terms of its micro-topography, molecular and supermolecular structure of the fibre surface layers on selected fibre surface and volumetric properties has been assessed. The performed tests and measurements have shown that the change in the general surface characteristics of PET fibres (micro-topography and hydrophilicity) results in very beneficial changes in both their volumetric (dyeability) and surface properties (wettability, pilling, oil-soil removal and electric properties).
Influence of Heat Treatment on the Bending Behaviour of LLDPE Monofilaments
1Department of Fashion and Textile, Polytechnic University of Tirana, Sheshi “Nënë Tereza”, no. 4, Tirana, Albania
2Department of Textiles, Ghent University, Technologiepark 907, 9052 Ghent, Belgium
Citation Information: Autex Research Journal. Volume 14, Issue 3, Pages 187–199, ISSN (Online) 2300-0929, DOI: 10.2478/aut-2014-0021, September 2014
It is known that artificial turf surfaces based on LLDPE monofilaments have the potential to replace natural turf surfaces used for several sport surfaces. Even though the production parameters have a strong influence on the behaviour of monofilaments and indirectly on the final product, the effect of heat treatment at different stages of the production lines is not studied in detail. Therefore, the influence of heat treatment during the production of monofilaments was investigated. This investigation includes a study of the mechanical properties such as tensile testing and bending behaviour and morphological analyses by employing DSC measurements. The results show that the applied heat treatment has a strong influence on the bending behaviour even though the classical studied morphology structures do not show significant changes. Heat treatment influences quite importantly the characteristics of the non-crystalline part of the monofilaments and results in better long-term properties, such as resilience, deformation recovery and fibrillation resistance.
Improving Thermo-Physiological Comfort of Polyester/Cotton Knits by Caustic and Cellulases Treatments
1National Textile University, Faisalabad, Punjab Pakistan
Citation Information: Autex Research Journal. Volume 14, Issue 3, Pages 200–204, ISSN (Online) 2300-0929, DOI: 10.2478/aut-2014-0034, September 2014
Cotton is one of the most commonly used fibres for making knitwear. Some of the limitations of pure cotton knits include their tendency to shrink, relatively limited durability, and poor wash and wear properties. In order to overcome these limitations knitwear are also produced from polyester and cotton blends, however, at the cost of reduction in comfort properties. The objective of this study was to improve the thermo-physiological comfort properties of knits made from polyester/cotton (P/C) blends through simple chemical and biological treatments. The specimens of P/C knits were subjected to treatments with caustic soda solutions and the cellulase enzymes. It was found that the air permeability and perspiration management properties of P/C knits can be significantly improved by appropriate caustic treatment. However, the biological treatment with cellulase enzymes is comparatively less effective in making any improvement in the thermo-physiological comfort properties of P/C knits.