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Oh S.-T.,Intelligent Textile System Research Center | Oh S.-T.,Research Institute for Agriculture and Life science | Oh S.-T.,University of Suwon | Kim W.-R.,Intelligent Textile System Research Center | And 9 more authors.
Fibers and Polymers | Year: 2011

Polyurethane (PU) foam was combined with protein drug-loaded pH-sensitive alginate-bentonite hydrogel for wound dressings. Alginate is a linear copolymer composed of 1-4-linked β-D-mannuronic acid (M) and its c-5-epimer α-Lguluronic acid (G). The amount of (M) and (G) and their sequential distribution are varied depending on the alginate source. Soluble sodium alginate can become a hydrogel when cross-linked with divalent cations and has widespread applications in the food, drink, pharmaceutical and bioengineering industries. Recently, it has been also proposed as a biomaterial for drug delivery systems. Bentonites are the natural inorganic polymers consisting of a large proportion of expandable clay minerals with a three-layer structure such as montmorillonite, beidellite, nontronite, etc. They are important adjutants and supports for medical products, and they have many useful physicochemical, mechanical, and biological properties such as absence of toxicity, indifference to other raw materials, sorption, swelling, and complex formation properties. Alginate-bentonite hydrogels were prepared at concentration ratios of 10/0, 7/3, 5/5, 3/7. PU foams were prepared using hydrophilic polyols. We investigated the controlled release of a protein drug from PU foam combined with alginate-bentonite hydrogel at different pH values of 4.2, 5.2, 7.2, 8.2. The mechanical properties and cytotoxicity tests of this foam were also studied. © 2011 The Korean Fiber Society and Springer Netherlands. Source

Roh J.-S.,Intelligent Textile System Research Center | Chi Y.-S.,Fashion Textile Center | Kang T.J.,Intelligent Textile System Research Center | Kang T.J.,Fashion Textile Center | Kang T.J.,Seoul National University
International Journal of Fashion Design, Technology and Education | Year: 2010

Owing to the rapid progress in fabrication technologies of conductive fibrous materials and the increasing demand for wireless communications in smart clothing systems, the potential application of wearable textile antennas in this field continues to increase. This article reviews a variety of wearable textile antennas in order to provide background information and application ideas for designing such antennas. The various materials used in the construction of wearable textile antennas, their fabrication methods, as well as the antenna types and their application fields are summarised. Owing to the high conductivity of metals, various metal composite yarns (MCYs) and fabrics have been used in the production of textile antennas. For inductively coupled near-field communication within smart clothing systems, woven or embroidered multiturn loop antennas are suggested. For far-field communication, a variety of broadband textile antennas were developed to counterbalance the detuning caused by the presence of a human body. Embroidered-folded dipole array antennas, metal-coated fabric patched bowtie and spiral antennas, a microstrip patch antenna array and a coplanar antenna made of metal-coated fabric patches and a ground plane, are the antennas that cover a broad spectrum and thus are capable of operating on the body. © 2010 Taylor & Francis. Source

Yun C.,Seoul National University | Park S.,Seoul National University | Park C.H.,Seoul National University | Park C.H.,Intelligent Textile System Research Center
Textile Research Journal | Year: 2013

Types of fabric movement inside a front-loading washer were analyzed in order to examine their effect on washing performance. A high-speed camera was used to record and track the outlines of the fabric inside a washer, and 13 movement indexes were derived. From this observation, fabric movements were divided into four categories, and the relationship between fabric movements and washing performance were examined. It was shown that the mechanical force from the complex movement where diverse fabric movements were mixed was stronger than that from the simple movement where only single fabric movement appeared. With regard to the detergency, it was also shown that complex movement was more effective than single movement. For fabric with a lower drape coefficient, there seemed to be a greater potential to generate more flexing under similar mechanical action, therefore resulting in higher washing performance. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav. Source

Chung S.E.,Intelligent Textile System Research Center | Park C.H.,Seoul National University
Journal of Applied Polymer Science | Year: 2010

The purpose of this study is to develop a protective and thermally intelligent filler by optimizing the preparing conditions and the thermoresponsive property of PU foam. The specimens were polyurethane synthesized by a one step process with 4,4′-diphenylmethane diisocyanate, polycaprolactone and 1,4-butanediol. After dissolving the polyurethane in tetrahydrofuran, the poly-urethane foam was manufactured by the salt leaching method. The appearance, compressive property, and thermal property of the manufactured foam as well as the shape memory effects were evaluated. In addition, air and water vapor permeabilities and the thermal insulation property were measured to examine the basic properties of the foam. The cell sizes of the completed foam were distributed in the range of 400-1,000 μm. The compressive stress of the foam was low in the initial compressive strain but increased dramatically above a compressive strain of 70%. However, the foam showed a very low capacity for compressive stress compared with an electrospun web or a film manufactured by using the identical shape memory polyurethane. The transition temperature of the foam was 30°C. The shape recovery and shape retention were 98% or higher. The foam, with a porous structure, was found to be generally good in both air and water vapor permeability. In the case of the foam that maintained its compressed shape below the transition temperature, these permeabilities of the foam decreased slightly, but not significantly. Because of the porous structure of the foam, the shape memory effect did not noticeably influence the permeability change with a change in temperature. © 2010 Wiley Periodicals, Inc. Source

Oh S.-T.,Hyosung Corporation | Kim S.-H.,Seoul National University | Kim S.-H.,Intelligent Textile System Research Center | Kim S.-H.,Research Institute for Agriculture and Life science | And 10 more authors.
Fibers and Polymers | Year: 2013

The purpose of this study is to fabricate a smart wound dressing by hybridizing hydrophilic polyurethane foam (PUF) and alginate hydrogel. Hydrophilic PUF is used to maintain damaged tissue in a moist environment. Despite its many strong points as a wound dressing, hydrophilic PUF cannot be loaded with ingredients such as growth factors and cytokines that would enhance wound healing. Therefore, we introduce a pH-sensitive alginate hydrogel with the ability to selectively release drugs within the pH range of wounded skin. Due to the small pore size of PUF and the high viscosity of the alginate solution, the two are not easily penetrable. As such, a vacuum method is used to insert alginate hydrogel into the PUF. The optimum conditions for the vacuum method chosen are to be proposed. However, the mechanical strength of PUF decreased after containing alginate hydrogel. Therefore, Na-alginate powder for PUF, various types of crosslinking agents and jute fiber for alginate hydrogel were introduced to improve the mechanical properties of hydrogel/PUF hybrid wound dressing. Three different types of crosslinking agents are used for the gel formation. The most suitable crosslinking agent and its concentration for alginate hydrogel is also determined by the experiments. The experimental results are discussed with proper schemes and reasonable explanations. © 2013 The Korean Fiber Society and Springer Science+Business Media Dordrecht. Source

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