3RD INTERNATIONAL CONGRESS ON TECHNOLOGY - ENGINEERING & SCIENCE - Kuala Lumpur - Malaysia (2017-02-09)
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Preparation Of Hollow Micro-tubes From Human Hair Via Heat Treatment
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Animal and human hair appears like a thin elongated cylinder. Especially, the human hair was readily available from the waste generated in barbershops and hair salons since it is cut and junk, periodically. The hair is composed of about 51% carbon, 17% nitrogen, 21% oxygen, 6% hydrogen, 5% sulfur, and trace amounts of iron, magnesium, arsenic, chromium and various minerals [1-3]. The hair is in the spotlight as an eco-friendly carbon material because it is a bioorganic material with high carbon contents and easy recycling. The hair shaft is mainly composed of three regions. The outermost region is the cuticle that is a thick sheath of several cell-like scales. The cuticle tightly protects the cortex that have account for most of hair volume that contains components as lipids, keratins, and melanin. The third part is the medulla, which is close to the center of hair. In the human hair, there are various cells piled up leaving large empty spaces in medulla. Cortex have a lot of micro and macro fibril structure such as macrofibril, intermediate filament and intermacrofibrilar matrix and so on. Each hair shaft has different thermal decomposition behaviors because of various thermal properties. Particularly, the thermal decomposition of hair starts from inner section. The thermal decomposition behaviour of hair could be confirmed by thermal analyses, such as differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). In this study, the effect of heat treatment temperature on the thermal decomposition of hair was examined in the middle range of temperature from 200 to 450℃. The cortex, inner part of hair, melted at about 250℃ and thus the hollow micro-tube was formed, while the cuticle became the compact structure. As the heat treatment temperature increased up to 450℃, the degradation area of inner cortex was expanded, and the empty space of hollow tube was increased. Therefore, the hollow tube structure might be resulted from the melting and degradation of cortex. Morphology and compositions of hollow micro-tube were obtained using a scanning electrochemical microscopy (SEM) and an elemental analysis (EA).
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Dong Su Im, Won Ho Park
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