Hye-Min Lee

A Study on Toxic Acidic Vapor Removal Behaviors of Continuously Nanostructured Copper/Nickel-Coated Nanoporous Carbons

Nanostructured copper (Cu)/nickel- (Ni-) coated nanoporous carbon sheets (NCS) were prepared to improve the toxic acidic vapor (hydrogen chloride, HCl) removal efficiency of NCS using a continuous bimetal electroplating method at various metal content ratios. The surface morphology and nanostructure of Cu/Ni-NCS were observed by scanning electron microscopy and X-ray diffraction, respectively. N2/77 K adsorption isotherms were investigated using the Brunauer-Emmett-Teller equation. HCl vapor removal efficiency was confirmed using two types of detection techniques: a gas detecting tube for low concentrations and gas chromatography for high concentrations. HCl removal efficiency was improved mainly in the copresence of nanostructured Cu/Ni clusters compared to the efficiencies of the as-received and single-metal-plated NCS. In particular, the removal efficiency of Cu/Ni-3 was increased by 270% compared to that of as-received sample, but Cu/Ni-5 showed lower efficiency than Cu/Ni-3, indicating that suitable metal composition on NCS can accelerate HCl removal behaviors of the NCS.

Preparation and thermal properties of polyethylene-based carbonized fibers

In this study, carbonized fibers were prepared by using acidically cross-linked LDPE fibers. The surface morphologies of the carbonized fibers were observed by SEM. The effects of cross-linking process temperatures were studied using thermal analyses such as DSC and TGA. The melting and heating enthalpy of the fibers decreased as the cross-linking temperature increased. The cross-linked fibers had a carbonization yield of over 50%. From SEM results the highest yield of carbonized LDPE-based fibers was obtained by cross-linking at a sulfate temperature (170oC). As a result, carbonation yield of the carbonized fibers was found to depend on the functions of the cross-linking ratio of the LDPE precursors.

Effects of cross-linking methods for polyethylene-based carbon fibers: review

In recent decades, there has been an increasing interest in the use of carbon fiber reinforced plastic (CFRP) in aerospace, renewable energy and other industries, due to its low weight and relatively good mechanical properties compared with traditional metals. However, due to the high cost of petroleum-based precursors and their associated processing costs, CF remains a specialty product and as such has been limited to use in high-end aerospace, sporting goods, automotive, and specialist industrial applications. The high cost of CF is a problem in various applications and the use of CFRP has been impeded by the high cost of CF in various applications. This paper presents an overview of research related to the fabrication of low cost CF using polyethylene (PE) control technology, and identifies areas requiring additional research and development. It critically reviews the results of cross-linked PE control technology studies, and the development of promising control technologies, including acid, peroxide, radiation and silane cross-linking methods.