Soo-Ryong Kim

Preparation of shape-controlled copper oxide powders from copper-containing solution

Abstract Shape-controlled copper oxides have been recovered from copper-containing waste etchant by neutralization with alkali hydroxide. Large amounts of copper-containing waste etchant composed of copper chloride, hydrochloric acid and water are generated from the printed circuit board (PCB) industry. In an environmental and economic point of view, the retrieval of the valuable natural resource from waste is important. In the recycling process of copper oxide from the waste etchant, reaction temperature controls the shapes and sizes of the products. Copper oxide recovered below the reaction temperature of 40 °C was of the needle shape, while copper oxide comes in a platy shape above 40 °C. As a result of the experiments, more than 99% of the copper in the waste etchant was recovered as copper oxide, and its by-products are only sodium chloride and water. Physical properties of the samples have been characterized using scanning electron microscopy (SEM), X-ray powder diffraction (XRD), thermal gravimetric analysis (TGA) and atomic absorption spectroscopy. The particle size scatters in the range of 0.5–10 μm. Shape-controlled copper oxides are expected to be promising precursors for synthesizing copper powder by reduction.

Preparation and Characterization of SiC Coated Graphite Foam

Graphite is widely used in electronic industry due to its excellent electrical and thermal properties. However, graphite starts to oxidize around 400℃ that seriously degrades its properties. SiC coating can be applied to graphite foam to improve its high temperature oxidation resistance. In this research, SiC coating on graphite foam was made via preceramic polymer using a polyphenylcarbosilane. 20% of polyphenylcarbosilane in hexane solution was coated onto graphite by dip coating method. Thermal oxidation was carried out at 200℃ for crosslink of the preceramic polymer and the sample were pyrolysized at 800℃~1200℃ under nitrogen to convert the preceramic polymer to SiC film. The microstructure of the SiC coating after pyrolysis was investigated using FESEM and oxidation resistance up to 800℃ was evaluated.

폴리페닐카보실란을 이용한 SiOC가 코팅된 스테인리스스틸 제조 및 이의 내부식성 특징

【To improve the chemical stability of metal, the ceramic coatings on metallic materials have attracted interest from many researchers due to the chemical inertness of ceramic materials. To endure strong acids, SiOC coating on metal substrate was carried out by dip coating method using 20wt% polyphenylcarbosilane solution; SiC powder was added to the solution at 10wt% and 15wt% to improve the mechanical properties and to prevent cracks of the film. Thermal oxidation as a curing step was carried out at

Effects of asperities and organic-inorganic interactions on the strength of nacre-mimetic composites.

200^{\circ}C

Formation of ZSM-5 on Silicon Carbide Fibers for Catalytic Support

for crosslinking of the polyphenylcarbosilane, and the coating samples were pyrolysized at

Synthesis and Characterization of Methyltriphenylsilane for SiOC(-H) Thin Film

800^{\circ}C

Synthesis and Characterization of the ZnO-TiO2 Nanoparticles by a Hydrothermal Processing

under argon to convert the polyphenylcarbosilane to SiOC film. The thicknesses of the SiOC coating films were

Uniform Zeolite Layer Formation on Glass Fiber Surface

2.36{\mu}m

The Preparation of Copper Powder Using Solvothermal Process and Its Application as EMI Shielding Agent

and

Measurement of Coarse Particle Mass in Alumina Powders Using Wet Sieve Method

3.16{\mu}m