본 연구는 기계화학적 활성화 된 스카치테이프가 금속 이온 수용액에서 유발하는 자발적 금속 나노입자 필름 형성의 구동력과 그 크기를 전기화학적 방법으로 분석했다. 은 필름이 형성된 테이프를 질산에 녹이고, 완충용액과 섞어 전기화학 측정용 샘플을 준비했다. 양극 벗김 전압전류법의 피크 신호를 통해, 은 입자의 자발적 환원에 소모된 전하량을 측정했다. 이를 검정 곡선에 대입하여, 환원된 은의 양을 구했다. 그 결과 은의 양이 선행 연구 대비 106배 많은 점, 수용액에서 전하를 가진 이온들의 짧은 수명을 참고하여, 자발적 반응의 구동력을 라디칼로 결론 냈다.

Li2O-LiCl 용융염을 이용한 전해환원기술은 사용후핵연료로부터 우라늄 금속을 회수하기 위해 연구되고 있다. 이 전해환원기술에서는 Li2O가 촉매로 이용되기 때문에 그 농도를 유지하는 것은 매우 중요한 운전인자이다. ZrO2는 피복관의 주성분이 Zr이기 때문에 사용후핵연료에 불가피하게 함유되며, 본 연구에서는 Li2O를 촉매로 이용하는 전해환원공정에서 ZrO2의 거동을 살펴보았다. Li2O와 ZrO2의 화학반응과 전해환원공정 중에서의 생성물을 분석한 결과, Li2ZrO3와 Li4ZrO4가 주요하게 관찰되었고, 이는 Li2O의 손실을 가져오는 원인이 된다. 즉, ZrO2는 Li2O를 소모하는 역할을 하며, 반응생성물은 전기화학적으로 안정하기 때문에 Li2O의 손실이 불가피하게 된다.

본 연구에서는 850℃의 CaCl2 용융염계에서 전해환원공정을 통해 TiO2로부터 금속티타늄을 제조하였 다. Ni-TiO2 조합전극을 환원전극으로 그라파이트를 산화전극으로 사용하였으며, 셀전위를 제어하면서 TiO2의 전해환원 특성을 관찰하였다. XRD 분석을 통해 TiO2가 CaTiO3, Ti2O, Ti6O와 같은 다양한 반응 중간생성물을 거쳐 Ti 스폰지로 환원되는 것이 밝혀졌다. 또한 SEM 분석을 통해 TiO2 전해환원 반응동안 펠렛의 바깥표면부터 환원반응이 시작되어 펠렛중심으로 진행이 되는 것이 확인되었다. 전해환원 반응도 중 환원된 티타늄금속은 초기에는 다공성 스폰지 구조를 보이나 고온에서 반응이 진행됨에 따라 점차 소 결에 의해 수축되어 다공성 구조가 사라지는 현상을 보였다.

Ni-GDC (gadolinia-doped ceria) composite powders, the anode material for the application of solid oxide fuel cells, were prepared by a solution reduction method using hydrazine. The distribution of Ni particles in the composite powders was homogeneous. The Ni-GDC powders were sintered at 1400˚C for 2 h and then reduced at 800˚C for 24 h in 3% H2. The percolation limit of Ni of the sintered composite was 20 vol%, which was significantly lower than these values in the literature (30-35 vol%). The marked decrease of percolation limit is attributed to the small size of the Ni particles and the high degree of dispersion. The hydrazine method suggests a facile chemical route to prepare well-dispersed Ni-GDC composite powders.

Hydrogen production via high high-temperature steam electrolysis consumes less electrical energy than compared to conventional low low-temperature water electrolysis, mainly due to the improved thermodynamics and kinetics at elevated temperaturetemperatures. The elementalElemental powders of Cu, Ni, and YSZ are were used to synthesize high high-temperature electrolysis cathodecathodes, of Ni/YSZ and Cu/YSZ composites, by mechanical alloying. The metallic particles of the composites were uniformly covered with finer YSZ particles. Sub-micron sized pores are were homogeneously dispersed in the Ni/YSZ and Cu/YSZ composites. In this study, The cathode materials were synthesized and their Characterizations properties were evaluated in this study: It was found that the better electric conductivity of the Cu/YSZ composite was measured improved compared tothan that of the Ni/YSZ composite. Slight A slight increase in the resistance can be produced for in a Cu/YSZ cathode by oxidation, but it this is compensated offset for by a favorable thermal expansion coefficient. Therefore, Cu/YSZ cermet can be adequately used as a suitable cathode material of in high high-temperature electrolysis.

[ ] oxide layer on the surface of each W(tungsten) nanopowder produced by the electric explosion of wire(EEW) process were formed during the 1vol.% air passivation process. The oxide layer hindered sintering densification of compacts during SPS process. The oxide phase was reduced to the pure W phase during SPS. The W nanopowder's compacts treated by the hydrogen reduction showed high sintered density of 94.5%. after SPS process at .

Isotopes of alkali and alkaline earth metals (AM and AEM) are the main contributors to the heat load and the radiotoxicity of spent fuel (SF) . These components are separated from the SF and dissolved in a molten LiCl in an electrolytic reduction process. A mass transfer model is developed to describe the diffusion behavior of Cs, Sr, and Ba in the SF into the molten salt. The model is an analytical solution of Fick's second law of diffusion for a cylinder which is the shape of a cathode in the electrolytic reduction process. And the model is also applied to depict the concentration profile of the oxygen ion which is produced by the electrolysis of LiO. The regressed diffusion coefficients of the model correlating the experimentally measured data are evaluated to be greater in the order of Ba, Cs, and Sr for the metal ions and the diffusion of the oxygen ion is slower than the metal ions which implies that different mechanisms govern the diffusion of the metal ions and the oxygen ions in a molten LiCl.

This laboratory study showed the performance evaluations of a improved C12A7 based mineral accelerator (I-CA) by both mortar and shotcrete tests. Performance of I-CA as a shotcrete accelerator was excellent by KCI-SC-102, which is a Korean specifications of shotcrete accelerator. In addition, I-CA showed equal qualities to the setting time and the compressive strength when compared those of the existing C12A7 based mineral accelerator (CA). The I-CA was manufactured with 40wt.% of electric arc furnace reducing slag, 24wt.% of lime, and 36wt.% of bauxite, indicating that the commercialization of I-CA contributed to recycle electric arc furnace reducing slag and to reduce the manufacturing cost of C12A7 based mineral accelerator due to the use a cheap raw material(electric arc furnace reducing slag), and to reduce the greenhouse gas emission due to the reductions in usage of lime and bauxite.

This study evaluated the standard consistency, setting time, hydration heat, and compressive strength of binary blended cement concrete (general and high strength) using air cooled ladle furnace slag (LFS) of 3, 5, 7, 10wt.% as an admixture for ordinary portland cement (OPC). Results showed that binary blended cements using the LFS of lower than 5wt.% shortened the setting time and reinforced the compressive strength of concrete (general and high-strength) compared to OPC concretes although binary blended cements needed more water to achieve the standard consistency. This indicated that LFS could be used as a useful admixture for manufacturing binary blended cement. Thus, we expected that the upcycling of LFS would be contributed to save energy consumption and reduce the greenhouse gas emission from the field of cement industry.

Electrochemical reductive extraction of tin from semiconductor plating process wastewater was experimented using synthetic wastewater. Copper and graphite plate were used as a cathode and an anode, respectively. The tin extraction could be optimized in pH 0.5 and polar space of 60 mm. The extraction rate of tin per minute was increased as current and initial tin concentration increased, and more than 87% and 97% of tin could be extracted within 80 minutes at 500 mg/L and 1,000 mg/L of initial tin concentration, respectively. The electrochemical reaction orders and kinetic coefficients were 1.24 ~ 1.26 and 0.004 ~ 0.006 (L/mg)(n − 1)min−1. The residual concentration of tin could be expressed as Ct= (Co −0.246+ 0.0012t)−4.065.

Electrochemical reductive extraction of copper from LCD manufacturing process and through hole plating process for PCB circuit board wastewater was experimented using synthetic wastewater. Copper plate which could be used as raw material through melting with extracted copper from wastewater and graphite plate were used as a cathode and an anode, respectively. The copper extraction could be optimized in pH 2 and polar space of 45mm. The extraction rate of copper per unit energy was decreased as HRT increased and initial copper concentration decreased. As the optimal HRTs which could maximize the productivity for copper on energy, 80 ~ 110 min at 50 mg/L, 64 min at 1,000 mg/L and 77 ~ 98 min at 3,000 mg/L were determined, respectively.

몇 가지 점토광물과 메틸바이올로젠 또는 메틸렌블루를 함유시킨 점토수식전극을 이용하여 산소환원에 대한 전기화학적 촉매성을 검토하였다. 점토광물로는 Na-몬모릴로나이트, Ca-몬모릴로나이트, 카오리나이트를 사용하였다. 점토수식전극은 유리탄소전극 표면에 점토 현탁액을 입히고 메틸바이올로젠을 흡착시킨 것을 사용하였으며, 전기화학적 산소환원의 정도는 순환 전압전류법(cyclic voltammetry)으로 측정하였다. 실험결과, 다른 점토시료에 비하여 Na-몬모릴로나이트가 메틸바이올로젠의 흡착효과가 가장 크게 나타났고, 메틸바이올로젠을 흡착시킨 점토수식전극이 산소환원에 대한 촉매성이 월등히 우수하였다. 즉 촉매산소환원 피크가 242.6 mV 만큼 +방향으로 이동하였다. 메틸바이올로젠을 흡착시킨 점토수식전극이 메틸렌블루를 흡착시킨 점토수식전극보다 산소환원에 대한 촉매성이 더 높게 나타났다. Ca-몬모릴로나이트의 경우는 변화가 없었으나 Na-몬모릴로나이트의 구조는 메틸바이올로젠의 흡착으로 변화되었다. 메틸바이올로젠- Na-몬모릴로나이트 점토수식전극은 현탁액의 점토 농도가 약 0.87 g/10 mL이고. 메틸바이올로젠의 수용액의 농도가 대략 2.5 mM일 때 산소환원 촉매 효과가 가장 탁월하였다. 지지전해질의 pH에 따른 점토수식 전극의 산소 환원 촉매성은 중성의 pH 범위(6.3과 8.3)에서보다 산성인 pH 3.7과 알칼리성인 pH 12.7에서 월등히 크게 나타났다.