본 연구에서는 다공성 활성탄소와 금속유기골격체 복합재료 기반의 전극 재료와 “이온젤” 이라고 불리는 고분자 고체 전해질을 이용하여 슈퍼커패시터를 제작 하였으며, 금속유기골격체의 함량에 따른 전기화학적 거동을 관찰하여 보았다. 슈퍼커패시터의 전기화학적 특성은 순환전압전류법(CV), 전기화학적 임피던스 분광법(EIS) 및 전정류 충·방전법(GCD)으로 분석하였으며, 그 결과로, 다공성 활성탄소 대비 금속유기골격체를 0.5 wt% 첨가 하였을 때 가장 높은 전기용량값을 확인 할 수 있었으며, 0.5 wt% 이상의 금속유기골격체의 함유량은 전기화학적 특성 감소에 영향을 주는 것으로 사료되며, 이러한 결과를 바탕으로 제조된 다공성 활성탄소/금속유기골격체 복합재료 기반의 슈퍼커패시터는 다양한 분야에 활용이 가능 할 것으로 판단된다.

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.

A zinc-air battery consists of a zinc anode, an air cathode, an electrolyte, and a separator. The active material of the positive electrode is oxygen contained in the ambient air. Therefore, zinc-air batteries have an open cell configuration. The external condition is one of the main factors for zinc-air batteries. One of the most important external conditions is temperature. To confirm the effect of temperature on the electrochemical properties of zinc-air batteries, we perform various analyses under different temperatures. Under 60 oC condition, the zinc-air cell shows an 84.98 % self-discharge rate. In addition, high corrosion rate and electrolyte evaporation rate are achieved at 60 oC. Among the cells stored at various temperature conditions, the cell stored at 50 oC delivers the highest discharge capacity; it also shows the highest self-discharge rate (65.33 %). On the other hand, the cell stored at 30 oC shows only 2.28 % self-discharge rate.

3 mol% yttria-doped stabilized zirconia (3YSZ) is synthesized by a solvothermal process, and its characteristics are investigated using various methods. Also, the dispersibility of synthesized 3YSZ nanoparticles is observed with the species of surface modifier. The 3YSZ nano sol prepared with an optimum condition is employed in prism coating and its properties are evaluated. The synthesized 3YSZ nanoparticles show a globular shape with about 10 to 20 nm crystallite size. The mixed phases with the nano sol show a high specific surface of 178 m2/g. The prism sheet coated with the 3YSZ nano sol present an excellent refractive index, transmittance, and luminance; refractive index is 1.603, transmittance is 90.2 %, and luminance of coating film is improved by 5.9 % compared to that of the film without 3YSZ nano sol. It is verified that the surface modified 3YSZ is suitable as the prism sheet for optical displays.

This study aimed to investigate the effect of storage temperature and pressure plate treatment on chemical composition in Prunus mume sugar extracts (PSEs). Green Prunus mume fruit was mixed with an equal amount of commercial sugar and stored at 4 or 25oC for 9 mon with or without a pressure plate. The alcohol contents in PSEs stored at 4oC were lower than those stored at 25oC. The amygdalin contents in PSEs stored at 25oC with pressure plate were significantly low. The sucrose in PSEs was converted into glucose and fructose during storage. The glucose, fructose and total phenol contents in PSEs stored at 25oC were higher compared with those at 4oC. The total soluble solid and polyphenol contents in PSEs were increased at 25oC until 90 d and 4oC until 150 d and then the contents were constant. The total acidity in PSEs stored at 4oC were higher than those at 25oC. These results indicate that storage temperature plays an important role in controlling the alcohol, amygdalin and sucrose contents in Prunus mume sugar extracts (PSEs).

The objective of this study was to determine chemical compositions affecting the physical and thermal properties of the textured vegetable protein (TVP). The 14 commercial TVPs were pulverized, followed by analyzing their morphology, chemical composition, water absorption index (WAI) and water solubility index (WSI) (for the pulverized and original TVPs), solubility, swelling power, melting property, and hardness. All TVPs showed the rough surface with irregular cracks and pores and the porous structure with varied pore sizes. WAI was positively correlated to moisture and crude protein contents and negatively correlated to the total carbohydrate content. WSI and solubility were directly and reversely influenced by the crude ash and total carbohydrate contents and the crude protein and total starch contents, respectively. The swelling power and melting temperature of TVPs did not significantly affect chemical compositions. Melting enthalpies increased with crude ash content, while decreased with the total starch content. The hardness of the rehydrated TVPs was enhanced with their crude ash and total carbohydrate contents, whereas reduced with their crude protein and total starch contents. Overall, the yield and texture of the rehydrated TVP could be modulated with the crude protein and ash contents of TVP.

본 연구에서는 친유성기의 크기는 같으면서 친수성기의 크기가 다른 계면활성제를 이용한 베타카로틴이 탑재된 에멀션을 제조하여, 에멀션의 계면특성과 산화방지제의 물리적 위치가 베타카로틴의 화학적 안정성에 미치는 영향 을 평가하였다. 계면활성제의 혼합은 에멀션에 탑재된 베타카로틴의 분해속도에 영향을 주었다. 에멀션을 Brij™ 계 면활성제 중 친수성기가 가장 작은 계면활성제(Brij™ S10)와 가장 큰 계면활성제(Brij™ S100)를 몰 비율 1:1로 각 각 3.17 mM의 농도와 1.00 mM의 농도로 제조하였을 때, 에멀션에 탑재된 베타카로틴은 계면활성제를 3.17 mM 농 도로 제조된 에멀션에서 1.00 mM 농도로 제조된 에멀션에 비해 더 급격하게 감소하였다. 친유성 산화방지제 (tert-butylhydroquinone (TBHQ))와 양친매성(lauryl gallate) 산화방지제 모두 에멀션에 포집된 베타카로틴의 화학적 안 정성을 향상시켰으며, 에멀션의 계면활성제의 농도와 계면 조성과는 무관하게 TBHQ가 lauryl gallate 보다 베타카로 틴의 분해를 지연시키는데 더 효과적이었다.

In this work, TiO2 3D nanostructures (TF30) were prepared via a facile wet chemical process using ammonium hexafluorotitanate. The synthesized 3D TiO2 nanostructures exhibited well-defined crystalline and hierarchical structures assembled from TiO2 nanorods with different thicknesses and diameters, which comprised numerous small beads. Moreover, the maximum specific surface area of TiO2 3D nanostructures was observed to be 191 m2g-1, with concentration of F ions on the surface being 2 at%. The TiO2 3D nanostructures were tested as photocatalysts under UV irradiation using Rhodamine B solution in order to determine their photocatalytic performance. The TiO2 3D nanostructures showed a higher photocatalytic activity than that of the other TiO2 samples, which was likely associated with the combined effects of a high crystallinity, unique features of the hierarchical structure, a high specific surface area, and the advantage of adsorbing F ions.