• Bulletin of the Korean Chemical Society
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• 제34권8호
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• pp.2491-2494
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• 2013

The effect of additives in an electrolyte solution on the conversion efficiency of a dye sensitized solar cell was investigated. A density functional theory (DFT) method was used to examine the physical and chemical properties of nitrogen-containing additives adsorbed on a $TiO_2$ surface. Our results show that additives which cause lower partial charges, higher Fermi level shifts, and greater adsorption energies tend to improve the performance of DSSCs. Steric effects that prevent energy losses due to electron recombination were also found to have a positive effect on the conversion efficiency. In this work, 3-amino-5-methylthio-1H-1,2,4-triazole (AMT) has been suggested as a better additive than the most popular additive, TBP, and verified with experiments.

• 대한화학회지
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• 제14권2호
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• pp.179-184
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• 1970

Four-ball EP and wear testers were used to study the effects of thickeners and additives on the EP and wear properties of some Korean greases. The EP property improved in the order of Li < Al < Ca, and the concentration of thickener did not affect the property when the same base oil and additives were used. The anti-wear property was improved in general when the additives were used.

• Macromolecular Research
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• 제17권11호
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• pp.856-862
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• 2009

This study examined the effects of liquid and solid additives on the morphological, mechanical and thermal insulating properties of rigid polyurethane foams (PUFs). The PUFs synthesized with tetramethylsilane (TEMS) as a liquid-type additive showed a smaller average cell size and lower thermal conductivity than those with the aerosil 200 and clay 30B as solid-type additives. When TEMS was added, the average cell size of the PUF became more uniform and finer due to the reduced surface tension of the polymer solution, which increased the nucleation rate and number of bubbles produced and reduced cell size. The PUFs with TEMS showed the highest closed cell contents among the PUFs prepared using TEMS, aerosil 200 and clay 30B. This suggests that the insulation properties of PUF can be determined by both the size of the cell structure and the amount of closed cell contents in the system. The compression and flexural strengths of the PUF increased slightly when the aerosil 200, clay 30B and TEMS were added compared those of the neat PUF. The reaction profiles of the PUFs showed a similar gel and tack tree time with the reaction time among the PUFs synthesized with three different additives and neat PUF. This suggests that the nucleating additives used in this study do not affect the bubble growth of the chemical reaction, and the additives may act as nucleating agents during the formation of PUF. From the above results of the cell size, thermal conductivity, closed cell contents and reaction profile of the PUFs, liquid-type nucleating agent, such as TEMS, is more effective in decreasing the thermal conductivity of the PUF than solid-type nucleating agent, such as aerosil 200 and clay 30B.

• 한국인터넷방송통신학회논문지
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• 제18권1호
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• pp.203-210
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• 2018

최근 웰빙(Well-Bing) 열품에 힘입어 화학적으로 가공되지 않은 천연 식품을 찾는 소비 형태가 많이 부각되고 있다. 하지만 현대 시대를 살아감에 있어 화학 식품 첨가물이 포함되지 않은 식품을 주변에서 찾기는 매우 힘들다. 또한 가공 조리된 식품에는 화학 식품 첨가물의 성분이 제대로 표기되어 있지 않거나 표기가 생략되어 나오는 제품이 상당수다. 본 논문은 한국의 연간 화학 식품 첨가물 소비량 데이터를 기반으로 첨가물 별 대두 되고 있는 암 발생을 빅 데이터 분석 기법 중 하나인 시계열 분석과 회귀 분석을 통해 검증 할 것이며, 이러한 식품 첨가물이 사회의 어떠한 요인 때문에 소비가 증가했는지에 대한 빅 데이터 분석을 실시해 검증한다.

• Computers and Concrete
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• 제25권1호
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• pp.59-65
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• 2020

The premise for the study reflected in this article is the need to dispose of industrial waste, which is increasingly being used in the construction materials industry. Also, dynamically developing building industry demands attention of scientists and a direction of their works on improvement of the technology of carrying out construction works. Thus, the article is devoted to studying the influence of various chemical additives and fine fillers (industrial wastes) available in Kazakhstan on self-compacting concrete (SCC) mixtures and its rheological, physical, and technical properties. According to the studies, revealed the most efficient type of fine-dispersed filler and the most optimal type of chemical additive to enable obtaining a high-quality SCC mixture based on local raw materials. As a result, the use of microsilica in comparison with other industrial wastes resulted in a conglomerate with high compressive strength of SCC at early terms of curing. In terms of economic efficiency and quality improvement, the results of study are of practical value for the manufacturers of ready-mixed concrete operating in Kazakhstan.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.304-307
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• 2003

Replacement of aluminum by copper for interconnections in the semiconductor industry has raised a number of important issues. The integration of copper interconnection can be carried out by CMP(chemical mechanical polishing) is used to planarize the surface topography. In this experiments, we evaluated the optimization of several conditions for chemical additives during Cu CMP process. It was presented that the main cause of grown particle size is tartaric acid. The particle size was in inverse propotion to a quantity of bead and the time of milling process. The slurry stabilizer and oxidizer have been shown to have very good effect by addition in later milling process.

• 대한화학회지
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• 제54권2호
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• pp.234-239
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• 2010

경유 첨가제로 사용할 수 있는 카보네이트 유도체를 합성하고 그들의 DCN 향상 효과를 살펴보았다. 1,2-글리세롤 카보네이트와 긴 알킬그룹을 가지는 지방산을 반응시켜 경유와 구조적으로 유사한 화합물을 얻었다. 경유에 대한 용해도를 증가시키기 위해 긴 체인 중간에 이중 결합을 도입하거나 카보닐 그룹의 알파 위치에 알킬기를 도입하였다. ASTM 방법을 통하여 측정한 이들의 DCN 증가 정도는 ~1 정도였으며 이 결과는 카보네이트 유도체 화합물이 연료 첨가제로서 사용이 가능하다는 것을 보여주고 있다.

• 마이크로전자및패키징학회지
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• 제19권4호
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• pp.39-43
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• 2012

Via-filling plating and through-hole plating are absolutely imperative for manufacturing of printed-wiring board. This Paper is introducing the latest developments of our company worked on the high-performance of acid copper plating additives for them.

• Journal of Electrochemical Science and Technology
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• 제13권2호
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• pp.269-278
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• 2022

Utilization of high-voltage electrolyte additive(s) at a small fraction is a cost-effective strategy for a good solid electrolyte interphase (SEI) formation and performance improvement of a lithium-rich layered oxide-based high-energy lithium-ion cell by avoiding the occurrence of metal-dissolution that is one of the failure modes. To mitigate metal-dissolution, we explored fluorinated dual-additives of fluoroethylene carbonate (FEC) and di(2,2,2-trifluoroethyl)carbonate (DFDEC) for building-up of a good SEI in a 4.7 V full-cell that consists of high-capacity silicon-graphite composite (15 wt% Si/C/CF/C-graphite) anode and Li_1.13Mn_0.463Ni_0.203Co_0.203O₂ (LMNC) cathode. The full-cell including optimum fractions of dual-additives shows increased capacity to 228 mAhg^-1 at 0.2C and improved performance from the one in the base electrolyte. Surface analysis results find that the SEI stabilization of LMNC cathode induced by dual-additives leads to a suppression of soluble Mn²⁺-O formation at cathode surface, mitigating metal-dissolution event and crack formation as well as structural degradation. The SEI and structure of Si/C/CF/C-graphite anode is also stabilized by the effects of dual-additives, contributing to performance improvement. The data give insight into a basic understanding of cathode-electrolyte and anode-electrolyte interfacial processes and cathode-anode interaction that are critical factors affecting full-cell performance.

• Korean Chemical Engineering Research
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• 제45권6호
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• pp.554-559
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• 2007

본 연구에서는 메탄올과 이산화탄소를 이용한 디메틸카보네이트(dimethyl carbonate, 이하 DMC) 의 직접 합성에서 수율 증대를 위하여 주입된 다양한 첨가제의 영향을 살펴보았다. 그리고 첨가제의 주입과 동시에 반응조건을 달리하여 얻어진 반응특성을 살펴봄으로써 필요한 반응조건의 최적화를 살펴보았다. Citric complexation method에 의해 제조된 복합금속산화물 $Ce_{1-x}Zr_xO_2$ 촉매들 가운데, 가장 높은 성능을 지니고 있는 $Ce_{0.8}Zr_{0.2}O_2$ 촉매가 DMC 합성에서 사용되었다. 황산염(sulfate) 계열, 질산염(nitrate) 계열, 인산염(phosphate) 계열 및 제올라이트 등의 다양한 첨가제가 사용된 가운데 DMC 생성량의 변화가 관찰되었다. 그 결과, $-SO_4$를 지니는 황산염 계열의 $K_2SO_4$ 및 $Na_2SO_4$ 등의 첨가제가 $Ce_{0.8}Zr_{0.2}O_2$ 촉매와 함께 사용됨으로써 가장 높은 DMC 생성량을 얻었다. 기존의 첨가제 없이 $Ce_{0.8}Zr_{0.2}O_2$ 촉매가 사용된 경우, 약 0.6 mmol의 DMC 생성량을 얻을 수 있었으며, $K_2SO_4$ 첨가제가 동시에 주입된 경우 가장 높은 0.91 mmol의 향상된 DMC 생성량을 얻었다.