• Elastomers and Composites
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• v.47 no.2
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• pp.168-173
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• 2012

Polystyrene-polyimide core-shell microsphere was prepared by dispersion polymerization using poly(amic acid) as the stabilizer. Iron oxide was formed at the microsphere by thermal decomposition of iron pentacarbonyl impregnated in the microsphere. The magnetic polystyrene-polyimide microsphere was monodisperse and the size was about 500 nm. The magnetic polystyrene-polyimide microsphere had 40% of iron oxide, which was identified as $Fe_3O_4$ by X-ray diffraction.

• Applied Chemistry for Engineering
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• v.32 no.1
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• pp.117-123
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• 2021

In this study, the composite was prepared by mixing SiOx, soft carbon, and carbon black and the electrochemical properties of lithium ion battery were investigated. The content of SiOx added to improve the capacity of the soft carbon anode material was varied to 0, 6, 8, 10, 20 wt%, and carbon black was added as a structural stabilizer for reducing the volume expansion of SiOx. The physical properties of prepared CB/SiOx/C composite were investigated through XRD, SEM, EDS and powder resistance analysis. In addition, the electrochemical properties of prepared composite were observed through the charge/discharge capacity, rate and impedance analysis of the lithium ion battery. The prepared CB/SiOx/C composite had an inner cavity capable of mitigating the volume expansion of SiOx by adding carbon black. The formed internal cavity showed a low initial efficiency when the SiOx content was less than 8 wt%, and low cycle stability when the content of SiOx was less than 20 wt%. The CB/SiOx/C composite containing 10 wt% of SiOx showed an initial discharge capacity of 537 mAh/g, a capacity retention rate of 88%, and a rate of 79 at 2C/0.1C. SiOx was added to improve the capacity of the soft carbon anode material, and carbon black was added as a structural stabilizer to buffer the volume change of SiOx. In order to use the CB/SiOx/C composite as a high-efficiency anode material, the mechanism of the optimal SiOx and the use of carbon black as a structural stabilizer was discussed.

• Journal of the Korean Wood Science and Technology
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• v.9 no.3
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• pp.7-15
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• 1981

A Japanese larch has been reforested very much in Korea, but it is not used as a wood resources for paper pulp by now. So this study is carried out to utilize the larchwood for paper pulp manufacture through the Asplund pulping process. The experiment on increasing in the brightness of the pulp is made through the addition of $MgSO_4$, $ZnSO_4$, $Al_2(SO_4)_3$, and KI as a cellulose stabilizer in chip treatment with caustic soda which is followed by high-temperature defibration and conventional peroxide bleaching (5% NaOH plus 2% additive salt per wood in cold pretreatment), or in high-consistency (30%) pulp bleaching of hydrogen peroxide and peracetic acid (100% acitve oxygen per lignin) for conventional one. The results obtained are as follows: 1. The solution of 0.5% additive salts had different pH by the sort of bases that was pH 5.7 in $MgSO_4$, liquor, pH 4.9 for $ZnSO_4$, and pH 2.9 for $Al_2(SO_4)_3$, and in the precepitation of bases which ranged to pH 6-13 for $MgSO_4$, pH 5-12 for $ZnSO_4$, and pH 3-10 for $Al_2(SO_4)_3$. 2. The cellulose stabilizer affective in high-consistency peroxide bleaching was KI, $MgSO_4$, and $ZnSO_4$, but has made a little improvement in de lignification and brightness of pulp in comparison with no addition. 3. The higher alkalinity in the chip treatment has made the higher strength and brightness of larchwood Aspiund pulp instead of downing the pulp yield. And the effective compound for cellulose stabilizer in caustic soda pretreatment of chip was $ZnSO_4$, $Al_2(SO_4)_3$ and KI in order for the conventional peroxide bleaching after Asplund pulping. 4. Therefore, the more effective additives for cellulose stabilization in high-temperature defibration of larchwood suppose to be $ZnSO_4$, $Al_2(SO_4)_3$, and KI, while KI and $MgSO_4$ for peroxide bleaching.

• Applied Chemistry for Engineering
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• v.28 no.5
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• pp.513-520
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• 2017

The application possibility of an alternative new method with low energy consumption was studied for the eco-friendly fabrication of foamed glasses from waste glasses. As a result, fabricating temperature can be reduced under $300^{\circ}C$ without using various expensive inorganic oxidants. The foamed glass can be fabricated at a proper mixing ratio of the waste glass powder, water glass, little surfactant and bubble stabilizer by induction heating method. In the experimental range, the assured optimal condition is 4 min heating on the induction machine with a steel-container ($100mm{\times}100mm{\times}20mm$) and followed by evaporating and drying process for 11 min with 110 g of glass powder, 80 g of water glass, 3 g of surfactant and 0.2 g of bubble stabilizer. When the foamed glass was fabricated at the optimal condition, the density of the glass was $0.85g/cm^3$ and the heat conduction was $0.052W/h{\cdot}K$. In addition, the compressive strength of the glass was above $50kg/cm^2$.

• The Korean Journal of Food And Nutrition
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• v.14 no.4
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• pp.300-304
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• 2001

The oxidative stability of salmon mince to which milk protein concentrate(MPC) added was investigated. Salmon mince was stored at 4$\^{C}$ for 21 days, at -18$\^{C}$ for 20 days and at -18$\^{C}$ for 20 days after cooking in an electric omen. At each storage point, peroxide values(POV) were determined. Salmon mince with 4% MPC increased greater oxidative stability than control (without MPC). Sensory evaluation for measuring the oxidative stability of salmon mince was accomplished. Sensory scares of salmon mince with 4% MPC were higher than those of control. The results indicate that MPC could be useful for oxidative stability, as stabilizing protein ingredient of salmon mince.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.399-402
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• 2009

폴리올프로세스에서 PVP(Poly Vinyl Pyrrolidone) 안정제와 $NaNO_3$ 첨가제를 통해 환원속도를 조절하여 6.8 nm의 나노 큐보옥타해드론을 합성하였다. 투과전자현미경을 통해 백금 나노입자의 격자구조를 관찰하였다. 전기화학적 측정방법을 통해 백금 큐보옥타해드론 촉매가 구형의 촉매보다 우수한 촉매 성능을 나타냄을 확인하였다. 순환전류법을 통해 백금 촉매의 역방향 픽과 순방향 픽의 비율이 더 높은 것을 관찰하였다. 이것은 백금 큐보옥타해드론 촉매가 반응중 생성되는 촉매독에 강하다는 것을 의미한다. 백금 큐보옥타해드론 촉매의 표면은 {111}면과 {100}면이 혼재하며 모서리가 많이 드러나 메탄올 산화반응에 더 우수한 촉매성능을 나타내는 것으로 사료된다. 백금 촉매의 모양을 조절함으로서 백금 촉매의 표면 구조를 조절하였으며 이를 통해 높은 전류밀도를 나타내는 우수한 촉매를 합성할 수 있었다. 또한 0 ~ 0.6 V(NHE) 영역에서 촉매의 안정성을 평가한 결과 더 높은 안정성을 나타냄을 확인하였다.

• Proceedings of the KAIS Fall Conference
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• 2008.11a
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• pp.93-96
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• 2008

500나노 입자 및 기본 물성이 우수한 이중층상구조금속수화물(LDH)를 합성하고 PVC 수지에 적용하여 고온, 저온열안정성 및 가공특성으로 인장강도, 신율, 체적저항 등이 우수한 시제품을 합성한 후 개발한 이중층상구조금속수화물(LDH) 시제품을 사용하여 무독성안정제(금속석검계), 내외부활제류, 가공조제, 산화방지제 등 기타 첨가제 등을 사용하여 PVC수지에 적용하여 수지배합에 따른 시험편을 제작하여 배합비별로 고온, 및 저온열안정성, 체적고유저항, 가공성(인장강도, 신율 등), 내후성, 초기 착색성 등 물성, 기계적 가공특성 및 성능이 우수한 할로겐수지용 무독성배합을 개발한다. 최종적으로 개발한 이중층상구조금속수화물(LDH)을 사용하여 제조하여 PVC 수지의 열안정성 및 기계적 가공특성이 우수한 중금속계대체용 무독성복합열안정제를 개발하였다.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.639-648
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• 2015

Some materials of fatty acids in the biodiesel affect the physical/chemical properties like density, kinematic viscosity, total acid number and oxidation stability by forming an organic fatty acid in combination with oxygen in the air. To solve the problem of the oxidative stability of biodiesel, various kinds of antioxidant has added and analyze the characteristics of the physical/chemical property changes by the addition of antioxidant. Oxidation stability increased by the increase of additives content. The TBHQ among the seven kinds of the additives showed the best performance. Also, 4 kinds of additives like propyl gallate, butyl-amine and pyrogallo has showed above 10 hr of oxidation stability at the addition of 500 ppm. In case of pyrogallo, this is not appropriate as an additive to suitable quality standards of total acid number. TBHA, DTBHQ of hydroquinone was satisfied with the quality standard of oxidation stability but the target of this research(above 10 hr) did not satisfied with oxidation stability. Propyl gallate is also a suitable at the quality standards of total acid number but it was shown not to be an appropriate to the additives due to increasing the total acid number by increasing of the content of additives at the addition of 500 ppm.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.1 no.1
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• pp.5-16
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• 1991

It was grown Cubic $ZrO_2(10 mol% Y_2O_3)$ single crystals doped with 1 wt% rare earth metal oxides (RE=Ce, Pr, Nd, Eu, Er) by Skull method. It was investigated electrical properties on (111) plane of grown single crystals by Impedance Spectroscopy. It was potted relation between temperature and electrical conductivities and observed the transition at $약300-400^{\circ}$ It was obtained activation energy on the migration of oxygen vacancy between low temperature (before the transition) and high temperature (after the transition till ${\11}500^{\circ}$) and its difference can be seen the activation energy of the formation of oxygen vacancies by break up defect complexes. It was obtained the activation energy according as add yttria and rare earth metal oxides and discussed ionic conduction mechanism. Grown single crystals showed Ce: orange - red, Pr: golden - yellow, Nd: lilac, Eu: light pink, Er: pink due to dopant effect from the light absorption data in the visible range.

• Tribology and Lubricants
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• v.31 no.6
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• pp.258-263
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• 2015

Biodiesel is an environmentally-friendly fuel with low smoke emission because it contains about 10% oxygen. Biodiesel fuel prepared by transesterification of vegetable oil or animal fats is susceptible to auto-oxidation. The rate of auto-oxidation depends on the number of methylene double bonds contained within the fatty acid methyl or ethyl ester groups. Biodiesel may be easily oxidized under several conditions, i.e., upon exposure to sunlight, temperature, oxygen environment. Maintenance of the fuel quality of biodiesel requires the development of technologies to increase the resistance of biodiesel to oxidation. Treatment with antioxidants is a promising approach for extending the shelf-life or storage time of biodiesel. The chemical properties of various amine-based antioxidants were evaluated after synthesis of the antioxidants by condensation of phenylenediamine with alkylamines at room temperature. In general, the oxidative stability can be assessed based on various experimental parameters. Such parameters may include temperature, pressure, and the flow rate of air through the samples. The Rancimat method (EN14112) was selected because it is a rapid technique that requires very little sample and provides good precision for oxidative degradation analysis. Specifically, the EN 14112 technique provides enhanced efficiency for oxidative stability evaluation when a larger ester head group is utilized. Therefore, this technique was employed for evaluation of the oxidation stability of biodiesel by the Rancimat method (EN14112).