• 폴리머
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• 제25권3호
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• pp.441-449
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• 2001

폴리페닐렌 에테르(PPE)/폴리아미드(PA)를 근간으로 하는 블렌드를 상용화하기 위하여 부타디엔 고무에 스티렌이 그라프트된 공중합체 (g-BS)를 합성하고 여기에 폴리아미드의 말단기인 아민기와 반응성이 높은 무수말레인산기를 그라프트시킨 g-BS*를 도입하여 블렌드의 형태학과 기계적 성질의 변화를 조사하고 상용화제로서의 성능을 평가하였다. 폴리아미드 연속상에 분산되어 있는 PPE상의 크기와 이에 따른 기계적 성질의 변화는 사용된 g-BS의 구조와 관능기의 함량과 밀접한 관계를 나타내었다. 블렌드의 내열성과 내충격성의 균형을 위하여 g-BS성분을 PPE상에 내재시키는 것이 중요하고, 이러한 상구조의 형성은 g-BS에 포함된 폴리스티렌의 함량과 분자량이 적절하게 유지될 때 가능하였다. 고무함량과 그라프트된 폴리스티렌의 분자량이 일정하게 고정된 상태에서, g-BS*에 존재하는 무수말레인산의 함량이 낮거나, 고무입자의 크기가 커질 경우에는 연속상과 분산상의 계면 보강이 효과적으로 이루어지지 못하여 기계적 성질이 저하되었다. 본 연구에서 적용한 g-BS*를 사용하면, 폴리페닐렌 에테르에 관능기를 도입하여 상용화하는 기존의 방법과 동등한 정도의 물성이 달성될 수 있으며, 자연 색상이 보다 우수한 수지의 제조가 가능함을 확인하였다.

• 한국세라믹학회지
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• 제44권12호
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• pp.690-695
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• 2007

Scandia stabilized zirconia (ScSZ) is adapted for electrolyte material of solid oxide fuel cell (SOFC) because of its high ionic conductivity and chemical stability. ScMnSZ1 powder having a composition of $((ZrO_2)_{0.89}(Sc_2O_3)_{0.1}(MnO_2)_{0.01})$ is synthesized by ultrasonic spray pyrolysis (USP) method. Porous ScMnSZ1 powder is obtained by using a pore forming agent. Microstructure and morphology, particle size distribution of porous powder synthesized with 3wt% pore forming agent are investigated. Sintered ScMnSZ1 sample with ground fine powder are also investigated their microstructure and electrical conductivity. The electrical conductivity of sintered ScMnSZ1 samples with ground fine powder was 0.082 S/cm, 0.127 S/cm and 0.249 S/cm at $750^{\circ}C$, $800^{\circ}C$ and $900^{\circ}C$, respectively.

• 한국세라믹학회지
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• 제47권6호
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• pp.627-632
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• 2010

In this paper the effect of the structure, particle size, morphology of nanofibers and nanoparticles for the electrochemical characteristics of $Li_4Ti_5O_{12}$ was investigated. The $H_2Ti_2O_5{\cdot}H_2O$ synthesized in hydrothermal treatment from a NaOH treatment on $TiO_2$ by ion exchange processing with HCl solutions. After the $Li_4Ti_5O_{12}$ nanofibers synthesized in hydrothermal treatment of $H_2Ti_2O_5{\cdot}H_2O$ and $LiOH{\cdot}H_2O$. The hydrogen titanate precursor prepared by ion exchange processing with 0.1~0.3M HCl solutions and the final products calcined at $350^{\circ}C{\sim}400^{\circ}C$. The $Li_4Ti_5O_{12}$ nanofibers showed well reversibility during the insertion and extraction of Li, good cycle performance, high capacity and low electrochemical reaction resistance than nanoparticles. also c-rate exhibited a discharge capacity of 172 mAh/g at 0.2C and 115mAh/g at 5C, which is the 77%, 67% of that obtained in the process charged, discharged at 0.2C.

• 전기전자학회논문지
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• 제23권4호
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• pp.1175-1181
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• 2019

논문에서는 1:10으로 희석된 실리카 슬러리에 산화망간(MnO₂) 연마제를 첨가하여 재처리된 혼합연마제 슬러리(Mixed Abrasive Slurry; MAS)의 화학기계적연마(CMP) 특성을 연구하였다. 최적의 연마 성능을 갖는 슬러리를 설계하기 위해서는 높은 연마율, 하부층에 대한 적절한 연마선택비, 연마 후의 낮은 표면결함, 슬러리의 안정성 등을 얻어야 한다. 산화망간이 첨가된 MAS의 연마 성능은 연마율 및 비균일도와 같은 CMP 성능, 입도 분석, 표면 형상에 대해 평가하였다. 실험결과, 높은 연마율과 낮은 비균일도 측면에서 볼 때 원액 실리카 슬러리와 대등한 슬러리 특성을 얻을 수 있었다. 따라서 본 연구에서 제안하는 MnO₂-MAS를 사용하면 고가의 소모재인 슬러리를 절약하는데 매우 유용할 것이다.

• 한국응용곤충학회지
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• 제23권4호
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• pp.209-214
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• 1984

1980년도부터 우리나라 Burley 종 잎담배산지에서 엽맥에 녹대병상 또는 괴저증상을 나타내는 새로운 병징이 관찰되기 시작하였다. 기주범위조사, 항혈청반응, 물리적성질조사, 복숭아혹진딧물에 의한 전염여부 및 바이러스 입자 관찰을 통해 이들은 서로 병징을 달리하는 PYY의 두가지 계통으로 밝혀졌다. 이 계통들은 잎담배포장에서 자연감염에 의해 나타난 주요병징에 따라 엽맥연대계통 (PVY-VB)과 엽맥괴저계통 (PVY-VN) 으로 명명하였다. PVY 항혈청과 이 계통들의 이병즙액을 반응시킨 결과 양성반응을 나타냈으며 그 반응에서는 두계통간의 차가 없었다. 이들과 병징이 유사한 tobacco etch virus 및 tobacco vein mottling virus 항혈청과의 반응에서는 음성반응을 나타냈다. 전자현미경에 의해 약 730 nm의 사상형 바이러스 입자가 관찰되었으며 그 형태와 크기에는 두 계통간 차가 없었다.

• 한국의류산업학회지
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• 제10권4호
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• pp.552-559
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• 2008

Recent days, various inner wears, sheets and interior goods are manufactured using materials dyed with loess emphasizing its improved blood circulation, metabolism, anti-bacterial, deodorizing properties, and far-infrared ray emissions. The purpose of this study is to investigate the effect of chitosan treatment on the dyeing of cotton fabric using loess as colorants. Particle size of loess, the morphology and dyeability(K/S) of chitosan crosslinked cotton fabrics, and washing durability of loess dyed cotton fabric were investigated. In this study, cotton fabrics were treated with a crosslinking agent, epichlorohydrin, in the presence of chitosan to improve the dyeing properties of cotton fabrics with natural dye by the chemical linking of chitosan to the cellulose structure. This process was applied by means of the conventional mercerizing process. The results obtained were as follows; Mean average diameter of loess was $1.13{\mu}m$. According to various conditions, the optimum dyeing conditions for cotton fabrics pretreated by 1% chitosan treatment was where 10%(owb) of loess was applied at $90^{\circ}C$ for 120minutes, while for cotton fabrics without chitosan treatment was where 15%(owb) of loess was applied at $90^{\circ}C$ for 150minutes. Overall, K/S value of loess dyed cotton fabric pretreated with 1% chitosan was higher than that of cotton fabrics without chitosan treatment. The Color fastness, washing fastness and light fastness of loess were excellent as 4-5grade.

• 한국의류산업학회지
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• 제17권6호
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• pp.1004-1012
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• 2015

The purpose of this study is to investigate the loess dyeability of soybean fabric using loess as colorants. Recent days, various textile products such as inner wears, sheets and interior goods are manufactured using materials dyed with loess emphasizing its improved metabolism, anti-bacterial, deodorizing properties, and far infrared ray emissions. Soybean fabric was dyed with loess solution according to concentration of loess, dyeing temperature and dyeing time. To improve washing fastness, soybean fabric and dyed soybean fabric with loess were mordanted by mordanting agents such as sodium chloride(NaCl), Acetic acid(CH₃COOH) and Aluminium Potassium Sulfate(AlK(SO₄)₂·12H₂O). Dyeability and color characteristics of dyed soybean fabric were obtained by CCM observation. Particle size distribution of loess, the dyeability(K/S) of soybean fabric, morphology and washing durability of loess dyed soybean fabric were investigated. The results obtained were as follows; Mean average diameter of loess was 1.08µm. The main components of loess used in this study were silicon dioxide(SiO₂), aluminium oxide(Al₂O₃), and iron oxide(Fe₂O₃). The content of these three component was above 75 weight %. The dyeability of soybean fabric was increased gradually with increasing concentration of loess. The optimum dyeing temperature and dyeing time were 90℃ and 60minutes expectively. The fastness to washing according to concentration of loess and mordanting method indicated good grade result as more than 4 degree in all conditions.

• 한국의류산업학회지
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• 제18권4호
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• pp.531-539
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• 2016

Charcoal dyed fabrics have been widely used in home textiles and functional clothing due to their anti-statics, antibacterial, deodorization, far infrared emitting and anion releasing. Soybean fiber were regenerated from soybean. Soybean fiber have biodegradable, microbiocidal, non-allergic, and anti-ageing properties. The purpose of this study is to investigate the dyeing characteristics of soybean fabric using charcoal as colorants. Soybean fabrics were dyed with charcoal solution according to concentration of charcoal, dyeing temperature, and dyeing time. To improve washing fastness and investigate mordanting condition, soybean fabric and dyed soybean fabric with charcoal were mordanted by mordanting agents such as $CH_3COOH$(acetic acid), NaCl(sodium chloride) and $AlK(SO_4)_2{\cdot}12H_2O$(Aluminium Potassium Sulfate). Dyeability and color characteristics of charcoal dyed soybean fabric were obtained by computer color matching and SEM morphology analysis. Particle size of charcoal and color fastness were also investigated. The results obtained were as follows; Mean average diameter of charcoal was $1.39{\mu}m$. The dyeability of soybean fabric using charcoal as colorants was increased gradually with increasing concentration of charcoal dyeing solution and saturated at about 8%(o.w.b.). The optimum dyeing temperature and dyeing time were $90{\sim}105^{\circ}C$ and 60~90 minutes respectively. The overall wash fastness at dyeing concentration 2~4%(o.w.b.) and 6~10%(o.w.b.) were 4 degree and 3-4 degree respectively. The fastness to washing according to mordanting method indicated good grade result as more than 4 degree in all conditions. On the other hand, the staining of adjacent fabrics, i.e. PET, Acryl, Wool, Acetate, Nylon and Cotton was found to be of grade 4 or 4-5 in all conditions.

• Bulletin of the Korean Chemical Society
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• 제35권7호
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• pp.2004-2008
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• 2014

This paper reports the facile synthesis methods of zinc oxide (ZnO) nanoparticles, Z1-Z10, using diethylene glycol (DEG) and polyethylene glycol (PEG400). The particle size and morphology were correlated with the PEG concentration and reaction time. With 0.75 mL of PEG400 in 150 mL of DEG and a 20 h reaction time, the ZnO nanoparticles began to disperse from a collective spherical grain shape. The ZnO nanoparticles were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and a $N_2$ adsorption-desorption studies. The Brunauer-Emmett-Teller (BET) surface areas of Z4, Z5 and Z10 were 157.083, 141.559 and 233.249 $m^2/g$, respectively. The observed pore diameters of Z4, Z5 and Z10 were 63.4, 42.0 and 134.0 ${\AA}$, respectively. The pore volumes of Z4, Z5 and Z10 were 0.249, 0.148 and 0.781 $cm^3/g$, respectively. The photocatalytic activity of the synthesized ZnO nanoparticles was evaluated by methylene blue (MB) degradation, and the activity showed a good correlation with the $N_2$ adsorption-desorption data.

• Bulletin of the Korean Chemical Society
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• 제35권12호
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• pp.3576-3582
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• 2014

Zeolite-templated carbons (ZTCs), which have high specific surface area, were prepared by a conventional templating method using microporous zeolite-Y for catalyst supports in direct methanol fuel cells. The ZTCs were synthesized at different temperatures to investigate the characteristics of the surface produced and their electrochemical properties. Thereafter, Pt-Ru was deposited at different carbonization temperatures by a chemical reduction method. The crystalline and structural features were investigated using X-ray diffraction and scanning electron microscopy. The textural properties of the ZTCs were investigated by analyzing $N_2$/77 K adsorption isotherms using the Brunauer-Emmett-Teller equation, while the micro- and meso-pore size distributions were analyzed using the Barrett-Joyner-Halenda and Harvarth-Kawazoe methods, respectively. The surface morphology was characterized using transmission electron microscopy and inductively coupled plasma-mass spectrometry. The electrochemical properties of the Pt-Ru/ZTCs catalysts were also analyzed by cyclic voltammetry measurements. From the results, the ZTCs carbonized at $900^{\circ}C$ show the highest specific surface areas. In addition, ZTC900-PR led to uniform dispersion of Pt-Ru on the ZTCs, which enhanced the electro-catalytic activity of the Pt-Ru catalysts. The particle size of ZTC900-PR catalyst is about 3.4 nm, also peak current density from the CV plot is $12.5mA/cm^2$. Therefore, electro-catalytic activity of the ZTC900-PR catalyst is higher than those of ZTC1000-PR catalyst.