• 폴리머
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• 제26권2호
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• pp.279-286
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• 2002

기능성고분자표면으로 개질하기 위해서 polyethylene(PE)표면에 아크릴산을 알곤 플라즈마를 이용하여 고정화와 그라프팅을 행하고 고정화와 그라프딩에 의한 개질효과를 ATR적외선스펙트럼의 분석, 접촉각과 접착강도 측정에 의하여 평가하였다. 아크릴산의 특성흡수띠와 접촉각의 현저한 감소사실로부터 친수성개질을 평가하였다. 그라프팅된 PE의 접촉각은 플라즈마처리시간에 따라서 무처리 PE에 비하여 47~$53^{\circ}$ 감소하였고 고정화된 PE는 이보다 작은 23~$26^{\circ}$ 감소하여 그라프팅이 고정화보다 더 효과적인 친수화 수단이 됨을 관찰할 수 있었다. 표면친수화의 정도는 플라즈마 처리시간과 방전출력에 강하게 의존하였다. 그라프팅의 경우 처리시간이 증가할수록 더욱 친수화되지만 고정화의 경우는 처리시간의 증가와 방전출력의 증가는 오히려 친수성을 감소시켰다. 개질된 PE표면의 peel test에 의한 접착강도측정 전파 역시 접촉각과 같은 경향을 나타내었다. 이러한 현상은 고정화과정 중에 아크릴산이 ablation되어 표면의 카복시친수성기가 감소하는 현상 때문으로 해석되었다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1997년도 추계 학술대회논문집
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• pp.43-48
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• 1997

When computing the flow around complex three dimensional aircraft configurations, the generation of the grid is the most time consuming part. This paper presents a survey of the grid generation technique. The technique for treating problems arising in surface grid generation for complex geometries is addressed. Several example grids are shown, demonstrating the ability of the method to discretize complex geometries.

• 한국세라믹학회지
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• 제21권1호
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• pp.41-50
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• 1984

The ion-exchange porous glasses were prepared by heat treating and subsequently acid treating the (95-y) $SiO_2$.$yB_2O_3$.$5Na_2O+xAl_2O_3$ glasses with y=55, 45, 35, 25. mole% and x=0, 2, 5, 9 mole% It was then investigated how the cation exchange capacity was affected by the phase separation in these glasses. For that matter such quantities as alkali extraction amount pore volume and specific surface area of the glasses were measured. The phase separation in these glasses was in general suppressed by the addition of $Al_2O_3$ maximally around the composition of 5 mole% $Al_2O_3$ This may be because the micro-phase separation prevailed in the glass of that composition over the macro-phase separation increasing thereby the specific surface area as well as the residual amount Al of after acid-treatment and accordingly the cation exchange capacity. The maximum values of the cation exchange capacity was observed to be about 150meq/100g for the glasses of (40-50) $SiO_2$ (55~45)$yB_2O_3$. $5Na_2O+5Al_2O_3$.

• Corrosion Science and Technology
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• 제17권1호
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• pp.1-5
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• 2018

As structural materials, magnesium (Mg) alloys have been widely used in the fields of aviation, automobiles, optical instruments, and electronic products. There are few studies on the effect of coating conditions on the compositional variation during the formation process of the conversion coatings. Rare-earth based conversion coating on AZ91 magnesium alloy was prepared in ceric sulfate and hydrogen peroxide contained solution. The element composition and valence as well as their distribution in the coating were analyzed with energy dispersive X-ray spectroscopy (EDS), Electron probe micro-analyzer (EPMA), X-ray photoelectron spectroscopy (XPS). The effect of treating process on the element composition were also studied. It was found that the conversion coating surface consists of Mg, Al, O, Ce, and the weight content of Ce in the coating was affected by the treating solution concentration and immersion time; the Ce element was distributed in the coating non-uniformly and existed in the form of $Ce^{+3}$ and $Ce^{+4}$, while the O element existed in the form of $OH^-$, $O^{2-}$, $H_2O$. Based on microscopic analysis results, the electrochemical deposition mechanism on the micro-anode and micro-cathode in the process of the coating growth was suggested.

• Elastomers and Composites
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• 제44권3호
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• pp.260-268
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• 2009

Clay의 표면을 bis[(3-triethoxysilylpropyl)tetra sulfide (TSS)으로 처리하면 clay 표면의 소수성이 증가 될 뿐만 아니라 high temperature vulcanization 형 silicone rubber(HTV)와 화학적 반응이 가능하기 때문에 clay와 silicone rubber 사이의 상용성이 향상될 수 있을 것으로 예상되어 TSS를 이용하여 Na-MMT와 Fe-MMT의 silicate 층 표면에 tetra sulfide 그룹을 도입시킨 Na-$MMTS_4$와 Fe-$MMTS_4$를 각각 제작하였다. 이들 clay를 HTV silicone rubber와 compounding하여 silicone rubber/clay composites를 제작하였으며, clay의 종류 및 표면개질에 따른 silicone rubber 복합체의 열적안정성 및 기계적 물성을 평가하였다.

• 열처리공학회지
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• 제2권2호
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• pp.17-26
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• 1989

This study has been performed to investigate into some effects of the Sursulf treatment time and the traveling speed of surface hardening treatment on the hardness and the wear characteristics by applying the combined heat treating techniques of Sursulf process followed by induction hardening treatment to mild steel. It has been shown that increasing the Sursulf treatment time increases the case depth, but both hardness and wear resistance are not considerably improved. When the combined heat treating technique of high frequency induction heating after Sursulf treatment is applied, an improvement in case depth as well as wear resistance is obtained. In particular, the hardness in diffusion zone is greatly increased due mainly to the formation of martensite and possibly lower bainite. Iron oxides formed during induction heating and subsequent water spray cooling in the outermost part of compound layer may be considered to cause some increases in hardness and wear resistance.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권6호
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• pp.540-545
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• 2008

Since mid 20th century, dental treatments with laser have been introduced and improved a lot. Because early $CO_2$, Nd:YAG, diode, argon, and holmium lasers are used for dealing soft tissue, so it applied just limited field. But, in 1997 the lasers of erbium family that able to dealing soft and hard tissue also were introduced, laser application fields are enlarged. In today, the application fields reach on implantation treatment, so clinicians can use the laser to make holes for implantation, and flap elevation, even though treating peri-implantitis. So our class want to discover the optimal setting of Er:YAG laser when treating peri-implantitis. We observed the surface that initially treated by RBM and TPS passion and laser with varied options of exposure time and power with SEM image. For this we conclude the optimal setting range that does not alter the implant surface structure and report it.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권10호
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• pp.553-558
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• 2000

This paper deals with change of contact angle, surface potential decay, surface resistivity and XPS of water-treated epoxy insulator. From the experimental results on the contact angle was reduced from $74^{\circ}$to $24^{\circ}$ due to the formation of polar hydroxyl groups on surface which was associated with intermolecular reaction between epoxy chains of three-dimensional network structure and water molecules. From the experimental results in the surface potential decay of water treated-samples, it was found that the accumulation of charge is decreased and the surface potential decay time is shortened by the interaction of polar hydroxyl groups induced on the treated surface as the increment of treatment time. The positive charging on the treated surface compared with negative charging is relatively lowered by the induction of polar hydroxyl groups. The surface resistivity was changed from $10^{15}[{\Omega}/cm^2$] to $10^{12}[{\Omega}/cm^2$] caused by water treatment. From XPS, it was found that the changes affected by the surface degradation of epoxy were caused by the generation of carboxyl groups through the chain decomposition and recombination with oxygen molecules in the air.

• 한국표면공학회지
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• 제44권5호
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• pp.220-225
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• 2011

304 stainless steel plate was colored by hot dip and electrochemical treatment in a solution containing sulphuric and chromic acids. In the process, treatment variables such as operating time and methode were changed. The surface characteristics that changed by the treatment of the samples such as surface composition, oxide film thickness, color, surface roughness and reflectivity were studied. Surface composition was varied as follows. Fe was decreased, but Cr and O were increased. Ni was increased until 20 min, but reveals decreasing tendency as time passed after that. These means the surface film becomes chrome rich oxide phase as the treatment times increase. The thickness of film was about 220 nm at 30 min by dip treatment and it reduced as the treatment times increased. On the other hand, the thickness was about 150 nm at 10 min by electrochemical method and it doesn't increased with time. Surface color changed from metallic white of the base plate to gray, black, red, and green-blue, gradually, as the treating time increased. The reflectivity of colored surface measured by UVVIS-NIR spectrophotometer was reduced from max 38% of basis metal to min 3.5%.

• 한국전기전자재료학회논문지
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• 제21권5호
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• pp.486-491
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• 2008

The plasma processing is applied to many industrial fields as thin film deposition or surface treatment technique. In this study, we investigated large-area uniformed surface treatment of PET film at low temperature by using Scanning Plasma Method(SPM). Then, we measured difference and distribution of temperature on film's surface by setting up a thermometer. We studied the condition of plasma for surface treatment by examining intensity of irradiation of uniformed plasma. And we compared contact angles of treated PET film by using Ar and $O_2$ plasma based low temperature. In our result, surface temperature of 3-point of treating is low temperature about $22^{\circ}C$, in other hands, there is scarcely any variation of temperature on film's surface. And by using Ar plasma treatment, contact angle is lower than untreatment or $O_2$ plasma treatment. In case of PET film having thermal weak point, low temperature processing using SPM is undamaged method in film's surface and uniformly treated film's surface. As a result, Ar plasma surface treatment using SPM is suitable surface treatment method of PET film.