• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.900-903
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• 2007

We introduce non-contact surface modification using trimethylchlorosilane (TMCS) for thin film transistor application. The surface is not contacted to the TMCS solution because it is vaporized at room temperature. The hydrophobic surface with contact angle $of\;{\sim}\;70^{\circ}$ can be achieved by the transfer of TMCS using a PDMS mold.

• 청정기술
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• 제25권1호
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• pp.33-39
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• 2019

활성탄(activated carbon, A.C)은 휘발성 유기화합물(volatile organic compounds, VOCs) 제거를 위해 가장 많이 사용되고 있지만 흡/탈착 시 열화현상으로 인한 화재위험성, 잦은 교체 주기로 인한 비용 부담, 수분에 의한 성능 저하 등의 문제점을 가지고 있다. 이러한 문제들을 해결하기 위하여 소수성 제올라이트 흡착제가 연구되고 있다. 본 연구에서는 소수성 개질법 중 하나인 수증기처리 및 산 처리를 통해 $NH_4{^+}Y$-zeolite를 소수성 Y-zeolite로 합성하여 높은 표면적, 열적 안정성과 습도저항성을 확보하고자 하였다. Y-zeolite와 개질된 Y-550-HN, Y-600-HN, Y-650-HN의 흡착성능은 23, 38, 77, $61mg\;g^{-1}$으로 나타났으며, 소수성 개질 정도를 확인할 수 있는 지표인 Si/Al ratio 변화를 XRF 분석으로 확인하였다. 그 결과, Y-zeolite를 개질하였을 때 흡착성능이 증진되었고, Si/Al 비는 Y, Y-550-HN, Y-600-HN, Y-650-HN 순으로 각각 3.1765, 6.6706, 7.3079, 7.4635 임을 확인하였다. 반면에 높은 열처리 온도에 의한 구조적 결정화가 성능 저하에 영향을 미칠 수 있음을 확인하였다. 반면에 Y-zeolite의 최적 열처리 온도가 존재하며, 이와 같은 최적 개질 조건 연구는 높은 내구성과 안정성을 갖는 흡착제를 제조할 수 있는 조건으로써 향후 활성탄을 대체할 수 있을 것으로 판단하였다.

• Membrane and Water Treatment
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• 제7권4호
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• pp.355-365
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• 2016

The improvement of fouling resistance of porous polymeric membrane is one of the most important targets in membrane preparation for water purification in many process like wastewater treatment. Membranes can be modified by various techniques, including the treatment of polymer material, blending of hydrophilic polymer into polymer solution, and post treatment of fabricated membrane. This research proposed the modifications of morphology and surface property of hydrophobic membrane by blending polyethersulfone (PES) with three polymeric additives, polyvinylpyrrolidone (PVP), Pluronic F127 (Plu), and Tetronic 1307 (Tet). PES hollow fiber membranes were fabricated via dry-wet spinning process by using a spinneret with inner and outer diameter of 0.7 and 1.0 mm, respectively. The morphology changes of PES blend membrane by those additives, as well as the change of performance in ultrafiltration module were comparatively observed. The surface structure of membranes was characterized by atomic force microscopy and Fourier transform infra red spectroscopy. The cross section morphology of PES blend hollow fiber membranes was investigated by scanning electron microscopy. The results showed that all polymeric additives blended in this system affected to improve the performances of PES membrane. The ultra-filtration experiment confirmed that PES-PVP membrane showed the best performance among the three membranes on the basis of filtration stability.

• 대한전자공학회논문지SD
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• 제41권12호
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• pp.1-6
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• 2004

본 연구는 PCB 기판용 FRP 재료의 열화현상을 규명하기 위하여 열 및 방전에 의한 열화를 각각 모의하여 표면에서의 화학적, 정전적 상관관계를 조사하였다. 열 처리에 따른 시료의 특성변화는 $200^{\circ}C$ 까지는 표면의 소수화로 인하여 접촉각 및 표면전위가 증가하였다. XPS에 의한 분석결과 열처리에 따라 표면측쇄상 산소기의 이탈과 탄소쇄의 불포화 이중결합의 증가로 처리시료에서는 소수성이 증가하였다. 또한 열처리로 인해 착색현상이 발생되었고, 이러한 현상은 ether기에 의해 발생된다는 것을 확인하였다. 방전 처리된 시료의 접촉각 및 표면전위는 표면에 카르복실기 라디칼을 포함하는 다량의 측쇄화가 집중적으로 발생되어 처리시간에 따라 급격한 친수화가 진행되었다.

• 상하수도학회지
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• 제32권4호
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• pp.301-307
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• 2018

Membrane distillation (MD) is a thermally driven desalination process with a hydrophobic membrane. MD process has been known to have a lower fouling potential compared to other pressure-based membrane desalination process (NF, RO). However, membrane fouling also occurs in MD process. In this study, the membrane fouling was observed in MD process according to the pre-treatment processes. The filtration and precipitation processes were applied as the pre-treatment to prevent the membrane fouling. The pore sizes of roughing filters were 0.4, 5, 10, 30, and $60{\mu}m$. The concentration of the coagulant was 1.2 mg/L as $FeCl_3$. The membrane fouling on MD membrane was successfully removed with both pre-treatment processes.

• 한국표면공학회지
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• 제45권1호
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• pp.8-14
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• 2012

The effects of the alkali surface modification process on the adhesion strength between electroless-plated Cu and polyimide films were investigated. The polyimide surfaces were effectively modified by alkali surface treatments from the hydrophobic to the hydrophilic states, and it was confirmed by the results of the contact angle measurement. The surface roughness increased by alkali surface treatments and the adhesion strength was proportional to the surface roughness. The adhesion strength of Cu/polyimide interface treated by KOH + EDA (Ethylenediamine) was 874 gf/cm which is better than that treated by KOH and KOH + $KMnO_4$. The results of XPS spectra revealed that the alkali treatment formed oxygen functional groups such as carboxyl and amide groups on the polyimide films which is closely related to the interfacial bonding mechanism between electroless-plated Cu and polyimide films. It could be suggested that the species and contents of functional group on polyimide films, surface roughness and contact angle were related with the adhesion strength of Cu/polyimide in combination.

• 한국표면공학회지
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• 제44권1호
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• pp.32-37
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• 2011

Numerical analysis is done to investigate the effect of surface treatment of a toilet on the cleanness. The surface treatment using plasma for the super-hydrophobic surface expects the self-cleaning effect of the toilet seat cover for preventing the droplets with a great quantity of bacteria during the toilet flushing after evacuation. In this study, the fluid analysis in the toilet during the flushing was performed by an ultrahigh-speed CCD camera with 1,000 frame/sec and the numerical modeling. And the spattering phenomenon from the toilet surface during urine was analyzed quantitatively by CFD-ACE+ with a free surface model and a mixed model of two fluids. If the surface tension of the toilet surface is weak, many urine droplets after collision bounded in spite of considering the gravity. The turbulence generated by the change of angle and velocity of urine and the variation of the collision phenomenon from toilet surface were modeled numerically.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.3313-3315
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• 1999

Si direct bonding(SDB) technology is very attractive for both Si-on-insulator(SOI) electric devices and MEMS applications because of its stress free structure and stability. This paper presents on pre-bonding according to HF pre-treatment conditions in Si wafer direct bonding. The characteristics of bonded sample were measured under different bonding conditions of HF concentration, and applied pressure. The bonding strength was evaluated by tensile strength method. The bonded interface and the void were analyzed by using SEM and IR camera respectively. A bond characteristic on the interface was analyzed by using IT- IR. Si-F bonds on Si surface after HF pre-treatment are replaced by Si-OH during a DI water rinse. Consequently, hydrophobic wafer was bonded by hydrogen bonding of Si $OH{\cdots}(HOH{\cdots}HOH{\cdots}HOH){\cdots}OH-Si$. The bond strength depends on the HF pre-treatment condition before pre- bonding (Min:$2.4kgf/crn^2{\sim}Max:14.9kgf/crn^2$)

• 한국응용과학기술학회지
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• 제27권3호
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• pp.282-289
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• 2010

In preparation of silica aerogel-based hybrid coating materials, the combination of hydrophobic aerogel with organic polar binder material is shown to be very limited due to dissimilar surface property between two materials. Accordingly, the surface modification of the aerogel would be required to obtain compatibilized hybrid coating sols with homogeneous dispersion. In this study, the surface of silica aerogel particles was modified by using both surfactant adsorption and heat treatment methods. Four types of surfactants with different molecular weights and HLB values were used to examine the effect of chain length and hydrophilicity. The surface property of the modified aerogel was evaluated in terms of visible observation for aerogel dispersion in water, water contact angle measurement, and FT-IR analysis. In surface modification using surfactants, the effects of surfactant type and content, and mixing time as process parameter on the degree of hydrophilicity for the modified aerogel. In addition, the temperature condition in modification process via heat treatment was revealed to be significant factor to prepare aerogel with highly hydrophilic property.

• 한국물환경학회지
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• 제20권5호
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• pp.500-505
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• 2004

While more attention has been paid in recent years to urban point source pollution control, no considerable measures have been taken to control urban non-point source pollution. Contaminants from non-point sources deposited on urban impermeable surfaces such as road and highway are easily released to the public waters by rainfall, leading to the deterioration in water quality in urban area. The present study investigated a system using filter media to reduce the level of contamination in urban road runoff. Three different media, designated as J-P (polypropylene, blowing type), B-P (polypropylene, fiber type), and P-F (Polyvinyl alcohol, cube and sheet type) were evaluated on the basis of pollutant removal efficiency as well as hydraulic property. Experiments were peformed using a 1/4-scale treatment unit at various pollutant roading and rainfall intensity with real rainwater runoff collected from road surfaces. The results at different rainfall intensities shows that the medium J-P is superior to the other media for water permeability. J-P was not blocked at 10 mm/hr rainfall and its permeability was stable. On the other hand, B-P and P-F resulted in substantial overflow ratio even at I mm/hr rainfall intensity. Comparing treatment efficiencies for suspended solids, all media showed similar removal ranged from 91 % to 95%. However, J-P seems to be better than the other media considering its higher water permeability. J-P and P-F, both hydrophobic, yielded over 76% of heavy metal removal. But, the hydrophilic media B-P showed much smaller removal ranging from 26% to 47%. This indicates that J-P and P-F are beneficial to remove heavy metal due to their hydrophobic property. The treatment efficiencies over PAHs (poly aromatic hydrocarbons) showed the similar removal efficiency ranging from 66% to 97% for all three media.