• 폴리머
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• 제24권4호
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• pp.520-528
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• 2000

본 연구는 고형분 70%인 하이솔리드 아크릴 수지 (BMHA)를 합성하여, 환경친화성 도료인 하이솔리드 아크릴/폴리이소시아네이트 도료(BNHS)에 적용하고 그의 도막특성을 살펴본 것에 그 의의가 있다. BMHA는 새로운 형의 단량체로서 acetoacetoxyethyl methacrylate (AAEM)을 도입하고 여기에 n-butyl acrylate, methyl methacrylate 및 2-hydroxyethyl acrylate를 4원공중합시켜 얻었다. BMHA 합성에 있어서 T$_{g}$ 값이 낮을수록, AAEM의 양이 많을수록 각각 높은 전환율을 나타내었고, T$_{g}$값 고정하의 OH 값 변화에 따른 전환율은 큰 차이가 없었다. BMHA와 폴리이소시아네이트를 상온경화시켜 하이솔리드 BNHS 도료를 제조하고서 자동차 상도용 도료로서의 적합성 여부를 알아보기 위하여 도막물성 시험을 한 결과, BNHS내에 AAEM 도입 전후의 도막물성 비교시험에서 AAEM 도입후에 내마모성과 내용제성이 향상됨으로써 자동차 상도용 도료로서의 응용가능성을 보여주었다.다.

• 한국대기환경학회지
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• 제29권2호
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• pp.125-134
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• 2013

Various antimicrobial technologies have been developed to inactivate bioaerosols in indoor environments. In this study, air filter media were treated with a natural antibacterial agent of Sophora flavescens in order to inactivate the bacteria collected on the air filter. Three treatment methods were applied to manufacture the test antibacterial air filter media: electrospray, nebulization and dip-coating methods. In case of electrospray and nebulization processes, the size distribution of aerosolized natural antibacterial agent was measured using a scanning mobility particle sizer. Staphylococcus epidermidis bacteria were aerosolized to test inactivation of the filter media treated with a natural antibacterial agent. The pressure drop and the antibacterial efficiency of the filter media increased with increasing the mass loading of natural antibacterial agent in each treatment method. The antibacterial efficiency per loaded antibacterial agent mass by the electrospray method was the highest and the filter treated by the dip-coating method was the lowest among three treatment methods.

• Journal of Electrochemical Science and Technology
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• 제7권2호
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• pp.132-138
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• 2016

In this study, we report the fabrication of functional complex fibers, which have been studied widely globally for numerous applications. Here, we fabricated conductive complex fibers with antibacterial properties by coating metal ions on the surface of plastic (polypropylene) fibers using the electroless and electrochemical deposition. First, we polished the polypropylene melt-blown fiber surface and obtained an absorbing Pd seed layer on its surface. Subsequently, we substituted the Pd with Cu. Bis-3-sulfopropyl-disulfide disodium salt (SPS), polyethylene glycol (PEG), and ethylene thiourea (ETU) were used as the brightener, carrier, and leveler, respectively for the electroplating. We focused on most achieving the stable plating condition to remove dendrites, which are normally during electroplating metals so that smooth layer is formed on the fiber surface. The higher the amount of SPS, the higher was the extent of irregular plate-like growth. Many irregularities in the form of round spheres were observed with increase in the amount of PEG and ETU. Hence, when the additives were used separately, a uniform coating could not be obtained. A stable coating was obtained when the three additives were combined and a uniform 5-9 μm thick copper layer with a stable morphology could be obtained around the fiber. We believe that our results can be applied widely to obtain conductive fibers with antibacterial properties and are useful in aiding research on conductive lightweight composite fibers for application in information technology and robotics.

• Journal of the Korean Wood Science and Technology
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• 제28권1호
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• pp.28-35
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• 2000

본 연구는 재면이 약한 낙엽송재의 재질개량의 일환으로 경도와 내마모성 등 표면성능의 개선을 도모하기 위한 표면 강화처리기술을 개발하기 위하여 수행되었다. 본 연구에서는 2가지의 도장법을 적용하였다. 첫째, UV경화형 에폭시아크릴에트수지도료에 관능성 모노머와 내마모제를 첨가하였으며, 둘째, 불포화폴리에스테르수지도료를 밑칠용으로 그리고 내마모제가 첨가된 아크릴수지도료를 마감칠로 사용하였다. 제 1도장법에 의해 표면경도가 2H에서 3H로 개선되었으며, 제 2도장법에 의해 4H로 크게 개선되었으며 내마모성도 향상되었다. 이들 처리에 의해 충격에 의한 도막의 갈라짐은 거의 발생하지 않았다. 제 2도장법에 의한 표면강화처리 마루판은 케루잉재의 대체재로서 중보행용의 실내 마루판으로 이용 가능한 것으로 시사된다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.217-217
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• 2011

Recently, demand for thermally stable metal nanoparticles suitable for chemical reactions at high temperatures has increased to the point to require a solution to nanoparticle coalescence. Thermal stability of metal nanoparticles can be achieved by adopting core-shell models and encapsulating supported metal nanoparticles with mesoporous oxides [1,2]. However, to understand the role of metal-support interactions on catalytic activity and for surface analysis of complex structures, we developed a novel catalyst design by coating an ultra-thin layer of titania on Pt supported silica ($SiO_2/Pt@TiO_2$). This structure provides higher metal dispersion (~52% Pt/silica), high thermal stability (~600$^{\circ}C$) and maximization of the interaction between Pt and titania. The high thermal stability of $SiO_2/Pt@TiO_2$ enabled the investigation of CO oxidation studies at high temperatures, including ignition behavior, which is otherwise not possible on bare Pt nanoparticles due to sintering [3]. It was found that this hybrid catalyst exhibited a lower activation energy for CO oxidation because of the metal-support interaction. The concept of an ultra-thin active metal oxide coating on supported nanoparticles opens-up new avenues for synthesis of various hybrid nanocatalysts with combinations of different metals and oxides to investigate important model reactions at high-temperatures and in industrial reactions.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.257-257
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• 2013

In order to selectively remove oil and organic compound from water, silica nanoparticles with hydrophobic coating was used. Since silica nanoparticles are generally hydrophilic, removal efficiency of oil and organic compound, such as toluene, in water can be decreased due to competitive adsorption with water. In order to increase the removal efficiency of oil and toluene, hydrophobic polydimethylsiloxane (PDMS) was coated on silica nanoparticles in the form of thin film. Hydrophobic property of the PDMS-coated silica nanoparticles and hydrophilic silica nanoparticles were easily confirmed by putting it in the water, hydrophilic particle sinks but hydrophobic particle floats. PDMS coated silica nanoparticles were dispersed on a slide glass with epoxy glue on and the water contact angle on the surface was determined to be over $150^{\circ}$, which is called superhydrophobic. FT-IR spectroscopy was used to check the functional group on silica nanoparticle surface before and after PDMS coating. Then, PDMS coated silica nanoparticles were used to selectively remove oil and toluene from water, respectively. It was demonstrated that PDMS coated nanoaprticles selectively aggregates with oil and toluene in the water and floats in the form of gel and this gel remained floating over 7 days. Furthermore, column filled with hydrophobic PDMS coated silica nanoparticles and hydrophilic porous silica was prepared and tested for simultaneous removal of water-soluble and organic pollutant from water. PDMS coated silica nanoparticles have strong resistibility for water and has affinity for oil and organic compound removal. Therefore PDMS-coated silica nanoparticles can be applied in separating oil or organic solvents from water.

• 방사선산업학회지
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• 제5권4호
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• pp.371-376
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• 2011

The surface property of the materials used in tissue engineering application has been essential to regulate cellular behaviors by directing their adhesion on the materials. To modulate surface property of the synthetic biodegradable materials, a variety of surface modification techniques have used to introduced surface functional groups or bioactive molecules, recently polydopamine coating method have been introduce as a facile modification method which can be coated on various materials such as polymers, metals, and ceramics regardless of their surface property. However, there are no reports about the degree of polydopamine coating on the materials with different hydrophilicity. In the present study, we prepared acrylic acid grafted nanofibrous meshes using electron-beam irradiation, and then coated meshes with polydopamine. Polydopamine successfully coated on the all meshes, both properties of acrylic acid and polydopamine were detected on the meshes. In addition, the degree of polydopamine deposition on the materials has been altered according to surface hydrophilicity, which was approximately 8-times greater than those on the non-modified materials. In conclusion, dual effect from the acrylic acid grafting and polydopamine may give a chance as a alternative tool in tissue engineering application.

• Journal of the Korean Wood Science and Technology
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• 제49권6호
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• pp.658-666
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• 2021

A novel flame retardant and antibacterial composite membrane coating for wood surfaces was prepared by adding POSS-based phosphorous nitrogen flame retardant (later referred to as NH₂-POSS) and silver nanoparticles (Ag NPs) to chitosan (CS). The effects of NH₂-POSS content (mass fractions of CS 0%, 0.5%, 1%, 3%, 5%, and 7%) on the structure and properties of the composite membrane coating on wood were investigated. The composite film was prepared by the method of blending and ducting. Contact angle, tensile property and antibacterial effects of the composite film were measured, and infrared spectroscopy was used. The results show that the addition of NH₂-POSS can not only improve the toughness of the membrane, but also the flame retardancy of the membrane, which improves the application of the membrane in wood products. However, with the addition of NH₂-POSS, the transparency of the composite membrane was weakened. The inhibitory effect of the composite membrane on the growth of Escherichia coli was enhanced with the increase in Ag NPs. This research provides a foundation for the application of functional wood.

• 한국결정성장학회지
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• 제31권3호
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• pp.137-142
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• 2021

본 연구에서는 상온경화형 silica-based 코팅제의 제조 및 해양구조물에 적용하여 가혹한 해양환경에서 방식 및 방오 성능 발현을 위한 실용화 개발 연구를 수행하였다. 구조상 외부에 노출된 부분이 많은 해양(플랜트) 구조물은 강한 자외선, 극심한 온도차, 염수에 의한 부식 등 가혹한 해양환경에 고립되어 운용된다. 이러한 환경 하에서는 쉽게 열화 되고 파도 등 물리적 자극에도 쉽게 침식되는 유기계 페인트들은 그 역할을 제대로 할 수 없다. 해양구조물에 치밀한 세라믹 코팅을 형성시킬 경우 녹이 발생하지 않고 경도가 높아 시설물을 해수환경 하에서도 치밀하게 보호할 수 있다. 세라믹 코팅제의 경우 그 기능의 장점들로 인해 해양 구조물에서 그 용도와 적용범위는 크게 증진될 수 있을 것이다. 따라서 colloidal silica를 기반으로 실란계 커플링제, 경화제 및 세라믹 충진제로 구성된 silica-based 코팅제 조성개발과 해수중 방식 및 방오용 보호코팅제로의 응용에 대해 연구하였다.

• 한국염색가공학회지
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• 제35권1호
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• pp.8-19
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• 2023

Silicone rubber is widely used in most industries due to diverse advantages like heat stability, UV stability, durability, chemical resistance, environment friendliness, inertness and so on. But there is limitation to expand applications due to relatively weak rubber strengths such as tensile strength and tear strength, especially in fabric coating applications. The purpose of this study is to find influence of coating agent on performances of rubber and coated fabrics and their correlation according to different crosslinking densities of silicone rubbers. Addition cure type of silicones were formulated using crosslinked MQ-type silicone resin consisting of M (R₃SiO_1/2) and Q (SiO_4/2) and linear polymers. Raw materials used were; 1) linear vinyl endblocked polymers and vinyl functional MQ resin as main polymers, 2) linear silicone hydride polymers as crosslinkers, 3) platinum catalyst and 4) inhibitor to control curing speed. Rubber specimens were prepared to check mechanical strength using universal testing machine (UTM). Crosslinking density was calculated using Flory-Rhener equation using solvent swelling method. Differential scanning calorimetry (DSC) and scanning electron microscope (SEM-EDS) were used to characterize rubbers. Consequently, it was found that physical properties of silicone rubbers and coated fabrics can be expected by crosslinking density of rubbers. Silicone rubber formulations that contain 20 ~ 30 wt% of vinyl MQ resin showed strongest balanced performances.