• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.06a
• /
• pp.205-206
• /
• 2008

The transparent conductive film was prepared by bar coating method of poly (3, 4-ethylenedioxythiophene) (PEDOT) and poly (sodium 4-stylenesulfonate) grafted multi-walled carbon nanotubes (MWNT-PSS) nanocomposites solution on the polyethylene terephthalate (PET) film. In this case, multi-wall carbon nanotubes was treated by chemical methods to obtain water soluble MWNT-PSS and then blending with PEDOT. The non-covalent bonding of polymer to the MWNT surface was confirmed by Fourier transform infrared (FT-IR), thermal gravimetric analysis (TGA) and Transmission electro microscope (TEM) investigation also showed a polymer-wrapped MWNT structure. Furthermore, the electrical, transmission properties of the transparent conductive film were investigated and compared with control samples are raw PEDOT films.

• Journal of IKEEE
• /
• v.21 no.3
• /
• pp.320-330
• /
• 2017

Porous nanosilica (PNS) has been identified as a potential candidate for controlled drug delivery. However, unmodified PNS-based carriers exhibited an initial release of loaded bioactive agents, which may limit their potential clinical applications. In this study, the surface of PNS was functionalized with adamantylamine (ADA) via disulfide bonds (-S-S-), PNS-S-S-ADA, which was then modified with cyclodextrin (CD)-heparin (Hep) (CD-Hep), PNS-S-S-CDH, for redox triggered rhodamine B (RhB) delivery. The obtained samples were then characterized by proton nuclear magnetic resonance ($^{1}H\;NMR$), Fourier transform infrared (FTIR), and transmission electron microscope (TEM). These results showed that PNS-S-S-CDH was successfully formed with spherical shape and average diameter of $45.64{\pm}2.33nm$. In addition, RhB was relatively encapsulated in the PNS-S-S-CDH (RhB@PNS-S-S-CDH) and slowly released up to 3 days. The release of RhB, in particular, was triggered due to the cleavage of -S-S- in the presence of dithiothreitol (DTT). It might be anticipated that the modified PNS can be used as redox-responsive drug delivery system in cancer therapy.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.29 no.2
• /
• pp.279-285
• /
• 2005

In order to activate the characteristics of charcoals in fiber systems, this study was carried out to experiment with the particle size from two micrometers to ten micrometers of charcoal powders on silk fabrics. The results obtained were as follows; The silk fabrics were dyed with gray color by charcoals effectively. The K/S value, that is indicative of the dye affinity, became higher as the increase of dyeing temperature, dyeing time, and dyeing concentration. Te dyeing effects were the highest with 50%(o.w.f.) of charcoals at $100^{\circ}C$ for 120 minutes in this experiments, It was observed the surfaces of silk fibers were mainly adcorbed with charcoal powders of the particle size from two micrometers to four micrometers by scanning electron microscope. Dyed silk fabrics showed comparatively low fastness to the fade of launding, the stain of the treatment of perspirations, and the strain of water fastness test, but good fastness to the stran of laundering, te drycleaning, the fade of treatment of perspirations, and the fade of water fastness test. In connection with the functional properties of dyed fabrics, the deodorizations were drastically improved, and the far-infrared emissions improved highly, and also the antibacterials were comparatively good.

• Proceedings of the Korean Society of Dyers and Finishers Conference
• /
• 2011.11a
• /
• pp.5-5
• /
• 2011

나노섬유를 제조하는 방법 중에는 상분리 현상을 이용한 방법, 자가 조립성을 이용한 방법, 템플레이트를 이용한 방법, 전기방사법이 있으며 특히 전기방사법은 연속적으로 균일한 나노섬유를 제조할 수 있다. 또한 전기방사법은 장비가 간단하며 고분자 blend ratio와 무기재료의 함량에 따라 뛰어난 특성을 나타내는 나노복합섬유를 만들 수 있다. 최근 식물에서 추출한 단백질을 전기방사법을 이용하여 나노입자 및 나노섬유를 제조하고 이를 의료 분야 등에 적용하기 위한 연구가 활발히 진행되고 있으며 이런 식물성 단백질은 동물성 단백질에 비하여 인체 적용이 용이하고 매장량이 풍부한 장점이 있다. 본 연구에서는 전기방사법을 이용하여 옥수수에서 추출한 단백질인 zein의 나노입자 및 나노섬유를 제조하였다. 또한 천연 추출물이 혼입된 복합 나노입자 및 나노섬유를 제조하여 zein이 가진 고유 특성 이외에 천연 추출물의 특성을 추가로 부여해서 더욱 발전된 나노입자 및 나노섬유를 제조하였다. 고분자 농도, 전압, 방사거리 등 다양한 공정변수를 조절하여 최적의 조건을 확립하였으며 제조된 나노입자 및 나노섬유는 field-emission type scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV/vis), fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC)를 이용하여 특성분석을 실시하였다.

• Journal of Biomedical Engineering Research
• /
• v.40 no.6
• /
• pp.235-241
• /
• 2019

The purpose of this study was to investigate the effect of the body temperature peripheral circulation with vibration shoes in healthy 10 adults. The magnetic vibration device with non-electric power was mounted in the midsole of the vibration shoes. The experiment was divided into two groups: vibration shoes and no vibration shoes. Subjects were randomly selected and measured body surface temperature by digital infrared thermal imaging (DITI) and non-invasive capillaries change by nailfold microscope (NFM). After walking in a treadmill for 15 minutes at 4.0 km/h speed wearing normal shoes or vibration shoes, DITI and NFM were measured. The walking with vibration shoes showed the body surface temperature shift from the proximal to the distal. In addition, the diameter of the nailfold capillary in the vibration shoes group was thicker and clearer due to the increased blood flow than that of the no vibration shoes group. The vibration shoes are easy to apply to anyone who can walk because it can give vibration stimulation by walking without additional time, cost, and effort in daily life. Further studies are needed to explain the physiological effects of vibration frequency and intensity on the long-term perspective of target subjects resulting from vascular dysfunction.

• Journal of Electrical Engineering and Technology
• /
• v.13 no.3
• /
• pp.1355-1362
• /
• 2018

In order to obtain a better understanding of the ageing process of the field composite insulators, it is necessary to explore a quantitative-valuation method for the aging state evaluation. And the linear relationship between volume resistivity and temperature is proposed. In this paper, the composite insulators with different lengths of operating lives from two manufacturers were tested. The relationship between trap characteristics and volume resistivity-temperature characteristics were analyzed based on Thermal Stimulated Current (TSC), volume resistivity-temperature test, Scanning Electron Microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). Furthermore, the application of trap characteristics in the quantitative evaluation of aging state of composite insulators was discussed. The results showed that there was a general negative correlation between the relative variation ratio of trap charges and the volume resistivity-temperature characteristics. Meanwhile, the physicochemical properties would change with the aging time, which would result in the increasing of electron traps. Combined with the TSC and volume resistivity test results, the trap characteristic thresholds which indicated the serious age of the composite insulators had been proposed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.07a
• /
• pp.44-45
• /
• 2005

Both $Al_2O_3$ and $SiO_2$ nanopowders were ball-milled to break large agglomerates$(500nm\sim10{\mu}m$). To improve the dispersion of ball-milled nanoparticles in transformer oil, surface modification was performed with oleic acid(OA). The modified nanoparticles were examined by the particle size analyzer, electron microscope, Infrared spectroscopy and stability analyser. Particle Size distributions were measured for ball-milled particles, and the results were compared with the size distribution of primary particles. FTIR results indicated that hydrophobicity of modified nanoparticles was due to the chemical reaction between hydroxyl groups of particle surface and oleic acid. The dispersion stability of surface-modified nanoparticles was quite good in transformer oil.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.348-348
• /
• 2010

Behaviors of $TiO_2$-based photocatalysts with different surface structures on the removal of gas-phase toluene with and without UV irradiation are reported. P-25(Degussa) $TiO_2$ powder dispersed in distilled water by sonication was deposited on the transparent glasses and then dried. Some of the samples were further annealed in oven for 1 hr. These samples obtained before and after annealing were characterized by Brunauer- Emmett-Teller (BET), Transmission Electron Microscope (TEM), X-ray Photoelectron Spectroscopy (XPS) and Fourier Transform Infrared (FT-IR) spectrometry, respectively. Based on BET and TEM data, no significant structural change upon annealing could be identified. However, the sample without annealing showed a significantly higher ability for removing toluene both in the presence and absence of the UV light. XPS and FT-IR results clearly revealed that the population of the OH groups on the surface of $TiO_2$ was higher for the sample without annealing, indicating that the OH groups can enhance the adsorption capacity and photocatalytic activity of $TiO_2$ for the removal of the gas-phase toluene.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.08a
• /
• pp.116.2-116.2
• /
• 2013

최근 그래핀, hexagonal boron nitride (h-BN) 및 $MoS_2$ (molybdenum disulfide)와 같은 2차원 결정 물질들은 무어의 법칙 (Moore's Law)를 뛰어넘어 계속적인 소자의 소형화를 가능케 하고 또한 대면적, 저비용 소자 개발을 가능케 하는 우수한 특성을 가진 차세대 반도체 트랜지스터 소재로 각광받고 있다. $MoS_2$는 bulk 상태일 때는 1.2 eV의 indirect 밴드갭을 가지지만 단층형태일 때는 1.8 eV의 direct 밴드갭을 가지며 dielectric screening 기법 등을 통해 mobility를 향상시킬 수 있는 것으로 연구된 바 있다. 본 연구에서는 화학기상증착(chemical vapor deposition, CVD)법을 이용하여 $MoS_2$박막을 형성하기 위한 기초연구인 Mo전구체의 특성 평가 및 적합한 공정조건 개발 연구를 수행하였다. 사용한 전구체는 $Mo(CO)^6$ (Molybdenum hexacarbonyl)이고, 온도 및 압력, 반응기체($H_2S$, Hydrogen sulfide) 유량 등의 공정 조건 변화에 따른 거동을 Fourier transform infrared spectroscopy (FT-IR) 시스템을 사용하여 측정하였다. 또한 $Mo(CO)^6$의 분자구조를 상용 프로그램인 Gaussian으로 시뮬레이션 하여 실제 FT-IR 측정 결과값과 비교 분석하였다. 화학기상증착법을 이용한 $MoS_2$ 증착조건 최적화를 위하여 다양한 온도, 유량, 압력, 및 기판 종류에 대하여 증착 실험을 수행하였으며, 증착된 샘플은 scanning electron microscope (SEM), Raman spectroscopy를 이용하여 분석하였다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.5 no.5
• /
• pp.458-461
• /
• 2004

In order to improve the adhesion properties of copper, MPS(3-mercaptopropyltrimethoxysilane) organic film were employed. The plasma pretreatment in pure He or $He/O_{2}$ mixed gas environment greatly increased adhesion force. Adhesion force was measured by scratch test with nano indenter. Microstructures and surface roughness were observed with scanning electron microscope(SEM). The characteristics of MPS layer for pretreatment were studied with flourier transform infrared spectroscope(FT-IR) and contact angle tester. The heighest adhesion was achieved in the specimen pretreated with mixed plasma and NPS coating, which was 56mN. Other specimen showed lower value by $20{\%}$ to $30{\%}$. The roughness of substrate was not affected by the bonding strength of copper plating.