• Journal of the KSME
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• v.44 no.12
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• pp.34-38
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• 2004

이 글에서는 최근 마이크로/나노 구조물에 대한 고분자 나노복제 공정에 있어서 그 중요성이 대두되고 있는 나노몰드 표면온도 제어기술에 대해 소개하고자 한다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.384-384
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• 2009

에폭시 수지에 유기화된 층상실리케이트 나노입자를 1wt% 충진한 경우 나노콤포지트와 마이크로 입자를 50wt% 충진한 경우 마이크로 콤포지트를 제조하였다. 초음파 분산법을 이용하여 나노 및 마이크로입자를 120분 동안 분산시킨 에폭시- 나노/마이크로 콤포지트이다. 나노콤포지트와 마이크로콤포지트의 단시간 교류절연파괴특성을 조사하기 위해 와이블 분포 plot을 통하여 나타내었다. 와이블 plot은 기울기로서 형상파라미터를 나타낸 경우로서 이는 파괴강도의 균질성을 의미하게 된다. 63.2% 누적분포함수를 나타낸 경우 척도파라미터로서 나타내어진다. 마이크로 콤포지트의 경우 형상파라미터가 2.99, 나노콤포지트는 8.96를 나타내었다. 또한 마이크로 콤포지트 및 나노콤포지트 스케일 파라미터는 164.25kV/mm, 245kV/mm를 얻었다. 또한 B10수명의 경우 마이크로콤포지트와 나노콤포지트의 경우 77.57kV/mm, 139.3 6kV/mm로서 나노콤포지트의 경우 완전하게 박리가 일어난 경우이다. 마이크로 입자를 분산시켜 입자간거리와 나노입자를 분산시켜 박리가 일어난 경우 입자간거리는 대단히 큰 차이를 나타내고 있다. 나노입자가 교번전계 하에서 주입된 전하 및 케리어 이동을 억제하는 경우로 이와같은 결과를 얻을 수 있다.

• Journal of the Korean Vacuum Society
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• v.19 no.4
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• pp.300-306
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• 2010

Superhydrophobic micro-nano hybrid structures were fabricated by reactive ion etching of hydrophobic polymer micro patterns using gold nanoparticles as etch masks. Micro structures of perfluoropolyether bisurethane methacrylate (PFPE) were prepared by soft-lithographic technique using polydimethylsiloxane (PDMS) molds. Water contact angles on the surfaces of various PFPE micro structures and corresponding micro-nano hybrid structures were compared to examine the effects of micro patterning and nanostructure formation in the manifestation of superhydrophobicity. The PFPE micro-nano hybrid structures exhibited a very stable superhydrophobicity, while the micro-only structures could not reach the superhydrophobicity but only showed the unstable hydrophobicity.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.6
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• pp.15-25
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• 2011

One dimensional combustion modeling of aluminum combustion behavior is proposed. Combustion model is assumed that region consists as follows ; preheat, reaction, post reaction region. Flame speed as a function of particle size, equivalence ratio for unitary particles and fraction ratio of micro to nano particle size for binary particles were investigated for lean burn condition at 1 atm. Results were compared with experimental data. For unitary particles, flame speed increase as particle size decreases, but opposite trend with equivalence ratio. For binary particles, flame speed increases proportionally as nano particle fraction increases. For flame structure, separated or overlapping flames are observed, depending on the fraction of nano sized particles.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.116-118
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• 2011

일반적으로 나노입자의 크기는 나노복합체의 역학적 특성에 상당한 영향을 미친다. 이에 본 연구에서는 나노입자 크기를 고려한 나노복합체 재료 구성모델 (Kim et al., 2011)을 소개하고자 한다. Kim et al. (2011)에 의해서 나노입자 크기효과를 위한 Size-dependent Eshelby tensor가 미세역학 모델에 적용되었으며, 나노스케일 해석과 함께 다양한 수치해석을 수행하였다. 특히, 본 연구에서는 이를 활용하여 $SiO_2$/Epoxy 나노복합체의 역학적 특성을 예측해 보았다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.46.1-46.1
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• 2009

우리 몸의 뼈를 재료적인 측면으로 보면, 주로 나노 크기의 콜라겐과 아파타이트로 이루어 져 있는 복합체이다. 때문에 최근 생체 모사적인 측면에서 나노 크기의 생체 활성 재료를 이용하여 골 재생 촉진이 우수한 지지체를 제작하고자 하는 많은 연구 들이 진행되고 있다. 이러한 나노 크기의 재료는 일반적인 마이크로 크기의 생체 재료에 비해 표면적이 월등히 크기 때문에 생체 활성 (bioactivity)이 우수하다고 알려져 있으며, 이를 골 재생용 지지체의 구성 재료로 사용하였을 경우 기계적 강도 또한 향상 시킬 수 있다고 알려져 있다. 따라서 본 연구에서는 나노 크기의 HA, CaSiO3 등 다양한 나노 생체 활성 입자들을 침전법 (precipitation method)을 통하여 제조하였으며, 이를 이용하여 골 재생 촉진을 위한 3차원 지지체를 제조 하였다. 또한 기존의 마이크로 크기의 생체 재료로 제작된 지지체와의 생물학적, 기계학적 비교 평가를 통하여 나노크기의 재료의 우수성을 입증하고자 하였다. 결론적으로, 나노 크기의 재료로 제작된 골 재생용 지지체의 경우 기존의 마이크로 크기의 재료로 제작된 지지체보다 골세포의 부착, 증식 및 분화능이 우수하였고, 지지체의 기계적 강도 또한 향상됨을 알 수 있었다. 이를 통하여 나노 크기의 생체 활성재료는 골 재생 촉진을 위한 지지체 제작에 응용 가능성이 높음을 확인 할 수 있었다.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.4
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• pp.418-430
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• 2012

The present paper reviews the micro and nano nondestructive evaluation(NDE) technique that is possible to investigate the surface and measure the acoustic properties. The technical theory, features and applications of the ultrasonic atomic force microscopy(UAFM) and scanning acoustic microscopy(SAM) are illustrated. Especially, these technologies are possible to evaluate the mechanical properties in micro/nano structure and surface through the measurement of acoustic properties in addition to the observation of surface and subsurface. Consequently, it is thought that technique developments and applications of these micro/nano NDE in advanced industrial parts together with present nondestructive industry are widely possible hereafter.

• Composites Research
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• v.31 no.4
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• pp.171-176
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• 2018

We proposed new and easy fabrication method of micro-nano hierarchical structures for synthetic dry adhesives and conducted feasibility tests of alignment characteristics of nano-materials in the microstructures by capillary effect. Candidates of fabrication conditions were selected based on the degree of cure and viscosity of mixtures of multiwall carbon nanotubes (MWCNTs) and polydimethylsiloxane (PDMS), which were measured with respect to the fabrication conditions. Scanning electron microscopy images of cross sections of MWCNT-PDMS microstructures were analyzed. MWCNT alignment in microstructures was better when fabrication temperature and degree of cure at fabricating start were lower, but areal density of MWCNTs was little affected by fabrication conditions.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.8
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• pp.875-880
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• 2014

Recently, three-dimensional scaffolds and nanofibers are being developed for bone tissue regeneration. In this study, we fabricated a hybrid scaffold using a nano-micro precision deposition system. The fabrication process involved the application of the solid freeform fabrication (SFF) technology and electrospinning. The hybrid scaffolds were combined using micro scaffolds and nanofibers. The nanofibers were deposited on each layer of the micro scaffolding using the electrospinning process. The micro scaffolds were fabricated using the SFF technology at a temperature of $100^{\circ}C$, pressure of 650 kPa, and scan velocity of 250 mm/s. Nanofiber fabrication was conducted by means of electrospinning using the flow rate, solution concentration, distance from the tip to the collector (TCD), and voltage. The nanofibers were fabricated using a flow rate of 0.1 ml/min, voltage of 5 kV, TCD of 1 mm, and 10 wt% of solution concentration. MG-63 cells were seeded into the hybrid scaffold for the purpose of its evaluation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.3 s.47
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• pp.295-305
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• 2004

Colloid and surface chemistry have been focused on surface area and surface energy. Local surface properties such as surface density, interaction, molecular orientation and reactivity have been one of interesting subjects. Systems of such surface energy being important would be listed as association colloid, emulsion, particle dispersion, foam, and 2-D surface and film. Such nanoparticle systems would be applied to drug delivery systems and functional cosmetics with biocompatible and degradable materials, while nanoparticles having its size of several nm to micron, and wide surface area, have been accepted as a possible drug carrier because their preparation, characteristics and drug loading have been inves-tigated. The biocompatible carriers were also used for the solubilization of insoluble drugs, the enhancement of skin absorption, the block out of UV radiation, the chemical stabilization and controlled release. Nano/micro emulstion system is classified into nano/microsphere, nano/microcapsule, nano/microemulsion, polymeric micelle, liposome according to its prep-aration method and size. Specially, the preparation method and industrial applications have been introduced for polymeric micelles self-assembled in aqueous solution, nano/microapsules controlling the concentration and activity of high concen-tration and activity materials, and monolayer or multilayer liposomes carrying bioactive ingredients.