• 대한화장품학회지
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• 제33권4호
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• pp.239-243
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• 2007

PFCs는 독특한 사용감과 특성으로 인하여 화장품에 응용되어질 때 많은 특장점을 가지고 있다. 그러나 이러한 장점에도 불구하고 화장품 제형에 적용하기에 많은 어려움을 가지고 있다. 즉, 물과 오일에 불용성, 높은 비중, 높은 증기압 등과 같은 원료의 특징으로 인하여 PFCs는 화장품에 적용하기 위하여 특별한 안정화 시스템을 필요로 한다. 본 연구에서 PFCs를 안정화하기 위하여 gel network, spherulite lamellar, nanostructure 이상의 세 가지 시스템을 이용하였으며 사용된 세 가지 시스템 중 nanostructure system이 가장 안정함을 알 수 있었다.

• 한국생산제조학회지
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• 제25권1호
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• pp.62-67
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• 2016

This paper presents a silicon nanostructure array embedded in a polymer film. The silicon nanostructure array was fabricated by using basic microelectromechanical systems (MEMS) processes such as photolithography, reactive ion etching, and anisotropic KOH wet etching. The fabricated silicon nanostructure array was transferred into polymer substrates such as polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), and polycarbonate (PC) through the hot-embossing process. In order to determine the transfer conditions under which the silicon nanostructures do not fracture, hot-embossing experiments were performed at various temperatures, pressures, and pressing times. Transfer was successfully achieved with a pressure of 1 MPa and a temperature higher than the transition temperature for the three types of polymer substrates. The transferred silicon nanostructure array was electrically evaluated through measurements with a semiconductor parameter analyzer (SPA).

• 한국수소및신에너지학회논문집
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• 제24권3호
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• pp.193-199
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• 2013

In this work, thin film type Cu/ZnO nanostructure catalysts were fabricated by several synthetic routes in order to maximize the performance of the micro reforming system. For this work, various Cu/ZnO nanostructure catalysts could be synthesized by means of four approaches which are chemical vapor method, wet solution method and their hybrid method. The reforming performance of these as-synthetic catalysts was evaluated as compared to the conventional catalysts. Among the as-synthetic nanostructures, sphere type catalysts with specific surface of $18.6m^2/g$ showed the best performance of hydrogen production rate of 30ml/min at the feed rate of 0.2ml/min. This work will give the first insight on thin film type Cu/ZnO nanostructure catalyst for micro reforming system for hydrogen production of portable electronic systems.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.181-181
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• 2013

Recently, nanostructure and the molecular orientation of organic thin films have been largely paid attention due to its importance in organic electronics such as organic thin film transistors (OTFTs), organic light emitting diodes (OLEDs), and organic photovoltaics (OPVs). Among various methods, the diffraction and scattering techniques based on synchrotron x-rays have shown powerful results in organic thin film systems. In this work, we introduce the in-situ annealing system installed at PLS-II (Pohang Light Source II) for organic thin films by simultaneously conducting various x-ray scattering measurements of x-ray reflectivity, conventional x-ray scattering, grazing incidence wide angle x-ray scattering (GI-WAXS) and so on. Using the in-situ measurement, we could obtain real time variation of nanostructure as well as molecular orientation during thermal annealing in metal-phthalocyanine thin films. The variation of surface and interface also could be simultaneously investigated by the x-ray reflectivity measurement.

• 한국재료학회지
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• 제25권11호
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• pp.622-629
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• 2015

Cu circuits were successfully fabricated on flexible PET(polyethylene terephthalate) substrates using wettability difference and electroless plating without an etching process. The wettability of Cu plating solution on PET was controlled by oxygen plasma treatment and $SiO_x$-DLC(silicon oxide containing diamond like carbon) coating by HMDSO(hexamethyldisiloxane) plasma. With an increase of the height of the nanostructures on the PET surface with the oxygen plasma treatment time, the wettability difference between the hydrophilicity and hydrophobicity increased, which allowed the etchless formation of a Cu pattern with high peel strength by selective Cu plating. When the height of the nanostructure was more than 1400 nm (60 min oxygen plasma treatment), the reduction of the critical impalement pressure with the decreasing density of the nanostructure caused the precipitation of copper in the hydrophobic region.

• 공업화학
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• 제28권4호
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• pp.375-382
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• 2017

전기화학 방법을 이용한 이산화티타늄 나노구조에 대한 기존 연구는 불소 이온을 함유한 전해질에서의 산화반응으로 형성된 나노튜브가 연구의 주를 이루고 있다. 최근, 불소 이온이 아닌 고온 인산염이 함유된 글리세롤계 전해질의 개발로 관련 연구가 활발히 진행되고 있다. 본 총설은 이러한 전해질을 활용하여 다양한 이산화티타늄 나노구조를 형성하는 연구 동향에 대해 다루고 있다. 새로운 양극산화법을 통해 형성된 이산화티타늄 나노구조는 기존의 나노튜브에 비하여 비표면적이 넓고 결정성과 접착력이 우수하여 여러 응용분야에 활용가치가 높다. 이에 본 총설에서는 새로운 양극산화법을 이용한 나노구조의 형성 원리, 특성에 대한 개괄적 접근 뿐만 아니라 실제 응용분야에서의 소재성능을 기존 나노튜브 구조와 비교한 결과 등을 망라하여 자세히 소개하고 있다.

• 한국전기전자재료학회논문지
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• 제17권3호
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• pp.319-322
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• 2004

ZnO nanostructures were formed on a Si substrate by off-axis pulsed laser deposition(PLD) system in which a substrate plane was tilted toward a plume propagation direction. Atomic force microscopy (AFM) showed islands of 20∼40 nm width. From the x-ray diffraction (XRD) pattern exhibiting only (002) ZnO peak, the islands observed in AFM image were found to well crystallized. Optical bandgap enlargement from 3.26 eV to 3.35 and 3.47 eV due to the quantum size effect of ZnO nanostructures were observed by Photoluminescence (PL) at room temperature.

• 한국결정성장학회지
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• 제16권1호
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• pp.12-19
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• 2006

Metalorganic chemical vapor deposition (MOCYD) techniques have been applied to fabricate semiconducting ZnO thin films and nanostructures, which are promising for novel optoelectronic device applications using their unique multifunctional properties. The growth and characterization of ZnO thin films on Si and $SiO_2$ substrates by MOCYD as fundamental study to realize ZnO nanostructures was carried out. The precise control of initial nucleation processes was found to be a key issue for realizing high quality epitaxial layers on the substrates. In addition, fabrication and characterization of ZnO nanodots with low-dimensional characteristics have been investigated to establish nanostructure blocks for ZnO-based nanoscale device application. Systematic realization of self- and artificially-controlled ZnO nanodots on $SiO_2/Si$ substrates was proposed and successfully demonstrated utilizing MOCYD in addition with a focused ion beam technique.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.389-390
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• 2012

In this study, we fabricate a superhydrophobic surface made of hierarchical nanostructures that combine wax crystalline structure with moth-eye structure using vacuum cluster system and measure their hydrophobicity and durability. Since the lotus effect was found, much work has been done on studying self-cleaning surface for decades. The surface of lotus leaf consists of multi-level layers of micro scale papillose epidermal cells and epicuticular wax crystalloids [1]. This hierarchical structure has superhydrophobic property because the sufficiently rough surface allows air pockets to form easily below the liquid, the so-called Cassie state, so that the relatively small area of water/solid interface makes the energetic cost associated with corresponding water/air interfaces smaller than the energy gained [2]. Various nanostructures have been reported for fabricating the self-cleaning surface but in general, they have the problem of low durability. More than two nanostructures on a surface can be integrated together to increase hydrophobicity and durability of the surface as in the lotus leaf [3,5]. As one of the bio-inspired nanostructures, we introduce a hierarchical nanostructure fabricated with a high vacuum cluster system. A hierarchical nanostructure is a combination of moth-eye structure with an average pitch of 300 nm and height of 700 nm, and the wax crystalline structure with an average width and height of 200 nm. The moth-eye structure is fabricated with deep reactive ion etching (DRIE) process. $SiO_2$ layer is initially deposited on a glass substrate using PECVD in the cluster system. Then, Au seed layer is deposited for a few second using DC sputtering process to provide stochastic mask for etching the underlying $SiO_2$ layer with ICP-RIE so that moth-eye structure can be fabricated. Additionally, n-hexatriacontane paraffin wax ($C_{36}H_{74}$) is deposited on the moth-eye structure in a thermal evaporator and self-recrystallized at $40^{\circ}C$ for 4h [4]. All of steps are conducted utilizing vacuum cluster system to minimize the contamination. The water contact angles are measured by tensiometer. The morphology of the surface is characterized using SEM and AFM and the reflectance is measured by spectrophotometer.

• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2367-2370
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• 2014

"Cat's eye"-shaped $[^{57}Co]CoO@SiO_2$ core-shell nanostructure was prepared by the reverse microemulsion method combined with radioisotope technique to investigate a potential imaging agent for a single photon emission computed tomography (SPECT) in nuclear medicine. The core cobalt oxide nanorods were obtained by thermal decomposition of $Co-(oleate)_2$ precursor from radio isotope Co-57 containing cobalt chloride and sodium oleate. The $SiO_2$ coating on the surface of the core cobalt oxide nanorods was produced by hydrolysis and a condensation reaction of tetraethylorthosilicate (TEOS) in the water phase of the reverse microemulsion system. In vivo test, micro SPECT image was acquired with nude mice after 30 min of intravenous injection of $[^{57}Co]CoO@SiO_2$ core-shell nanostructure.