이 작품은 부분적으로 과학 연구에 대한 보조금의 원조 (번호 24225003)에 의해 지원되었다. 이 작품은 JX 니폰 오일 &amp; 에너지 사에 의해 재정적으로 지원되었다.

활성 레이어 솔루션 1. 준비 <ol><li> 아민 첨가 PFD 장치의 활성층 용액 주 : PFD, 4,4 &#39;, 4&#39; &#39;- 트리스 [2- 나프 틸 (페닐) 아미노] 트리 페닐 아민 (2-TNATA), 9,9- 다이 메틸 N, N&#39;- 디 (1- 나프 틸) - N 수신으로, N &#39;- 디 페닐로 -9H- 플루 오렌 -2,7- 디아민 (DMFL-NPB)는, 폴리 (에틸렌 옥사이드) (PEO)를 사용 하였다. 칼륨 트리 플루오로 메탄 술포 네이트 (K 2 CF 3 SO 3)를 사용하기 전에 1 시간 동안 200 ℃에서 진공 건조 하였다. <ol><li> 하나의 아민 비율하십시오 PFD를 갖는 디바이스의 경우 0.25, PFD 10mg을 클로로포름 1 ㎖에 방향족 아민 250 mg을 용해하고, 40 ℃에서 1 시간 동안 교반한다. 1 아민 비율 :하십시오 PFD 가진 사람들을 위해 1, 방향족 아민 10 mg을 사용합니다. </li><li> (1)를 개별적으로, 시클로 헥사 논 1 ㎖에 PEO 10 ㎎을 용해하고, 60 ℃에서 1 시간 동안 교반하고, 칼륨, 트리 플루오로 메탄 술포 네이트 2.5 ㎎을 용해 (KCF 3 SO 3)시클로 헥사 논 용액 및 40 ° C에서 1 시간 동안 교반한다. </li><li> PEO 용액 0.78 mL 및 마이크로 피펫을 사용하여 PFD 솔루션에 KCF 3 SO 3 용액의 0.147 ML을 추가합니다. 40 ° C에서 4 시간 동안 혼합 용액을 교반한다. </li><li> 스핀 코팅 이전의 멤브레인 필터를 사용하여 혼합 용액을 필터. </li></ol></li><li> 도핑 PFD 장치 활성층 용액 <ol><li> 도핑 PFD 장치 클로로포름 1 ㎖에 PFD 10 ㎎을 용해하고, 40 ℃에서 1 시간 동안 교반한다. 1.1.4 - 수행 단계 1.1.2의 아민 도핑 PFDs 대해 전술 한 것과 동일하다. </li></ol></li></ol> LEC 장치 2. 제조 주 : LEC 장치의 제조 공정은도 1에 요약 하였다. <ol><li> 이온수, 아세톤 및 2- 프로판올은을 사용하여 희석 하였다 세제로 초음파 깨끗한 무늬 인듐 - 주석 산화물 (ITO) 유리 기판각 단계에 대한 3 분 동안 데스크톱 초음파 목욕 (38 kHz에서). 마지막으로, N 2 송풍기를 이용하여 용매를 제거한다. </li><li> 제조 업체의 프로토콜에 따라 유닛을 치료 자외선 / O 3를 사용하여 3 분 동안 UV / O 3 기판을 취급합니다. 글러브 박스에서, 불활성 분위기 하에서 활성층 코팅 공정을 수행한다. </li><li> 스핀 코터의 머리에 청소 기판을 설정합니다. 마이크로 피펫을 사용하여 활성층 용액을 약 100 μl를 분배. 다음으로 기판을 스핀 : 800 rpm으로 60 초 후, 10 초 동안 1000 rpm에서 스핀 3 초 동안 1000 rpm으로 속도를 증가시킨다. 활성층의 두께는 약 150 나노 미터 일 것이다. </li><li> 글러브 박스 하룻밤에 코팅 된 기판을 건조시킵니다. </li><li> 적절한 전극 연결 및 캡슐화를 보장하기 위해 여분의 중합체를 닦아냅니다. </li><li> 알루미늄 증착하기위한 증착 홀더에 기판을 놓습니다. 증착 챔버 내의 홀더로드 및 열적 알루미늄을 100 nm의 층을 증착3mm 알루미늄 대향 전극을 증착 넓은 개구부를 갖는 스테인리스 스틸 마스크를 통해 증착 0.4 ㎚ / 초의 증착 속도로. </li><li> 증착이 완료 될 때, 불활성 분위기 하의 글로브 박스에 반송 장치. 디스펜서를 사용하여 사각형 형상으로 UV 경화형 에폭시 수지의 비드를 적용한다. 커버 유리 (15mm X X 0.7 mm 두께 12mm) 장치를 캡슐화 수지에 (그림 1 참조)을 놓습니다. </li><li> 자외선 LED를 광원으로 사용하는 수지 UV 방사선 (: 6000 mJ의 / ㎠, 파장 365 nm의 누적 투여 량)을 치료. </li></ol> 3. 특성 <ol><li> JVL 측정 주 : 전류 밀도 (J) - 전압 (V) -luminance (L)은 (JVL) 특성 및 국제 조명위원회 드 난 ECLAIRAGE (CIE) 좌표는 DC 전압 전류원 모니터가 장착 된 스펙트럼 광 검출기를 사용하여 측정 하였다. 측정 시스템은 제어되고데이터 수집을위한 사용자 지정 컨트롤 소프트웨어를 PC. 이 시스템은 다음 제조업 자의 프로토콜을 교정하고, 측정 검정 커튼하에 어둠 속에서 수행 하였다. <ol><li> 악어 클립 장치의 연락처에 단자를 연결합니다. 측정 단계에서 장치를 놓습니다. </li><li> 데이터 수집을위한 제어 소프트웨어를 실행합니다. 이 시스템은 시간에 따른인가 된 전압과 전류를 제어하고, 광파이버를 통하여 분광기에 의한 발광 스펙트럼을 수집한다. </li></ol></li></ol>

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The authors have nothing to disclose.

LEC의 소수성 PFD 및 방향족 아민과 친수성 폴리에틸렌 옥사이드와 KCF 3 SO 3을 포함하는 활성층을 가지고있다. 이러한 물질은 매우 다른 용해성을 가지고 있기 때문에, 스핀 코팅 용액의 제조 조심 불완전 매화를 피하기 위해 중요하다. 각 제 균일 한 혼합물을 형성 한 다음이 용액을 함께 혼합되어 충분한 매화 능력을 가진 용매에 개별적으로 완전히 용해되어야한다. 엑시톤과 excipl...

Research and development of polymer light-emitting electrochemical cells (PLECs) have expanded in recent years.1-15 PLECs are similar to organic light-emitting diodes (OLEDs) in that both are surface emitting organic devices and are expected to find their way into future lighting applications. OLEDs are already on the market, but the cost is still high, one reason being that OLEDs need a complicated device structure with multiple layers. In contrast, PLECs have a very simple device structure which consists of a single active layer (emitting layer) between a pair of electrodes. This means that PLECs are suited to mass production processes such as roll-to-roll printing and coating. 
A PLEC has an active layer consisting of a fluorescent &#960;-conjugated polymer (FCP). The FCP can be electrochemically doped with a polymer electrolyte (a mixture of an ion conducting polymer and a salt). The FCP is p-doped on the anode side and n-doped on the cathode side during operation, and generates excitons which emit light between the p- and n-doped regions. Therefore, the emission color reflects the exciton emission (=fluorescence) wavelength of the FCP.
Stable white light emission is important for lighting applications, and color mixing techniques which employ two or more emitters have been widely used to achieve this.10-14 Recently, we presented a different approach for obtaining stable white light emission, using an active layer which contains blue-fluorescent poly(9,9-di-n-dodecylfluorenyl-2,7-diyl) (PFD) and &#960;-conjugated aromatic amines15. This white light emission comes from exciplexes formed between PFD and amine molecules in excited states. Exciplex emission has a broader spectrum compared to the exciton emission from the PDF and/or amines, which gives it a color close to that of natural light. This translates to a higher color rendering index (CRI), which is preferable for lighting applications.
In this article, the authors describe the procedure used to fabricate the exciplex based LECs and show the stability of their white light emission.

<table border="0" cellpadding="0" cellspacing="0" width="734">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">Poly(9,9-di-n-dodecylfluorenyl-2,7-diyl) (PFD)</td>
			<td style="width:99px;">Aldrich</td>
			<td style="width:115px;">571660</td>
			<td style="width:189px;"></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:332px;">4,4&#8217;,4&#8217;&#8217;-Tris[2-naphthyl(phenyl)amino]triphenylamine (2-TNATA)</td>
			<td style="width:99px;">Aldrich</td>
			<td style="width:115px;">768669</td>
			<td style="width:189px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:332px;">9,9-Dimethyl-N,N&#8217;-di(1-naphthyl)-N,N&#8217;-diphenyl-9H-fluorene-2,7-diamine (DMFL-NPB)</td>
			<td style="width:99px;">Aldrich</td>
			<td style="width:115px;"></td>
			<td style="width:189px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">Poly(ethylene oxide) (PEO)</td>
			<td style="width:99px;">Aldrich</td>
			<td style="width:115px;">182028</td>
			<td style="width:189px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:332px;">Potassium tirifluoromethansulfonate (KCF3SO3)</td>
			<td style="width:99px;">Aldrich</td>
			<td style="width:115px;">422843</td>
			<td style="width:189px;">dried under vacuum at 200 &#176;C for 2 hr prior to use</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:332px;">Chloroform</td>
			<td style="width:99px;">Kanto Chemical Co.</td>
			<td style="width:115px;">08097-25</td>
			<td style="width:189px;">dehydrated</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:332px;">Cyclohexanone</td>
			<td style="width:99px;">Kanto Chemical Co.</td>
			<td style="width:115px;">07555-00</td>
			<td style="width:189px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:332px;">SCAT 20-X (detergent)</td>
			<td style="width:99px;">Daiichi Kogyo Seiyaku</td>
			<td style="width:115px;"></td>
			<td style="width:189px;">diluted with water</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:332px;">Acetone</td>
			<td style="width:99px;">Kanto Chemical Co.</td>
			<td style="width:115px;">01866-25</td>
			<td style="width:189px;">Electronic grage</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:332px;">2-propanol</td>
			<td style="width:99px;">Kanto Chemical Co.</td>
			<td style="width:115px;">32439-75</td>
			<td style="width:189px;">Electronic grage</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:332px;">13mm GD/X Disposable Filter Device PVDF Filter Media, Polypropylene Housing</td>
			<td style="width:99px;">Whatman</td>
			<td style="width:115px;">6872-1304</td>
			<td style="width:189px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:332px;">UV/O3 Treating Unit</td>
			<td style="width:99px;">SEN Lights Co.&#160;</td>
			<td style="width:115px;">SSP16-110</td>
			<td style="width:189px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:332px;">Spectral Photo Detector</td>
			<td style="width:99px;">Otsuka Electronics</td>
			<td style="width:115px;">MCPD 9800</td>
			<td style="width:189px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:332px;">Voltage Current Source Monitor</td>
			<td style="width:99px;">&#160;ADCMT</td>
			<td style="width:115px;">6241A&#160;</td>
			<td style="width:189px;"></td>
		</tr>
		<tr height="168">
			<td height="168" style="height:168px;width:332px;">Evaporation Mask</td>
			<td style="width:99px;">&#160;Tokyo Process Service Co., Ltd.</td>
			<td style="width:115px;">NA</td>
			<td style="width:189px;">The evaporation mask was wet-etched to create openings for patterned deposition of aluminum. The size of the mask is 100 mm x 100 mm x 0.2 mm-thick.</td>
		</tr>
	</tbody>
</table>

fabrication of white light-emitting electrochemical cells with stable emission from exciplexes

저자 (청색 형광 폴리 (9,9- 디 -n- dodecylfluorenyl -2,7- 디일)으로 구성되는 활성층을 갖는 고분자 발광 전기 화학 전지에서 안정된 백색 발광 (PLECs)를 제조하는 방법을 제시 PFD)와 π 공역 트리 페닐 아민 분자. 이 백색 발광 전자적으로 흥분 상태에 PFD 및 아민 사이에 형성 exciplexes에서 유래. &#39;, 4&#39; &#39;PFD 4,4를 포함하는 장치 - 트리스 [2- 나프 틸 (페닐) 아미노] 트리 페닐 아민 (2-TNATA), 폴리 (에틸렌 옥사이드) 및 K 2 CF 3 SO 3 국제위원회 백색 발광을 나타내었다 드 난 ECLAIRAGE (CIE)는 (0.33, 0.43) 좌표와 연색 지수 (CRI)가 3.5 V. 일정한 전압 측정의인가 전압에서 라 = 73의는 CIE는 (0.27, 0.37), 라 좌표 것으로 나타났다 67, 5 V의 전압을인가 한 직후 관찰 발광색 거의 변하지 이후의 안정300 초.

전계 발광 (EL) 스펙트럼은 CIE 좌표 및 CRI 값 (도 2, 4, 5)를 계산하는데 사용되었다. 발광 소자의 사진 이미지가 발광 (도 3)의 백색도를 확인하기 위해 수집 하였다. 아민 첨가 PFD 장치 및 도핑되지 않은 PFD 장치의 EL 스펙트럼을도 2에 나타낸다. 도핑 된 PFD 장치 PFD 여기자 방출에 해당하는 ?...

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Fabrication of White Light-emitting Electrochemical Cells with Stable Emission from Exciplexes

The authors present a method for fabricating stable white-light-emitting electrochemical cells utilizing emission from exciplexes formed between a blue-emitting fluorene polymer and aromatic amines.

화이트의 제작 Exciplexes에서 안정 방출과 전기 화학 셀 라이트 발광

The authors present an approach for fabricating stable white light emission from polymer light-emitting electrochemical cells (PLECs) having an active ...

fabrication-white-light-emitting-electrochemical-cells-with-stable

Research

JoVE Journal

Engineering

8.0K 조회수.  JX Nippon Oil & Energy Corporation. The authors present a method for fabricating stable white-light-emitting electrochemical cells utilizing emission from exciplexes formed between a blue-emitting fluorene polymer and aromatic amines.

비디오: Fabrication of White Light-emitting Electrochemical Cells with Stable Emission from Exciplexes

Echo Particle Image Velocimetry

The transport of mass, momentum, and energy in fluid flows is ultimately determined by spatiotemporal distributions of the fluid velocity field.1 Consequently, a prerequisite for understanding, predicting, and controlling fluid flows is the capability to measure the velocity field with adequate spatial and temporal resolution.2 For velocity measurements in optically opaque fluids or through optically opaque geometries, echo particle image velocimetry (EPIV) is an attractive diagnostic technique to generate "instantaneous" two-dimensional fields of velocity.3,4,5,6 In this paper, the operating protocol for an EPIV system built by integrating a commercial medical ultrasound machine7 with a PC running commercial particle image velocimetry (PIV) software8 is described, and validation measurements in Hagen-Poiseuille (i.e., laminar pipe) flow are reported.
For the EPIV measurements, a phased array probe connected to the medical ultrasound machine is used to generate a two-dimensional ultrasound image by pulsing the piezoelectric probe elements at different times. Each probe element transmits an ultrasound pulse into the fluid, and tracer particles in the fluid (either naturally occurring or seeded) reflect ultrasound echoes back to the probe where they are recorded. The amplitude of the reflected ultrasound waves and their time delay relative to transmission are used to create what is known as B-mode (brightness mode) two-dimensional ultrasound images. Specifically, the time delay is used to determine the position of the scatterer in the fluid and the amplitude is used to assign intensity to the scatterer. The time required to obtain a single B-mode image, t, is determined by the time it take to pulse all the elements of the phased array probe. For acquiring multiple B-mode images, the frame rate of the system in frames per second (fps) = 1/&delta;t. (See 9 for a review of ultrasound imaging.)
For a typical EPIV experiment, the frame rate is between 20-60 fps, depending on flow conditions, and 100-1000 B-mode images of the spatial distribution of the tracer particles in the flow are acquired. Once acquired, the B-mode ultrasound images are transmitted via an ethernet connection to the PC running the PIV commercial software. Using the PIV software, tracer particle displacement fields, D(x,y)[pixels], (where x and y denote horizontal and vertical spatial position in the ultrasound image, respectively) are acquired by applying cross correlation algorithms to successive ultrasound B-mode images.10 The velocity fields, u(x,y)[m/s], are determined from the displacements fields, knowing the time step between image pairs, &Delta;T[s], and the image magnification, M[meter/pixel], i.e., u(x,y) = MD(x,y)/&Delta;T. The time step between images &Delta;T = 1/fps + D(x,y)/B, where B[pixels/s] is the time it takes for the ultrasound probe to sweep across the image width. In the present study, M = 77[&mu;m/pixel], fps = 49.5[1/s], and B = 25,047[pixels/s]. Once acquired, the velocity fields can be analyzed to compute flow quantities of interest.

An echo particle image velocimetry (EPIV) system capable of acquiring two-dimensional fields of velocity in optically opaque fluids or through optically opaque geometries is described, and validation measurements in pipe flow are reported.

The transport of mass, momentum, and energy in fluid flows is ultimately determined by spatiotemporal distributions of the fluid velocity field.1 ...

연구

공학

Fabrication of VB2/Air Cells for Electrochemical Testing

A technique to investigate the properties and performance of new multi-electron metal/air battery systems is proposed and presented. A method for synthesizing nanoscopic VB2 is presented as well as step-by-step procedure for applying a zirconium oxide coating to the VB2 particles for stabilization upon discharge. The process for disassembling existing zinc/air cells is shown, in addition construction of the new working electrode to replace the conventional zinc/air cell anode with a the nanoscopic VB2 anode. Finally, discharge of the completed VB2/air battery is reported. We show that using the zinc/air cell as a test bed is useful to provide a consistent configuration to study the performance of the high-energy high capacity nanoscopic VB2 anode.

Fabrication of VB2/Air Cells for Electrochemical Testing

A protocol is presented to study multi-electron metal/air battery systems by using previous technology developed for the zinc/air cell. Electrochemical testing is then performed on fabricated batteries to evaluate performance.

VB의 제작<sub&gt; 2</sub전기 테스트를위한&gt; / 공기 전지

A technique to investigate the properties and performance of new multi-electron metal/air battery systems is proposed and presented. A method for ...

Fabrication of Low Temperature Carbon Nanotube Vertical Interconnects Compatible with Semiconductor Technology

We demonstrate a method for the low temperature growth (350 &#176;C) of vertically-aligned carbon nanotubes (CNT) bundles on electrically conductive thin-films. Due to the low growth temperature, the process allows integration with modern low-&#954; dielectrics and some flexible substrates. The process is compatible with standard semiconductor fabrication, and a method for the fabrication of electrical 4-point probe test structures for vertical interconnect test structures is presented. Using scanning electron microscopy the morphology of the CNT bundles is investigated, which demonstrates vertical alignment of the CNT and can be used to tune the CNT growth time. With Raman spectroscopy the crystallinity of the CNT is investigated. It was found that the CNT have many defects, due to the low growth temperature. The electrical current-voltage measurements of the test vertical interconnects displays a linear response, indicating good ohmic contact was achieved between the CNT bundle and the top and bottom metal electrodes. The obtained resistivities of the CNT bundle are among the average values in the literature, while a record-low CNT growth temperature was used.

A method for the growth of low temperature vertically-aligned carbon nanotubes, and the subsequent fabrication of vertical interconnect electrical test structures using semiconductor fabrication is presented.

반도체 기술과 호환 저온 탄소 나노 튜브 수직 상호 연결의 제작

We demonstrate a method for the low temperature growth (350 &#176;C) of vertically-aligned carbon nanotubes (CNT) bundles on electrically conductive ...

Indirect Fabrication of Lattice Metals with Thin Sections Using Centrifugal Casting

One of the typical methods to manufacture 3D lattice metals is the direct-metal additive manufacturing (AM) process such as Selective Laser Melting (SLM) and Electron Beam Melting (EBM). In spite of its potential processing capability, the direct AM method has several disadvantages such as high cost, poor surface finish of final products, limitation in material selection, high thermal stress, and anisotropic properties of parts. We propose a cost-effective method to manufacture 3D lattice metals. The objective of this study is to provide a detailed protocol on fabrication of 3D lattice metals having a complex shape and a thin wall thickness; e.g., octet truss made of Al and Cu alloys having a unit cell length of 5 mm and a cell wall thickness of 0.5 mm. An overall experimental procedure is divided into eight sections: (a) 3D printing of sacrificial patterns (b) melt-out of support materials (c) removal of residue of support materials (d) pattern assembly (e) investment (f) burn-out of sacrificial patterns (g) centrifugal casting (h) post-processing for final products. The suggested indirect AM technique provides the potential to manufacture ultra-lightweight lattice metals; e.g., lattice structures with Al alloys. It appears that the process parameters should be properly controlled depending on materials and lattice geometry, observing the final products of octet truss metals by the indirect AM technique.

An indirect additive manufacturing method combining a 3D printing of polymers with a centrifugal casting is outlined for manufacturing 3D octet truss metals (Al and Cu alloys) having a unit cell length of 5 mm with a wall thickness of 0.5 mm.

One of the typical methods to manufacture 3D lattice metals is the direct-metal additive manufacturing (AM) process such as Selective Laser Melting (SLM) ...

A Fabrication Method for Highly Stretchable Conductors with Silver Nanowires

Stretchable electronics are identified as a key technology for electronic applications in the next generation. One of the challenges in fabrication of stretchable electronic devices is the preparation of stretchable conductors with great mechanical stability. In this study, we developed a simple fabrication method to chemically solder the contact points between silver nanowire (AgNW) networks. AgNW nanomesh was first deposited on a glass slide via spray coating method. A reactive ink composed of silver nanoparticle (AgNPs) precursors was applied over the spray coated AgNW thin films. After heating for 40 min, AgNPs were preferentially generated over the nanowire junctions to solder the AgNW nanomesh, and reinforced the conducting network. The chemically modified AgNW thin film was then transferred to polyurethane (PU) substrates by casting method. The soldered AgNW thin films on PU exhibited no obvious change in electrical conductivity under stretching or rolling process with elongation strains up to 120%.

A simple synthesis method is used to chemically solder silver nanowire thin film to fabricate highly stretchable and conductive metal conductors.

Stretchable electronics are identified as a key technology for electronic applications in the next generation. One of the challenges in fabrication of ...

Printing Fabrication of Bulk Heterojunction Solar Cells and In Situ Morphology Characterization

Polymer-based materials hold promise as low-cost, flexible efficient photovoltaic devices. Most laboratory efforts to achieve high performance devices have used devices prepared by spin coating, a process that is not amenable to large-scale fabrication. This mismatch in device fabrication makes it difficult to translate quantitative results obtained in the laboratory to the commercial level, making optimization difficult. Using a mini-slot die coater, this mismatch can be resolved by translating the commercial process to the laboratory and characterizing the structure formation in the active layer of the device in real time and in situ as films are coated onto a substrate. The evolution of the morphology was characterized under different conditions, allowing us to propose a mechanism by which the structures form and grow. This mini-slot die coater offers a simple, convenient, material efficient route by which the morphology in the active layer can be optimized under industrially relevant conditions. The goal of this protocol is to show experimental details of how a solar cell device is fabricated using a mini-slot die coater and technical details of running in situ structure characterization using the mini-slot die coater.

Printing Fabrication of Bulk Heterojunction Solar Cells and In Situ Morphology Characterization

Here, we present a protocol to fabricate organic thin film solar cells using a mini-slot die coater and related in-line structure characterizations using synchrotron scattering techniques.

벌크 이종 접합 태양 전지의 인쇄 제작 및<em&gt; 현장에서</em&gt; 형태학 특성

Polymer-based materials hold promise as low-cost, flexible efficient photovoltaic devices. Most laboratory efforts to achieve high performance devices ...

Emission Spectroscopic Boundary Layer Investigation during Ablative Material Testing in Plasmatron

Ablative Thermal Protection Systems (TPS) allowed the first humans to safely return to Earth from the moon and are still considered as the only solution for future high-speed reentry missions. But despite the advancements made since Apollo, heat flux prediction remains an imperfect science and engineers resort to safety factors to determine the TPS thickness. This goes at the expense of embarked payload, hampering, for example, sample return missions. 
Ground testing in plasma wind-tunnels is currently the only affordable possibility for both material qualification and validation of material response codes. The subsonic 1.2MW Inductively Coupled Plasmatron facility at the von Karman Institute for Fluid Dynamics is able to reproduce a wide range of reentry environments. This protocol describes a procedure for the study of the gas/surface interaction on ablative materials in high enthalpy flows and presents sample results of a non-pyrolyzing, ablating carbon fiber precursor. With this publication, the authors envisage the definition of a standard procedure, facilitating comparison with other laboratories and contributing to ongoing efforts to improve heat shield reliability and reduce design uncertainties.
The described core techniques are non-intrusive methods to track the material recession with a high-speed camera along with the chemistry in the reactive boundary layer, probed by emission spectroscopy. Although optical emission spectroscopy is limited to line-of-sight measurements and is further constrained to electronically excited atoms and molecules, its simplicity and broad applicability still make it the technique of choice for analysis of the reactive boundary layer. Recession of the ablating sample further requires that the distance of the measurement location with respect to the surface is known at all times during the experiment. Calibration of the optical system of the applied three spectrometers allowed quantitative comparison. At the fiber scale, results from a post-test microscopy analysis are presented.

Development of new ablative materials and their numerical modeling requires extensive experimental investigation. This protocol describes procedures for material response characterization in plasma flows with the core techniques being non-intrusive methods to track the material recession along with the chemistry in the reactive boundary layer by emission spectroscopy.

Plasmatron에서 절제 재료 시험 중에 방출 분광 경계 계층 조사

Ablative Thermal Protection Systems (TPS) allowed the first humans to safely return to Earth from the moon and are still considered as the only solution ...

Electrochemical Etching and Characterization of Sharp Field Emission Points for Electron Impact Ionization

A new variation of the drop-off method for fabricating field emission points by electrochemically etching tungsten rods in a NaOH solution is described. The results of studies in which the etching current and the molarity of the NaOH solution used in the etching process were varied are presented. The investigation of the geometry of the tips, by imaging them with a scanning electron microscope, and by operating them in field emission mode is also described. The field emission tips produced are intended to be used as an electron beam source for ion production via electron impact ionization of background gas or vapor in Penning trap mass spectrometry applications.

A method for electrochemically etching field emission tips is presented. Etching parameters are characterized and the operation of the tips in field emission mode is investigated.

전기 화학적 에칭 및 전자 충격 이온화 샤프 전계 방출 포인트의 특성

A new variation of the drop-off method for fabricating field emission points by electrochemically etching tungsten rods in a NaOH solution is described. ...

A System to Create Stable Nanoparticle Aerosols from Nanopowders

Nanoparticle aerosols released from nanopowders in workplaces are associated with human exposure and health risks. We developed a novel system, requiring minimal amounts of test materials (min. 200 mg), for studying powder aerosolization behavior and aerosol properties. The aerosolization procedure follows the concept of the fluidized-bed process, but occurs in the modified volume of a V-shaped aerosol generator. The airborne particle number concentration is adjustable by controlling the air flow rate. The system supplied stable aerosol generation rates and particle size distributions over long periods (0.5-2 hr and possibly longer), which are important, for example, to study aerosol behavior, but also for toxicological studies. Strict adherence to the operating procedures during the aerosolization experiments ensures the generation of reproducible test results. The critical steps in the standard protocol are the preparation of the material and setup, and the aerosolization operations themselves. The system can be used for experiments requiring stable aerosol concentrations and may also be an alternative method for testing dustiness. The controlled aerosolization made possible with this setup occurs using energy inputs (may be characterized by aerosolization air velocity) that are within the ranges commonly found in occupational environments where nanomaterial powders are handled. This setup and its operating protocol are thus helpful for human exposure and risk assessment.

We designed and developed an effective nanopowder aerosolization setup and operating protocol. The system generated nanoparticle aerosols with stable number concentrations and size distributions for long durations, requiring only small quantities of test material (min. 200 mg).

시스템은 나노 분말에서 안정적인 나노 입자 에어로졸을 만드는 방법

Nanoparticle aerosols released from nanopowders in workplaces are associated with human exposure and health risks. We developed a novel system, requiring ...

Production and Characterization of Vacuum Deposited Organic Light Emitting Diodes

A method for producing simple and efficient thermally-activated delayed fluorescence organic light-emitting diodes (OLEDs) based on guest-host or exciplex donor-acceptor emitters is presented. With a step-by-step procedure, readers will be able to repeat and produce OLED devices based on simple organic emitters. A patterning procedure allowing the creation of personalized indium tin oxide (ITO) shape is shown. This is followed by the evaporation of all layers, encapsulation and characterization of each individual device. The end goal is to present a procedure that will give the opportunity to repeat the information presented in cited publication but also using different compounds and structures in order to prepare efficient OLEDs.

A protocol for the production of simple structured organic light-emitting diodes (OLEDs) is presented.

A method for producing simple and efficient thermally-activated delayed fluorescence organic light-emitting diodes (OLEDs) based on guest-host or exciplex ...

화이트의 제작 Exciplexes에서 안정 방출과 전기 화학 셀 라이트 발광

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