O autor correspondente gostaria de reconhecer Conselho Nacional de Ciência e Tecnologia CONACYT do Governo do México para a prestação de uma bolsa de estudos.

NOTA: As instruções abaixo são para protocolo A (Figura 1). Modificações para Protocolo B, C, e D estão indicadas. 1. Aluminum Bar Preparação <ol><li> Coloque um pedaço grande (500 g - 1 kg) de pureza comercial lingote de alumínio em um cadinho. </li><li> Colocar o cadinho num forno a 800 ° C durante cerca de 1 hora, até fundir. </li><li> Tirar o cadinho do forno e despeje o alumínio fundido no interior de um molde cilíndrico que é de 50 mm de diâmetro, ligeiramente menor que o diâmetro final da câmara a ser utilizados para a infiltração (51 mm) dando uma folga de cerca de ½ mm. </li><li> Aguarde 1 hora para o bar para se refrescar. </li><li> Remover a barra a partir do molde. </li><li> Usando uma serra de fita, corte em 4 pedaços do mesmo tamanho. </li><li> Areia das extremidades de cada pedaço de assegurar um bom encaixe no molde infiltração. </li></ol> 2. Preparação Furnace <ol><li> Programar o forno para atingir um 740 &amp; #176; planalto C durante pelo menos 2 horas. </li><li> Definir a taxa de aquecimento do forno para 20 ° C / min. </li></ol> 3. Preparação Preform NOTA: Dependendo da altura da espuma destinado para, variar a quantidade de NaCl ao usar para a infiltração entre 100 g e 300 g. <ol><li> Escolha a infiltração de NaCl de usar, com um diâmetro correspondente ao intervalo de tamanho de poro requerido (por exemplo, uma gama entre 1,4 mm e 1,7 milímetros). O material pode ser obtido a partir de fornecedores de produtos químicos, em elevado grau de pureza, ou comprados supermercado sal de mesa pode ser usado (tal material irá ter aditivos tais como agentes de iodo e anti-aglomeração, mas estes não influência na prática o processo de forma significativa). </li><li> Escolha de peneiras de um intervalo de tamanho apropriado e da pilha de um recipiente de base com o tamanho da abertura menor na parte inferior. </li><li> De saco de NaCl dos fornecedores, levar aproximadamente 500 g e derramá-lo nas peneiras empilhadas. </li><li> Agitar os crivos, Quer manualmente ou utilizando um agitador de peneiro, durante 1 min. </li><li> Descartar o NaCl deixado no maior tamanho de crivo de abertura e o recipiente inferior, o NaCl deixado no menor peneira de abertura é utilizada para a infiltração. </li><li> Pesar a quantidade de obtida a infiltração de NaCl. </li><li> Se a quantidade for insuficiente, repita os passos de 3,4-3,7. NOTA: Para protocolos B, C ou D, obter 100 g de multa NaCl (&lt;500 mm). Isto cria um espaço extra no molde para o ar retido no pré-molde durante a infiltração no caso de o ar dentro do pré-molde não escape da câmara de forma adequada. </li></ol> Preparação 4. Mold <ol><li> Usando uma lixa e rolo de papel de laboratório, limpe o cilindro de molde (Figura 2), tendo especial atenção para as bordas superior e inferior, e mantendo o molde livre de quaisquer impurezas visíveis de uso anterior. </li><li> Pulverizar o interior do cilindro de molde de nitreto de boro com o pulverizador de aerossol, a criação de um revestimento de camada finao interior do molde. NOTA: Este é alcançado quando a cor original do molde é substituída por uma camada branca do spray; não é necessário medir a sua concentração específica. </li><li> Deixar secar o cilindro de molde durante pelo menos 5 min à temperatura ambiente (aquecimento para cerca de 100 ° C durante até 1 hora pode ser aplicado para a secagem adicional, se desejado). </li><li> Usando uma lixa fina, remover qualquer resíduo de nitreto de boro a partir das bordas do cilindro de molde, para melhorar a vedação entre o cilindro de molde e a base do molde. NOTA: As próximas três etapas são para Protocolos A e B; Protocolos para C e D cortar apenas um anel de vedação para a tampa. </li><li> Corte 2 anéis de vedação de um milímetro de espessura folha de grafite (OD = 60 mm, ID = 51 mm), uma para a união entre a borda superior do cilindro molde e a tampa do molde que antecederam o sistema de válvula, o outro para a união entre o bordo inferior do cilindro de molde e a base do molde. </li><li> Coloque uma das juntas na ranhura da base do molde. </li><li> Coloque o Bottom o cilindro de molde para dentro da ranhura com a junta de vedação. </li><li> Toque levemente com um martelo sobre o topo do cilindro de molde para fixar a parte inferior do sulco de base. NOTA: Para Protocolo B, C, ou D, adicione o seguinte passo. <ol><li> Despeje a 100 g de multa NaCl (&lt;500 mm) no cilindro molde e alise a parte superior com uma barra de alumínio sem cortes tocando no topo da-o levemente com o martelo para garantir a multa NaCl é embalado a uma alta densidade. NOTA: Para Protocol D adicione o seguinte passo. </li><li> Corte 2 círculos de SOFT 2 mm de espessura de cerâmica Kaowool cobrir o tamanho do diâmetro do molde (51 mm) e colocá-los em cima da multa NaCl, use a barra de alumínio sem cortes e o martelo para pressioná-los contra a multa NaCl. </li></ol></li><li> Verter a NaCl a ser infiltrada no cilindro de molde. NOTA: Para Protocol D adicione o seguinte passo. <ol><li> Fixe o molde e base para uma mesa vibratória, certificando-se de cilindro do molde não se move a partir da ranhura base. Vibrardurante 1 min a 50 Hz, com uma amplitude de 0,01 m. </li></ol></li><li> Segurando o topo do cilindro no lugar, pegar a base e agitar levemente até que o NaCl no interior do molde forma uma superfície plana na parte superior. </li><li> Coloque a barra de alumínio preparado no topo do pré-molde de NaCl. </li><li> Colocar uma junta de vedação de grafite na ranhura da tampa do molde. </li><li> Ao lado do parafuso 4 pregos de aço inoxidável para a base e fixá-los com quatro conjuntos de porcas e anilhas de aço inoxidável sobre a parte superior da base, com uma chave e colocar a tampa do molde no topo do cilindro de molde por meio de pernos. </li><li> Com uma chave de torque fixado em 16 N · m, aperte os 4 conjuntos de porcas e arruelas de aço sobre os quatro parafusos sem parafusados ​​na base e que se estende até através da tampa, onde as porcas são apertados para travar a tampa do molde no lugar. </li><li> Fixar a parte superior da tampa, para o sistema de válvula com o anel de vedação, pinça, parafuso e porca de borboleta. </li><li> Fechar todas as válvulas do sistema. </li><li> Abra a válvula levando a tque bomba de vácuo e o molde (válvula 3). </li><li> Ligue a bomba de vácuo até que o relógio de medição do sistema de válvula indica a pressão mais baixa possível. </li><li> Desligue a bomba de vácuo. </li><li> Se a perda de vácuo no sistema é inferior a uma taxa de 50 Torr / seg para os primeiros 10 segundos depois de desligar a bomba de vácuo a vedação é suficientemente bom para a infiltração. </li><li> Deixar a válvula de tampa aberta (válvula 3) para manter o sistema à pressão ambiente e fechar a válvula da bomba de vácuo (válvula 1). </li><li> , Sem desmontar o sistema de válvula, coloque o molde no forno pré-aquecido e esperar durante 1 h. </li></ol> 5. Infiltração <ol><li> Fechar todas as válvulas do sistema (Figura 3). </li><li> Abrir a válvula que conduz à garrafa de gás árgon (válvula 2). </li><li> Abrir a válvula principal no tanque de gás árgon e ajustar a pressão de infiltração com a válvula reguladora (por uma gama de 1,4 mm a 1,7 mm de tamanho de partícula de NaCl, usar uma pressão de 3,5 bar). NOTA: Para Protocolo B, uma pressão de infiltração de 3 bar é usado. Use uma pressão de 1 bar para Protocolos C e D. </li><li> De uma maneira rápida, abra a válvula da tampa (válvula 3). </li><li> Após 1 min, remover o molde do forno e colocá-lo em cima de uma superfície de arrefecimento (neste caso um bloco de cobre). NOTA: Durante o arrefecimento, a pressão no sistema será alterado. Pela primeira 5 min deste processo, preste muita atenção para a pressão indicada pelo regulador e ajuste de volta para a pressão de infiltração, se necessário. </li></ol> Extração 6. Amostra <ol><li> Após 30 minutos, quando o molde é legal o suficiente para lidar com luvas resistentes ao calor luz, desligar o sistema de válvula e coloque a base do molde em um torno de bancada. Abrir a tampa da parte superior do cilindro. </li><li> Com a tampa, bata levemente o topo do cilindro molde com um martelo numa direcção perpendicular ao aperto do torno para soltar o cilindro de molde a partir da base de ranhura. </li><li&gt; Retire a base do molde do torno e coloque o cilindro molde no aperto vise. </li><li> Com o martelo bater o alumínio restante no topo da amostra para empurrá-lo para fora do cilindro molde. </li><li> Usando uma serra de fita, corta a parte inferior da amostra de espuma, removendo o excedente de alumínio. </li><li> Dependendo da altura da espuma necessário, cortar, quando desejado, próximo do topo da amostra. </li><li> Coloque a espuma infiltrada num copo com água e uma barra de agitação magnética numa placa quente agitada para dissolver o pré-molde de NaCl. </li><li> Definir a temperatura da placa quente a 60 ° C. Mudar a água a cada 10 min até que não haja NaCl deixado na espuma. NOTA: Para assegurar que não haja NaCl deixado na espuma, alterar a água de aproximadamente 10 vezes. É também possível fazer verificações periódicas do peso da amostra após uma breve fase de secagem. Quando esta cessa a mudar significativamente com mais de imersão, o NaCl deve ser completamente removido. </li><li> Finalmente utilizando um elétricoar mais seco retire toda a água deixada na espuma. A amostra de espuma é preparada. </li></ol>

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The authors declare that they have no competing financial interests.

O método básico aqui descrito foi usado em diferentes formas por outros investigadores. Algumas das variantes fundamentais que permitem que as espumas de diferentes tipos de ser criado são discutidos. Ao caracterizar estas espumas medimos a porosidade, pois esta é uma avaliação rápida e fácil de fazer, mas a caracterização de outras características estruturais, tais como o tamanho dos poros, área superficial específica ou escorar espessura pode ser necessária para se obter um entendimento completo de carac...

A journal reference was corrected in the publication of <a href="http://www.jove.com/video/52268">Casting Protocols for the Production of Open Cell Aluminum Foams by the Replication Technique and the Effect on Porosity</a>. Reference 21 and 22 were originally merged together as one reference. They have been separated into references 21 and 22 in the article. The reference numbers have been updated in the article to reflect this additional reference citation. It has been updated from:
<ol start="21"><li>LeMay, J.D., Hopper, R.W., Hrubesh, L.W., &#38; Pekala, R.W. Low-Density Microcellular Materials. Materials Research Society Bulletin. 15 (12), 19&#8211;20 (1990).Seliger, H., &#38; Deuther U. Die Herstellung von Schaum- und Zellaluminium. Feiburger Forschungshefte. 103&#8211;129 (1965).</li></ol>
to:
<ol start="21"><li>LeMay, J.D., Hopper, R.W., Hrubesh, L.W., &#38; Pekala, R.W. Low-Density Microcellular Materials. Materials Research Society Bulletin. 15 (12), 19&#8211;20 (1990).</li>
<li>Seliger, H., &#38; Deuther U. Die Herstellung von Schaum- und Zellaluminium. Feiburger Forschungshefte. 103&#8211;129 (1965).</li></ol>

Erratum: Casting Protocols for the Production of Open Cell Aluminum Foams by the Replication Technique and the Effect on Porosity

Espumas metálicas têm atraído uma grande quantidade de interesse e esforço de pesquisa nos últimos anos, como o demonstra o grande corpo de trabalho citado em ampla revisão de artigos, tais como Banhart 1, Conde et al. 2 ou mais recentemente Goodall e Mortensen 3. Entre os métodos utilizados para a produção do material, o processo de replicação se distingue pela sua simplicidade experimental e o grau de controle sobre a estrutura da espuma final que pode ser oferecido. Deve notar-se que, embora na literatura tais materiais são geralmente descritos como espumas (e aqui), como eles não são produzidos por bolhas de gás dentro de um líquido que é mais adequadamente chamada metais porosos ou metais microcelulares. O primeiro relatório do processo de replicação foi no início dos anos 1960 4, e que tem sido desenvolvido em diferentes fases, desde então, com notáveis ​​avanços por parte do grupo de pesquisa Mortensen na Ecole Polytechnique Federale de Lausanne, na Suíça. O processo baseia-se na fundição do metal em torno de um pré-molde de partículas que define a forma da porosidade do material final, em 2, 5. Depois de arrefecer a pré-forma pode ser removido por lixiviação de solvente ou de pirólise, que provoca a oxidação. Um uso popular dessa técnica utiliza NaCl como um suporte de espaço para produzir alumínio 5-10 ou ligas de alumínio espumas 11-14. NaCI tem várias vantagens, tais como serem facilmente acessíveis, não tóxico e pode ser removido a partir da espuma por dissolução em água. Por ter um ponto de fusão de 801 ° C, que pode ser usado com metais que têm um ponto mais baixo do que este valor, mais geralmente de alumínio de fusão, mas existem também exemplos do uso com materiais tais como os vidros metálicos a granel, por humidificação de uma mistura de líquido liga vidro metálico em massa-base de paládio e NaCl grânulos 15. Substituição do NaCl com materiais de ponto de fusão mais elevada também permite a produção de espumas a partir de metais de ponto de fusão mais elevado 16. Isto pode incluir outros materiais solúveis em água, ou insolúveis, incluindo os diferentes tipos de areia. Nesta forma, o processo torna-se mais como areia de fundição convencional como para remover a areia, jatos de água de alta pressão 17, 18 ou diferentes formas de lavagem 19 ou agitação 20 são obrigatórios. O processo prossegue por 21 essencial tendo grãos de NaCl e colocando-os num molde 4, 22, 23. O método básico foi usado para fazer espumas de alumínio e de ligas de alumínio 24-26 para uma vasta gama de investigações do comportamento de espuma. Passos adicionais foram introduzidas para controlar ainda mais a densidade e para aumentar a interconectividade dos poros; estes incluem a densificação do pré-molde. Para densificar o pré-molde, de sinterização foi utilizado 27, 28, e tem sido utilizado em experiências diferentes, desde 13, com o comportamento de sinterizaçãoNaCl com base na temperatura, o tamanho do grânulo e a densidade descrito por Goodall et ai. 29. Outro método utilizado para esta finalidade é prensagem isostática a frio (CIP) 5, 30; esta é uma técnica mais rápida que pode atingir um maior espectro de densidades comparáveis. O procedimento também pode ser realizado no estado sólido com metal em pó e grãos de NaCl, e, em seguida, é por vezes chamado de sinterização e Dissolução do Processo 31. Um levantamento completo da utilização de uma técnica de replicação de data e comparação com outras técnicas é apresentado em Goodall e Mortensen 3. Neste trabalho descrevemos em detalhe equipamento e protocolos experimentais que têm sido utilizados para o processamento de espumas metálicas pelo método de replicação, e que são relativamente fáceis de implementar em um ambiente de laboratório de pesquisa. É importante reconhecer que as outras versões do equipamento, com diferentes capacidades existem em outras pesquisas gs grupos, e que, embora o equipamento aqui apresentada é adequada para processar o material, não é a única versão ou protocolo que pode ser posto a funcionar. Em qualquer caso, uma compreensão completa de qualquer método particular é essencial para o sucesso experimental. Os protocolos precisos utilizados são detalhados a seguir. As variações no protocolo (A, B, C e D) têm pequenas alterações entre eles, principalmente destinado a alterar a densidade das espumas produzidas. A porosidade foi calculada a partir de medições do peso das amostras de grandes quantidades, o seu volume e a densidade de alumínio (2,7 g / cm 3). No desenvolvimento dos métodos descritos para a produção de espuma de alumínio por replicação, têm sido feitas tentativas para reduzir a quantidade de equipamento avançado para a menor medida do possível, de tal forma que o método é tão fácil quanto possível para implementar. Outras variações que podem ser utilizadas em diferentes estágios são discutidos mais tarde.

<table border="0" cellpadding="0" cellspacing="0" width="1664">
	<tbody>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Name of Reagent/ Equipment</td>
			<td style="width:187px;">Company</td>
			<td style="width:429px;">Catalog Number</td>
			<td style="width:833px;">Comments/Description</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Salt</td>
			<td style="width:187px;">Hydrosoft</td>
			<td style="width:429px;">Granular Salt 25 kg 855754</td>
			<td>http://www.travisperkins.co.uk/p/hydrosoft-granular-salt-25kg/855754/3893446</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Aluminum</td>
			<td style="width:187px;">William Rowland</td>
			<td style="width:429px;">Aluminum Ingots 99.87% pure 25 kg drum</td>
			<td>http://www.william-rowland.com/products/high-purity-metals#product-id-1</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Crucible</td>
			<td style="width:187px;">Morgan Advance Materials</td>
			<td style="width:429px;">Syncarb Crucible</td>
			<td>http://www.morganmms.com/crucibles-foundry-products/crucibles/syncarb/</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Furnace</td>
			<td style="width:187px;">Elite Thermal Systems</td>
			<td style="width:429px;">TLCF10/27-3216CP &#38; 2116 O/T</td>
			<td>http://www.elitefurnaces.com/eng/products/furnaces/1200%20Top%20Loading%20Furnaces.php</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Bar Mold</td>
			<td style="width:187px;">The University of Sheffield</td>
			<td style="width:429px;">Custom Made</td>
			<td>Stainless Steel 304, 15 cm height, 5 cm inner diameter, 6 cm outer diameter</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Band Saw</td>
			<td style="width:187px;">Clarke</td>
			<td style="width:429px;">CBS45MD (6&#34; x 4 1/2&#34;) 370W 060710025</td>
			<td>http://www.machinemart.co.uk/shop/product/details/cbs45md-41-2in-x-6in-metal-cutting-ban</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Sandpaper</td>
			<td style="width:187px;">Wickes</td>
			<td style="width:429px;">Specialist wet &#38; dry sandpaper 501885</td>
			<td>http://www.wickes.co.uk/Specialist-Wet+Dry-Sandpaper-PK4/p/501885</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Sieves</td>
			<td style="width:187px;">Fisher Scientific</td>
			<td style="width:429px;">Fisherbrand test sieves 200 mm diamater</td>
			<td>http://www.fisher.co.uk/product/brand_listing.php/F/Fisherbrand/Sieve</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Balance</td>
			<td style="width:187px;">Precisa</td>
			<td style="width:429px;">XB 6200C</td>
			<td>http://www.precisa.co.uk/precision_balances.php</td>
		</tr>
		<tr height="37">
			<td height="37" style="height:37px;width:216px;">Boron Nitride</td>
			<td style="width:187px;">Kennametal</td>
			<td style="width:429px;">500 ml spray can</td>
			<td style="width:833px;">http://www.kennametal.com/content/dam/kennametal/kennametal/common/Resources/Catalogs-Literature/Advanced%20Materials%20and%20Wear%20Components/B-13-03401_ceramic_powders 
			_brochure_EN.pdf</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Infiltration Mold, Base and Lid</td>
			<td style="width:187px;">The University of Sheffield</td>
			<td style="width:429px;">Custom Made</td>
			<td>Stainless Steel 304, 15 cm height, 5.1 cm inner diameter, 6 cm outer diameter</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Cylindrical Mold</td>
			<td style="width:187px;">The University of Sheffield</td>
			<td style="width:429px;">Custom Made</td>
			<td>Low carbon steel 1020, 15 cm height, 5 cm inner diameter, 6 cm outer diameter</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Graphite Gasket</td>
			<td style="width:187px;">Gee Graphite</td>
			<td style="width:429px;">Geegraf Stainless Steel Reinforced Graphite 1 mm thick</td>
			<td>http://www.geegraphite.com/steel_reinforced.html</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Mallet</td>
			<td style="width:187px;">Thor Hammer Co. Ltd.</td>
			<td style="width:429px;">Round Solid Super Plastic Mallet</td>
			<td>http://www.thorhammer.com/Mallets/Round/</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Wrench</td>
			<td style="width:187px;">Kennedy Professional</td>
			<td style="width:429px;">13 mm Ratchet Combination Wrench KEN5822166K</td>
			<td>https://www.cromwell.co.uk/KEN5822166K</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Nuts</td>
			<td style="width:187px;">Matlock</td>
			<td style="width:429px;">M8 Steel hex full nut galvanized</td>
			<td>https://www.cromwell.co.uk/CTL6400068J</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Washers</td>
			<td style="width:187px;">Matlock</td>
			<td style="width:429px;">M8 Form-A steel washer bzp</td>
			<td>https://www.cromwell.co.uk/CTL6451208H</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">SS Nuts</td>
			<td style="width:187px;">Matlock</td>
			<td style="width:429px;">M8 A2 st/st hex full nut</td>
			<td>https://www.cromwell.co.uk/CTL6423008F</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">SS Washers</td>
			<td style="width:187px;">Matlock</td>
			<td style="width:429px;">M8 A2 st/st Form-A washer</td>
			<td>https://www.cromwell.co.uk/CTL6464008H</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Stainless Steel Studding</td>
			<td style="width:187px;">Cromwell</td>
			<td style="width:429px;">M8 x 1 Mtr A2 Stainless Steel Studding QFT6397080K</td>
			<td>https://www.cromwell.co.uk/QFT6397080K</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Valves</td>
			<td style="width:187px;">Edwards</td>
			<td style="width:429px;">C33205000 SP16K, Nitrile Diaphragm</td>
			<td>https://www.edwardsvacuum.com/Products/View.aspx?sku=C33205000</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Fitting Cross</td>
			<td style="width:187px;">Edwards</td>
			<td style="width:429px;">C10512412 NW16 Cross Piece Aluminum</td>
			<td>https://www.edwardsvacuum.com/Products/C10512412/View.aspx</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Fitting T</td>
			<td style="width:187px;">Edwards</td>
			<td style="width:429px;">C10512411 NW16 T-Piece Aluminum</td>
			<td>https://www.edwardsvacuum.com/Products/C10512411/View.aspx</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Vacuum Pump</td>
			<td style="width:187px;">Edwards</td>
			<td style="width:429px;">A36310940 E2M18 200-230/380-415V,3-ph, 50Hz</td>
			<td>http://www.edwardsvacuum.com/Products/View.aspx?sku=A36310940</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Dial Gauge</td>
			<td style="width:187px;">Edwards</td>
			<td style="width:429px;">D35610000 CG16K, 0-1040mbar</td>
			<td>http://www.edwardsvacuum.com/Products/View.aspx?sku=D35610000</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Argon Gas</td>
			<td style="width:187px;">BOC</td>
			<td style="width:429px;">Pureshield Argon Gas</td>
			<td>http://www.boconline.co.uk/en/products-and-supply/industrial-gases/inert-gases/pureshield-argon/pureshield-argon.html</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Stainless Steel Hose</td>
			<td style="width:187px;">BOC</td>
			<td style="width:429px;">Stainless Steel Hose</td>
			<td>http://www.boconline.co.uk/en/products-and-supply/speciality-equipment/hoses-and-pigtails/index.html</td>
		</tr>
		<tr height="37">
			<td height="37" style="height:37px;width:216px;">Regulator</td>
			<td style="width:187px;">BOC</td>
			<td style="width:429px;">HP 1500 Series Regulator</td>
			<td style="width:833px;">http://www.boconline.co.uk/en/products-and-supply/speciality-equipment/regulators/single-stage-regulators/hp1500-series/hp1500-series.html</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Copper Block</td>
			<td style="width:187px;">William Rowland</td>
			<td style="width:429px;">Copper Ingot 25 kg</td>
			<td>http://www.william-rowland.com/products/high-purity-metals#product-id-18</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Vise</td>
			<td style="width:187px;">Record</td>
			<td style="width:429px;">T84-34 H/Duty Eng Vice 4 1/2&#34; Jaws REC5658326K</td>
			<td>https://www.cromwell.co.uk/REC5658326K</td>
		</tr>
		<tr height="37">
			<td height="37" style="height:37px;width:216px;">Beaker</td>
			<td style="width:187px;">Fisher Scientific</td>
			<td style="width:429px;">11567402 - Beaker, squat form, with graduations and spout 800mL</td>
			<td style="width:833px;">https://webshop.fishersci.com/insight2_uk/getProduct.do;jsessionid=16D5812 
			D71B8CB37B475E94281E2BEA 
			5.ukhigjavappp11?productCode=11567402&#38;resultSet 
			Position=0</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Stirring Hot Plate</td>
			<td style="width:187px;">Corning</td>
			<td style="width:429px;">Corning stirring hot plate Model 6798-420d</td>
			<td>http://www.corning.com/lifesciences/us_canada/en/technical_resources/product_guid/shp/shp.aspx</td>
		</tr>
		<tr height="37">
			<td height="37" style="height:37px;width:216px;">Stir Bar</td>
			<td style="width:187px;">Fisher Scientific</td>
			<td style="width:429px;">11848862 - PTFE Stir bar + Ring 25x6 mm</td>
			<td style="width:833px;">https://webshop.fishersci.com/insight2_uk/getProduct.do;jsessionid=16D5812 
			D71B8CB37B475E94281E2BEA 
			5.ukhigjavappp11?productCode=11848862&#38;resultSet 
			Position=0</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Air dryer</td>
			<td style="width:187px;">V05</td>
			<td style="width:429px;">V05 Max Air Turbo Dryer DR-120-GB</td>
			<td>http://reviews.boots.com/2111-en_gb/1120627/v05-v05-max-air-turbo-hair-dryer-dr-120-gb-reviews/reviews.htm</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Ceramic Sheet</td>
			<td style="width:187px;">Morgan Advance Materials</td>
			<td style="width:429px;">Kaowool Blanket 2 mm thick</td>
			<td>http://www.morganthermalceramics.com/downloads/datasheets?f[0]=field_type%3A84</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:216px;">Vibrating Table</td>
			<td style="width:187px;">Pevco</td>
			<td style="width:429px;">Pevco Vibrating Table 1.25m x 0.625m x 0.6m</td>
			<td>http://www.peverilmachinery.co.uk/equipment/vibrating-tables</td>
		</tr>
	</tbody>
</table>

casting protocols for the production of open cell aluminum foams by the replication technique and the effect on porosity

Espumas metálicas são materiais interessantes, tanto uma compreensão fundamental e aplicações práticas ponto de vista. Utilizações têm sido propostos, e em muitos casos validado experimentalmente, por peso luz ou energia de impacto de estruturas absorventes, como permutadores de calor de superfície elevadas ou área de eléctrodos, como implantes para o corpo, e muitos mais. Apesar de grandes progressos feitos na compreensão suas relações estrutura-propriedades, o grande número de técnicas de processamento diferentes, cada material de produção com diferentes características e estrutura, significa que a compreensão dos efeitos individuais de todos os aspectos da estrutura não é completa. O processo de replicação, onde o metal fundido é infiltrada entre os grãos de um material pré-forma amovível, permite que um marcadamente elevado grau de controlo e tem sido usado com bons resultados para elucidar alguns destes relacionamentos. No entanto, o processo tem muitas etapas que são dependentes indivíduo &quot;know-how&quot;, eeste trabalho tem como objetivo fornecer uma descrição detalhada de todas as fases de uma concretização deste método de processamento, utilizando materiais e equipamentos que seria relativamente fácil de configurar em um ambiente de pesquisa. O objetivo deste protocolo e suas variantes é produzir espumas metálicas de uma forma eficaz e simples, dando a possibilidade de adaptar os resultados das amostras, modificando certas etapas dentro do processo. Seguindo este, as espumas de célula aberta de alumínio, com dimensões de poros de 1-2,36 mm de diâmetro e 61% a 77% de porosidade pode ser obtido.

Na Figura 4, a morfologia dos grãos de NaCl pode ser visto (angular e esférica), para fins ilustrativos. As espumas obtidas com o Protocolo A foram feitas com grãos em forma angular e os outros foram feitos com os grãos esféricos. Verificou-se que o uso de forma diferente grãos de NaCl não teve nenhum efeito observado sobre a porosidade obtida nas amostras. A partir dos resultados pode-se determinar que as amostras a, b, e c (feito com o protocolo A), são, em média,...

Watch this Scientific Journal Video about Casting Protocols for the Production of Open Cell Aluminum Foams by the Replication Technique and the Effect on Porosity at JoVE.com

Casting Protocols for the Production of Open Cell Aluminum Foams by the Replication Technique and the Effect on Porosity

Replication is one of the processing techniques used for the production of porous metal sponges. In this paper one implementation of the method for the production of open celled porous aluminum is shown in detail.

Fundição protocolos para a Produção de Abra a pilha de alumínio Espumas pela técnica de replicação e o Efeito da porosidade

Metal foams are interesting materials from both a fundamental understanding and practical applications point of view. Uses have been proposed, and in many ...

casting-protocols-for-production-open-cell-aluminum-foams-replication

Research

JoVE Journal

Engineering

14.4K visualizações.  The University of Sheffield. Replication is one of the processing techniques used for the production of porous metal sponges. In this paper one implementation of the method for the production of open celled porous aluminum is shown in detail.

Vídeo: Casting Protocols for the Production of Open Cell Aluminum Foams by the Replication Technique and the Effect on Porosity

Harvesting Solar Energy by Means of Charge-Separating Nanocrystals and Their Solids

Conjoining different semiconductor materials in a single nano-composite provides synthetic means for the development of novel optoelectronic materials offering a superior control over the spatial distribution of charge carriers across material interfaces. As this study demonstrates, a combination of donor-acceptor nanocrystal (NC) domains in a single nanoparticle can lead to the realization of efficient photocatalytic1-5 materials, while a layered assembly of donor- and acceptor-like nanocrystals films gives rise to photovoltaic materials.
Initially the paper focuses on the synthesis of composite inorganic nanocrystals, comprising linearly stacked ZnSe, CdS, and Pt domains, which jointly promote photoinduced charge separation. These structures are used in aqueous solutions for the photocatalysis of water under solar radiation, resulting in the production of H2 gas. To enhance the photoinduced separation of charges, a nanorod morphology with a linear gradient originating from an intrinsic electric field is used5. The inter-domain energetics are then optimized to drive photogenerated electrons toward the Pt catalytic site while expelling the holes to the surface of ZnSe domains for sacrificial regeneration (via methanol). Here we show that the only efficient way to produce hydrogen is to use electron-donating ligands to passivate the surface states by tuning the energy level alignment at the semiconductor-ligand interface. Stable and efficient reduction of water is allowed by these ligands due to the fact that they fill vacancies in the valence band of the semiconductor domain, preventing energetic holes from degrading it. Specifically, we show that the energy of the hole is transferred to the ligand moiety, leaving the semiconductor domain functional. This enables us to return the entire nanocrystal-ligand system to a functional state, when the ligands are degraded, by simply adding fresh ligands to the system4.
To promote a photovoltaic charge separation, we use a composite two-layer solid of PbS and TiO2 films. In this configuration, photoinduced electrons are injected into TiO2 and are subsequently picked up by an FTO electrode, while holes are channeled to a Au electrode via PbS layer6. To develop the latter we introduce a Semiconductor Matrix Encapsulated Nanocrystal Arrays (SMENA) strategy, which allows bonding PbS NCs into the surrounding matrix of CdS semiconductor. As a result, fabricated solids exhibit excellent thermal stability, attributed to the heteroepitaxial structure of nanocrystal-matrix interfaces, and show compelling light-harvesting performance in prototype solar cells7.

A general strategy for the development of charge-separating semiconductor nanocrystal composites deployable for solar energy production is presented. We show that assembly of donor-acceptor nanocrystal domains in a single nanoparticle geometry gives rise to a photocatalytic function, while bulk-heterojunctions of donor-acceptor nanocrystal films can be used for photovoltaic energy conversion.

Captação de energia solar por meio da carga de separação de nanocristais e seus sólidos

Conjoining different semiconductor materials in a single nano-composite provides synthetic means for the development of novel optoelectronic materials ...

Engenharia

Monolayer Contact Doping of Silicon Surfaces and Nanowires Using Organophosphorus Compounds

Monolayer Contact Doping (MLCD) is a simple method for doping of surfaces and nanostructures1. MLCD results in the formation of highly controlled, ultra shallow and sharp doping profiles at the nanometer scale. In MLCD process the dopant source is a monolayer containing dopant atoms.
In this article a detailed procedure for surface doping of silicon substrate as well as silicon nanowires is demonstrated. Phosphorus dopant source was formed using tetraethyl methylenediphosphonate monolayer on a silicon substrate. This monolayer containing substrate was brought to contact with a pristine intrinsic silicon target substrate and annealed while in contact. Sheet resistance of the target substrate was measured using 4 point probe. Intrinsic silicon nanowires were synthesized by chemical vapor deposition (CVD) process using a vapor-liquid-solid (VLS) mechanism; gold nanoparticles were used as catalyst for nanowire growth. The nanowires were suspended in ethanol by mild sonication. This suspension was used to dropcast the nanowires on silicon substrate with a silicon nitride dielectric top layer. These nanowires were doped with phosphorus in similar manner as used for the intrinsic silicon wafer. Standard photolithography process was used to fabricate metal electrodes for the formation of nanowire based field effect transistor (NW-FET). The electrical properties of a representative nanowire device were measured by a semiconductor device analyzer and a probe station.

A detailed procedure for surface doping of Silicon interfaces is provided. The ultra-shallow surface doping is demonstrated by using phosphorus containing monolayers and rapid annealing process. The method can be used for doping of macroscopic area surfaces as well as nanostructures.

Monolayer Contact Doping (MLCD) is a simple method for doping of surfaces and nanostructures1. MLCD results in the formation of highly controlled, ultra ...

Fast Imaging Technique to Study Drop Impact Dynamics of Non-Newtonian Fluids

In the field of fluid mechanics, many dynamical processes not only occur over a very short time interval but also require high spatial resolution for detailed observation, scenarios that make it challenging to observe with conventional imaging systems. One of these is the drop impact of liquids, which usually happens within one tenth of millisecond. To tackle this challenge, a fast imaging technique is introduced that combines a high-speed camera (capable of up to one million frames per second) with a macro lens with long working distance to bring the spatial resolution of the image down to 10 &#181;m/pixel. The imaging technique enables precise measurement of relevant fluid dynamic quantities, such as the flow field, the spreading distance and the splashing speed, from analysis of the recorded video. To demonstrate the capabilities of this visualization system, the impact dynamics when droplets of non-Newtonian fluids impinge on a flat hard surface are characterized. Two situations are considered: for oxidized liquid metal droplets we focus on the spreading behavior, and for densely packed suspensions we determine the onset of splashing. More generally, the combination of high temporal and spatial imaging resolution introduced here offers advantages for studying fast dynamics across a wide range of microscale phenomena.

Drop impact of non-Newtonian fluids is a complex process since different physical parameters influence the dynamics over a very short time (less than one tenth of a millisecond). A fast imaging technique is introduced in order to characterize the impact behaviors of different non-Newtonian fluids.

Técnica rápida de imagens para o Estudo de Impacto Dynamics Gota de fluidos não-newtonianos

In the field of fluid mechanics, many dynamical processes not only occur over a very short time interval but also require high spatial resolution for ...

Integrating a Triplet-triplet Annihilation Up-conversion System to Enhance Dye-sensitized Solar Cell Response to Sub-bandgap Light

The poor response of dye-sensitized solar cells (DSCs) to red and infrared light is a significant impediment to the realization of higher photocurrents and hence higher efficiencies. Photon up-conversion by way of triplet-triplet annihilation (TTA-UC) is an attractive technique for using these otherwise wasted low energy photons to produce photocurrent, while not interfering with the photoanodic performance in a deleterious manner. Further to this, TTA-UC has a number of features, distinct from other reported photon up-conversion technologies, which renders it particularly suitable for coupling with DSC technology. In this work, a proven high performance TTA-UC system, comprising a palladium porphyrin sensitizer and rubrene emitter, is combined with a high performance DSC (utilizing the organic dye D149) in an integrated device. The device shows an enhanced response to sub-bandgap light over the absorption range of the TTA-UC sub-unit resulting in the highest figure of merit for up-conversion assisted DSC performance to date.

An integrated device, incorporating a dye-sensitized solar cell and triplet-triplet annihilation up-conversion unit was produced, affording enhanced light harvesting, from a wider section of the solar spectrum. Under modest irradiation levels a significantly enhanced response to low energy photons was demonstrated, yielding a record figure of merit for dye-sensitized solar cells.

Integrando um Triplet-triplete Annihilation Sistema Up-conversion para melhorar Dye-sensibilizadas Response célula solar para a Luz Sub-bandgap

The poor response of dye-sensitized solar cells (DSCs) to red and infrared light is a significant impediment to the realization of higher photocurrents ...

Ambient Method for the Production of an Ionically Gated Carbon Nanotube Common Cathode in Tandem Organic Solar Cells

A method of fabricating organic photovoltaic (OPV) tandems that requires no vacuum processing is presented. These devices are comprised of two solution-processed polymeric cells connected in parallel by a transparent carbon nanotubes (CNT) interlayer. This structure includes improvements in fabrication techniques for tandem OPV devices. First the need for ambient-processed cathodes is considered. The CNT anode in the tandem device is tuned via ionic gating to become a common cathode. Ionic gating employs electric double layer charging to lower the work function of the CNT electrode. Secondly, the difficulty of sequentially stacking tandem layers by solution-processing is addressed. The devices are fabricated via solution and dry-lamination in ambient conditions with parallel processing steps. The method of fabricating the individual polymeric cells, the steps needed to laminate them together with a common CNT cathode, and then provide some representative results are described. These results demonstrate ionic gating of the CNT electrode to create a common cathode and addition of current and efficiency as a result of the lamination procedure.

A method of fabricating, in ambient conditions, organic photovoltaic tandem devices in a parallel configuration is presented. These devices feature an air-processed, semi-transparent, carbon nanotube common cathode.

Método ambiente para a produção de um Common Cathode ionicamente fechado de Nanotubos de Carbono em Células solares orgânicas Tandem

A method of fabricating organic photovoltaic (OPV) tandems that requires no vacuum processing is presented. These devices are comprised of two ...

Electron Channeling Contrast Imaging for Rapid III-V Heteroepitaxial Characterization

Misfit dislocations in heteroepitaxial layers of GaP grown on Si(001) substrates are characterized through use of electron channeling contrast imaging (ECCI) in a scanning electron microscope (SEM). ECCI allows for imaging of defects and crystallographic features under specific diffraction conditions, similar to that possible via plan-view transmission electron microscopy (PV-TEM). A particular advantage of the ECCI technique is that it requires little to no sample preparation, and indeed can use large area, as-produced samples, making it a considerably higher throughput characterization method than TEM. Similar to TEM, different diffraction conditions can be obtained with ECCI by tilting and rotating the sample in the SEM. This capability enables the selective imaging of specific defects, such as misfit dislocations at the GaP/Si interface, with high contrast levels, which are determined by the standard invisibility criteria. An example application of this technique is described wherein ECCI imaging is used to determine the critical thickness for dislocation nucleation for GaP-on-Si by imaging a range of samples with various GaP epilayer thicknesses. Examples of ECCI micrographs of additional defect types, including threading dislocations and a stacking fault, are provided as demonstration of its broad, TEM-like applicability. Ultimately, the combination of TEM-like capabilities &#8211; high spatial resolution and richness of microstructural data &#8211; with the convenience and speed of SEM, position ECCI as a powerful tool for the rapid characterization of crystalline materials.

The use of electron channeling contrast imaging in a scanning electron microscope to characterize defects in III-V/Si heteroexpitaxial thin films is described. This method yields similar results to plan-view transmission electron microscopy, but in significantly less time due to lack of required sample preparation.

Electron Canalização Contraste de imagem para Rápido III-V heteroepitaxiais Caracterização

Misfit dislocations in heteroepitaxial layers of GaP grown on Si(001) substrates are characterized through use of electron channeling contrast imaging ...

Experiments on Ultrasonic Lubrication Using a Piezoelectrically-assisted Tribometer and Optical Profilometer

Friction and wear are detrimental to engineered systems. Ultrasonic lubrication is achieved when the interface between two sliding surfaces is vibrated at a frequency above the acoustic range (20 kHz). As a solid-state technology, ultrasonic lubrication can be used where conventional lubricants are unfeasible or undesirable. Further, ultrasonic lubrication allows for electrical modulation of the effective friction coefficient between two sliding surfaces. This property enables adaptive systems that modify their frictional state and associated dynamic response as the operating conditions change. Surface wear can also be reduced through ultrasonic lubrication. We developed a protocol to investigate the dependence of friction force reduction and wear reduction on the linear sliding velocity between ultrasonically lubricated surfaces. A pin-on-disc tribometer was built which differs from commercial units in that a piezoelectric stack is used to vibrate the pin at 22 kHz normal to the rotating disc surface. Friction and wear metrics including effective friction force, volume loss, and surface roughness are measured without and with ultrasonic vibrations at a constant pressure of 1 to 4 MPa and three different sliding velocities: 20.3, 40.6, and 87 mm/sec. An optical profilometer is utilized to characterize the wear surfaces. The effective friction force is reduced by 62% at 20.3 mm/sec. Consistently with existing theories for ultrasonic lubrication, the percent reduction in friction force diminishes with increasing speed, down to 29% friction force reduction at 87 mm/sec. Wear reduction remains essentially constant (49%) at the three speeds considered.

We present a protocol for using a piezoelectrically-assisted tribometer and optical profilometer to investigate the dependence of ultrasonic wear and friction reduction on linear velocity, contact pressure, and surface properties.

Experimentos em Ultrasonic Lubrificação Usando um tribômetro piezoelectricamente-assistida e Profilometer Optical

Friction and wear are detrimental to engineered systems. Ultrasonic lubrication is achieved when the interface between two sliding surfaces is vibrated at ...

Quantification of Hydrogen Concentrations in Surface and Interface Layers and Bulk Materials through Depth Profiling with Nuclear Reaction Analysis

Nuclear reaction analysis (NRA) via the resonant 1H(15N,&#945;&#947;)12C reaction is a highly effective method of depth profiling that quantitatively and non-destructively reveals the hydrogen density distribution at surfaces, at interfaces, and in the volume of solid materials with high depth resolution. The technique applies a 15N ion beam of 6.385 MeV provided by an electrostatic accelerator and specifically detects the 1H isotope in depths up to about 2 &#956;m from the target surface. Surface H coverages are measured with a sensitivity in the order of ~1013 cm-2 (~1% of a typical atomic monolayer density) and H volume concentrations with a detection limit of ~1018 cm-3 (~100 at. ppm). The near-surface depth resolution is 2-5 nm for surface-normal 15N ion incidence onto the target and can be enhanced to values below 1 nm for very flat targets by adopting a surface-grazing incidence geometry. The method is versatile and readily applied to any high vacuum compatible homogeneous material with a smooth surface (no pores). Electrically conductive targets usually tolerate the ion beam irradiation with negligible degradation. Hydrogen quantitation and correct depth analysis require knowledge of the elementary composition (besides hydrogen) and mass density of the target material. Especially in combination with ultra-high vacuum methods for in-situ target preparation and characterization, 1H(15N,&#945;&#947;)12C NRA is ideally suited for hydrogen analysis at atomically controlled surfaces and nanostructured interfaces. We exemplarily demonstrate here the application of 15N NRA at the MALT Tandem accelerator facility of the University of Tokyo to (1) quantitatively measure the surface coverage and the bulk concentration of hydrogen in the near-surface region of a H2 exposed Pd(110) single crystal, and (2) to determine the depth location and layer density of hydrogen near the interfaces of thin SiO2 films on Si(100).

We illustrate the application of 1H(15N,&#945;&#947;)12C resonant nuclear reaction analysis (NRA) to quantitatively evaluate the density of hydrogen atoms on the surface, in the volume, and at an interfacial layer of solid materials. The near-surface hydrogen depth profiling of a Pd(110) single crystal and of SiO2/Si(100) stacks is described.

Quantificação de concentrações de hidrogénio nas camadas superficiais e interface e materiais a granel através de perfis de profundidade com Análise reação nuclear

Nuclear reaction analysis (NRA) via the resonant 1H(15N,&#945;&#947;)12C reaction is a highly effective method of depth profiling that quantitatively and ...

Effect of Bending on the Electrical Characteristics of Flexible Organic Single Crystal-based Field-effect Transistors

The charge transport in an organic semiconductor depends highly on the molecular packing in the crystal, which influences the electronic coupling immensely. However, in soft electronics, in which organic semiconductors play a critical role, the devices will be bent or folded repeatedly. The effect of bending on the crystal packing and thus the charge transport is crucial to the performance of the device. In this manuscript, we describe the protocol to bend a single crystal of 5,7,12,16-tetrachloro-6,13-diazapentacene (TCDAP) in the field-effect transistor configuration and to obtain reproducible I-V characteristics upon bending the crystal. The results show that bending a field-effect transistor prepared on a flexible substrate results in nearly reversible yet opposite trends in charge mobility, depending on the bending direction. The mobility increases when the device is bent toward the top gate/dielectric layer (upward, compressive state) and decreases when bent toward the crystal/substrate side (downward, tensile state). The effect of bending curvature was also observed, with greater mobility change resulting from higher bending curvature. It is suggested that the intermolecular &#960;-&#960; distance changes upon bending, thereby influencing the electronic coupling and the subsequent carrier transport ability.

This manuscript describes the bending process of an organic single crystal-based field-effect transistor to maintain a functioning device for electronic property measurement. The results suggest that bending causes changes in the molecular spacing in the crystal and thus in the charge hopping rate, which is important in flexible electronics.

Efeito da flexão no Características elétricas dos transistores de efeito de campo baseados em cristal flexível Orgânico Um único

The charge transport in an organic semiconductor depends highly on the molecular packing in the crystal, which influences the electronic coupling ...

Experimental Implementation of a New Composite Fabrication Method: Exposing Bare Fibers on the Composite Surface by the Soft Layer Method

The bipolar plate is a key component in proton exchange membrane fuel cells (PEMFCs) and vanadium redox flow batteries (VRFBs). It is a multi-functional component that should have high electrical conductivity, high mechanical properties, and high productivity.
In this regard, a carbon fiber/epoxy resin composite can be an ideal material to replace the conventional graphite bipolar plate, which often leads to the catastrophic failure of the entire system because of its inherent brittleness. Though the carbon/epoxy composite has high mechanical properties and is easy to manufacture, the electrical conductivity in the through-thickness direction is poor because of the resin-rich layer that forms on its surface. Therefore, an expanded graphite coating was adopted to solve the electrical conductivity issue. However, the expanded graphite coating not only increases the manufacturing costs but also has poor mechanical properties.
In this study, a method to expose fibers on the composite surface is demonstrated. There are currently many methods that can expose fibers by surface treatment after the fabrication of the composite. This new method, however, does not require surface treatment because the fibers are exposed during the manufacture of the composite. By exposing bare carbon fibers on the surface, the electrical conductivity and mechanical strength of the composite are increased drastically.

A protocol to expose bare fibers on the composite surface by eliminating resin rich area is presented. The fibers are exposed during fabrication of the composites, not by the post surface treatment. The exposed carbon composites exhibit high electrical conductivity in the through-thickness direction and high mechanical property.

Implementação experimental de um novo método de fabricação de compósitos: expondo desencapadas fibras na superfície composta pelo método suave camada

The bipolar plate is a key component in proton exchange membrane fuel cells (PEMFCs) and vanadium redox flow batteries (VRFBs). It is a multi-functional ...