Yazarlar anodically dokulu alüminyum ustası ve İsviçre Federal Enerji Dairesi ve finansman için İsviçre Ulusal Bilim Vakfı için AFM, W. Lee ile yardım için M. Leboeuf ederim. Bu çalışmanın bir parçası FP7 proje hibe anlaşması hiçbir 283.501 kapsamında Avrupa Komisyonu tarafından finanse edilen &quot;Fast Track&quot; çerçevesinde yürütülmüştür.

1. Kalıp İmalatı Biz. Negatif kalıp aşağıdaki Ref imalatı için 6 bizim ev yapımı nanoimprinting kurulum kullanabilirsiniz, ancak herhangi bir alternatif nanoimprinting kurulum düzgün çalışmaz. Alternatif bir Fonksiyonlu polidimetilsiloksan (PDMS) kalıp da işe yarayabilir. <ol><li> Fabrikasyona veya aktarılacak nano desen taşıyan uygun bir usta satın. Prensip olarak, nanoimprinting için uygun herhangi bir ana iş yapacak. Biz yöntemini göstermek için bir ana yapı olarak 3.1 &#39;de açıklanan yatırılan bir cam levha üzerinde dokulu ZnO tabakası (Schott, AF32 eko, 41 mm x 41 mm x 0,5 mm) kullanın. </li><li> 2&#39;de tarif edildiği gibi, ana yapıya, bir anti-yapışkan tabakaya uygulanır. </li><li> 2 dakika daha için ultrasonik isopropanol banyosu ardından 2 dakika süreyle ultrasonik aseton banyosu içinde bir polietilen naphtalate (PEN) sac (Goodfellow, 82 mm x 41 mm x 0.125 mm) temizleyin. Izopropanol ile bir kez daha durulayın ve nitrojen ile kurutun. </li><li> Mevduat bir PEN kağıda Cr yapışma tabakası (5-10 nm) püskürtülür. </li><li> Spin-mont 5,000 rpm&#39;de PEN kağıda UV-kurutmalı reçine (Microresist, Ormoser, 1-2 ml) bir üniforma kapsama almak. </li><li> 80 sıcak bir plaka üzerinde 5 dakika boyunca bir prebake gerçekleştirin ° C çözücü buharlaşması, PEN sayfasına filmi tekdüzelik ve yapışma geliştirmek. </li><li> UV-kurutmalı reçine içine ana desen damga için nanoimprinting kurulum kullanın. Zorunlu olmamasına rağmen, biz esnek bir silikon membran üzerinde 1 bar homojen bir basınç uygulayarak balonu kapanımlar engellemek için vakum altında damgalama gerçekleştirin. Bizim kurulumunda, silikon membran iki alt-bölmeye vakum odasına ayırır. Alt bölme vakum altında kaldığı sürece basınç, havalandırma üst bölme tarafından oluşturulur. Havalandırma damgalama başlatan dibe doğru esnek membran iter. </li><li> Reçinenin çapraz bağlama reaksiyonu tetikleyen için UV ışığı ile reçine Açığa. Biz ılımlı bir ışık uygulamakçeşitli LED&#39;ler tarafından sağlanan 365 nm dalga boyunda 1.4 mW / cm 2 yoğunluğu. PEN sayfası aracılığıyla Pozlama süresi genellikle 15-20 dakikadır. </li><li> Dikkatlice elle ana yapısı kapalı kalıp soyulması ile demould. </li><li> Reçine ileri işleme önce ortam atmosferi ile bir fırında 6-8 saat boyunca soyma spontan, biz 150 hafif termal sonrası fırında gerçekleştirmek ° C yol açabilir fonksiyonel malzemenin depolanması sırasında hafif bir daralma, tabi olabilir gibi. </li></ol> 2. Anti-yapışma Katman Başarılı bir kalıptan çıkarma için, anti-yapışkan tabakaya malzeme ve kalıp pürüzlülük için adapte edilmelidir. Genellikle kaba desenleri düşük yapışma katsayıları gerektirir. Düz kalıpları düşük yapışma katsayısı kalıptan fonksiyonel materyal soyulma yol açabilir. Kaba desenler High yapışmasını katsayıları adheren olarak kalıp imalat sırasında PEN sayfasından reçine soyulmasına neden olabilirana reçine ce güçlüdür. <ol><li> Coat ile kalıp (veya ana) bir anti-yapışma ajan yapışma teşvik etmek krom tabakası (5-10 nm) püskürtülür. Pürüzsüz desenler için biz bu adımı bırakın. Bazı durumlarda krom tabaka etch ana yapı için anti-yapışma ajan önleyebilir. </li><li> Bir cam slayt üzerinde anti-yapışma ajan küçük bir damla (Sigma-Aldrich, (1H, 1H, 2H, 2H-Perfluoroctyl)-trichlorsilane) uygulanır. Bir vakum odasına kalıp ile birlikte cam slayt koyun ve aşağı pompalayınız. Anti-yapışma ajanı buharlaşması ve kalıp üzerinde moleküler tek tabaka olarak yatıracaktır. </li><li> 80, 1-2 saat boyunca tavlama ° C ile anti yapışma ajan Anchor </li></ol> 3. Malzeme Biriktirme Biz nanomoulding çok yönlülüğünü göstermek için burayı materyal birikimi için uygun üç depolama teknikleri göstermektedir. Diğer biriktirme yöntemleri de uygulanabilir olabilir. Üçüncü örnek fa açıklartam bir ince film silisyum güneş pili yağlanmalarına. <ol><li> Çinko oksit kimyasal buhar biriktirme (CVD): 180 ısıtıldı CVD reaktörün ısıtma plakası ° C üzerine kalıp koyun ZnO çökelimi esnasında PEN kalıp eğilmesini önlemek için metal bir çerçeve kullanın. Reaktör kapatın, aşağı pompalayınız ve termalizasyon sağlar. Öncü gazlar (H 2 O ve (C 2 H 5) 2 Zn) kabul et. Doping Ayrıca biz doz B 2 küçük miktarlarda H 6. ZnO tabakası kalınlığı çökelme süresi ile doğru orantılıdır. Biz ZnO tabakası tipik olarak 1-5 mikron kalınlıkta kullanın. Tipik depolanmaları parametreleri Detayları Ref bulunabilir. 7 </li><li> Fiziksel buhar biriktirme (PVD) / gümüş fışkırtması: PVD sistemi içine kalıp koyun. Sistemi kapatın ve aşağı pompalayınız. Argon süreç gazı itiraf. DC jeneratör açın. Ag tabaka kalınlığı tekrar çökelme süresi ile doğru orantılıdır. Biz Ag tabaka genellikle 1 mikron kalınlıkta kullanın. Tipik birikimi parameters 5.5x10 -3 mbar argon basıncı ve yaklaşık 45 nm / sn birikimi hızı verimli 250 W bir kurulum spesifik DC güç vardır. </li><li> Plazma destekli kimyasal buhar biriktirme (PE-CVD): 3.1 &#39;deki gibi Mevduat ZnO). 200 ısıtıldı PE-CVD reaktör ° C kalıp içine koyun Reaktör kapatın, aşağı pompalayınız ve termalizasyon sağlar. Öncü gazlar (SiH 4 ve H 2) kabul et. Buna ek olarak bu doz B küçük miktarlarda (CH3) 3 ve p-ve n-tipi katkılama elde etmek için pH 3. Güneş pillerinin açık devre gerilimi arttırmak için, biz de katkılı katmanları için CH 4 ve CO 2 küçük miktarlarda kullanın. 3.1 açıklandığı gibi pin amorf silikon güneş hücresi birikimi sonra, biz bir ZnO backcontact yatırmak. </li><li> Bükme tevdi tabaka sıyrılmasına sebep olabilir gibi, kalıp aşırı bükme kaçının. </li></ol> 4. Katmanı Aktarım Biz cam kullanımıNihai substrat olarak s slaytlar (Schott AF32 eko, 41 mm x 41 mm x 0,5 mm). Ancak, metal folyo ya da polimer levhalar dahil olmak üzere, diğer substratlar, alternatif olarak kullanılabilir. <ol><li> Aseton ve izopropanol ve azot ile kuru darbe ile temizleyin cam slaytlar. </li><li> 5,000 rpm&#39;de cam slayt üzerine Spin-kat UV-kurutmalı reçine (Microresist, Ormoser, 1-2 ml). </li><li> Nihai yüzeye yatırılan katmanları taşıyan kalıp demirlemek için nanoimprinting kurulum kullanın. Damgalama gelince, biz 1 bar homojen bir basınç uygulayarak vakum altında ankraj gerçekleştirin. </li><li> Çapraz bağlama reaksiyonu kışkırtmak için UV ışığa reçine Açığa. Biz birkaç LED&#39;ler tarafından sağlanan 365 nm dalga boyunda 1.4 mW / cm 2 &#39;nin orta şiddette uygulayabilirsiniz. Cam slayt aracılığıyla Pozlama süresi PEN ile karşılaştırıldığında cam yüksek UV iletimi nedeniyle sadece 1-3 dk. </li><li> El cam slayt kapalı kalıp soyulması ile Demould. </li></ol> 5. Numune Karakterizasyonu <ol&gt; <li> Nanomoulded örnekleri karakterize etmek için en sevdiğiniz morfolojik, elektriksel veya optik tekniği kullanın. Burada taramalı elektron mikroskobu (SEM) ve atomik kuvvet mikroskobu (AFM) kullanarak bizim nanomoulded örnekleri karakterize. </li></ol>

<ol>
	<li>Geissler, M., Xia, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Patterning:+Principles+and+Some+New+Developments.">Patterning: Principles and Some New Developments.</a> Advanced Materials. 16 (15), 1249-1269 (2004).</li><li>Guo, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanoimprint+Lithography:+Methods+and+Material+Requirements.">Nanoimprint Lithography: Methods and Material Requirements.</a> Advanced Materials. 19, 495-513 (2007).</li><li>Ahn, S. H., Guo, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Large-Area+Roll-to-Roll+and+Roll-to-Plate+Nanoimprint+Lithography:+A+Step+toward+High-Throughput.">Large-Area Roll-to-Roll and Roll-to-Plate Nanoimprint Lithography: A Step toward High-Throughput.</a> Application of Continuous Nanoimprinting. ACS Nano. 3 (8), 2304-2310 (2009).</li><li>Battaglia, C., Escarr&#233;, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanoimprint+Lithography+for+High-Efficiency+Thin-Film+Silicon+Solar+Cells.">Nanoimprint Lithography for High-Efficiency Thin-Film Silicon Solar Cells.</a> Nano Letters. 11, 661-665 (2011).</li><li>Battaglia, C., Escarr&#233;, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanomoulding+of+Transparent+Zinc+Oxide+Electrodes+for+Efficient+Light+Trapping+in+Solar+Cells.">Nanomoulding of Transparent Zinc Oxide Electrodes for Efficient Light Trapping in Solar Cells.</a> Nature Photonics. 5, 535-538 (2012).</li><li>Escarr&#233;, J., S&#246;derstr&#246;m, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+Fidelity+Transfer+of+Nanometric+Random+Textures+by+UV+Embossing+for+Thin+Film+Solar+Cells+Applications.">High Fidelity Transfer of Nanometric Random Textures by UV Embossing for Thin Film Solar Cells Applications.</a> Solar Energy Materials &amp; Solar Cells. 95, 881-886 (2011).</li><li>Fa&#255;, S., Feitknecht, L., Schl&#252;chter, R., Kroll, U., Vallat-Sauvain, E., Shah, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rough+ZnO+layers+by+LP-CVD+process+and+their+effect+in+improving+performances+of+amorphous+and+microcrystalline+silicon+solar+cells.">Rough ZnO layers by LP-CVD process and their effect in improving performances of amorphous and microcrystalline silicon solar cells.</a> Solar Energy Materials and Solar Cells. 90, 2960-2967 (2006).</li><li>Zhao, X. -. M., Xia, Y., Whitesides, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+of+Three-Dimensional+Micro-Structures:+Microtransfer+Molding.">Fabrication of Three-Dimensional Micro-Structures: Microtransfer Molding.</a> Advanced Materials. 8, 837-840 (1996).</li><li>Hampton, M. J., Williams, S. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Patterning+of+Sub-500+nm+Inorganic+Oxide+Structures.">The Patterning of Sub-500 nm Inorganic Oxide Structures.</a> Advanced Materials. 20, 2667-2673 (2008).</li><li>Bass, J. D., Schaper, C. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transfer+Molding+of+Nanoscale+Oxides+Using+Water-Soluble+Templates.">Transfer Molding of Nanoscale Oxides Using Water-Soluble Templates.</a> ACS Nano. 5 (5), 4065-4072 (2011).</li><li>Escarr&#233;, J., Nicolay, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanomoulded+front+ZnO+contacts+for+thin+film+silicon+solar+cell+applications.">Nanomoulded front ZnO contacts for thin film silicon solar cell applications.</a> , (2012).</li><li>Sontheimer, T., Rudigier-Voigt, E., Bockmeyer, M., Klimm, C., Schubert-Bischoff, P., Becker, C., Rech, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Large-area+fabrication+of+equidistant+free-standing+Si+crystals+on+nanoimprinted+glass.">Large-area fabrication of equidistant free-standing Si crystals on nanoimprinted glass.</a> Phys. Status Solidi. RRL. 5, 376-379 (2011).</li></ol>

Çıkar çatışması ilan etti.

Nanomoulding keyfi fonksiyonel malzemeler üzerinde nanopatterns de transferini sağlar. Şekil 1 ve 2 içinde her bir işlem adımları karşılaştırılması nanomoulding ve nanoimprinting arasındaki yakın ilişki ortaya çıkmaktadır. Nanomoulding ve nanoimprinting arasındaki en önemli fark Şekil 2e yılında ek malzeme biriktirme adımdır. Kalan işlem akışı aynıdır. Nanomoulding bu nedenle herhangi bir müsait nanoimprinting kurulum üzerinde gerçekle...

Nanopatterning nanoteknoloji ve uygulamalı bilimlerin birçok alanında büyük önem kazanmıştır. Desen nesil ilk adımdır ve bu tür Nanokürecikli litografi veya blok kopolimer litografi 1 olarak öz-montaj yöntemleri dayalı elektron demeti litografi veya aşağıdan-yukarıya yaklaşımlar olarak yukarıdan-aşağı yaklaşımlarla gerçekleştirilebilir. Desen üretimi kadar önemli desen çoğaltma. Fotolitografi Ayrıca nanoimprinting (Şekil 1) düşük maliyetli 2-4 high-throughput büyük alanlı nano desenleme için uygun özellikle umut verici bir alternatif olarak ortaya çıkmıştır. Fotolitografi desenli bir maske gerektirir iken, nanoimprinting bir prefabrik ana yapıya dayanır. Dan Model ana aktarma genellikle bir termoplastik ya da bir UV-ya da termal olarak iyileştirilebilir polimer içine yapılır. Bu doğrudan doğruya fonksiyonel bir malzeme üzerine transfer etmek için arzu edilen bir model olduğu Ancak pek çok durumda bulunmaktadır. &lt;p class = &quot;jove_content&quot;&gt; Burada nanomoulding ve biz son zamanlarda Ref tanıtılan tabaka transferi (Şekil 2) dayalı bir çoğaltma yöntemi açıklar. 5 fonksiyonel çinko oksit elektrot üzerine nano desenleri aktarmak için. Bir nanoimprinting kurulumu varsa Bizim nanomoulding yöntem kolaylıkla uygulanabilir. Nanomoulding kalıp malzemesi bu madde birikimi süreç (ler) ile uyumlu olduğu gibi seçilmiş olması koşuluyla, diğer birçok fonksiyonel malzemeler, malzeme yığınları ve hatta tam cihazlara jeneralize olma potansiyeline sahiptir. Bir örnek olarak biz burada 5 güneş hücreleri ışık yakalayıcı geliştirmek için kendi uygulama bulmak kimyasal buhar biriktirme (CVD) tarafından tevdi saydam iletken çinko oksit (ZnO) elektrotlar nanomoulding sunuyoruz.

<table border="1"><tbody><tr><td> Reaktif Adı </td><td> Şirket </td><td> Katalog Numarası </td><td> Yorumlar (isteğe bağlı) </td></tr><tr><td> Nanoimprinting reçine </td><td> Microresist </td><td> Ormostamp </td><td></td></tr><tr><td> (1H, 1H, 2H, 2H-Perfluoroctyl)-trichlorsilane, anti-yapışma ajan </td><td> Sigma Aldrich </td><td> 448931-10G </td><td></td></tr><tr><td> Cam slayt </td><td> Schott </td><td> AF32 eko </td><td> 0.5 mm </td></tr><tr><td> Polietilen naphtalate (PEN) yaprak </td><td> Goodfellow </td><td> ES361090 </td><td> 0,125 mm </td></tr><tr><td> (C 2 H 5) 2 Zn </td><td> Akzo Nobel </td><td></td><td></td></tr><tr><td> Ag hedef 4N sputter </td><td> Heraeus </td><td> 81062165 </td><td></td></tr><tr><td> B 2 H 6, SiH 4, 2 H, B (CH3) 3, PH 3, 4 CH, CO 2 </td><td> Messer </td><td></td><td></td></tr><tr><td></td><td></td><td></td><td> EKİPMAN </td></tr><tr><td> Sistemi Nanoimprinting </td><td> Ev- </td><td></td><td></td></tr><tr><td> LP-CVD sistemi </td><td> Ev- </td><td></td><td></td></tr><tr><td> PVD sistemi </td><td> Leybold </td><td> Univex 450 B </td><td></td></tr><tr><td> PE-CVD reaktör </td><td> Indeotec </td><td> Ahtapot I </td><td></td></tr><tr><td> SEM </td><td> JEOL </td><td> JSM-7500 TFE </td><td></td></tr><tr><td> AFM </td><td> Dijital Aletler </td><td> NanoScope 3100 </td><td></td></tr></tbody></table>

nanomoulding of functional materials, a versatile complementary pattern replication method to nanoimprinting

Biz fonksiyonel malzemeler, malzeme yığınları ve tam cihazların düşük maliyetli nano desenleme sağlayan bir nanomoulding tekniği tarif. Tabaka ile birleştirilmiş transferi Nanomoulding fonksiyonel materyal üzerine bir ana yapısı isteğe bağlı yüzey desenleri çoğaltma sağlar. Nanomoulding herhangi nanoimprinting kurulum üzerinde gerçekleştirilebilir ve malzemeler ve çökelme süreçleri geniş bir aralığı için uygulanabilir. Özellikle biz güneş hücreleri ışık yakalama uygulamaları için desenli şeffaf çinko oksit elektrot fabrikasyonu göstermektedir.

<html> Şekil 3, nanomoulded yapıların açıklayıcı örnekler özetlenmiştir. Camına KVH tarafından yetiştirilen bir ZnO ana yapısı (a) &#39;da gösterilmiştir. Karşılık gelen nanomoulded ZnO kopya (d) &#39;de gösterilmiştir. Yerel yüksekliği (g) ve AFM görüntüleri elde açısı (j) histogramlar Karşılaştırılması nanomoulding sürecinin yüksek sadakat göstermektedir. Benzeri sonuçlar girişime litografi (b, e, h, k) ve anodically dokulu alüminyum (c, f, i, l) tarafından uy...

Watch this Scientific Journal Video about Nanomoulding of Functional Materials, a Versatile Complementary Pattern Replication Method to Nanoimprinting at JoVE.com

Nanomoulding of Functional Materials, a Versatile Complementary Pattern Replication Method to Nanoimprinting

Biz fonksiyonel malzemeler, malzeme yığınları ve tam cihazların düşük maliyetli nano desenleme sağlayan bir nanomoulding tekniği tarif. Nanomoulding herhangi nanoimprinting kurulum üzerinde gerçekleştirilebilir ve malzemeler ve çökelme süreçleri geniş bir aralığı için uygulanabilir.

Fonksiyonel Malzemelerin Nanomoulding, Nanoimprinting bir yönlü Tamamlayıcı Desen Çoğaltma Yöntemi

We describe a nanomoulding technique which  allows low-cost nanoscale patterning of functional materials, materials stacks  and full devices. Nanomoulding ...

nanomoulding-functional-materials-versatile-complementary-pattern

Research

JoVE Journal

Engineering

11.6K Görüntüleme.  Ecole Polytechnique Fédérale de Lausanne (EPFL). Biz fonksiyonel malzemeler, malzeme yığınları ve tam cihazların düşük maliyetli nano desenleme sağlayan bir nanomoulding tekniği tarif. Nanomoulding herhangi nanoimprinting kurulum üzerinde gerçekleştirilebilir ve malzemeler ve çökelme süreçleri geniş bir aralığı için uygulanabilir.

Video: Nanomoulding of Functional Materials, a Versatile Complementary Pattern Replication Method to Nanoimprinting

Using Neutron Spin Echo Resolved Grazing Incidence Scattering to Investigate Organic Solar Cell Materials

The spin echo resolved grazing incidence scattering (SERGIS) technique has been used to probe the length-scales associated with irregularly shaped crystallites. Neutrons are passed through two well defined regions of magnetic field; one before and one after the sample. The two magnetic field regions have opposite polarity and are tuned such that neutrons travelling through both regions, without being perturbed, will undergo the same number of precessions in opposing directions. In this case the neutron precession in the second arm is said to &#34;echo&#34; the first, and the original polarization of the beam is preserved. If the neutron interacts with a sample and scatters elastically the path through the second arm is not the same as the first and the original polarization is not recovered. Depolarization of the neutron beam is a highly sensitive probe at very small angles (&#60;50&#160;&#956;rad) but still allows a high intensity, divergent beam to be used. The decrease in polarization of the beam reflected from the sample as compared to that from the reference sample can be directly related to structure within the sample.
In comparison to scattering observed in neutron reflection measurements the SERGIS signals are often weak and are unlikely to be observed if the in-plane structures within the sample under investigation are dilute, disordered, small in size and polydisperse or the neutron scattering contrast is low. Therefore, good results will most likely be obtained using the SERGIS technique if the sample being measured consist of thin films on a flat substrate and contain scattering features that contains a high density of moderately sized features (30 nm to 5 &#181;m) which scatter neutrons strongly or the features are arranged on a lattice. An advantage of the SERGIS technique is that it can probe structures in the plane of the sample.

Progress has been made in utilizing spin echo resolved grazing incidence scattering (SERGIS) as a neutron scattering technique to probe the length-scales in irregular samples. Crystallites of [6,6]-phenyl-C61-butyric acid methyl ester have been probed using the SERGIS technique and the results confirmed by optical and atomic force microscopy.

Nötron Spin Echo'nun Kullanılması, Organik Güneş Hücresi Malzemelerini Araştırmak İçin Otlatma İnsidansını Dağıtmayı Çözdü

The spin echo resolved grazing incidence scattering (SERGIS) technique has been used to probe the length-scales associated with irregularly shaped ...

Mühendislik

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

Metal foams are interesting materials from both a fundamental understanding and practical applications point of view. Uses have been proposed, and in many cases validated experimentally, for light weight or impact energy absorbing structures, as high surface area heat exchangers or electrodes, as implants to the body, and many more. Although great progress has been made in understanding their structure-properties relationships, the large number of different processing techniques, each producing material with different characteristics and structure, means that understanding of the individual effects of all aspects of structure is not complete. The replication process, where molten metal is infiltrated between grains of a removable preform material, allows a markedly high degree of control and has been used to good effect to elucidate some of these relationships. Nevertheless, the process has many steps that are dependent on individual &#8220;know-how&#8221;, and this paper aims to provide a detailed description of all stages of one embodiment of this processing method, using materials and equipment that would be relatively easy to set up in a research environment. The goal of this protocol and its variants is to produce metal foams in an effective and simple way, giving the possibility to tailor the outcome of the samples by modifying certain steps within the process. By following this, open cell aluminum foams with pore sizes of 1&#8211;2.36 mm diameter and 61% to 77% porosity can be obtained.

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.

Çoğaltma Tekniği açın Hücre Alüminyum Köpüklerin Üretimi ve Porosity&#39;sinden Üzerindeki Etki için Protokolleri Döküm

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

Preparation and Reactivity of Gasless Nanostructured Energetic Materials

High-Energy Ball Milling (HEBM) is a ball milling process where a powder mixture placed in the ball mill is subjected to high-energy collisions from the balls. Among other applications, it is a versatile technique that allows for effective preparation of gasless reactive nanostructured materials with high energy density per volume (Ni+Al, Ta+C, Ti+C). The structural transformations of reactive media, which take place during HEBM, define the reaction mechanism in the produced energetic&#160;composites. Varying the processing conditions permits fine tuning of the milling-induced microstructures of the fabricated composite particles. In turn, the reactivity, i.e., self-ignition temperature, ignition delay time, as well as reaction kinetics, of high energy density materials depends on its microstructure. Analysis of the milling-induced microstructures suggests that the formation of fresh oxygen-free intimate high surface area contacts between the reagents is responsible for the enhancement of their reactivity. This manifests itself in a reduction of ignition temperature and delay time, an increased rate of chemical reaction, and an overall decrease of the effective activation energy of the reaction. The protocol provides a detailed description for the preparation of reactive nanocomposites with tailored microstructure using short-term HEBM method. It also describes a high-speed thermal imaging technique to determine the ignition/combustion characteristics of the energetic materials. The protocol can be adapted to preparation and characterization of a variety of nanostructured energetic composites.

This protocol describes the preparation of gasless nanostructured energetic materials (Ni+Al, Ta+C, Ti+C) using the short-term high-energy ball milling (HEBM) technique. It also describes a high-speed thermal imaging method to study the reactivity of mechanically fabricated nanocomposites. These protocols can be extended to other reactive nanostructured energetic materials.

Hazırlık ve Gazsız nanoyapılı reaktivitesi Enerjik Malzemeler

High-Energy Ball Milling (HEBM) is a ball milling process where a powder mixture placed in the ball mill is subjected to high-energy collisions from the ...

Synthesis and Functionalization of 3D Nano-graphene Materials: Graphene Aerogels and Graphene Macro Assemblies

Efforts to assemble graphene into three-dimensional monolithic structures have been hampered by the high cost and poor processability of graphene. Additionally, most reported graphene assemblies are held together through physical interactions (e.g., van der Waals forces) rather than chemical bonds, which limit their mechanical strength and conductivity. This video method details recently developed strategies to fabricate mass-producible, graphene-based bulk materials derived from either polymer foams or single layer graphene oxide. These materials consist primarily of individual graphene sheets connected through covalently bound carbon linkers. They maintain the favorable properties of graphene such as high surface area and high electrical and thermal conductivity, combined with tunable pore morphology and exceptional mechanical strength and elasticity. This flexible synthetic method can be extended to the fabrication of polymer/carbon nanotube (CNT) and polymer/graphene oxide (GO) composite materials. Furthermore, additional post-synthetic functionalization with anthraquinone is described, which enables a dramatic increase in charge storage performance in supercapacitor applications.

This video method describes the synthesis of high surface area, monolithic 3D graphene-based materials derived from polymer precursors as well as single layer graphene oxide.

Sentezi ve 3D Nano-grafen Malzemelerin fonksiyonalizasyonu: Grafen Aerogels ve Graphene Makro Meclisleri

Efforts to assemble graphene into three-dimensional monolithic structures have been hampered by the high cost and poor processability of graphene. ...

Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials

Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film synthesis) for the purpose of exploratory materials research. Certain materials pose a challenge wherein the traditional bulk Hall bar device fabrication method is insufficient to produce a measureable device for sample transport measurement, principally because the single crystal size is too small to attach wire leads to the sample in a Hall bar configuration. This can be, for example, because the first batch of a new material synthesized yields very small single crystals or because flakes of samples of one to very few monolayers are desired. In order to enable rapid characterization of materials that may be carried out in parallel with improvements to their growth methodology, a method of device fabrication for very small samples has been devised to permit the characterization of novel materials as soon as a preliminary batch has been produced. A slight variation of this methodology is applicable to producing devices using exfoliated samples of two-dimensional materials such as graphene, hexagonal boron nitride (hBN), and transition metal dichalcogenides (TMDs), as well as multilayer heterostructures of such materials. Here we present detailed protocols for the experimental device fabrication of fragments and flakes of novel materials with micron-sized dimensions onto substrate and subsequent measurement in a commercial superconducting magnet, dry helium close-cycle cryostat magnetotransport system at temperatures down to 0.300 K and magnetic fields up to 12 T.

We describe the methodology of mechanical exfoliation and deposition of flakes of novel materials with micron-sized dimensions onto substrate, fabrication of experimental device structures for transport experimentation, and the magnetotransport measurement in a dry helium close-cycle cryostat at temperatures down to 0.300 K and magnetic fields up to 12 T.

Yeni Malzemelerin Düşük sıcaklık Magnetotransport Ölçüm İleri Deneysel Yöntemler

Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film ...

Standardized Method for Measuring Collection Efficiency from Wipe-sampling of Trace Explosives

One of the limiting steps to detecting traces of explosives at screening venues is effective collection of the sample. Wipe-sampling is the most common procedure for collecting traces of explosives, and standardized measurements of collection efficiency are needed to evaluate and optimize sampling protocols. The approach described here is designed to provide this measurement infrastructure, and controls most of the factors known to be relevant to wipe-sampling. Three critical factors (the applied force, travel distance, and travel speed) are controlled using an automated device. Test surfaces are chosen based on similarity to the screening environment, and the wipes can be made from any material considered for use in wipe-sampling. Particle samples of the explosive 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) are applied in a fixed location on the surface using a dry-transfer technique. The particle samples, recently developed to simulate residues made after handling explosives, are produced by inkjet printing of RDX solutions onto polytetrafluoroethylene (PTFE) substrates. Collection efficiency is measured by extracting collected explosive from the wipe, and then related to critical sampling factors and the selection of wipe material and test surface. These measurements are meant to guide the development of sampling protocols at screening venues, where speed and throughput are primary considerations.

Optimized sampling protocols and the development of new wipe materials can be facilitated by standardized measurements of collection efficiency from wipe-sampling. Our approach for sampling trace explosives uses an automated device to control speed, force, and distance during wipe-sampling followed by extraction of collected explosives.

İz Patlayıcı Wipe-örneklemenin toplama verimi ölçümü için standart yöntem

One of the limiting steps to detecting traces of explosives at screening venues is effective collection of the sample. Wipe-sampling is the most common ...

A Novel Method for In Situ Electromechanical Characterization of Nanoscale Specimens

Electrically assisted deformation (EAD) is increasingly being used to improve the formability of metals during processes such as sheet metal rolling and forging. Adoption of this technique is proceeding despite disagreement concerning the underlying mechanism responsible for EAD. The experimental procedure described herein enables a more explicit study compared to previous EAD research by removing thermal effects, which are responsible for disagreement in interpreting previous EAD results. Furthermore, as the procedure described here enables EAD observation in situ and in real time in a transmission electron microscope (TEM), it is superior to existing post-mortem methods that observe EAD effects post-test. Test samples consist of a single crystal copper (SCC) foil having a free-standing tensile test section of nanoscale thickness, fabricated using a combination of laser and ion beam milling. The SCC is mounted to an etched silicon base that provides mechanical support and electrical isolation while serving as a heat sink. Using this geometry, even at high current density (~3,500 A/mm2), the test section experiences a negligible temperature increase (&#60;0.02 &#176;C), thus eliminating Joule heating effects. Monitoring material deformation and identifying the corresponding changes to microstructures, e.g. dislocations, are accomplished by acquiring and analyzing a series of TEM images. Our sample preparation and in situ experiment procedures are robust and versatile as they can be readily utilized to test materials with different microstructures, e.g., single and polycrystalline copper.

A Novel Method for In Situ Electromechanical Characterization of Nanoscale Specimens

Isolating electrical and thermal effects on electrically assisted deformation (EAD) is very difficult using macroscopic samples. Metallic sample micro- and nanostructures together with a custom test procedure have been developed to evaluate the impact of applied current on the formation without joule heating and evolution of dislocations on these samples.

Için yeni bir yöntem<em&gt; Yerinde</emNanoscale Örneklerinin Elektromekanik Karakterizasyonu

Electrically assisted deformation (EAD) is increasingly being used to improve the formability of metals during processes such as sheet metal rolling and ...

A Fabrication and Measurement Method for a Flexible Ferroelectric Element Based on Van Der Waals Heteroepitaxy

Flexible non-volatile memories have received much attention as they are applicable for portable smart electronic device in the future, relying on high-density data storage and low-power consumption capabilities. However, the high-quality oxide based nonvolatile memory on flexible substrates is often constrained by the material characteristics and the inevitable high-temperature fabrication process. In this paper, a protocol is proposed to directly grow an epitaxial yet flexible lead zirconium titanate memory element on muscovite mica. The versatile deposition technique and measurement method enable the fabrication of flexible yet single-crystalline non-volatile memory elements necessary for the next generation of smart devices.

In this paper, we present a protocol to directly grow an epitaxial yet flexible lead zirconium titanate memory element on muscovite mica.

Bir imalat ve Van Der Waals Heteroepitaxy dayanan esnek bir Ferroelectric öğesi için ölçüm yöntemi

Flexible non-volatile memories have received much attention as they are applicable for portable smart electronic device in the future, relying on ...

Multiscale Structures Aggregated by Imprinted Nanofibers for Functional Surfaces

Multiscale surface structures have attracted increasing interest owing to several potential applications in surface devices. However, an existing challenge in the field is the fabrication of hybrid micro-nano structures using a facile, cost-effective, and high-throughput method. To overcome these challenges, this paper proposes a protocol to fabricate multiscale structures using only an imprint process with an anodic aluminum oxide (AAO) filter and an evaporative self-aggregation process of nanofibers. Unlike previous attempts that have aimed to straighten nanofibers, we demonstrate a unique fabrication method for multiscale aggregated nanofibers with high aspect ratios. Furthermore, the surface morphology and wettability of these structures on various liquids were investigated to facilitate their use in multifunctional surfaces.

Presented is an easy method to fabricate nano-micro multiscale structures, for functional surfaces, by aggregating nanofibers fabricated using an anodic aluminum oxide filter.

Fonksiyonel yüzeyler için baskılı Nanofibers tarafından toplanan multiscale yapıları

Multiscale surface structures have attracted increasing interest owing to several potential applications in surface devices. However, an existing ...

Studying Large Amplitude Oscillatory Shear Response of Soft Materials

We investigate the sequence of physical processes exhibited during large amplitude oscillatory shearing (LAOS) of polyethylene oxide (PEO) in dimethyl sulfoxide (DMSO) and xanthan gum in water &#8212; two concentrated polymer solutions used as viscosifiers in foods, enhanced oil recovery, and soil remediation. Understanding the nonlinear rheological behavior of soft materials is important in the design and controlled manufacturing of many consumer products. It is shown how the response to LAOS of these polymer solutions can be interpreted in terms of a clear transition from linear viscoelasticity to viscoplastic deformation and back again during a period. The LAOS results are analyzed via the fully quantitative Sequence of Physical Processes (SPP) technique, using free MATLAB-based software. A detailed protocol of performing a LAOS measurement with a commercial rheometer, analyzing nonlinear stress responses with the freeware, and interpreting physical processes under LAOS is presented. It is further shown that, within the SPP framework, a LAOS response contains information regarding the linear viscoelasticity, the transient flow curves, and the critical strain responsible for the onset of nonlinearity.

We present a detailed protocol outlining how to perform nonlinear oscillatory shear rheology on soft materials, and how to run the SPP-LAOS analysis to understand the responses as a sequence of physical processes.

Büyük genlik salınım kesme yanıt yumuşak malzeme eğitim

We investigate the sequence of physical processes exhibited during large amplitude oscillatory shearing (LAOS) of polyethylene oxide (PEO) in dimethyl ...