Bu çalışma Kimya Bölümü&#39;nden ve Araştırma Dairesi (RCAP 13-8032) iç destek de dahil olmak üzere Fen ve Mühendislik, Batı Kentucky Üniversitesi Ogden Koleji tarafından desteklenmiştir. WKU Mikroskopi Tesisi Dr. John Andersland (SEM görüntüleri) ve Yanma Bilimi ve Mühendisliği (BET analizleri) için WKU Enstitüsü Doçent Yan Cao yardımı bu işi yürütmek için merkezi olmuştur.

Emülsiyon hazırlanması 1. <ol><li> Emülsiyon İçerik <ol><li> Kütle tuzunun, uygun bir miktar 0,03-M çözelti 10 ml üretmek. Platin (IV) klorür ölçüsü 0,101 g, çinko (II) klorid (ZnCl2) ölçüsü 0,032 g ve sodyum klorür (NaCl) ölçüsü 0,018 g için. </li><li> Ayrı ayrı test tüpleri içinde, DI 10 ml su her bir tuzu çözülür. Daha sonra kullanmak üzere bir kenara koyun. </li><li> Bu işlem boyunca içeriği için bir 20-ml kapatılabilir Cam şişe kullanın. Cam şişeye bir denge Dara. </li><li> Yavaş bir karıştırma çubuğu tekrar sıfırlanmış ölçekte dinlenme bir cam şişe içine dökülerek, vinil-sonlu polidimetilsiloksan tartılır. (1,080 ml eşdeğer) 1.02 g tartılır. NOT: Bu polimerin yüksek viskoziteli pipetleme uygulanamaz hale getirir. </li><li> Pipet şişeye n-Heptan 1,02 mi. Şişeye iyonik olmayan yüzey aktif madde (sorbitan monooleat olabilir) 2 damla ekleyin. Pipet tuzu çözeltisinin 0,3 ml şişeye DI su 0.45 ml. </li><li> Sıkıca kapağı vidalama cam şişe Seal. Sonikasyon başlamadan önce emülsiyon başlatmak için 60 saniye boyunca kuvvetlice çalkalayın. </li></ol></li><li> Su banyosu Sonikatör Aparatı İnşaatı <ol><li> Minimum doldurma çizgisine kadar su ile sonikatör doldurun. 400 ml&#39;lik bir deney şişesine musluk suyu 250 ml ilave edilir. Su seviyesi sadece RIM böylece buz ile 400 ml beher doldurun. </li><li> Su banyosu sonikatör içinde bu behere koyun. Sonikatöre dolgu hattı, gerekirse ayarlama edin. Bir halka su banyosu sonikatör hemen yanında durmak yerleştirin. </li><li> Bir kol dışarı uzatılmış, böylece iki yüzük, kelepçeler durmak onları konumlandırmak kullanarak, halka dik durmak ve buzlu su ile dolu beher içine aşağıya bakacak şekilde diğeri su banyosu doğru uzatılır. Sıcaklık sonikasyon boyunca izlenebilir ve böylece halka bir kelepçe aşağı 400 ml&#39;lik bir behere bir termometre ile öne takın. </li></ol></li><li> Emülsiyonlaştırıcılarication Prosedürü <ol><li> Tam beher içine çıkıntı yapan ve kelepçe içine sabitleyerek 400 ml&#39;lik bir behere daldırılır ve böylece emülsiyon ihtiva eden şişe yerleştirin. </li><li> PDMS karışımı içeren cam şişe sürtünmeden kaynaklanan ısının ortadan kaldırmak için beherin tarafları dokunmadan olmadığından emin olun. </li><li> Sonikatöre açın ve 7 dakika sonication süresini ayarlayın. Emülsiyon ait ısıya karşı hassas olduğundan, beher içinde sıcaklığı 0 ° C ila 5 sonikasyon boyunca olduğundan emin olun. Beher içindeki sıcaklık arzu edilir bir kez sonikasyon başlatın. </li><li> Sonikasyon 7 dakika sonra, emülsiyon içindeki oluşturacağı kümeleri ortadan kaldırmak için şişenin üst tutarak 1 dakika / girdap yavaşça çalkalayın flakon kaldırıp. </li><li> Beher içeriğinin atınız. 250 ml su ilave ediniz ve 1 cm mesafede olan dolgu beherin üstünü buz eklenir. </li><li> Geri kelepçe flakon yerleştirin. Resum buz su altında daldırın7 dakika için sonikasyon e. </li><li> Yineleyin sekiz, 7 dakikalık sonication dönemleri olmak üzere toplam 1.3.6 için 1.3.3 adımları veya sonikasyon homojen görünüyor ve hiçbir kümeleri mevcut olana kadar. Oda sıcaklığında saklayın. Not: emülsiyonlaştırıcı birkaç gün stabil olması gerekir, ama homojen görünene kadar 7 dakikalık aralıklarla yukarıda sonikasyon ile geri kazanılabilir. Oda sıcaklığında saklayın. </li></ol></li></ol> 2. Çapraz bağlama <ol><li> Trietoksisilan / yüzey aktif madde çözeltisinin eklenmesi için kurulum <ol><li> Pipet 5.4 ml bir test tüpüne trietoksisilan. Daha sonra kullanılmak üzere kaputun altında bir test tüpü rafta yerleştirin. </li><li> Buzlu su ile 400 ml&#39;lik beher doldurun ve kaputun altına yerleştirin. Sonraki halka bağlı bir kelepçe ile ayakta 400 ml beher yere, beher açılması üzerine doğrudan genişletilmiş. Bu trietoksisilan eklenmesi için buz banyosu olacaktır. </li><li> Halka destekle diğer tarafında bir sıcak plaka koyun. Yaklaşık 700 ml ile 800 ml beher doldurunmusluk suyu. Sıcak plaka üzerine yerleştirin. </li><li> Sıcak plaka açın ve 800 ml&#39;lik bir behere içinde 85 ° C 75 bir sıcaklığı muhafaza. 800 ml&#39;lik bir cam içindeki suyun sıcaklığının izlenebilir bir halka stand bir termometre ile bir kelepçe takın. </li><li> Su 375 ml (4,62 mM) sodyum dodesil sülfat 0.5 g çözülmesiyle yüzey aktif madde çözeltisi üretir. Temiz, boş test tüpüne yüzey aktif madde solüsyonu, yaklaşık 10 ml ekleyin. </li><li> Halka başka kelepçe yüzey test tüpü ile kaputun altında durmak takın sıvı seviyesi 800 ml beher içine su yüzeyinin altında olduğu gibi güvenli. Termal dengeleme için 10 dakika bekleyin. </li><li> Filtre kağıdı parçası ıslatın ve küçük bir huninin üst yerleştirin. 250 ml&#39;lik bir Erlenmeyer balon içerisinde huninin Vidalı mil ve başlık altında balon yerleştirin. </li></ol></li><li> Trietoksisilan ilavesi <ol><li> Buzlu su gaga üzerinde kelepçe emülsiyon flakon yerleştirinkaput içinde er. Kavanozun içeriği, su yüzeyinin altında, böylece kelepçe PDMS karışımı yerleştirin. Trietoksisilan eklenmesi ekzotermik bir reaksiyonun neden olur, bu yüzden emülsiyon yapısını korumak için soğuk tutulmalıdır. </li><li> Gaz birikmesini önlemek için cam şişeye kapağını çıkarın. </li><li> Yavaşça yaklaşık 10 sn (yaklaşık 0.5 ml / sn) bir süre boyunca sürekli bir akış içinde bir cam şişe içine tüp içeren trietoksisilan dökün. DİKKAT: trietoksisilan eklenmesi ekzotermik bir reaksiyonun ve kostik hidrojen klorür (HCl) gazın serbest başlatır. Flakon son derece sıcak olacak ve zehirli bir gaz karışımından gelişecektir. Trietoksisilan eklerken içeriğini KARISTIR ETMEYİN. </li><li> Bir ısı koruyucu eldiven giyerek tamamen trietoksisilan ekledikten sonra, yavaşça cam karıştırma çubuğu ile içeriği karıştırın. 2 dakika süreyle veya tüpten gelişen gaz durana kadar bekleyin. </li><li> Follçapraz bağlantı sayesinde, numune görünür hiç bir faz ayrılması bulunmaktadır. Kümeleri varsa, şişeyi mühür ve kapakla şişeyi tutarken 20 saniye boyunca titizlikle çalkalayın. </li></ol></li><li> Boncuk üretimi <ol><li> Cam şişeye gelen çapraz bağlı emülsiyonu çizmek için temiz, cam Pasteur pipet kullanın. Damla damla test tüpü damlalar arasında mümkün olduğu kadar az zaman alması için (75 ve 85 ° C arasında muhafaza edilmelidir) yüzey aktif madde çözeltisine çapraz bağlanmış emülsiyonu ekleyin. </li><li> 30 sn emülsiyon ilave edildikten sonra 1 dakika için katı bir test tüpüne içinde oluşmaya başlar olarak, yüzey aktif madde çözeltisi yavaş yavaş gazı ortaya başlayacaktır. </li><li> Isı koruyucu eldiven giyerek, kelepçe dışında deney tüpünü alıp başlık altında filtreleme aparatı içine tüm içeriğini dökün. 5 dakika boyunca Filtre. Filtreden filtre kağıdı çıkarın. </li><li> S&#39;in altındaki O / N kurutulması için bir saat camı ve ayrı boncuklar üzerine süzülmüş katı aktarınood. Boncuk temizleme süresiz olarak ertelendi edilebilir. Mağaza gerekli olana kadar kapalı bir cam şişe içinde oda sıcaklığında kurutuldu boncuklar, ve temiz kullanımdan hemen önce. </li></ol></li><li> Boncuk Temizlik <ol><li> Başlık altında bir filtreleme aparatı oluşturma ve filtre kağıdı üzerine huni içinde kurutuldu boncuklar yerleştirin. </li><li> Tüm boncuklar durulanır sağlamak için etrafında hafifçe hareket hafifçe boncuk durulamak için DI-su ile dolu bir plastik yıkama şişesi kullanın. </li><li> Boncuklar kaputun altında bir saat camına yerleştirerek 1 saat kurumasını bekleyin. Su ile durulama için aynı yöntemi kullanarak boncuk durulayın hekzan ile dolu bir yıkama şişesi kullanın. </li><li> Bir saat camına boncuk yerleştirin. Izlemek camını yerleştirin ve kaputun altında boncuklar kuru. </li><li> Boncuklar tamamen kuruduktan sonra, ileride kullanmak üzere oda sıcaklığında küçük bir yapışmalı cam şişe ve mağaza koyun. </li></ol></li><li> SEM Analizi ve SEM Ayarları için Boncuk Montaj <ol><li> Do bir şerit yerleştirinboncuklar monte edileceği üzerine saplama üstünde uble taraflı karbon iletken bant. Makas kullanarak, kenarları üzerinde hiçbir kaset kilitleniyor sağlamak için saplama etrafında kırpın. </li><li> Düz bir yüzeye saplama altında filtre bir parça kağıt yerleştirin. Yapışkan alt maruz böylece banttan üst tabaka çıkarın. </li><li> Yavaşça saplama üzerine boncuk dökün. Bazı boncuklar bant sopa, ama çoğu filtre kağıdı üzerinde kapalı çıkma ve arazi olacak. Onlar filtre kağıdı üzerinde kaldı, şişenin içine bu geri dökün. Gerekirse kontamine hale (2.4.5 için 2.4.2 göre) herhangi bir boncuk yıkama, tekrarlayın. </li><li> Boncuk saplama güvenli olmasını sağlamak için, ampul şırınga kullanmak ve hafifçe saplama yüzeye çok yakın darbe. Sadece birkaç bant yapıştırılır eğer saplama üzerinde daha fazla boncuk dökün. Tüm boncuklar SEM odasına saplama yerleştirme ve tahliye önce güvenli olduğundan emin olun. </li><li> Numuneler düzgün monte edildikten sonra artık SEM anal geçmesi hazırızYsis 15. Boncuk yüzey özellikleri çözünürlüğünü optimize etmek için 15 keV de DÜŞÜK VAC modunda görüntüleri toplayın. </li></ol></li></ol>

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The authors have nothing to disclose.

Şekil 1&#39;de diğer SEM görüntüleri Şekil 1A karşılaştırılması ile görüldüğü gibi, bu protokolü kullanarak (ve elektrolit konsantrasyonu ve kimliğini ayarlayarak) üretilen boncuklar., Düşük iyonik kuvvet emülsiyonu ile üretilen temelde farklı Bizim ilk raporu kullanılan ayrıca sulu-alifatik bir arayüz 14 polimerizasyon çapraz bağlanmasını katalize niyeti ile PTCL 4. Bu raporda, büyük konkav girintiler görüldü. Bu raporda, biz ...

Polydimethylsiloxane (PDMS) is one of the most widely used silicone compounds. Its biocompatibility has led to widespread use in implant and other biomedical engineering structures1,2. It is trivially cross-linked into elastic structures using an organosilyl compound (such as triethoxysilane), a simple and reliable procedure which has made it useful for cast polymer applications where some flexibility is required3. Once cross-linked, PDMS is largely inert, particularly in biological conditions, and is therefore useful for a variety of food and medical applications4,5. Ease of casting, chemical inertness, and hydrophobicity have made it a natural choice for microfluidic devices6,7. Its affinity for non-halogenated, non-polar organic compounds has made it a popular stationary phase in separations chemistry8-10. 
Recently, microbubble fabrications have been used to generate porous beads for use as catalyst structural substrates or in chemical separations11,12. In both applications, ideal materials will have a maximized surface-area-to-volume (SAV) ratio for best efficiency. In a microbubble fabrication process, microstructuring of materials is typically accomplished by isolating the polymer in aliphatic &#8220;microbubbles&#8221; by emulsification in an aqueous continuous phase. The initial report of microporous PDMS beads produced them by mechanical emulsification of two phases (aliphatic and aqueous)13. The stock PDMS liquid (and its cross-linking agent) is dissolved into the aliphatic phase, which is structured into microscopic beads by being forced to cavitate within the (continuous) aqueous phase. The emulsification is stabilized by the addition of a non-ionic surfactant. When the emulsion is added dropwise to a heated bath, solid beads form by agglomeration of the microbubbles into clusters of tiny spheres of cross-linked PDMS. Our goal in this protocol is to modify this procedure to develop beads with an inverted porosity to improve the SAV ratio of the material.
As reported previously, control of the beads can be directed to some extent by the aliphatic:aqueous ratios in the emulsion. However, we have reported recently that addition of platinum(IV) chloride (PtCl4) inverts the porosity: materials are formed in which the PDMS is riddled with concave pores14. This indicates that the aqueous layer cavitates inside the aliphatic one, despite having similar aliphatic:aqueous ratios to those published in the original work13. The primary advantage of our method is that this concave porosity should naturally result in an increased SAV ratio, and thus, improved efficiency for analytical chemistry applications. While we are continuing to explore the specific effects of the addition of the platinum compound, we show here that the same effect can be accomplished using any aqueously soluble ionic compound, though perhaps to a reduced extent. Because our techniques also differ in some key aspects from what has been previously reported, we present our protocols here as a video to encourage others to extend our methods. Most notably, we use a common bath sonicator of the type used to clean glassware or other equipment, rather than the (considerably more expensive) probe sonicator often used in microbubble fabrication. This adjusted approach to the microbubble fabrication procedure could potentially be extended for the production of large quantities of bulk materials as well, creating porous sheets or slabs which could have applications for biomedical devices, aerospace and automotive industry, or substrates for chemical catalysis. Users seeking to generate high-SAV-ratio, microstructured materials using other similar polymers for such analyses may find that our protocols can be extended to any polymer for which the microbubble emulsion technique can be applied.

<table border="0">
	<tbody>
		<tr>
			<td>Poly(dimethylsiloxane), vinyl terminated</td>
			<td>Sigma-Aldrich</td>
			<td>68083-19-2</td>
			<td></td>
		</tr>
		<tr>
			<td>n-Heptane</td>
			<td>Sigma-Aldrich</td>
			<td>142-82-5</td>
			<td>Flammable</td>
		</tr>
		<tr>
			<td>Triethoxysilane</td>
			<td>Sigma-Aldrich</td>
			<td>998-30-1</td>
			<td>Flammable, Accutely Toxic</td>
		</tr>
		<tr>
			<td>Sorbitan Monoleate (Span-80)</td>
			<td>Fluker</td>
			<td>1338-43-8</td>
			<td></td>
		</tr>
		<tr>
			<td>Platinum (IV) Chloride</td>
			<td>Sigma-Aldrich</td>
			<td>13454-96-1</td>
			<td>Accutely Toxic</td>
		</tr>
		<tr>
			<td>Zinc (II) Chloride</td>
			<td>Sigma-Aldrich</td>
			<td>7646-85-7</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium Chloride</td>
			<td>Sigma-Aldrich</td>
			<td>7647-14-5</td>
			<td></td>
		</tr>
		<tr>
			<td>2.8L Water Bath Sonicator</td>
			<td>VWR</td>
			<td>97043-964</td>
			<td></td>
		</tr>
	</tbody>
</table>

microbubble fabrication of concave-porosity pdms beads

Microbubble fabrication (by use of a fine emulsion) provides a means of increasing the surface-area-to-volume (SAV) ratio of polymer materials, which is particularly useful for separations applications. Porous polydimethylsiloxane (PDMS) beads can be produced by heat-curing such an emulsion, allowing the interface between the aqueous and aliphatic phases to mold the morphology of the polymer. In the procedures described here, both polymer and crosslinker (triethoxysilane) are sonicated together in a cold-bath sonicator. Following a period of cross-linking, emulsions are added dropwise to a hot surfactant solution, allowing the aqueous phase of the emulsion to separate, and forming porous polymer beads. We demonstrate that this method can be tuned, and the SAV ratio optimized, by adjusting the electrolyte content of the aqueous phase in the emulsion. Beads produced in this way are imaged with scanning electron microscopy, and representative SAV ratios are determined using Brunauer&#8211;Emmett&#8211;Teller (BET) analysis. Considerable variability with the electrolyte identity is observed, but the general trend is consistent: there is a maximum in SAV obtained at a specific concentration, after which porosity decreases markedly.

Farklı elektrolit koşulları emülsiyonlardan oluşan boncukların Örnek SEM görüntüleri, Şekil 1 &#39;de gösterilmiştir. Şekil 1A DUFAUD ile elde edilenler, ve ark., 13 benzer bir boncuk gösterir, herhangi bir elektrolit ilavesi olmadan, prosedürler kullanılarak üretilmiş. Boncuk her metal iyonu için farklı morfolojileri sonuçlanan Şekil 1B-D gösterilen. Gösterilen tüm görüntüler için, 0,03-M elektrolit çözeltileri 300 ul bu faz içinde 0...

Watch this Scientific Journal Video about Microbubble Fabrication of Concave-porosity PDMS Beads at JoVE.com

Microbubble Fabrication of Concave-porosity PDMS Beads

Procedures used to generate microstructured concave-porosity polydimethylsiloxane beads are presented. Effects of electrolyte concentration and identity within the aqueous phase are particularly emphasized.

Konkav-gözenek PDMS Boncuk mikro-Fabrikasyon

Microbubble fabrication (by use of a fine emulsion) provides a means of increasing the surface-area-to-volume (SAV) ratio of polymer materials, which is ...

microbubble-fabrication-of-concave-porosity-pdms-beads

Research

JoVE Journal

Chemistry

8.2K Görüntüleme.  Western Kentucky University. Procedures used to generate microstructured concave-porosity polydimethylsiloxane beads are presented. Effects of electrolyte concentration and identity within the aqueous phase are particularly emphasized. 

Video: Microbubble Fabrication of Concave-porosity PDMS Beads

Fabrication of Large-area Free-standing Ultrathin Polymer Films

This procedure describes a method for the fabrication of large-area and ultrathin free-standing polymer films. Typically, ultrathin films are prepared using either sacrificial layers, which may damage the film or affect its mechanical properties, or they are made on freshly cleaved mica, a substrate that is difficult to scale. Further, the size of ultrathin film is typically limited to a few square millimeters. In this method, we modify a surface with a polyelectrolyte that alters the strength of adhesion between polymer and deposition substrate. The polyelectrolyte can be shown to remain on the wafer using spectroscopy, and a treated wafer can be used to produce multiple films, indicating that at best minimal amounts of the polyelectrolyte are added to the film. The process has thus far been shown to be limited in scalability only by the size of the coating equipment, and is expected to be readily scalable to industrial processes. In this study, the protocol for making the solutions, preparing the deposition surface, and producing the films is described.

We describe a method for the fabrication of large-area (up to 13 cm diameter) and ultrathin (as thin as 8 nm) polymer films. Instead of using a sacrificial interlayer to delaminate the film from its substrate, we use a self-limiting surface treatment suitable for arbitrarily large areas.

Geniş alanlı Fabrikasyon Ultrathin Polimer Filmler Serbest ayakta

This procedure describes a method for the fabrication of large-area and ultrathin free-standing polymer films.  Typically, ultrathin films are prepared ...

Kimya

Flow-pattern Guided Fabrication of High-density Barcode Antibody Microarray

Antibody microarray as a well-developed technology is currently challenged by a few other established or emerging high-throughput technologies. In this report, we renovate the antibody microarray technology by using a novel approach for manufacturing and by introducing new features. The fabrication of our high-density antibody microarray is accomplished through perpendicularly oriented flow-patterning of single stranded DNAs and subsequent conversion mediated by DNA-antibody conjugates. This protocol outlines the critical steps in flow-patterning DNA, producing and purifying DNA-antibody conjugates, and assessing the quality of the fabricated microarray. The uniformity and sensitivity are comparable with conventional microarrays, while our microarray fabrication does not require the assistance of an array printer and can be performed in most research laboratories. The other major advantage is that the size of our microarray units is 10 times smaller than that of printed arrays, offering the unique capability of analyzing functional proteins from single cells when interfacing with generic microchip designs. This barcode technology can be widely employed in biomarker detection, cell signaling studies, tissue engineering, and a variety of clinical applications.

This protocol outlines the fabrication of a large-scale, multiplexed two-dimensional DNA or antibody array, with potential applications in cell signaling studies and biomarker detection.

Yüksek yoğunluklu Barkod Antikor Mikroarray Akışı-desen Rehberli Fabrikasyon

Antibody microarray as a well-developed technology is currently challenged by a few other established or emerging high-throughput technologies. In this ...

Immobilization of Multi-biocatalysts in Alginate Beads for Cofactor Regeneration and Improved Reusability

We have recently developed a simple, reusable and coupled whole-cell biocatalytic system with the capability of cofactor regeneration and biocatalyst immobilization for improved production yield and sustained synthesis. Described herewith is the experimental procedure for the development of such a system consisting of two E. coli strains that express functionally complementary enzymes. Together, these two enzymes can function co-operatively to mediate the regeneration of expensive cofactors for improving the product yield of the bioreaction. In addition, the method of synthesizing an immobilized form of the coupled biocatalytic system by encapsulation of whole cells in calcium alginate beads is reported. As an example, we present the improved biosynthesis of L-xylulose from L-arabinitol by coupling E. coli cells expressing the enzymes L-arabinitol dehydrogenase or NADH oxidase. Under optimal conditions and using an initial concentration of 150 mM L-arabinitol, the maximal L-xylulose yield reached 96%, which is higher than those reported in the literature. The immobilized form of the coupled whole-cell biocatalysts demonstrated good operational stability, maintaining 65% of the yield obtained in the first cycle after 7 cycles of successive re-use, while the free cell system almost completely lost the catalytic activity. Therefore, the methods reported here provides two strategies that could help improve the industrial production of L-xylulose, as well as other value-added compounds requiring the use of cofactors in general.

Presented is the protocol for co-immobilizing whole-cell biocatalysts for cofactor regeneration and improved reusability, using the production of L-xylulose as an example. The cofactor regeneration is achieved by coupling two Escherichia coli strains expressing functionally complementary enzymes; the whole-cell biocatalyst immobilization is achieved by cell encapsulation in calcium alginate beads.

Kofaktör Yenilenme ve Geliştirilmiş kullanırlılık için Aljinat Boncuk Multi-biyokatalizi immobilizasyonu

We have recently developed a simple, reusable and coupled whole-cell biocatalytic system with the capability of cofactor regeneration and biocatalyst ...

Influence of Hybrid Perovskite Fabrication Methods on Film Formation, Electronic Structure, and Solar Cell Performance

Hybrid organic/inorganic halide perovskites have lately been a topic of great interest in the field of solar cell applications, with the potential to achieve device efficiencies exceeding other thin film device technologies. Yet, large variations in device efficiency and basic physical properties are reported. This is due to unintentional variations during film processing, which have not been sufficiently investigated so far. We therefore conducted an extensive study of the morphology and electronic structure of a large number of CH3NH3PbI3 perovskite where we show how the preparation method as well as the mixing ratio of educts methylammonium iodide and lead(II) iodide impact properties like film formation, crystal structure, density of states, energy levels, and ultimately the solar cell performance.

We present an extensive study on the effects of different fabrication methods for organic/inorganic perovskite thin films by comparing crystal structures, density of states, energy levels, and ultimately the solar cell performance.

Film Oluşumunda Hybrid Perovskit Fabrikasyon Yöntemleri, Elektronik Yapısı ve Güneş Pili Performans Etkisi

Hybrid organic/inorganic halide perovskites have lately been a topic of great interest in the field of solar cell applications, with the potential to ...

Fabrication and Testing of Photonic Thermometers

In recent years, a push for developing novel silicon photonic devices for telecommunications has generated a vast knowledge base that is now being leveraged for developing sophisticated photonic sensors. Silicon photonic sensors seek to exploit the strong confinement of light in nano-waveguides to transduce changes in physical state to changes in resonance frequency. In the case of thermometry, the thermo-optic coefficient, i.e., changes in refractive index due to temperature, causes the resonant frequency of the photonic device such as a Bragg grating to drift with temperature. We are developing a suite of photonic devices that leverage recent advances in telecom compatible light sources to fabricate cost-effective photonic temperature sensors, which can be deployed in a wide variety of settings ranging from controlled laboratory conditions, to the noisy environment of a factory floor or a residence. In this manuscript, we detail our protocol for the fabrication and testing of photonic thermometers.

We describe the process of fabrication and testing of photonic thermometers.

İmalat ve fotonik termometreler test

In recent years, a push for developing novel silicon photonic devices for telecommunications has generated a vast knowledge base that is now being ...

Fabrication and Testing of Catalytic Aerogels Prepared Via Rapid Supercritical Extraction

Protocols for preparing and testing catalytic aerogels by incorporating metal species into silica and alumina aerogel platforms are presented. Three preparation methods are described: (a) the incorporation of metal salts into silica or alumina wet gels using an impregnation method; (b) the incorporation of metal salts into alumina wet gels using a co-precursor method; and (c) the addition of metal nanoparticles directly into a silica aerogel precursor mixture. The methods utilize a hydraulic hot press, which allows for rapid (&#60;6 h) supercritical extraction and results in aerogels of low density (0.10 g/mL) and high surface area (200-800 m2/g). While the work presented here focuses on the use of copper salts and copper nanoparticles, the approach can be implemented using other metal salts and nanoparticles. A protocol for testing the three-way catalytic ability of these aerogels for automotive pollution mitigation is also presented. This technique uses custom-built equipment, the Union Catalytic Testbed (UCAT), in which a simulated exhaust mixture is passed over an aerogel sample at a controlled temperature and flow rate. The system is capable of measuring the ability of the catalytic aerogels, under both oxidizing and reducing conditions, to convert CO, NO and unburned hydrocarbons (HCs) to less harmful species (CO2, H2O and N2). Example catalytic results are presented for the aerogels described.

Here we present protocols for preparing and testing catalytic aerogels by incorporating metal species into silica and alumina aerogel platforms. Methods for preparing materials using copper salts and copper-containing nanoparticles are featured. Catalytic testing protocols demonstrate the effectiveness of these aerogels for three-way catalysis applications.

İmalat ve katalitik Aerogels hızlı süperkritik ayıklama hazırlanan test

Protocols for preparing and testing catalytic aerogels by incorporating metal species into silica and alumina aerogel platforms are presented. Three ...

Preparation of Poly(pentafluorophenyl acrylate) Functionalized SiO2 Beads for Protein Purification

We demonstrate a simple method to prepare poly(pentafluorophenyl acrylate) (poly(PFPA)) grafted silica beads for antibody immobilization and subsequent immunoprecipitation (IP) application. The poly(PFPA) grafted surface is prepared via a simple two-step process. In the first step, 3-aminopropyltrimethoxysilane (APTMS) is deposited as a linker molecule onto the silica surface. In the second step, poly(PFPA) homopolymer, synthesized via the reversible addition and fragmentation chain transfer (RAFT) polymerization, is grafted to the linker molecule through the exchange reaction between the pentafluorophenyl (PFP) units on the polymer and the amine groups on APTMS. The deposition of APTMS and poly(PFPA) on the silica particles are confirmed by X-ray photoelectron spectroscopy (XPS), as well as monitored by the particle size change measured via dynamic light scattering (DLS). To improve the surface hydrophilicity of the beads, partial substitution of poly(PFPA) with amine-functionalized poly(ethylene glycol) (amino-PEG) is also performed. The PEG-substituted poly(PFPA) grafted silica beads are then immobilized with antibodies for IP application. For demonstration, an antibody against protein kinase RNA-activated (PKR) is employed, and IP efficiency is determined by Western blotting. The analysis results show that the antibody immobilized beads can indeed be used to enrich PKR while non-specific protein interactions are minimal.

Preparation of Polypentafluorophenyl acrylate Functionalized SiO2 Beads for Protein Purification

A protocol for the preparation of poly(pentafluorophenyl acrylate) (poly(PFPA)) grafted silica beads is presented. The poly(PFPA) functionalized surface is then immobilized with antibodies and used successfully for the protein separation through immunoprecipitation.

Poly(pentafluorophenyl acrylate) Functionalized SiO2 boncuk hazırlanması için Protein Saflaştırma

We demonstrate a simple method to prepare poly(pentafluorophenyl acrylate) (poly(PFPA)) grafted silica beads for antibody immobilization and subsequent ...

Fabrication of Thin Film Silver/Silver Chloride Electrodes with Finely Controlled Single Layer Silver Chloride

This paper aims to present a protocol to form smooth and well-controlled films of silver/silver chloride (Ag/AgCl) with designated coverage on top of thin film silver electrodes. Thin film silver electrodes sized 80 &#181;m x 80 &#181;m and 160 &#181;m x 160 &#181;m were sputtered on quartz wafers with a chromium/gold (Cr/Au) layer for adhesion. After passivation, polishing and cathodic cleaning processes, the electrodes underwent galvanostatic oxidation with consideration of Faraday&#39;s Law of Electrolysis to form smooth layers of AgCl with a designated degree of coverage on top of the silver electrode. This protocol is validated by inspection of scanning electron microscope (SEM) images of the surface of the fabricated Ag/AgCl thin film electrodes, which highlights the functionality and performance of the protocol. Sub-optimally fabricated electrodes are fabricated as well for comparison. This protocol can be widely used to fabricate Ag/AgCl electrodes with specific impedance requirements (e.g., probing electrodes for impedance sensing applications like impedance flow cytometry and interdigitated electrode arrays).

This paper aims to present a method to form smooth and well-controlled films of silver chloride (AgCl) with designated coverage on top of thin film silver electrodes.

İnce Kontrollü Tek Katmanlı Gümüş Klorürlü İnce Film Gümüş/Gümüş Klorür Elektrotlarının İmalatı

This paper aims to present a protocol to form smooth and well-controlled films of silver/silver chloride (Ag/AgCl) with designated coverage on top of thin ...

Akış Sitometrisinde Porfirin ile Modifiye Edilmiş Boncuklar

Porphyrin-Modified Beads for Use as Compensation Controls in Flow Cytometry

Flow cytometry can rapidly characterize and quantify diverse cell populations based on fluorescence measurements. The cells are first stained with one or more fluorescent reagents, each functionalized with a different fluorescent molecule (fluorophore) that binds to cells selectively based on their phenotypic characteristics, such as cell surface antigen expression. The intensity of fluorescence from each reagent bound to cells can be measured on the flow cytometer using channels that detect a specified range of wavelengths. When multiple fluorophores are used, the light from individual fluorophores often spills over into undesired detection channels, which requires a correction to the fluorescence intensity data in a process called compensation. 
Compensation control particles, typically polymer beads bound to a single fluorophore, are needed for each fluorophore used in a cell labeling experiment. Data from compensation particles from the flow cytometer are used to apply a correction to the fluorescence intensity measurements. This protocol describes the preparation and purification of polystyrene compensation beads covalently functionalized with the fluorescent reagent meso-tetra(4-carboxyphenyl) porphine (TCPP) and their application in flow cytometry compensation. In this work, amine-functionalized polystyrene beads were treated with TCPP and the amide coupling reagent EDC (N-(3-dimethylaminopropyl)-N&#8242;-ethylcarbodiimide hydrochloride) at pH 6 and at room temperature for 16 h with agitation. The TCPP beads were isolated by centrifugation and resuspended in a pH 7 buffer for storage. TCPP-related particulates were observed as a byproduct. The number of these particulates could be reduced using an optional filtration protocol. The resultant TCPP beads were successfully used on a flow cytometer for compensation in experiments with human sputum cells labeled with multiple fluorophores. The TCPP beads proved stable following storage in a refrigerator for 300 days.

Yazar Spot Işığı: Akış Sitometrisinde Kompanzasyon Kontrolleri Olarak Kullanım için Porfirin ile Modifiye Edilmiş Boncuklar  

The protocol describes how porphyrin-based compensation beads for flow cytometry are prepared by the reaction of amine-functionalized polystyrene beads with the porphyrin TCPP and the amide coupling reagent EDC. A filtration procedure is used to reduce the particulate byproducts.

Akış sitometrisinde kompanzasyon kontrolleri olarak kullanılmak üzere porfirin modifiye edilmiş boncuklar

Flow cytometry can rapidly characterize and quantify diverse cell populations based on fluorescence measurements. The cells are first stained with one or ...