Name: facile preparation of ultrafine aluminum hydroxide particles with or without mesoporous mcm-41 in ambient environments
Uploaded: 2017-05-11T15:00:00.000+00:00
Duration: 5 min 50 s
Description: Watch this Scientific Journal Video about Facile Preparation of Ultrafine Aluminum Hydroxide Particles with or without Mesoporous MCM-41 in Ambient Environments at JoVE.com

Yazarlar, küçük açılı X-ışını kırınımı ve toz X-ışını kırınımı konusundaki analizleri ve uzmanlıkları için Rutgers Üniversitesi&#39;nden Dr. Thomas J. Emge ve Wei Liu&#39;ya teşekkürlerini sunar. Yazarlar ayrıca Hao Wang&#39;ı N 2 adsorpsiyon deneyleriyle desteklediği için onaylarlar.

1. Al (OH) 3 Nanopartikül Sentezi <ol><li> 1.40 g alüminyum klorid hekzahidrat 5.822 g deiyonize suda eritilir. </li><li> Manyetik olarak karıştırılarak sulu alüminyum klorür solüsyonuna 2.778 g L-arginin ilave edin. L-arginin yavaşça ilave edilir, böylece eklenen arginin erir ve büyük kümeler veya parçalar oluşturmaz; Ayrıca, yavaş bir ilave, yerel alkalilik konsantrasyonlarını azaltır ve daha kontrol edilebilir bir hidroliz için koşullar sağlar. </li><li> Tüm arginin çözeltiye karıştıktan sonra, çözeltiyi 50 ° C&#39;de 72 saat ısıtın; Bu noktada, çözüm bulutlu bir süspansiyon halinde görünebilir. </li></ol> 2. Al (OH) 3&#39;ün NaCI ile çökeltilmesi <ol><li> 49 uzunluğunda ve 1.125 çapında bir GPC sütunu hazırlayın. Jel ilavesinin ardışık basamaklarında jel koyun ve jel boncukları arasında en az boşluk bırakarak doğru ambalajlamayı sağlamak için suyun kolondan akmasına izin verin. Paketini verJel sütunun yaklaşık% 80&#39;i; Paketlenen jel miktarı her seferinde değişir ve yalnızca ayrılan türlerin alıkonma zamanını etkiler. </li><li> 10 mL&#39;lik enjektör döngüsü ile bir HPLC pompası kullanarak 10 mL sentezlenmiş Al (OH) 3 nanoparçacık süspansiyonu (adım 1.3&#39;te hazırlanan) kolona sokun. Enjektör döngüsünü, yaklaşık 0.125 inç çapında ve 10 mL enjekte edilen numuneyi vermek üzere kalibre edilen bir boru kullanılarak özel hale getirin. </li><li> DRI tepe konumu ile ilişkili aralıklarla sütun elution&#39;u toplayın. GPC çıktısını bir diferansiyel kırınım indeksi (dRI) dedektörünün girişine bağlayın. NOT: Ayrılan türler GPC&#39;den çıktıklarında, dri dedektöründe tepe noktası olarak görülür ve daha sonra 125 mL&#39;lik şişelerde toplanır. GPC sütunu, aljinik spektrumundan arginini ayırt etmek için, hem boyut tahliye kromatografisi (SEC) hem de elemental analiz (EA) ile toplanan ve analiz edilen iki iyi çözülmüş tepe noktası üretirleri. Toplanan toplam hacim, GPC sütununun boyutuna, kullanılan toplam paketleme maddesinin miktarına ve kolonun ayrılması için kullanılan deiyonize suyun debisine bağlı olacaktır. <ol><li> Pik 1 fraksiyonunun çoğunluğunu 0,2 mL / dakika akış oranında 100 dakika boyunca toplayın. </li><li> Eluent&#39;i, GPC sütununun RI detektöründe bir pik ortaya çıkınca 30 dakika aralıklarla toplayın. NOT: Aralık aralığının değiştirilmesi sonuçtaki saflaştırılmış zirve 1 maddesinin konsantrasyonunu ve saflığını değiştirir. Belirli bir kolon için en yüksek konsantrasyon ve pik 1 türünün hangi bölümünü içerdiğini belirlemek için zirveden küçük aralıklar toplamak daha iyidir. </li></ol></li><li> Ağırlıkça% 1 NaCl hazırlayın. </li><li> Hazırlanan NaCl solüsyonunu 10 mL saf Al (OH) 3 nanopartiküllerine damla damla ilave edin; NaCl çökeltme kullanılarak hazırlanan materyal daha deneyler için kullanılmaz. </li></ol> 3. Al-MCM-41&#39;in hazırlanması <ol><li> ACVakumlu bir fırında 3 saat süreyle 120 ° C&#39;de yaklaşık 1.0 g MCM-41&#39;yi aktif hale getirin. </li><li> 9.6926 g AlCl3.6H20 ile 40.3074 g deiyonize su birleştirilerek 50.0 g alüminyum klorür çözeltisi hazırlanır. </li><li> 0,7 g aktif MCM-41&#39;i, 50.0 g alüminyum klorür çözeltisine ilave edin (aşama 3.2&#39;de hazırlanmıştır). </li><li> MCM-41 kanalları boyunca yayılmış AlCl 3 homojenliğini sağlamak için yeterli karıştırma süresine (1 saat) izin verin. </li><li> Manyetik karıştırma altında 2.75&#39;lik bir Arg / Al molar oranına kadar heterojen karışıma L-arginin ilave edin. Adım 1.2&#39;ye benzer şekilde, arjinini, eklemeye devam etmeden önce, anında oluşan çöplerin tekrar çözülüp indirgenmesini ve arjininin kümeleşmesini azaltmasını sağlayacak kadar yavaş yavaş ilave edin. </li><li> Bir kez homojen hale getirildiğinde, karışım 50 ° C&#39;de 72 saat ısıtılır. </li><li> Elde edilen heterojen çözeltiyi vakum altında ve niteliksel 90 mm filtre kağıdı daireleriyle donatılmış bir Buchner hunisi kullanarak filtre edin(Veya uygun herhangi bir filtre kâğıdı). </li><li> Üretilen Al-MCM-41 materyalinden reaksiyona girmemiş alüminyum klorür, arginin veya suda çözünür yan ürünlerin uzaklaştırılmasını sağlamak için filtrelenmiş beyaz tozu fazla miktarda deiyonize su ile yıkayın. </li></ol>

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Yazarların açıklayacak bir şeyi yok.

Sulu bir alüminyum klorür çözeltisinin hazırlanması, alüminyum kloridin kristal halinde bir hekzahidrat tuzunun kullanılmasını gerektirdi. Susuz form da kullanılabilmesine rağmen, önemli higroskopik özelliklerinden dolayı tercih edilmemektedir; bu da, alüminyum konsantrasyonunu kontrol etmek ve kontrol etmek zorlaşmaktadır. Alüminyum klorür çözeltisinin hazırlığın birkaç gün içinde kullanılması gerektiğini dikkate alarak dikkatli olun çünkü zamanla [Al (H20) 6 ] 3 +</su...

Alüminyum hidroksit malzemelerin kataliz, ilaç, su arıtma ve kozmetik dahil olmak üzere endüstriyel uygulamalar için umut vadeden adaylar vardır. 1 , 2 , 3 , 4 Yüksek sıcaklıklarda, alüminyum hidroksit (Al2O3) üretmek için parçalanma esnasında önemli miktarda ısı emer ve bu da alev geciktirici bir ajan haline gelir. Alüminyum hidroksitin bilinen dört polimorfu ( yani , gibbsite, bayerit, nordstrandit ve doyleit) hesaplama ve deney yöntemleriyle araştırılarak oluşum ve yapılarının anlaşılması 6 . Nano ölçekli parçacıkların hazırlanması, kuantum efektleri sergileme potansiyeli ve teorilerinkinden farklı özelliklere sahip olması nedeniyle özellikle ilgi çekicidirR toplu meslektaşları. 100 nm düzeyindeki boyutlara sahip nanogibsit parçacıkları çeşitli koşullar altında kolaylıkla hazırlanır 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 . Parçacık boyutlarını daha da azaltmakla ilgili olarak ortaya çıkan zorlukların üstesinden gelmek zordur; Bu nedenle, nanogibbsite parçacıkların boyutları 50 nm civarında olduğu yalnızca birkaç durum mevcuttur. 14 , 15 , 16 , 17 Bildiğimiz kadarıyla, 50 nm&#39;den daha küçük nanogibit partikülleri raporu bulunmamaktadır. Kısmen, nanoparçacıkların elektrostatik istikrarsızlıktan ötürü yığılma eğilimi gösterdiği düşünülmektedirVe özellikle polar protik çözücülerde koloidal partiküller arasında hidrojen bağlarının oluşma ihtimali yüksektir. Amacımız, yalnızca güvenli maddeleri ve öncülleri kullanarak küçük Al (OH) 3 nanopartiküllerini sentezlemekti. Mevcut çalışmada, bir tampon ve stabilizör olarak bir amino asit ( yani , L-arginin) eklenerek sulu parçacık agregasyonu engellendi. Dahası guanidinyum içeren argininin, alüminyum hidroksit parçacıklarının büyümesini ve toplanmasını önlediği ve ortalama parçacık boyutları 10-30 nm olan sulu bir koloidal süspansiyon oluşturduğu bildirilmektedir. Argininin amfoterik ve zvitteriyonik özelliklerinin, hafif hidroliz sırasında alüminyum hidroksit nanopartikülleri yüzey yükünü hafiflettiği ve 30 nm&#39;nin ötesinde partikül büyümesini hafiflettiği önerilir. Arginin, parçacık boyutunu 10 nm&#39;nin altına düşürememekle birlikte, bu parçacıklar, &quot;kafes&quot; sınırlandırıcı etkiden yararlanılarak elde edilmiştirMCM-41&#39;in mezo gözeneklerinde. Al-MCM-41 bileşik maddesinin karakterizasyonu, 2.7 nm&#39;lik bir ortalama gözenek boyutuna sahip olan mezo-gözenekli silisyum içinde ultra ince alüminyum hidroksit nanopartiküllerini ortaya çıkarmıştır.

<table><tbody><tr><td>aluminum chloride hexahydrate</td><td>Alfa Aesar</td><td>12297</td><td></td></tr><tr><td>L-arginine</td><td>BioKyowa</td><td>N/A</td><td></td></tr><tr><td>aluminum hydroxide</td><td>Sigma Aldrich</td><td>239186</td><td></td></tr><tr><td>Bio-Gel P-4 Gel</td><td>Bio-Rad</td><td>150-4128</td><td></td></tr><tr><td>Mesoporous siica (MCM-41 type)</td><td>Sigma Aldrich</td><td>643645</td><td></td></tr></tbody></table>

facile preparation of ultrafine aluminum hydroxide particles with or without mesoporous mcm-41 in ambient environments

Nanogibbsite ait sulu bir süspansiyon, alüminyum su asidi [Al (H20) 6 ] 3+ &#39;nın L-arginin ile pH 4.6&#39;ya titrasyonu ile sentezlendi. Sulu alüminyum tuzlarının hidrolizinin, geniş bir boyut dağılımı dağılımına sahip geniş bir ürün yelpazesi ürettiği bilinmekle birlikte, çeşitli son teknoloji cihazlar ( yani, 27 Al / 1 H NMR, FTIR, ICP-OES , TEM-EDX, XPS, XRD ve BET), sentez ürünlerini ve yan ürünlerin tanımlanmasını karakterize etmek için kullanıldı. Nanopartiküllerden (10-30 nm) oluşan ürün, jel permeasyon kromatografisi (GPC) sütun tekniği kullanılarak izole edildi. Fourier transform infrared (FTIR) spektroskopisi ve toz X-ışını kırınımı (PXRD) saflaştırılmış materyali alüminyum hidroksitin gibbsite polimorfu olarak tanımladı. İnorganik tuzların ( örn. , NaCl) ilavesi, süspansiyonun elektrostatik istikrarsızlaştırılmasına yol açtı, böylece nanoparçacıkların yoğundurulması sağlandıAl Al (OH) 3 , büyük parçacık boyutlarıyla çökelir. Burada tarif edilen yeni sentetik metodu kullanarak Al (OH) 3 , MCM-41&#39;in yüksek derecede düzenlenmiş mezo-gözenekli çerçevesinin içinde ortalama gözenek boyutları 2.7 nm olan kısmen yüklendi ve hem oktahedral hem de tetrahedral Al (O / saat) ile bir alüminosilikat malzeme üretti. T d = 1.4). Enerji dağılımlı X-ışını spektrometresi (EDX) kullanılarak ölçülen toplam Al içeriği,% 2.9 Si / Al molar oranı ile% 11 idi. Toplu EDX&#39;in yüzey X-ışını fotoelektron spektroskopisi (XPS) element analizi ile karşılaştırılması, alüminosilikat materyal içindeki Al dağılımı hakkında bilgi sağlamıştır. Dahası, dış yüzeyde (3.6) hacim (2.9) ile karşılaştırıldığında Si / Al oranının daha yüksek olduğu görülmüştür. O / Al oranlarının yaklaşıklıkları sırasıyla çekirdeğin ve dış yüzeyin yakınında daha yüksek bir Al (O) 3 ve Al (O) 4 konsantrasyonuna işaret etmektedir. Al-MCM-41&#39;in yeni geliştirilmiş sentezi,Sıralı yüksek silisyum dioksit muhteviyatı sağlarken, sıralı silis çerçevesinin bütünlüğünü korur ve hidratlı veya susuz AI203 nanopartiküllerin avantajlı olduğu uygulamalar için kullanılabilir.

Nanogibsit Sentezi Nanogibsit, AlCl3 · 6H20 (ağırlıkça% 14) L-arginin ile son bir Arg / Al mol oranının 2.75&#39;e kadar titre edilmesiyle hazırlandı. Nanogibbsite parçacıkların sentezi, kısmen hidrolize edilmiş alüminyum klorür çözeltileri için yaygın olarak kullanılan bir analiz tekniği olan, zirveleri 1, 2, 3, 4 ve 5 1 olarak belirlenen beş alanı belirleyebilen SEC aracılığıy...

Watch this Scientific Journal Video about Facile Preparation of Ultrafine Aluminum Hydroxide Particles with or without Mesoporous MCM-41 in Ambient Environments at JoVE.com

Facile Preparation of Ultrafine Aluminum Hydroxide Particles with or without Mesoporous MCM-41 in Ambient Environments

Çok ince bir alüminyum hidroksit nanoparçacık süspansiyonu, MCM-41&#39;in mezogözenekli kanalları içinde kafes efekti kısıtlaması olmaksızın ve olmadan 4.6&#39;ya kadar L-arginin ile [Al (H20)] 3&#39;ün kontrollü titrasyonu ile hazırlandı.

Ortofim Ortamlarda Mesafor MCM-41&#39;li olsun olmasın Ultrafine Alüminyum Hidroksit Parçacıklarının Kolay Hazırlanması

An aqueous suspension of nanogibbsite was synthesized via the titration of aluminum aqua acid [Al(H2O)6]3+ with L-arginine to pH 4.6. Since the hydrolysis ...

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10.8K Görüntüleme.  Colgate-Palmolive Company.  Çok ince bir alüminyum hidroksit nanoparçacık süspansiyonu, MCM-41'in mezogözenekli kanalları içinde kafes efekti kısıtlaması olmaksızın ve olmadan 4.6'ya kadar L-arginin ile [Al (H20)] 3'ün kontrollü titrasyonu ile hazırlandı. 

Video: Facile Preparation of Ultrafine Aluminum Hydroxide Particles with or without Mesoporous MCM-41 in Ambient Environments

Preparation of Silica Nanoparticles Through Microwave-assisted Acid-catalysis

Microwave-assisted synthetic techniques were used to quickly and reproducibly produce silica nanoparticle sols using an acid catalyst with nanoparticle diameters ranging from 30-250 nm by varying the reaction conditions. Through the selection of a microwave compatible solvent, silicic acid precursor, catalyst, and microwave irradiation time, these microwave-assisted methods were capable of overcoming the previously reported shortcomings associated with synthesis of silica nanoparticles using microwave reactors. The siloxane precursor was hydrolyzed using the acid catalyst, HCl. Acetone, a low-tan &#948; solvent, mediates the condensation reactions and has minimal interaction with the electromagnetic field. Condensation reactions begin when the silicic acid precursor couples with the microwave radiation, leading to silica nanoparticle sol formation. The silica nanoparticles were characterized by dynamic light scattering data and scanning electron microscopy, which show the materials&#39; morphology and size to be dependent on the reaction conditions. Microwave-assisted reactions produce silica nanoparticles with roughened textured surfaces that are atypical for silica sols produced by St&#246;ber&#39;s methods, which have smooth surfaces.

Silica nanoparticles were prepared using acid-catalysis of a siloxane precursor and microwave-assisted synthetic techniques resulting in the controlled growth of nanomaterials ranging from 30-250 nm in diameter. The growth dynamics can be controlled by varying the initial silicic acid concentration, time of the reaction, and temperature of reaction.

Microwave-assisted synthetic techniques were used to quickly and reproducibly produce silica nanoparticle sols using an acid catalyst with nanoparticle ...

Kimya

Preparation of Hydrophobic Metal-Organic Frameworks via Plasma Enhanced Chemical Vapor Deposition of Perfluoroalkanes for the Removal of Ammonia

Plasma enhanced chemical vapor deposition (PECVD) of perfluoroalkanes has long been studied for tuning the wetting properties of surfaces. For high surface area microporous materials, such as metal-organic frameworks (MOFs), unique challenges present themselves for PECVD treatments. Herein the protocol for development of a MOF that was previously unstable to humid conditions is presented. The protocol describes the synthesis of Cu-BTC (also known as HKUST-1), the treatment of Cu-BTC with PECVD of perfluoroalkanes, the aging of materials under humid conditions, and the subsequent ammonia microbreakthrough experiments on milligram quantities of microporous materials. Cu-BTC has an extremely high surface area (~1,800 m2/g) when compared to most materials or surfaces that have been previously treated by PECVD methods. Parameters such as chamber pressure and treatment time are extremely important to ensure the perfluoroalkane plasma penetrates to and reacts with the inner MOF surfaces. Furthermore, the protocol for ammonia microbreakthrough experiments set forth here can be utilized for a variety of test gases and microporous materials.

Herein the procedures for plasma enhanced chemical vapor deposition of perfluoroalkanes on microporous materials such as metal-organic frameworks to enhance their stability and hydrophobicity are described. Furthermore, breakthrough testing of milligram quantities of samples is described in detail.

Plazma ile Hidrofobik Metal-Organik Altyapıları hazırlanması Amonyak Kaldırma için perfluorobütanlar Kimyasal Buhar Kaplama Geliştirilmiş

Plasma enhanced chemical vapor deposition (PECVD) of perfluoroalkanes has long been studied for tuning the wetting properties of surfaces. For high ...

Ultrahigh Density Array of Vertically Aligned Small-molecular Organic Nanowires on Arbitrary Substrates

In recent years &pi;-conjugated organic semiconductors have emerged as the active material in a number of diverse applications including large-area, low-cost displays, photovoltaics, printable and flexible electronics and organic spin valves. Organics allow (a) low-cost, low-temperature processing and (b) molecular-level design of electronic, optical and spin transport characteristics. Such features are not readily available for mainstream inorganic semiconductors, which have enabled organics to carve a niche in the silicon-dominated electronics market. The first generation of organic-based devices has focused on thin film geometries, grown by physical vapor deposition or solution processing. However, it has been realized that organic nanostructures can be used to enhance performance of above-mentioned applications and significant effort has been invested in exploring methods for organic nanostructure fabrication.	
A particularly interesting class of organic nanostructures is the one in which vertically oriented organic nanowires, nanorods or nanotubes are organized in a well-regimented, high-density array. Such structures are highly versatile and are ideal morphological architectures for various applications such as chemical sensors, split-dipole nanoantennas, photovoltaic devices with radially heterostructured "core-shell" nanowires, and memory devices with a cross-point geometry. Such architecture is generally realized by a template-directed approach. In the past this method has been used to grow metal and inorganic semiconductor nanowire arrays. More recently &pi;-conjugated polymer nanowires have been grown within nanoporous templates. However, these approaches have had limited success in growing nanowires of technologically important &pi;-conjugated small molecular weight organics, such as tris-8-hydroxyquinoline aluminum (Alq3), rubrene and methanofullerenes, which are commonly used in diverse areas including organic displays, photovoltaics, thin film transistors and spintronics.	
Recently we have been able to address the above-mentioned issue by employing a novel "centrifugation-assisted" approach. This method therefore broadens the spectrum of organic materials that can be patterned in a vertically ordered nanowire array. Due to the technological importance of Alq3, rubrene and methanofullerenes, our method can be used to explore how the nanostructuring of these materials affects the performance of aforementioned organic devices. The purpose of this article is to describe the technical details of the above-mentioned protocol, demonstrate how this process can be extended to grow small-molecular organic nanowires on arbitrary substrates and finally, to discuss the critical steps, limitations, possible modifications, trouble-shooting and future applications.

We report a simple method for fabricating an ultrahigh density array of vertically ordered small-molecular organic nanowires. This method allows for synthesis of complex heterostructured hybrid nanowire geometries, which can be inexpensively grown on arbitrary substrates. These structures have potential applications in organic electronics, optoelectronics, chemical sensing, photovoltaics and spintronics.

Keyfi Yüzeyler üzerinde Dikey dizilmiş Küçük-moleküler Organik Nanoteller bir ultra yüksek Yoğunluk Dizi

In  recent years &pi;-conjugated  organic semiconductors have emerged as the active material in a number of  diverse applications including large-area, ...

Mühendislik

Reverse Microemulsion-mediated Synthesis of Monometallic and Bimetallic Early Transition Metal Carbide and Nitride Nanoparticles

A reverse microemulsion is used to encapsulate monometallic or bimetallic early transition metal oxide nanoparticles in microporous silica shells. The silica-encapsulated metal oxide nanoparticles are then carburized in a methane/hydrogen atmosphere at temperatures over 800 &#176;C to form silica-encapsulated early transition metal carbide nanoparticles. During the carburization process, the silica shells prevent the sintering of adjacent carbide nanoparticles while also preventing the deposition of excess surface carbon. Alternatively, the silica-encapsulated metal oxide nanoparticles can be nitridized in an ammonia atmosphere at temperatures over 800 &#176;C to form silica-encapsulated early transition metal nitride nanoparticles. By adjusting the reverse microemulsion parameters, the thickness of the silica shells, and the carburization/nitridation conditions, the transition metal carbide or nitride nanoparticles can be tuned to various sizes, compositions, and crystal phases. After carburization or nitridation, the silica shells are then removed using either a room-temperature aqueous ammonium bifluoride solution or a 0.1 to 0.5 M NaOH solution at 40-60 &#176;C. While the silica shells are dissolving, a high surface area support, such as carbon black, can be added to these solutions to obtain supported early transition metal carbide or nitride nanoparticles. If no high surface area support is added, then the nanoparticles can be stored as a nanodispersion or centrifuged to obtain a nanopowder.

A &#8220;removable ceramic coating method&#8221; is presented in visual format for the synthesis of non-sintered and metal-terminated monometallic and bimetallic early transition metal carbide and nitride nanoparticles with tunable sizes and crystal structures.

Monometalik ve Bimetalik Erken Geçiş Metal Carbide ve Nitrür Nanopartiküller Ters Mikroemülsiyon aracılı sentezi

A reverse microemulsion is used to encapsulate monometallic or bimetallic early transition metal oxide nanoparticles in microporous silica shells. The ...

Experimental Protocol to Investigate Particle Aerosolization of a Product Under Abrasion and Under Environmental Weathering

The present article presents an experimental protocol to investigate particle aerosolization of a product under abrasion and under environmental weathering, which is a fundamental element to the approach of nanosafety-by-design of nanostructured products for their durable development. This approach is basically a preemptive one in which the focus is put on minimizing the emission of engineered nanomaterials' aerosols during the usage phase of the product's life cycle. This can be attained by altering its material properties during its design phase without compromising with any of its added benefits. In this article, an experimental protocol is presented to investigate the nanosafety-by-design of three commercial nanostructured products with respect to their mechanical solicitation and environmental weathering. The means chosen for applying the mechanical solicitation is an abrasion process and for the environmental weathering, it is an accelerated UV exposure in the presence of humidity and heat. The eventual emission of engineered nanomaterials is studied in terms of their number concentration, size distribution, morphology and chemical composition. The purpose of the protocol is to study the emission for test samples and experimental conditions which are corresponding to real life situations. It was found that the application of the mechanical stresses alone emits the engineered nanomaterials' aerosols in which the engineered nanomaterial is always embedded inside the product matrix, thus, a representative product element. In such a case, the emitted aerosols comprise of both nanoparticles as well as microparticles. But if the mechanical stresses are coupled with the environmental weathering, the experimental protocol reveals then the eventual deterioration of the product, after a certain weathering duration, may lead to the emission of the free engineered nanomaterial aerosols too.

In this article, an experimental protocol to investigate particle aerosolization of a product under abrasion and under environmental weathering is presented. Results on the emission of engineered nanomaterials, in the form of aerosols are presented. The specific experimental set-up is described in detail.

Deneysel Protokol Aşınma altında ve Çevre Ayrışma altında Ürünün Parçacık aerosol haline Araştırma

The present article presents an experimental protocol to investigate particle aerosolization of a product under abrasion and under environmental ...

Nanothermite with Meringue-like Morphology: From Loose Powder to Ultra-porous Objects

The goal of the protocol described in this article is to prepare aluminothermic compositions (nanothermites) in the form of porous, monolithic objects. Nanothermites are combustible materials made up of inorganic fuel and an oxidizer. In nanothermite foams, aluminum is the fuel and aluminum phosphate and tungsten trioxide are the oxidizing moieties. The highest flame propagation velocities (FPVs) in nanothermites are observed in loose powders and FPVs are strongly decreased by pelletizing nanothermite powders. From a physical standpoint, nanothermite loose powders are metastable systems. Their properties can be altered by unintentional compaction induced by shocks or vibrations or by the segregation of particles over time by settling phenomena, which originates from the density differences of their components. Moving from a powder to an object is the challenge that must be overcome to integrate nanothermites in pyrotechnic systems. Nanothermite objects must have both a high open porosity and good mechanical strength. Nanothermite foams meet both of these criteria, and they are prepared by dispersing a nano-sized aluminothermic mixture (Al/WO3) in orthophosphoric acid. The reaction of aluminum with the acid solution gives the AlPO4 &#34;cement&#34; in which Al and WO3 nanoparticles are embedded. In nanothermite foams, aluminum phosphate plays the dual role of binder and oxidizer. This method can be used with tungsten trioxide, which is not altered by the preparation process. It could probably be extended to some oxides, which are commonly used for the preparation of high performance nanothermites. The WO3-based nanothermite foams described in this article are particularly insensitive to impact and friction, which makes them far safer to handle than loose Al/WO3 powder. The fast combustion of these materials has interesting applications in pyrotechnic igniters. Their use in detonators as primers would require the incorporation of a secondary explosive in their composition.

This manuscript describes the synthesis of combustible aluminophosphate matrices by the reaction of orthophosphoric acid (H3PO4) with aluminum nanopowder. When this reaction is carried out with excess aluminum in the presence of tungsten trioxide nanopowder, it leads to a solid, porous nanothermite foam.

Nanothermite beze gibi görünümdeki: Ultra gözenekli nesnelere gevşek toz üzerinden

The goal of the protocol described in this article is to prepare aluminothermic compositions (nanothermites) in the form of porous, monolithic objects. ...

Simultaneous Multi-surface Anodizations and Stair-like Reverse Biases Detachment of Anodic Aluminum Oxides in Sulfuric and Oxalic Acid Electrolyte

After reporting on the two-step anodization, nanoporous anodic aluminum oxides (AAOs) have been widely utilized in the versatile fields of fundamental sciences and industrial applications owing to their periodic arrangement of nanopores with relatively high aspect ratio. However, the techniques reported so far, which could be only valid for mono-surface anodization, show critical disadvantages, i.e., time-consuming as well as complicated procedures, requiring toxic chemicals, and wasting valuable natural resources. In this paper, we demonstrate a facile, efficient, and environmentally clean method to fabricate nanoporous AAOs in sulfuric and oxalic acid electrolytes, which can overcome the limitations that result from conventional AAO fabricating methods. First, plural AAOs are produced at one time through simultaneous multi-surfaces anodization (SMSA), indicating mass-producibility of the AAOs with comparable qualities. Second, those AAOs can be separated from the aluminum (Al) substrate by applying stair-like reverse biases (SRBs) in the same electrolyte used for the SMSAs, implying simplicity and green technological characteristics. Finally, a unit sequence consisting of the SMSAs sequentially combined with SRBs-based detachment can be applied repeatedly to the same Al substrate, which reinforces the advantages of this strategy and also guarantees the efficient usage of natural resources.

A protocol for fabricating nanoporous anodic aluminum oxides via simultaneous multi-surfaces anodization followed by stair-like reverse biases detachments is presented. It can be applied repeatedly to the same aluminum substrate, exhibiting a facile, high-yield, and environmentally clean strategy.

Eşzamanlı çoklu yüzey Anodizations ve merdiven gibi ters önyargıları dekolmanı anodik alüminyum oksit içinde sülfürik ve oksalik asit elektrolit

After reporting on the two-step anodization, nanoporous anodic aluminum oxides (AAOs) have been widely utilized in the versatile fields of fundamental ...

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 ...

Solvothermal Synthesis of MIL-96 and UiO-66-NH2 on Atomic Layer Deposited Metal Oxide Coatings on Fiber Mats

Metal-organic frameworks (MOFs), which contain reactive metal clusters and organic ligands allowing for large porosities and surface areas, have proven effective in gas adsorption, separations, and catalysis. MOFs are most commonly synthesized as bulk powder, requiring additional processes to adhere them to functional devices and fabrics that risk decreasing the powder porosity and adsorption capacity. Here, we demonstrate a method of first coating fabrics with metal oxide films using atomic layer deposition (ALD). This process creates conformal films of controllable thickness on each fiber, while providing a more reactive surface for MOF nucleation. By submerging the ALD coated fabric in solution during solvothermal MOF synthesis, the MOFs create a conformal, well-adhered coating on the fibers, resulting in a MOF-functionalized fabric, without additional adhesion materials that may block MOF pores and functional sites. Here we demonstrate two solvothermal synthesis methods. First, we form a MIL-96(Al) layer on polypropylene fibers using synthetic conditions that convert the metal oxide to MOF. Using initial inorganic films of varying thicknesses, diffusion of the organic linker into the inorganic allows us to control the extent of MOF loading on the fabric. Second, we perform a solvothermal synthesis of UiO-66-NH2 in which the MOF nucleates on the conformal metal oxide coating on polyamide-6 (PA-6) fibers, thereby producing a uniform and conformal thin film of MOF on the fabric. The resulting materials can be directly incorporated into filter devices or protective clothing and eliminate the maladroit qualities of loose powder.

Solvothermal Synthesis of MIL-96 and UiO-66-NH2 on Atomic Layer Deposited Metal Oxide Coatings on Fiber Mats

Metal-organic frameworks are effective in gas storage and heterogeneous catalysis, but typical synthesis methods result in loose powders that are difficult to incorporate into smart materials. We demonstrate a method of first coating fabrics with ALD metal oxides, resulting in conformal films of MOF on the fabrics during solvothermal synthesis.

Solvothermal sentez MIL-96 ve UIO-66-NH2 atom katman üzerinde Metal oksit kaplama Fiber paspaslar üzerine yatırılır.

Metal-organic frameworks (MOFs), which contain reactive metal clusters and organic ligands allowing for large porosities and surface areas, have proven ...

Electrophoretic Crystallization of Ultrathin High-performance Metal-organic Framework Membranes

We report the synthesis of thin, highly intergrown, polycrystalline metal-organic framework (MOF) membranes on a wide range of unmodified porous and non-porous supports (polymer, ceramic, metal, carbon, and graphene). We developed a novel crystallization technique, which is termed the ENACT approach: the electrophoretic nuclei assembly for the crystallization of highly intergrown thin films (ENACT). This approach allows for a high density of heterogeneous nucleation of MOFs on a chosen substrate via the electrophoretic deposition (EPD) directly from the precursor sol. The growth of well-packed MOF nuclei leads to a highly intergrown polycrystalline MOF film. We show that this simple approach can be used for the synthesis of thin, intergrown zeolite imidazole framework (ZIF)-7 and ZIF-8 films. The resulting 500 nm-thick ZIF-8 membranes show a considerably high H2 permeance (8.3 x 10-6 mol m-2 s-1 Pa-1) and ideal gas selectivities (7.3 for H2/CO2, 15.5 for H2/N2, 16.2 for H2/CH4, and 2655 for H2/C3H8). An attractive performance for C3H6/C3H8 separation is also achieved (a C3H6 permeance of 9.9 x 10-8 mol m-2 s-1 Pa-1 and a C3H6/C3H8 ideal selectivity of 31.6 at 25 &#176;C). Overall, the ENACT process, owing to its simplicity, can be extended to synthesize intergrown thin films of a wide range of nanoporous crystalline materials.

A simple, reproducible, and versatile approach for the synthesis of intergrown, polycrystalline metal-organic framework membranes on a wide range of unmodified porous and non-porous supports is presented.

Elektroforetik kristalizasyon Ultrathin yüksek performanslı Metal organik Framework membranlar

We report the synthesis of thin, highly intergrown, polycrystalline metal-organic framework (MOF) membranes on a wide range of unmodified porous and ...

Ortofim Ortamlarda Mesafor MCM-41'li olsun olmasın Ultrafine Alüminyum Hidroksit Parçacıklarının Kolay Hazırlanması

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