저자는 소각 X- 선 회절 및 분말 X- 선 회절에 대한 분석 및 전문 지식으로 Rutgers University의 Thomas J. Emge 및 Wei Liu 박사에게 감사를 전한다. 또한, 저자는 N 2 흡착 실험에 대한 Hao Wang의지지를 인정했다.

1. Al (OH) 3 나노 입자 합성 <ol><li> 1.40g의 염화 알루미늄 6 수화물을 5.822g의 탈 이온수에 용해시킨다. </li><li> 마그네틱 교반시키면서 2.778g의 L- 아르기닌을 염화 알루미늄 수용액에 첨가한다. 첨가 된 아르기닌이 용해되어 큰 덩어리 또는 덩어리를 형성하지 않도록 L- 아르기닌을 서서히 첨가하십시오. 또한, 느린 첨가는 국부적 인 알칼리 농도를 감소시키고 더욱 조절 가능한 가수 분해를위한 조건을 제공한다. </li><li> 모든 아르기닌이 용액에 용해되면 50 ° C에서 72 시간 동안 용액을 가열합니다. 이 시점에서 솔루션은 흐린 서스펜션으로 나타날 수 있습니다. </li></ol> 2. NaCl에 의한 Al (OH) 3의 침전 <ol><li> 길이가 49 인치이고 직경이 1.125 인 GPC 칼럼을 준비하십시오. 겔을 추가하고 겔 구슬 사이의 공간을 최소화하면서 적절한 패킹을 보장하기 위해 컬럼을 통해 물이 흐르도록 연속 단계로 젤을 포장하십시오. 팩겔에서 컬럼의 약 80 %; 포장되는 겔의 양은 매번 변화하며 분리 된 종의 체류 시간에만 영향을 미친다. </li><li> 10mL 주사기 루프가있는 HPLC 펌프를 사용하여 10mL의 합성 된 Al (OH) 3 나노 입자 현탁액 (단계 1.3에서 준비)을 컬럼에 넣습니다. 약 0.125 in의 외경과 주입 된 시료 10 mL를 전달할 수있는 길이의 튜빙을 사용하여 인젝터 루프를 사용자 정의하십시오. </li><li> dRI 피크 위치와 관련된 간격으로 컬럼 용리액을 수집하십시오. GPC 출력을 차동 굴절률 (dRI) 검출기의 입력에 연결하십시오. 참고 : 분리 된 종은 GPC에서 나오므로 dRI 탐지기에 피크로 나타나며 125ml 병에 수집됩니다. GPC 컬럼은 두 개의 잘 분해 된 피크를 생성하며, 이들 모두는 크기 - 배제 크로마토 그래피 (SEC) 및 원소 분석 (EA)으로 수집 및 분석되어 알루미늄 스피릿으로부터 아르기닌을 분별한다cies. 수집 된 전체 부피는 GPC 칼럼의 크기, 사용 된 포장재의 총량 및 칼럼을 용리시키기 위해 사용 된 탈 이온수의 유속에 의존 할 것이다. <ol><li> 0.2 mL / min 유속에서 100 분에 걸친 피크 1 분획의 대부분을 수집하십시오. </li><li> GPC 칼럼의 RI 검출기에 피크가 나타나면 30 분 간격으로 용리액을 수집하십시오. 참고 : 간격 범위를 변경하면 정화 피크 1 물질의 농도와 순도가 변경됩니다. 특정 컬럼에 대해 최고 농도와 최고 순도를 포함하는 부분을 결정하기 위해 작은 간격의 피크를 먼저 수집하는 것이 좋습니다. </li></ol></li><li> 1 wt %의 NaCl을 조제한다. </li><li> 10 mL의 정제 된 Al (OH) 3 나노 입자에 준비된 NaCl 용액을 적가한다. NaCl 침전을 사용하여 제조 된 물질은 추후 실험에 사용되지 않는다. </li></ol> 3. Al-MCM-41의 제조 <ol><li> Ac진공 오븐에서 3 시간 동안 120 ° C에서 약 1.0 g의 MCM-41을 진공하에 가볍게 흔들어 준다. </li><li> 9.6926g의 AlCl3 · 6H2O와 40.3074g의 탈 이온수를 합하여 50.0g의 염화 알루미늄 용액을 조제한다. </li><li> 활성화 된 MCM-41 0.7g을 염화 알루미늄 용액 50.0g에 넣으십시오 (3.2 단계에서 준비). </li><li> MCM-41 채널 전체에 확산되는 AlCl 3의 균질성을 보장하기 위해 적절한 혼합 시간 (1 시간)을 허용하십시오. </li><li> 자기 교반하에 2.75의 Arg / Al 몰비로 이종 혼합물에 L- 아르기닌을 첨가한다. 단계 1.2와 유사하게, 아르기닌을 천천히 첨가하여 순간적으로 형성된 응집제가 재용 해되고 첨가를 계속하기 전에 아르기닌의 응집을 감소 시키도록한다. </li><li> 균질 해지면 혼합물을 50 ° C에서 72 시간 가열합니다. </li><li> 진공하에 부 흐너 깔때기를 사용하여 수득 된 이질 용액을 여과하고 질적 인 90 mm 여과지 서클(또는 다른 적절한 여과지). </li><li> 생성 된 Al-MCM-41 물질에서 미 반응의 염화 알루미늄, 아르기닌 또는 수용성 부산물을 제거하기 위해 과량의 탈 이온수로 여과 된 흰색 분말을 씻으십시오. </li></ol>

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저자는 공개 할 것이 없습니다.

염화 알루미늄 수용액의 제조는 염화 알루미늄의 결정 성 6 수화물 염의 사용을 수반했다. 무수 형태가 또한 사용될 수 있지만, 알루미늄의 농도를 조절하고 조절하는 것을 어렵게하는 상당한 흡습성 때문에 바람직하지 못하다. 시간이 지남에 따라 [Al (H 2 O) 6 ] 3 + aqua acid가 가수 분해되어 궁극적으로 최종 수율 및 순도를 감소시킬 수있는 원하지 않는 부산물을 생성하기 ?...

수산화 알루미늄으로 만들어진 물질은 촉매 작용, 의약품, 수처리 및 화장품을 포함한 다양한 산업 분야에서 유망한 후보 물질입니다. 1 , 2 , 3 , 4 고온에서 수산화 알루미늄은 분해하는 동안 상당량의 열을 흡수하여 알루미나 (Al 2 O 3 )를 생성하여 유용한 난연제로 사용됩니다. 수산화 알루미늄 ( 즉 , gibbsite, bayerite, nordstrandite 및 doyleite)의 4 가지 알려진 다 형체는 그 형성과 구조에 대한 우리의 이해를 향상시키기 위해 컴퓨터 및 실험 기술을 사용하여 조사되었다. 나노 크기 입자의 준비는 양자 효과와 특성을 보여줄 잠재 성 때문에 특히 중요하다.r 일괄 대응. 100nm 정도의 치수를 갖는 Nanogibbsite 입자는 다양한 조건 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 에서 쉽게 준비됩니다. 입자 크기를 줄이는 것과 관련된 고유 한 문제를 해결하는 것은 더욱 어렵습니다. 따라서, 나노 기 브 사이트 (nanogibbsite) 입자가 50nm 정도의 치수를 갖는 경우는 단지 약간의 경우 밖에 존재하지 않는다. 14 , 15 , 16 , 17 우리가 아는 한, 나노 기 브 사이트 (nanogibbsite) 입자는 50 nm보다 작다는보고는 없었다. 부분적으로, 이는 나노 입자가 정전기 불안정성으로 인하여 응집되는 경향이 있다는 사실에 기인한다특히 극성 프로톤 성 용매에서 콜로이드 입자 사이의 수소 결합 형성 가능성이 높다. 우리의 목표는 독점적으로 안전한 성분과 전구체를 사용하여 작은 Al (OH) 3 나노 입자를 합성하는 것이 었습니다. 현재 연구에서, 수성 입자 응집은 완충제 및 안정 화제로서 아미노산 ( 즉 , L- 아르기닌)을 혼입함으로써 억제되었다. 또한, 구아니딘 함유 아르기닌은 수산화 알루미늄 입자 성장 및 응집을 방지하여 평균 입자 크기가 10 내지 30 nm 인 콜로이드 수성 현탁액을 생성하는 것으로보고되었다. 아르기닌의 양쪽 성 및 양쪽 성 이온 성질이 온화한 가수 분해 동안 알루미늄 수산화물 나노 입자의 표면 전하를 완화시켜 30 nm를 초과하는 입자 성장을 감내한다고 제안되었다. 아르기닌은 입자 크기를 10 nm 이하로 줄일 수 없었지만 그러한 입자는 &quot;새장 (cage)&quot;감금 효과를 이용하여 얻을 수있었습니다MCM-41의 중세 공이다. Al-MCM-41 복합 재료의 특성은 평균 기공 크기가 2.7 nm 인 중형 다공성 실리카 내의 초 미세한 수산화 알루미늄 나노 입자를 나타내었다.

<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

나노 기 브 사이트의 수성 현탁액은 알루미늄 수조 [Al (H 2 O) 6 ] 3+ 와 L- 아르기닌을 pH 4.6으로 적정하여 합성 하였다. 수성 알루미늄 염의 가수 분해는 넓은 범위의 크기 분포를 갖는 다양한 제품을 생성하는 것으로 알려져 있기 때문에 다양한 첨단 기기 ( 즉, 27 Al / 1 H NMR, FTIR, ICP-OES , TEM-EDX, XPS, XRD 및 BET)를 사용하여 합성 산물 및 부산물의 특성을 분석했습니다. 나노 입자 (10-30 nm)로 구성된 생성물을 겔 투과 크로마토 그래피 (GPC) 컬럼 기술을 사용하여 분리 하였다. 푸리에 변환 적외선 (FTIR) 분광학 및 분말 X 선 회절 (PXRD)은 정제 된 물질을 수산화 알루미늄의 gibbsite 다 형체로 확인했습니다. 무기 염 ( 예 : NaCl)의 첨가는 현탁액의 정전 기적 불안정화를 유도하여 나노 입자를 응집시켜 yie큰 입자 크기의 Al (OH) 3 침전물. Al (OH) 3 는 여기에 기술 된 새로운 합성 방법을 이용하여 MCM-41의 고도로 정돈 된 메조 포러스 골격 내부에 부분적으로 장입되었고 평균 기공 크기는 2.7 nm였으며 팔면체 및 사면체 Al (Oh / T d = 1.4). Energy-dispersive X-ray spectrometry (EDX)를 사용하여 측정 한 총 Al 함량은 11 % w / w이고 Si / Al 몰비는 2.9이었다. 표면 X 선 광전자 분광법 (XPS) 원소 분석과 벌크 EDX의 비교는 알루미 노 실리케이트 물질 내의 Al 분포에 대한 통찰력을 제공했다. 또한, 벌크 (2.9)에 비해 외부 표면 (3.6)에서 Si / Al의 높은 비율이 관찰되었다. O / Al 비율의 근사값은 코어 및 외부 표면 근처에서 Al (O) 3 및 Al (O) 4 그룹의 농도가 각각 더 높다는 것을 나타냅니다. 새로 개발 된 Al-MCM-41의 합성은Al 2 O 3 나노 입자가 유리한 응용 분야에 사용될 수 있습니다.

Nanogibbsite 합성 Nanogibbsite는 2.75의 최종 Arg / Al 몰비로 L- 아르기닌으로 AlCl3 · 6H2O (14 중량 %)를 적정하여 제조 하였다. 나노 입자 덩어리 입자의 합성은 부분 가수 분해 된 염화 알루미늄 용액에 대해 널리 사용되는 분석 기법 인 SEC 를 통해 모니터되어 1, 2, 3, 4 및 5 1 피크로 임의로 지정된 5 개 영역을 구별...

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

MCM-41의 메조 다공성 채널 내에서 케이지 효과 감금 (cage-effect confinement)과 함께 또는없이 pH4.6으로 [Al (H 2 O)] 3+ 와 L- 아르기닌의 조절 된 적정을 통해 초 미세 수산화 알루미늄 나노 입자 현탁액을 제조 하였다.

대기 환경에서의 메조 포러스 MCM-41 유무에 따른 초 미세 수산화 알루미늄 입자의 간편한 제조

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 ...

facile-preparation-ultrafine-aluminum-hydroxide-particles-with-or

Research

JoVE Journal

Chemistry

10.8K 조회수.  Colgate-Palmolive Company.  MCM-41의 메조 다공성 채널 내에서 케이지 효과 감금 (cage-effect confinement)과 함께 또는없이 pH4.6으로 [Al (H 2 O)] 3+ 와 L- 아르기닌의 조절 된 적정을 통해 초 미세 수산화 알루미늄 나노 입자 현탁액을 제조 하였다. 

비디오: 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.

전자 레인지를 이용한 산 - 촉매 반응을 통해 실리카 나노 입자의 제조

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

연구

화학

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.

플라즈마 통해 소수성 유기 금속 프레임 워크의 제조 암모니아의 제거에 대한 퍼플 루오로 알칸의 화학 증착을 강화

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.

임의 기판에 수직으로 정렬 작은 분자 유기 나노 와이어의 초 밀도 배열

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

공학

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.

단본위제 및 바이메탈 조기 전이 금속 탄화물 및 질화물 나노 입자의 역 마이크로 에멀젼 매개 합성

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.

실험 프로토콜 마모에서 환경 풍화에서 제품의 입자 에어로졸을 조사하기

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.

머 랭 같은 형태와 Nanothermite: 초 다공성 개체에 느슨한 분말에서

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.

동시-표면 Anodizations와 황산에 양극 알루미늄 산화물 및 괭이밥에서 채취한 산 성 전해질의 계단 처럼 역방향 바이어스 분리

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.

제조 및 급속 한 초 임계 추출 통해 준비 촉매 Aerogels의 테스트

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.

밀-96와 UiO-66-NH2 원자 층 Solvothermal 합성 섬유 매트에 금속 산화물 코팅을 입금

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.

Ultrathin 높은 성능 금속-유기 프레임 워크 막의 전기 이동 화

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