Name: supercritical nitrogen processing for the purification of reactive porous materials
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Description: Watch this Scientific Journal Video about Supercritical Nitrogen Processing for the Purification of Reactive Porous Materials at JoVE.com

Dette arbejde blev støttet af de europæiske Brændselsceller og Hydruogen fællesforetagende under samarbejdsprojekt BOR4STORE (tilskudsaftale nr 303428) og infrastruktur program H2FC (tilskudsaftale nr FP7-284522).

1. Apparatur <ol><li> Brug en grundlæggende superkritisk tørring (ScD) apparat består af fire primære komponenter forbundet af højtryksgas slange: gastilførslen, et vakuumsystem, sensorer (temperatur og tryk), og prøven miljø (som kan blive nedsænket i et bad). Sørg for, at konstruktionen er af høj kvalitet rustfrit stål ventiler, fittings og slanger, pres-rated til mindst 10 MPa i temperaturområdet mellem 80-300 K. Bemærk: En skematisk er vist i figur 1. </li><li> For kvælstof S...

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Måske på grund af dets forholdsvis lave kritiske temperatur (126 K), N2 er historisk blevet overset som en effektiv ScD opløsningsmiddel. I tidligere rapporter, 3,17,42,43 Det har kun været hentydet til i forbindelse med forarbejdning af temperaturer ved eller over omgivelsernes, hvor det udviser kun beskedne solvatisering magt på grund af dets lave fluiddensitet i denne region af dens fasediagram (undtagen ved ekstremt høje tryk 43). Det afgørende skridt i at realisere den prakti...

Superkritisk ekstraktion (SFE) og tørring (SCD) metoder er veletableret i en lang række praktiske anvendelser, især i fødevare- og olieindustrien, men også i kemisk syntese, analyse og materialeforarbejdning. 1-6 Anvendelse af tørring eller ekstraktion medier ved betingelser over deres kritiske punkter er ofte hurtigere, renere og mere effektive end traditionelle (flydende) teknikker, og har den yderligere fordel at være stærkt, variabelt i forhold til solvatiseringen effekt af fluidet ved mindre justering af driftsbetingelserne . 3,7 En simpel ScD metoden består af tre grundlæggende trin. Det første trin er at udsætte det faste stof (eller måske væske) udgangsmateriale, som indeholder mål-urenhedsforbindelse til en hensigtsmæssigt valgt ScD væske i flydende (eller næsten flydende superkritisk) fase, hvor dens høj densitet svarer til en høj (og måske selektiv 7) power opløsningsmiddel med hensyn til målarterne. Than andet trin er opvarmning og komprimering af systemet over den valgte ScD væske kritiske punkt i en lukket beholder, så væsken og dens opløste målarter ikke kan passere en fase grænse, som kan resultere i separation. Det sidste trin er langsomt at reducere trykket af ScD fluid til vakuum ved en temperatur over den kritiske temperatur, således at væsken indeholdende målarterne at undslippe, igen uden at støde en fasegrænse eller eventuelle skadelige overfladespænding effekter undervejs. Udgangsmaterialet efterlades tømt af målarterne og kan udsættes for itererede behandlinger, hvis det er nødvendigt. I tilfælde af superkritisk fluid ekstraktion, mål-opløste arter er det ønskede produkt, og opsamles fra opløsning til yderligere anvendelse. 8,9 I andre tilfælde, det tørrede eller oprenset udgangsmateriale er det ønskede produkt, og de ​​ekstraherede urenheder kasseres. Denne sidstnævnte situation omtalt herisom SCD fremgangsmåde blev opdaget at være en effektiv strategi til forbehandling af højt overfladeareal, mikroporøse materialer, såsom metal-organiske rammer (MOF), hvor traditionelle varme-behandlingsmetoder under vakuum som i mange tilfælde i clearing porerne ikke er tilstrækkelig af alle uønskede gæster, eller resultere i pore sammenbrud. 10 Kuldioxid ScD (CScD) behandlingen er nu en rutinemæssig post-syntetisk proces til MOFs, 11, der fører til stigninger i kvælstof-tilgængelige arealer end ubehandlede materialer på op til 1.000% 12 og andre forbedringer, såsom i katalytisk aktivitet. 13 Andre bemærkelsesværdige superkritiske fluide anvendelser er som et bredt afstemmelige medium for kemiske reaktioner, 14-16 superkritisk fluid kromatografi (SCFC) 6,17,18 og syntese af aerogeler og avancerede kompositmaterialer. 19- 22 Til tørring af applikationer, er en ScD væske udvalgte, baseret på to kriterier: a) den nærhed af sinkritiske punkt til omgivende betingelser (for nemheds skyld og for at reducere energiomkostningerne eller proces kompleksitet) og b) sin solvatisering magt med hensyn til målarterne. Kuldioxid (CO 2) har vist sig at være en bekvem ScD væske i mange applikationer, da det er ugiftigt, ikke-brændbar, og billige, og kan indstilles til at udvise en høj solvatisering effekt mod en række almindelige organiske målarter i sin nær-væske tilstand (ved tryk på &lt;10 MPa og temperaturer på 273-323 K). 1-3,7-9 Andre almindelige superkritiske opløsningsmidler (eller co-solventer) omfatter vand (der spænder over en bemærkelsesværdig vifte af opløsningsmiddel egenskaber mellem dens omgivende og superkritisk tilstand 23), acetone, ethylen, methanol, ethanol og ethan, der dækker spektret fra polær (protisk og aprot) til ikke-polær, og som har kritiske punkter forholdsvis nær til omgivelsesbetingelser. Kuldioxid er langt den mest almindelige ScD væske anvendes. I etablerede CScD metoder, reaktivitetenaf udgangsmaterialet er ikke en hæmmende faktor, da CO2 er kun meget svagt reaktive ved temperaturer nær dets kritiske punkt. Dog kan visse klasser af materialer, såsom de såkaldte komplekse hydrider (f.eks alanates og borhydrider) nuværende unikke udfordringer i håndtering på grund af deres stærke reaktivitet i nærvær af vand eller CO2 foruden deres (måske bevidst skræddersyet) ustabilitet under opvarmning . 24-26 Desuden er der stor international interesse for sådanne materialer som high-density brint lagring forbindelser, 27-30 og dermed også i nanostruktureret og / eller porøse sorter 31-33. For effektiv rensning af sådanne reaktive, ustabile og nanostrukturerede materialer, ScD metoder er en lovende strategi. 34 A ScD skal bru- som har en lille molekyldiameter passende for indtrængning i smalle hulrum, og som også har en høj solvatisering effekt mod target urenheder, while resterende ikke-reaktive mod udgangsmaterialet selv. Heri er anvendelsen af overkritisk nitrogen (N2) som en effektiv væske til en sådan ekstraktion og især tørring blev indgivet. En specifik superkritisk nitrogen tørring (nscd) metodik er beskrevet nedenfor til oprensning af γ-fase magnesium borhydrid hvor målarterne omfatter både diboran og en n-butyl forbindelse (svarende til, men ikke specifikt identificeres som n-butan). Følgende protokol kan let ændres til generel udvidelse til andre superkritiske kvælstof tørring eller ekstraktionsprocesser.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Compressed Nitrogen Gas</td>
			<td>Messer Schweiz AG</td>
			<td></td>
			<td>50 L bottle, purity &#62; 99.999%, &#60;3 ppmv H2O</td>
		</tr>
		<tr>
			<td>Liquid Nitrogen</td>
			<td>Pan Gas AG</td>
			<td></td>
			<td>Bulk storage, on site</td>
		</tr>
		<tr>
			<td>Custom Supercritical Drying Apparatus</td>
			<td>Empa</td>
			<td></td>
			<td>Swagelok (compression fitting and VCR) components</td>
		</tr>
		<tr>
			<td>Custom Cryogenic Furnace Bath</td>
			<td>Empa</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Custom Labview Interface</td>
			<td>Empa</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

supercritical nitrogen processing for the purification of reactive porous materials

Supercritical fluid extraction and drying methods are well established in numerous applications for the synthesis and processing of porous materials. Herein, nitrogen is presented as a novel supercritical drying fluid for specialized applications such as in the processing of reactive porous materials, where carbon dioxide and other fluids are not appropriate due to their higher chemical reactivity. Nitrogen exhibits similar physical properties in the near-critical region of its phase diagram as compared to carbon dioxide: a widely tunable density up to ~1 g ml-1, modest critical pressure (3.4 MPa), and small molecular diameter of ~3.6 &#197;. The key to achieving a high solvation power of nitrogen is to apply a processing temperature in the range of 80-150 K, where the density of nitrogen is an order of magnitude higher than at similar pressures near ambient temperature. The detailed solvation properties of nitrogen, and especially its selectivity, across a wide range of common target species of extraction still require further investigation. Herein we describe a protocol for the supercritical nitrogen processing of porous magnesium borohydride.

Alkali og alkaliske jordarters metalborhydrider er potentielle brint opbevaring materialer, der leverer et stort indhold af gasformig brint ved nedbrydning. 27,29 Andre nedbrydningsprodukter såsom diboran har også nogle gange blevet påvist i gassen desorberede, men deres oprindelse er ikke a priori klar ; det er muligt, de er produkter af den rene fase nedbrydning, men kan også være urenheder eller produkter af reaktioner af urenheder tilovers fra kemisk syntese. 35 Det porøse fase af magnesi...

Watch this Scientific Journal Video about Supercritical Nitrogen Processing for the Purification of Reactive Porous Materials at JoVE.com

Supercritical Nitrogen Processing for the Purification of Reactive Porous Materials

Kvælstof er et effektivt superkritisk fluid til udvinding eller tørring på grund af sin lille molekylstørrelse, høj densitet i nær-væske superkritisk regime, og kemisk stabilitet. Vi præsenterer en overkritisk nitrogen tørring protokol for rensning af reaktive, porøse materialer.

Superkritisk Nitrogen Behandling til rensning af reaktive porøse materialer

Supercritical fluid extraction and drying methods are well established in numerous applications for the synthesis and processing of porous materials. ...

Research

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Chemistry

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Foldning og karakterisering af en Bio-responsiv Robot fra DNA Origami

The DNA nanorobot is a hollow hexagonal nanometric device, designed to open in response to specific stimuli and present cargo sequestered inside. Both ...

Preparation of Highly Porous Coordination Polymer Coatings on Macroporous Polymer Monoliths for Enhanced Enrichment of Phosphopeptides

Udarbejdelse af meget porøse Koordinering Polymer Belægninger på Makroporøse Polymer Monoliths for styrkede Berigelse af phosphopeptider

We describe a protocol for the preparation of hybrid materials based on highly porous coordination polymer coatings on the internal surface of macroporous ...

On-line Analysis of Nitrogen Containing Compounds in Complex Hydrocarbon Matrixes

On-line analyse af nitrogenholdige forbindelser i Kompleks kulbrintestof Matricer

The shift to heavy crude oils and the use of alternative fossil resources such as shale oil are a challenge for the petrochemical industry. The ...

Insights into the Interactions of Amino Acids and Peptides with Inorganic Materials Using Single-Molecule Force Spectroscopy

Indsigt i samspillet mellem aminosyrer og peptider med uorganiske materialer Brug Single-Molecule force spektroskopi

The interactions between proteins or peptides and inorganic materials lead to several interesting processes. For example, combining proteins with minerals ...

Facet-to-facet Linking of Shape-anisotropic Colloidal Cadmium Chalcogenide Nanostructures

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Here, we describe a protocol that allows for shape-anisotropic cadmium chalcogenide nanocrystals (NCs), such as nanorods (NRs) and tetrapods (TPs), to be ...

Fabrication and Testing of Catalytic Aerogels Prepared Via Rapid Supercritical Extraction

Fabrikation og afprøvning af katalytisk aerogeler fremstillet Via Rapid superkritisk ekstraktion

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

Deposition of Porous Sorbents on Fabric Supports

Deposition af porøse Sorbents på stof understøtter

A microwave deposition technique for silanes, previously described for production of oleophobic fabrics, is adapted to provide a fabric support material ...

Chemical Synthesis of Porous Barium Titanate Thin Film and Thermal Stabilization of Ferroelectric Phase by Porosity-Induced Strain

Kemisk syntese af porøse Barium Titanate tynd Film og termisk stabilisering af Ferroelectric fase af porøsitet-induceret stamme

Barium titanate (BaTiO3, hereafter BT) is an established ferroelectric material first discovered in the 1940s and still widely used because of its ...

Synthesis and Bioconjugation of Thiol-Reactive Reagents for the Creation of Site-Selectively Modified Immunoconjugates

Syntese og Bioconjugation af Thiol-reaktiv reagenser til oprettelse af hjemmeside-selektivt modificerede Immunoconjugates

Maleimide-bearing bifunctional probes have been employed for decades for the site-selective modification of thiols in biomolecules, especially antibodies. ...

Evaluation of Oxidative Stress in Biological Samples Using the Thiobarbituric Acid Reactive Substances Assay

Evaluering af oxidativ stress i biologiske prøver ved hjælp af analysen af thiobarbitursyrereaktive stoffer

Despite its limited analytical specificity and ruggedness, the thiobarbituric acid reactive substances (TBARS) assay has been widely used as a generic ...