Siamo grati alla scienza nucleare di processo Pacific Northwest National Laboratory (PNNL) di iniziativa (NPSI)-fondo laboratorio diretto di ricerca e sviluppo (LDRD) per il supporto. Dr. Sayandev Chatterjee fornito le particelle boehmite sintetizzato. Accesso strumentale è stata fornita attraverso una proposta di utente generale W. R. Wiley Ambientale Molecular Sciences Laboratory (EMSL). EMSL è una struttura di uso scientifico nazionale sponsorizzata dall'ufficio di biologico e ambientale ricerca (BER) a PNNL. PNNL è gestito da Battelle per il DOE sotto contratto DE-AC05-76RL01830.

<ol>
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P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Environmental+Scanning+Electron+Microscopy+Study+of+Water+in+Carbon+Nanopipes.">Environmental Scanning Electron Microscopy Study of Water in Carbon Nanopipes.</a> Nano Lett. 4 (5), 989-993 (2004).</li><li>Nune, S. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anomalous+water+expulsion+from+carbon-based+rods+at+high+humidity.">Anomalous water expulsion from carbon-based rods at high humidity.</a> Nat Nano. 11 (9), 791-797 (2016).</li><li>Soumya, E. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Scanning Electron Microscopy (SEM) and Environmental SEM: Suitable Tools for Study of Adhesion Stage and Biofilm Formation. , (2012).</li><li>Thiberge, S. Y., Nechushtan, A., Sprinzak, D., Moses, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Scanning+electron+microscopy+of+cells+and+tissues+under+fully+hydrated+conditions.">Scanning electron microscopy of cells and tissues under fully hydrated conditions.</a> Proc Natl Acad Sci U S A. 101 (10), 3346-3351 (2004).</li><li>Thiberge, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Scanning+electron+microscopy+of+cells+and+tissues+under+fully+hydrated+conditions.">Scanning electron microscopy of cells and tissues under fully hydrated conditions.</a> Proc Natl Acad Sci U S A. 101 (10), 3346-3351 (2004).</li><li>Thiberge, S., Zik, O., Moses, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+apparatus+for+imaging+liquids,+cells,+and+other+wet+samples+in+the+scanning+electron+microscopy.">An apparatus for imaging liquids, cells, and other wet samples in the scanning electron microscopy.</a> Rev Sci Instrum. 75 (7), 2280-2289 (2004).</li><li>Yu, X. -. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Systems+and+methods+for+analyzing+liquids+under+vacuum.">Systems and methods for analyzing liquids under vacuum.</a> USA patent. , (2011).</li><li>Yang, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+situ+SEM+and+ToF-SIMS+analysis+of+IgG+conjugated+gold+nanoparticles+at+aqueous+surfaces.">In situ SEM and ToF-SIMS analysis of IgG conjugated gold nanoparticles at aqueous surfaces.</a> Surf Interface Anal. 46 (4), 224-228 (2014).</li><li>Liu, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+situ+chemical+probing+of+the+electrode-electrolyte+interface+by+ToF-SIMS.">In situ chemical probing of the electrode-electrolyte interface by ToF-SIMS.</a> Lab Chip. 14 (5), 855-859 (2014).</li><li>Ding, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+situ+Molecular+Imaging+of+the+Biofilm+and+Its+Matrix.">In situ Molecular Imaging of the Biofilm and Its Matrix.</a> Anal Chem. 88 (22), 11244-11252 (2016).</li><li>Hua, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two-dimensional+and+three-dimensional+dynamic+imaging+of+live+biofilms+in+a+microchannel+by+time-of-flight+secondary+ion+mass+spectrometry.">Two-dimensional and three-dimensional dynamic imaging of live biofilms in a microchannel by time-of-flight secondary ion mass spectrometry.</a> Biomicrofluidics. 9 (3), 031101 (2015).</li><li>Hua, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemical+imaging+of+molecular+changes+in+a+hydrated+single+cell+by+dynamic+secondary+ion+mass+spectrometry+and+super-resolution+microscopy.">Chemical imaging of molecular changes in a hydrated single cell by dynamic secondary ion mass spectrometry and super-resolution microscopy.</a> Integr Biol. 8 (5), 635-644 (2016).</li><li>Hua, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+situ+molecular+imaging+of+a+hydrated+biofilm+in+a+microfluidic+reactor+by+ToF-SIMS.">In situ molecular imaging of a hydrated biofilm in a microfluidic reactor by ToF-SIMS.</a> Analyst. 139 (7), 1609-1613 (2014).</li><li>Yu, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Capturing+the+transient+species+at+the+electrode-electrolyte+interface+by+in+situ+dynamic+molecular+imaging.">Capturing the transient species at the electrode-electrolyte interface by in situ dynamic molecular imaging.</a> Chem Commun. 52 (73), 10952-10955 (2016).</li><li>Yang, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Making+a+hybrid+microfluidic+platform+compatible+for+in+situ+imaging+by+vacuum-based+techniques.">Making a hybrid microfluidic platform compatible for in situ imaging by vacuum-based techniques.</a> J Vac Sci Technol, A. 29 (6), (2011).</li><li>Yang, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Probing+liquid+surfaces+under+vacuum+using+SEM+and+ToF-SIMS.">Probing liquid surfaces under vacuum using SEM and ToF-SIMS.</a> Lab Chip. 11 (15), 2481-2484 (2011).</li><li>Yao, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Switchable+1,8-diazabicycloundec-7-ene+and+1-hexanol+ionic+liquid+analyzed+by+liquid+ToF-SIMS.">Switchable 1,8-diazabicycloundec-7-ene and 1-hexanol ionic liquid analyzed by liquid ToF-SIMS.</a> Surf Sci Spectra. 23 (1), 9-28 (2016).</li><li>Yu, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Capturing+the+transient+species+at+the+electrode-electrolyte+interface+by+in+situ+dynamic+molecular+imaging.">Capturing the transient species at the electrode-electrolyte interface by in situ dynamic molecular imaging.</a> Chem Commun. 52 (73), 10952-10955 (2016).</li><li>Clark, S. B., Buchanan, M., Wilmarth, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Basic Research Needs for Environmental Management. , (2016).</li><li>Mills, O. P., Rose, W. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Shape+and+surface+area+measurements+using+scanning+electron+microscope+stereo-pair+images+of+volcanic+ash+particles.">Shape and surface area measurements using scanning electron microscope stereo-pair images of volcanic ash particles.</a> Geosphere. 6, 805-811 (2010).</li><li>Li, S., Jiang, F., Yin, Q., Jin, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Scanning+electron+acoustic+microscopy+of+semiconductor+materials.">Scanning electron acoustic microscopy of semiconductor materials.</a> Solid State Commun. 99 (11), 853-857 (1996).</li><li>Dohnalkova, A. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+Hydrated+Microbial+Extracellular+Polymers:+Comparative+Analysis+by+Electron+Microscopy.">Imaging Hydrated Microbial Extracellular Polymers: Comparative Analysis by Electron Microscopy.</a> Appl Environ Microbiol. 77 (4), 1254-1262 (2011).</li><li>Yu, X. -. Y., Liu, B., Yang, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+liquids+using+microfluidic+cells.">Imaging liquids using microfluidic cells.</a> Microfluid Nanofluid. 15 (6), 725-744 (2013).</li><li>Barshack, I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Novel+Method+for+"Wet"+SEM.">A Novel Method for "Wet" SEM.</a> Ultrastruct Pathol. 28 (1), 29-31 (2004).</li><li>Cameron, R. E., Donald, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Minizing+sample+evaporation+in+the+Environmental+Scanning+Microscope.">Minizing sample evaporation in the Environmental Scanning Microscope.</a> J Microsc. (Oxford, U. K.). 173 (3), 227-237 (1994).</li><li>Danilatos, G. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=REVIEW+AND+OUTLINE+OF+ENVIRONMENTAL+SEM+AT+PRESENT.">REVIEW AND OUTLINE OF ENVIRONMENTAL SEM AT PRESENT.</a> J Microsc (Oxford, U.K.). 162 (3), 391-402 (1991).</li><li>Stokes, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+advances+in+electron+imaging,+image+interpretation+and+applications:+environmental+scanning+electron+microscopy.">Recent advances in electron imaging, image interpretation and applications: environmental scanning electron microscopy.</a> Philos Trans R Soc, A. 361 (1813), 2771-2787 (2003).</li></ol>

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SEM è una potente tecnica di caratterizzazione delle superfici di materiali organici ed inorganici a livello di nanoscala (nm) con alta risoluzione1. Ad esempio, è ampiamente usato per l'analisi dei campioni solidi e asciutti come materiali geologici a semiconduttore e26 27. Tuttavia, ha limiti nel caratterizzare i campioni liquidi e bagnati a causa dell'incompatibilità di liquido all'interno dell'ambiente altamente aspirato necessaria per microsc...

Microscopio elettronico a scansione (SEM) è stato ampiamente applicato per indagare su una serie di esemplari con la produzione di imaging ad alta risoluzione1. La spettroscopia di raggi x dispersiva di energia (EDX) connessa con il SEM consente la determinazione della composizione elementare1. Tradizionalmente, SEM è applicato per l'imaging di campioni solo asciutti e solidi. Negli ultimi 30 anni, SEM ambientale (ESEM) è stato sviluppato per analizzare i campioni idratati parziali in un vapore ambiente2,3,4,5. Tuttavia, ESEM è in grado di immagine i campioni bagnati, completamente fluidi con alta risoluzione desiderata6. Bagnate le cellule SEM sono state sviluppate anche agli esemplari di immagine bagnato utilizzando SEM7,8; Tuttavia, queste cellule sono state sviluppate principalmente per campioni biologici e retrodiffusa formazione immagine dell'elettrone e sono più accessibili per le applicazioni con quei disegni9,10.
Per affrontare le sfide nell'analizzare vari campioni nel loro ambiente nativo di liquido utilizzando SEM, abbiamo inventato un dispositivo microfluidico compatibile vuoto, sistema per l'analisi a liquido vuoto interfaccia (SALVI), per consentire un'alta risoluzione spaziale secondaria analisi elementare e imaging elettronico (SE) di campioni liquidi utilizzando la modalità high vuoto in SEM. Questa tecnica novella include le seguenti caratteristiche uniche: 1) liquido è sondato direttamente in una piccola apertura di 1-2 µm di diametro; 2) liquido si svolge all'interno del foro dalla tensione superficiale; e 3) SALVI è portatile e può essere adattato a più di una piattaforma analitica11,12,13,14,15,16,17 ,18.
SALVI è costituito da una membrana di nitruro (SiN) di 100 nm silicio di spessore e un microchannel ampia 200 µm in blocco di polidimetilsilossano (PDMS). La finestra di membrana peccato viene applicata per sigillare il microchannel. I dettagli di fabbricazione e le considerazioni di progettazione chiave erano dettagliati in precedenti lavori e brevetti11,19,20. Attualmente, un produttore e distributore leader di approvvigionamento dei materiali di consumo per microscopia ha acquistato la licenza per vendere dispositivi SALVI commercialmente per liquido SEM applicazioni21,22.
Le applicazioni di SALVI in strumenti analitici basati su vuoto sono state dimostrate usando una varietà di soluzioni acquose e le miscele complesse di liquide tra cui biofilm, cellule di mammifero, nanoparticelle ed elettrodo materiali12, 14 , 17 , 20 , 23 , 24. Tuttavia, gran parte del lavoro di cui sopra utilizzati spettrometria di massa di ioni secondari di tempo di volo (ToF-SIMS) come lo strumento di analisi della chiave, quindi l'applicazione del liquido SEM con SALVI non è stato esplorato completamente. In questo lavoro, SALVI è stato utilizzato per studiare le più grandi particelle colloidali non sferica in liquido utilizzando liquido SEM imaging e l'analisi elementare EDX. L'esempio è costituito da particelle di AlOOH sintetizzate presso il nostro laboratorio. Particelle di dimensioni submicrometriche boehmite sono conosciute per esistere in scorie altamente radioattive presso il sito di Hanford. Sono lenti a sciogliere e può causare problemi reologici nel trattamento dei rifiuti. Pertanto, è importante avere la capacità di caratterizzare le particelle boehmite in liquido25. Questo approccio tecnico può essere utilizzato per studiare boehmite in varie condizioni fisico-chimiche per migliorare la comprensione di queste particelle e le proprietà reologiche correlate. Queste particelle sono state utilizzate per illustrare passo passo come applicare SALVI per alto vuoto SEM al fine di studiare le particelle sospese in un liquido. Punti chiave tecniche per l'integrazione di SALVI e SEM e acquisizione dati SEM sono evidenziati all'interno della carta.
Il protocollo prevede la dimostrazione dell'analisi campione liquido utilizzando SALVI e liquido SEM imaging, per coloro che sono interessati ad utilizzare questa tecnica novella in diverse applicazioni di liquido SEM in futuro.

<table><tbody><tr><td>Carbon Coater</td><td>Cressington</td><td>208 Carbon</td><td>It is accompanied with thickness monitor MTM-10.</td></tr><tr><td>SEM</td><td>FEI</td><td>Quanta 3D FEG</td><td>It provides highly resolved scanning electron microscopy and elemental analysis.</td></tr><tr><td>System for Analysis at the Liquid Vacuum Interface (SALVI)</td><td>Pacific Northwest National Laboratory</td><td>N/A</td><td>SALVI is a unique, vacuum compatible microfluidic cell that enables the characterization of the liquid sample using vacuu- based scientific instrument.</td></tr><tr><td>PEEK Union</td><td>Valco</td><td>ZU1TPK</td><td>The polyether ether ketone union is used for connecting the inlet and outlet of SALVI</td></tr><tr><td>Syringe</td><td>BD</td><td>309659</td><td>1 mL</td></tr><tr><td>Pipette</td><td>Thermo Fisher Scientific</td><td>21-377-821</td><td>Range: 100 to 1,000 mL</td></tr><tr><td>Pipette Tip 1</td><td>Neptune</td><td>2112.96.BS</td><td>1,000 &amp;micro;L</td></tr><tr><td>Pipette Tip 2</td><td>Rainin</td><td>17001865</td><td>20 &amp;micro;L</td></tr><tr><td>Syringe Pump</td><td>Harvard Apparatus</td><td>70-2213</td><td>It is used to inject the liquid sample into the SALVI device.</td></tr><tr><td>pH meter</td><td>Fisher Scientific/accumet</td><td>13-636-AP72</td><td>It is used for measuring the pH of AlOOH in DI water.</td></tr><tr><td>Barnstead Ultrapure Water System, UV/UF</td><td>Thermo Scientific Barnstead</td><td>Nanopure diamond D11931</td><td>It is used for producing DI water.</td></tr><tr><td>Centrifuge tubes</td><td>Fisher scientific/Falcon</td><td>15-527-90</td><td>15 mL</td></tr><tr><td>Bransonic ultrasonic cleaner</td><td>Sigma-Aldrich</td><td>2510</td><td>It is used to ultrasonicate the AlOOH liquid sample.</td></tr><tr><td>Balance</td><td>Mettler Toledo</td><td>11106015</td><td>XS64</td></tr><tr><td>AlOOH</td><td>Pacific Northwest National Laboratory</td><td>N/A</td><td>It is synthesized by scientists at Pacific Northwest National Laboratory.</td></tr><tr><td>xT microscope Control</td><td>FEI</td><td>Quanta 3D FEG</td><td>Default microscope control software of SEM Quanta 3D FEG</td></tr><tr><td>EDAX Genesis software</td><td>EDAX</td><td>N/A</td><td>The software is used for collecting the EDX elemental information of the samples.</td></tr><tr><td>Teflon tubing</td><td>SUPELCO</td><td>58697-U</td><td>It is used for introducing the sample into the microchannel and holding adequate volume of liquid.</td></tr></tbody></table>

in situ characterization of boehmite particles in water using liquid sem

In situ un analisi elementale e imaging delle particelle boehmite (AlOOH) in acqua è realizzato utilizzando il sistema per analisi all'interfaccia liquido di vuoto (SALVI) e microscopia elettronica a scansione (SEM). Questo documento descrive il metodo e passi cruciali nell'integrare il vuoto SAVLI compatibile a SEM e ottenere elettroni secondari (SE) immagini di particelle nel liquido in alto vuoto. Spettroscopia di raggi x dispersiva di energia (EDX) viene utilizzata per ottenere analisi elementare delle particelle nel liquido e controllo campioni inclusi acqua deionizzata (DI) solo e anche un canale vuoto. Boehmite sintetizzato (AlOOH) particelle sospese in un liquido sono usate come modello nell'illustrazione liquido SEM. I risultati dimostrano che le particelle possono essere imaged in modalità SE con buona risoluzione (cioè, 400 nm). Lo spettro di AlOOH EDX Mostra segnale significativo dall'alluminio (Al) se confrontato con l'acqua DI ed il controllo di canale vuoto. In situ liquido SEM è una tecnica potente per studiare le particelle nel liquido con molte applicazioni interessanti. Questa procedura mira a fornire il know-how tecnico per condotta liquido SEM imaging e l'analisi EDX utilizzando SALVI e ridurre potenziali problemi quando si utilizza questo approccio.

I risultati rappresentativi vengono presentati per mostrare come le particelle vengono ripresi e analizzati usando in situ liquido imaging SEM accoppiato con EDX. I risultati includono SE immagini e spettri EDX. Le immagini SE sono state ottenute a 100.000 X e 200.000 X ingrandimenti nella Figura 1. Figura 1a raffigura l'immagine SE di AlOOH, Figura 1b DI acqua e Figura ...

Watch this Scientific Journal Video about In Situ Characterization of Boehmite Particles in Water Using Liquid SEM at JoVE.com

In Situ Characterization of Boehmite Particles in Water Using Liquid SEM

In Situ Caratterizzazione delle particelle Boehmite in acqua usando liquido SEM

Presentiamo una procedura per l'analisi di composizione elementare di boehmite particelle in acqua deionizzata e immagini in tempo reale di in situ liquido scansione microscopia elettronica.

In situ imaging and elemental analysis of boehmite (AlOOH) particles in water is realized using the System for Analysis at the Liquid Vacuum Interface ...

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Universidad de Cartagena UDEC

Research

JoVE Journal

Chemistry

In Situ Characterization of Boehmite Particles in Water Using Liquid SEM

9.2K Views.  Pacific Northwest National Laboratory. Presentiamo una procedura per l'analisi di composizione elementare di boehmite particelle in acqua deionizzata e immagini in tempo reale di in situ liquido scansione microscopia elettronica.

Video: In Situ Characterization of Boehmite Particles in Water Using Liquid SEM

Simulation of the Planetary Interior Differentiation Processes in the Laboratory

A planetary interior is under high-pressure and high-temperature conditions and it has a layered structure. There are two important processes that led to that layered structure, (1) percolation of liquid metal in a solid silicate matrix by planet differentiation, and (2) inner core crystallization by subsequent planet cooling. We conduct high-pressure and high-temperature experiments to simulate both processes in the laboratory. Formation of percolative planetary core depends on the efficiency of melt percolation, which is controlled by the dihedral (wetting) angle. The percolation simulation includes heating the sample at high pressure to a target temperature at which iron-sulfur alloy is molten while the silicate remains solid, and then determining the true dihedral angle to evaluate the style of liquid migration in a crystalline matrix by 3D visualization. The 3D volume rendering is achieved by slicing the recovered sample with a focused ion beam (FIB) and taking SEM image of each slice with a FIB/SEM crossbeam instrument. The second set of experiments is designed to understand the inner core crystallization and element distribution between the liquid outer core and solid inner core by determining the melting temperature and element partitioning at high pressure. The melting experiments are conducted in the multi-anvil apparatus up to 27 GPa and extended to higher pressure in the diamond-anvil cell with laser-heating. We have developed techniques to recover small heated samples by precision FIB milling and obtain high-resolution images of the laser-heated spot that show melting texture at high pressure. By analyzing the chemical compositions of the coexisting liquid and solid phases, we precisely determine the liquidus curve, providing necessary data to understand the inner core crystallization process.

The high-pressure and high-temperature experiments described here mimic planet interior differentiation processes. The processes are visualized and better understood by high-resolution 3D imaging and quantitative chemical analysis.

Simulazione del Planetary Interior differenziazione processi in Laboratorio

A planetary interior is under high-pressure and high-temperature conditions and it has a layered structure. There are two important processes that led to ...

Ricerca

Ingegneria

Atom Probe Tomography Analysis of Exsolved Mineral Phases

Element diffusion rates and temperature/pressure control a range of fundamental volcanic and metamorphic processes. Such processes are often recorded in lamellae exsolved from host mineral phases. Thus, the analysis of the orientation, size, morphology, composition and spacing of exsolution lamellae is an area of active research in the geosciences. The conventional study of these lamellae has been conducted by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and more recently with focused ion beam (FIB)-based nanotomography, yet with limited chemical information. Here, we explore the use of atom probe tomography (APT) for the nanoscale analysis of ilmenite exsolution lamellae in igneous titanomagnetite from ash deposits erupted from the active Soufri&#232;re Hills Volcano (Montserrat, British West Indies). APT allows the precise calculation of interlamellar spacings (14&#8211;29 &#177; 2 nm) and reveals smooth diffusion profiles with no sharp phase boundaries during the exchange of Fe and Ti/O between the exsolved lamellae and the host crystal. Our results suggest that this novel approach permits nanoscale measurements of lamellae composition and interlamellar spacing that may provide a means to estimate the lava dome temperatures necessary to model extrusion rates and lava dome failure, both of which play a key role in volcanic hazard mitigation efforts.

Analysis of the morphology, composition, and spacing of exsolution lamellae can provide essential information to understand geological processes related to volcanism and metamorphism. We present a novel application of APT for the characterization of such lamellae and compare this approach to the conventional use of electron microscopy and FIB-based nanotomography.

Analisi tomografia atomo sonda delle fasi minerali essolte

Element diffusion rates and temperature/pressure control a range of fundamental volcanic and metamorphic processes. Such processes are often recorded in ...

Ambiente

Processing of Bulk Nanocrystalline Metals at the US Army Research Laboratory

Given their potential for significant property improvements relative to their large grained counterparts, much work has been devoted to the continued development of nanocrystalline metals. Despite these efforts, the transition of these materials from the lab bench to actual applications has been blocked by the inability to produce large scale parts that retain the desired nanocrystalline microstructures. Following the development of a method proven to stabilize the nanosized grain structure to temperatures approaching that of the melting point for the given metal, the US Army Research Laboratory (ARL) has progressed to the next stage in the development of these materials - namely the production of large scale parts suitable for testing and evaluation in a range of relevant test environments. This report provides a broad overview of the ongoing efforts in the processing, characterization, and consolidation of these materials at ARL. In particular, focus is placed on the methodology used for producing the nanocrystalline metal powders, in both small and large-scale amounts, that are at the center of ongoing research efforts.

This paper provides a brief overview of the ongoing efforts at the Army Research Laboratory on the processing of bulk nanocrystalline metals with an emphasis on the methodologies used for the production of the novel metal powders.

Lavorazione dei metalli nanocristallini Bulk presso la US Army Research Laboratory

Given their potential for significant property improvements relative to their large grained counterparts, much work has been devoted to the continued ...

Determination of Aggregate Surface Morphology at the Interfacial Transition Zone (ITZ)

Here, we present a comprehensive method to illustrate the uneven distribution of the interfacial transition zone (ITZ) around the aggregate and the effect of aggregate surface morphology on the formation of ITZ. First, a model concrete sample is prepared with a spherical ceramic particle in roughly the central part of the cement matrix, acting as a coarse aggregate used in common concrete/mortar. After curing until the designed age, the sample is scanned by X-ray computed tomography to determine the relative location of the ceramic particle inside the cement matrix. Three locations of the ITZ are chosen: above the aggregate, on the side of the aggregate, and below the aggregate. After a series of treatments, the samples are scanned with a SEM-BSE detector. The resultant images were further processed using a digital image processing method (DIP) to obtain quantitative characteristics of the ITZ. The surface morphology is characterized at the pixel level based on the digital image. Thereafter, K-means clustering method is used to illustrate the effect of surface roughness on ITZ formation.

Determination of Aggregate Surface Morphology at the Interfacial Transition Zone ITZ

Hereby, we proposed a protocol to illustrate the effect of aggregate surface morphology on the ITZ microstructure. The SEM-BSE image were quantitatively analyzed to obtain ITZ's porosity gradient via digital image processing and a K-means clustering algorithm was further employed to establish a relationship between porosity gradient and surface roughness.

Determinazione della morfologia di superficie aggregata nella zona di transizione interfacciale (IT)

Here, we present a comprehensive method to illustrate the uneven distribution of the interfacial transition zone (ITZ) around the aggregate and the effect ...

Nanoscale Characterization of Liquid-Solid Interfaces by Coupling Cryo-Focused Ion Beam Milling with Scanning Electron Microscopy and Spectroscopy

Physical and chemical processes at solid-liquid interfaces play a crucial role in many natural and technological phenomena, including catalysis, solar energy and fuel generation, and electrochemical energy storage. Nanoscale characterization of such interfaces has recently been achieved using cryogenic electron microscopy, thereby providing a new path to advancing our fundamental understanding of interface processes.
This contribution provides a practical guide to mapping the structure and chemistry of solid-liquid interfaces in materials and devices using an integrated cryogenic electron microscopy approach. In this approach, we pair cryogenic sample preparation which allows stabilization of solid-liquid interfaces with cryogenic focused ion beam (cryo-FIB) milling to create cross-sections through these complex buried structures. Cryogenic scanning electron microscopy (cryo-SEM) techniques performed in a dual-beam FIB/SEM enable direct imaging as well as chemical mapping at the nanoscale. We discuss practical challenges, strategies to overcome them, as well as protocols for obtaining optimal results. While we focus in our discussion on interfaces in energy storage devices, the methods outlined are broadly applicable to a range of fields where solid-liquid interface play a key role.

Cryogenic Focused Ion Beam (FIB) and Scanning Electron Microscopy (SEM) techniques can provide key insights into the chemistry and morphology of intact solid-liquid interfaces. Methods for preparing high quality Energy Dispersive X-ray (EDX) spectroscopic maps of such interfaces are detailed, with a focus on energy storage devices.

Caratterizzazione su scala nanometrica di interfacce liquido-solido mediante accoppiamento di fresatura a fascio ionico crio-focalizzato con microscopia elettronica a scansione e spettroscopia

Physical and chemical processes at solid-liquid interfaces play a crucial role in many natural and technological phenomena, including catalysis, solar ...

<meta charset="utf8"></head><body>Analisi multimodale della formazione ossea utilizzando modelli di espianto

Comprehensive Characterization of Tissue Mineralization in an Ex Vivo Model

The extensive characterization of tissue mineralization in the context of bone regeneration represents a significant challenge, given the numerous modalities that are currently available for analysis. Here, we propose a workflow for a comprehensive evaluation of new bone formation using a relevant large animal osseous ex vivo explant. A bone defect (diameter = 3.75 mm; depth = 5.0 mm) is created in an explanted sheep femoral head and injected with a macroporous bone substitute loaded with a pro-osteogenic growth factor (bone morphogenetic protein 2 - BMP2). Subsequently, the explant is maintained in culture for a 28-day period, allowing cellular colonization and subsequent bone formation. To evaluate the quality and structure of newly mineralized tissue, the following successive methods are set up: (i) Characterization and high-resolution 3D images of the entire explant using micro-CT, followed by deep learning image analyses to enhance the discrimination of mineralized tissues; (ii) Nano-indentation to determine the mechanical properties of the newly formed tissue; (iii) Histological examinations, such as Hematoxylin/Eosin/Saffron (HES), Goldner's trichrome, and Movat's pentachrome to provide a qualitative assessment of mineralized tissue, particularly with regard to the visualization of the osteoid barrier and the presence of bone cells; (iv) Back-scattering scanning electron microscopy (SEM) mapping with internal reference to quantify the degree of mineralization and provide detailed insights into surface morphology, mineral composition, and bone-biomaterial interface; (v) Raman spectroscopy to characterize the molecular composition of the mineralized matrix and to provide insights into the persistence of BMP2 within the cement through the detection of peptide bonds. This multimodal analysis will provide an effective assessment of newly formed bone and comprehensive qualitative and quantitative insights into mineralized tissues. Through the standardization of these protocols, we aim to facilitate interstudy comparisons and improve the validity and reliability of research findings.

<meta charset="utf8"></head><body>Autore in primo piano: Tecniche avanzate per la caratterizzazione della mineralizzazione tissutale nella ricerca sulla rigenerazione ossea

The proposed protocol entails a global approach to assess bone formation in the context of bone regeneration using multimodal analyses. It aims to provide qualitative and quantitative information on new bone formation, enhancing the rigor and validity of basic and pre-clinical investigations.

Caratterizzazione completa della mineralizzazione tissutale in un modello ex vivo

The extensive characterization of tissue mineralization in the context of bone regeneration represents a significant challenge, given the numerous ...

Bioingegneria

Characterization of Calcification Events Using Live Optical and Electron Microscopy Techniques in a Marine Tubeworm

Characterizing the first event of biological production of calcium carbonate requires a combination of microscopy approaches. First, intracellular pH distribution and calcium ions can be observed using live microscopy over time. This allows identification of the life stage and the tissue with the feature of interest for further electron microscopy studies. Life stage and tissues of interest are typically higher in pH and Ca signals. 
Here, using H. elegans, we present a protocol to characterize the presence of calcium carbonate structures in a biological specimen on the scanning electron microscope (SEM), using energy-dispersive X-ray spectroscopy (EDS) to visualize elemental composition, using electron backscatter diffraction (EBSD) to determine the presence of crystalline structures, and using transmission electron microscopy (TEM) to analyze the composition and structure of the material. In this protocol, a focused ion beam (FIB) is used to isolate samples with dimension suitable for TEM analysis. As FIB is a site specific technique, we demonstrate how information from the previous techniques can be used to identify the region of interest, where Ca signals are highest.

We demonstrate the use of various microscopy methods that are useful in observing the calcification of a tubeworm, Hydroides elegans, as well as locating and characterizing the first calcified material. Live microscopy and electron microscopy are used together to provide functional and material information that are important in studying biomineralization.

Caratterizzazione di calcificazione eventi utilizzando dal vivo ottica ed elettronica Microscopia tecniche in un tubeworm Marine

Characterizing the first event of biological production of calcium carbonate requires a combination of microscopy approaches. First, intracellular pH ...

Biologia

Bottom-Up In Vitro Methods to Assay the Ultrastructural Organization, Membrane Reshaping, and Curvature Sensitivity Behavior of Septins

Membrane remodeling occurs constantly at the plasma membrane and within cellular organelles. To fully dissect the role of the environment (ionic conditions, protein and lipid compositions, membrane curvature) and the different partners associated with specific membrane reshaping processes, we undertake in vitro bottom-up approaches. In recent years, there has been keen interest in revealing the role of septin proteins associated with major diseases. Septins are essential and ubiquitous cytoskeletal proteins that interact with the plasma membrane. They are implicated in cell division, cell motility, neuro-morphogenesis, and spermiogenesis, among other functions. It is, therefore, important to understand how septins interact and organize at membranes to subsequently induce membrane deformations and how they can be sensitive to specific membrane curvatures. This article aims to decipher the interplay between the ultra-structure of septins at a molecular level and the membrane remodeling occurring at a micron scale. To this end, budding yeast, and mammalian septin complexes were recombinantly expressed and purified. A combination of in vitro assays was then used to analyze the self-assembly of septins at the membrane. Supported lipid bilayers (SLBs), giant unilamellar vesicles (GUVs), large unilamellar vesicles (LUVs), and wavy substrates were used to study the interplay between septin self-assembly, membrane reshaping, and membrane curvature.

Bottom-Up In Vitro Methods to Assay the Ultrastructural Organization, Membrane Reshaping, and Curvature Sensitivity Behavior of Septins

Septins are cytoskeletal proteins. They interact with lipid membranes and can sense but also generate membrane curvature at the micron scale. We describe in this protocol bottom-up in vitro methodologies for analyzing membrane deformations, curvature-sensitive septin binding, and septin filament ultrastructure.

Metodi in vitro bottom-up per saggiare l'organizzazione ultrastrutturale, il rimodellamento della membrana e il comportamento di sensibilità alla curvatura delle settine

In Situ Caratterizzazione delle particelle Boehmite in acqua usando liquido SEM

Riepilogo

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Simulazione del Planetary Interior differenziazione processi in Laboratorio

Analisi tomografia atomo sonda delle fasi minerali essolte

Lavorazione dei metalli nanocristallini Bulk presso la US Army Research Laboratory

Determinazione della morfologia di superficie aggregata nella zona di transizione interfacciale (IT)

Caratterizzazione su scala nanometrica di interfacce liquido-solido mediante accoppiamento di fresatura a fascio ionico crio-focalizzato con microscopia elettronica a scansione e spettroscopia

Caratterizzazione completa della mineralizzazione tissutale in un modello ex vivo

Caratterizzazione completa della mineralizzazione tissutale in un modello ex vivo

Caratterizzazione completa della mineralizzazione tissutale in un modello ex vivo

Caratterizzazione di calcificazione eventi utilizzando dal vivo ottica ed elettronica Microscopia tecniche in un tubeworm Marine

Metodi in vitro bottom-up per saggiare l'organizzazione ultrastrutturale, il rimodellamento della membrana e il comportamento di sensibilità alla curvatura delle settine