The authors acknowledge National Science Foundation grant CHE- 1214068 for supporting this research project.

1. Préparation de GMS <ol><li> Utilisez tous les produits chimiques dans le processus suivant l&#39;achat. </li><li> Préparer 75 ml de 2 M d&#39;acide chlorhydrique (HCl) solution. Peser 2,0 g de poly (éthylène glycol) -bloc-poly (propylene glycol) -bloc-poly (éthylène glycol) (P123, MW = 5800) et transférer dans le 75 préparé ml de solution 2 M de HCl. A température ambiante, sous agitation magnétique à appliquer la solution à une vitesse de 350 tr / min jusqu&#39;à ce que P123 est complètement dissous. La solution doit être limpide. </li><li> Peser 4 g de tétraéthoxysilane (TEOS, PM = 208,33) dans un petit flacon et le transfert de 180 pi de bis [3- (triéthoxysilyl) propyl] -tetrasulfide (TESPTS, PM = 538,94) dans le flacon. Secouer doucement le flacon pour mélanger les deux produits chimiques. Dans un autre flacon, peser 38 mg d&#39;acide chloroaurique (HAuCl4, 99,90%) et les dissoudre dans 1 ml d&#39;eau DI. </li><li> Augmenter la température de la solution de P123 à 35 ° C dans un bain d&#39;huile à température contrôlée par thermocouple. </li><li> Ajouter la totalité du mélange de TEOS etTESPTS préparés à l&#39;étape 1.3 à la solution P123, et de garder la solution à agitation magnétique vigoureuse de 700 r / min. Conserver la solution en remuant pendant 2 min, puis ajoutez les HAuCl4 solution préparée dans l&#39;étape 1.3 goutte à goutte dans les 30 sec. </li><li> Conserver la solution sous agitation à 700 tr / min pendant 24 heures à 35 ° C. </li><li> Après 24 heures, transférer la solution dans un flacon scellé et entreposé dans un four réglé à 100 ° C pendant 72 heures. Ceci est appelé traitement hydrothermique. </li><li> Après le traitement hydrothermique, filtrer la solution avec un papier n ° 1 de filtration et de la pression négative dans un entonnoir, puis laver avec de l&#39;eau deux fois et l&#39;éthanol trois fois pour éliminer HCl restant. Au cours de chaque processus de lavage, ajouter de l&#39;eau ou de l&#39;éthanol 1 cm au-dessus solide et attendre pour le matériau à sécher. </li><li> Transfert précipitation de filtration à un creuset en céramique et calciné à 550 ° C pendant 4 heures. Réglez le programme de rampe comme suit: 25 ° C à 550 ° C pendant 2 heures, gardez à 550 ° C pendant 4h, puis laisser l&#39;échantillon de rester dans le four avec la porte fermée jusqu&#39;à ce que la température descend en dessous de 40 ° C. </li><li> Après calcination, le produit à transférer un flacon en verre avec une spatule en plastique. Le matériau synthétisé a une couleur rouge. </li></ol> 2. réaction catalytique, oxydation de l&#39;alcool benzylique <ol><li> Etant donné que l&#39;oxydation de l&#39;alcool benzylique est une réaction en phase liquide sans solvant séparé, mesurer 5 ml d&#39;alcool benzylique (99,8%) et la transfère dans un ml à trois cols 25, puis peser 10 mg de catalyseur GMS et ajouter à un groupe benzyle l&#39;alcool. </li><li> Configuration d&#39;un bain d&#39;huile à température contrôlée sous agitation magnétique pour assurer une commande précise et uniforme de la température de réaction. </li><li> Mettez le ballon avec de l&#39;alcool benzylique et catalyseur dans le bain d&#39;huile, puis réglez la température à 100 ° C et agiter à 150 r / min. </li><li> Du débit d&#39;oxygène gazeux à 99,9% de pureté dans le ballon à 2 ml / min contrôlées par un contrôleur de débit massique. </li><li> Quand letempérature du bain d&#39;huile atteint 100 ° C et se stabilise, introduire de l&#39;oxygène gazeux dans le ballon à trois cols. </li><li> Maintenir le taux d&#39;écoulement d&#39;oxygène et de température constante, et laisser la réaction se dérouler pendant 6 heures. </li><li> Après la réaction, on filtre le produit avec un papier de filtration # 1. Recueillir la phase liquide et transférer une aliquote à une chromatographie en phase gazeuse (GC) flacon. Dans le flacon de GC, mélanger l&#39;acide acétique quatre parties HPLC de qualité pour chaque échantillon d&#39;une partie (par exemple, utiliser 36 pi échantillon et 144 pi d&#39;acide acétique.) Mettez le flacon sur un échantillonneur automatique de chromatographe en phase gazeuse pour analyse. Laver le précipité solide sur le papier filtre avec de l&#39;eau DI et de l&#39;éthanol puis laisser sécher à l&#39;air. Recueillir le solide séché avec une spatule en tant que catalyseur recyclé. </li><li> Répétez la même procédure de l&#39;expérience de l&#39;étape 2.3 à 2.7 avec le catalyseur recyclé trois fois. Dans chaque répétition, ajuster la quantité d&#39;alcool benzylique pour correspondre le rapport décrit à l&#39;étape 2.2. </li></ol> 3. TherTraitement mal de GMS pour les essais de stabilité thermique <ol><li> Peser trois portions de 300 mg séparées de GMS synthétisés, et les stocker dans des flacons de verre. Ceux-ci sont marqués comme lot 1, lot 2 et le lot 3. Conserver lot 1 que le groupe de contrôle, et de mettre le lot 2 et le lot 3 dans un four de traitement thermique. </li><li> Programme du four comme suit pour le traitement à 400 ° C: rampe de 25 ° C à 400 ° C en 0,5 heure, maintenir à 400 ° C pendant 4 heures, laisser l&#39;échantillon de rester dans le four avec la porte fermée jusqu&#39;à ce que les chutes de température dessous de 40 ° C. Mettez le lot 2 dans un creuset et démarrer le programme. </li><li> Programme du four comme suit pour le traitement à 650 ° C: rampe de 25 ° C à 650 ° C en 0,75 heure, maintenir à 650 ° C pendant 4 heures, laisser l&#39;échantillon de rester dans le four avec la porte fermée jusqu&#39;à ce que la température tombe en dessous 40 ° C. Mettez le lot 3 dans un creuset et démarrer le programme. </li></ol> 4. CaractérisationMatériaux de GMS 21,22 <ol><li> Sur l&#39;instrument de physisorption, Degas GMS matériaux avec le programme suivant: 90 ° C pendant 60 min, puis 350 ° C pendant 480 min. Exécutez une analyse complète isotherme sur les matériaux dégazé pour obtenir des données de physisorption. </li><li> Disperse GMS échantillon sur une grille de TEM de carbone à trous 200 mesh et observer l&#39;échantillon sous un microscope électronique à transmission. Restreindre grossissement sous 44,000X pour protéger le matériel. </li><li> XRD courir avec Cu Ka rayonnement (λ = 1,5418 Å). Ensemble de tube de tension 45 kV, courant du tube et de 40 mA. Recueillir intensité dans la plage de 2θ compris entre 10 ° et 90 ° avec une taille de pas de 0,008 ° et un temps de mesure de 5 secondes à chaque étape. </li></ol>

<ol>
	<li>Liguras, D. K., Kondarides, D. I., Verykios, X. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Production+of+hydrogen+for+fuel+cells+by+steam+reforming+of+ethanol+over+supported+noble+metal+catalysts.">Production of hydrogen for fuel cells by steam reforming of ethanol over supported noble metal catalysts.</a> Appl. Catal. B-Environ. 43 (4), 345-354 (2003).</li><li>Gelin, P., Primet, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Complete+oxidation+of+methane+at+low+temperature+over+noble+metal+based+catalysts:+a+review.">Complete oxidation of methane at low temperature over noble metal based catalysts: a review.</a> Appl. Catal. B-Environ. 39 (1), 1-37 (2002).</li><li>Lu, S. F., Pan, J., Huang, A. B., Zhuang, L., Lu, J. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alkaline+polymer+electrolyte+fuel+cells+completely+free+from+noble+metal+catalysts.">Alkaline polymer electrolyte fuel cells completely free from noble metal catalysts.</a> Proc. Natl. Acad. Sci. U. S. A. 105 (52), 20611-20614 (2008).</li><li>Ma, C. 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=Catalytic+oxidation+of+benzyl+alcohol+on+Au+or+Au&#8211;Pd+nanoparticles+confined+in+mesoporous+silica.">Catalytic oxidation of benzyl alcohol on Au or Au&#8211;Pd nanoparticles confined in mesoporous silica.</a> Applied Catalysis B: Environmental. 92 (1-2), 202-208 (2009).</li><li>Bamwenda, G. R., Tsubota, S., Nakamura, T., Haruta, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+influence+of+the+preparation+methods+on+the+catalytic+activity+of+platinum+and+gold+supported+on+TiO2+for+CO+oxidation.">The influence of the preparation methods on the catalytic activity of platinum and gold supported on TiO2 for CO oxidation.</a> Catalysis Letters. 44 (1-2), 83-87 (1997).</li><li>Brown, K. R., Walter, D. G., Natan, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Seeding+of+colloidal+Au+nanoparticle+solutions.+2.">Seeding of colloidal Au nanoparticle solutions. 2.</a> Improved control of particle size. 12 (2), 306-313 (2000).</li><li>Niesz, K., Grass, M., Somorjai, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Precise+control+of+the+Pt+nanoparticle+size+by+seeded+growth+using+EO13PO30EO13+triblock+copolymers+as+protective+agents.">Precise control of the Pt nanoparticle size by seeded growth using EO13PO30EO13 triblock copolymers as protective agents.</a> Nano Lett. 5 (11), 2238-2240 (2005).</li><li>Yuranov, 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=Pd/SiO2+catalysts:+synthesis+of+Pd+nanoparticles+with+the+controlled+size+in+mesoporous+silicas.">Pd/SiO2 catalysts: synthesis of Pd nanoparticles with the controlled size in mesoporous silicas.</a> J. Mol. Catal. A-Chem. 192, 1-2 (2003).</li><li>Brinas, R. P., Hu, M. H., Qian, L. P., Lymar, E. S., Hainfeld, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gold+nanoparticle+size+controlled+by+polymeric+Au(I)+thiolate+precursor+size.">Gold nanoparticle size controlled by polymeric Au(I) thiolate precursor size.</a> J. Am. Chem. Soc. 130 (3), 975-982 (2008).</li><li>Zhu, H. G., Liang, C. D., Yan, W. F., Overbury, S. H., Dai, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+highly+active+silica-supported+Au+catalysts+for+CO+oxidation+by+a+solution-based+technique.">Preparation of highly active silica-supported Au catalysts for CO oxidation by a solution-based technique.</a> J. Phys. Chem. B. 110 (22), 10842-10848 (2006).</li><li>Gabaldon, J. P., Bore, M., Datye, A. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mesoporous+silica+supports+for+improved+thermal+stability+in+supported+Au+catalysts.">Mesoporous silica supports for improved thermal stability in supported Au catalysts.</a> Top. Catal. 44 (1-2), 253-262 (2007).</li><li>Li, F. B., Li, X. Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+enhancement+of+photodegradation+efficiency+using+Pt-TiO2+catalyst.">The enhancement of photodegradation efficiency using Pt-TiO2 catalyst.</a> Chemosphere. 48 (10), 1103-1111 (2002).</li><li>Sakthivel, 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=Enhancement+of+photocatalytic+activity+by+metal+deposition:+characterisation+and+photonic+efficiency+of+Pt,+Au+and+Pd+deposited+on+TiO2+catalyst.">Enhancement of photocatalytic activity by metal deposition: characterisation and photonic efficiency of Pt, Au and Pd deposited on TiO2 catalyst.</a> Water Res. 38 (13), 3001-3008 (2004).</li><li>Jia, C. G., Wang, Y. P., Feng, H. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+and+Catalytic+Properties+Of+Polymer-Supported+Fe-Co-Cu+And+Fe-Co-Au+Pentametallic+Clusters.">Preparation and Catalytic Properties Of Polymer-Supported Fe-Co-Cu And Fe-Co-Au Pentametallic Clusters.</a> React. Polym. 18 (3), 203-211 (1992).</li><li>Yu, X. Q., 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=Reduced+graphene+oxide+supported+Au+nanoparticles+as+an+efficient+catalyst+for+aerobic+oxidation+of+benzyl+alcohol.">Reduced graphene oxide supported Au nanoparticles as an efficient catalyst for aerobic oxidation of benzyl alcohol.</a> Appl. Surf. Sci. 280, 450-455 (2013).</li><li>Xu, Y. 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=Au@Pt+core-shell+nanoparticles+supported+on+multiwalled+carbon+nanotubes+for+methanol+oxidation.">Au@Pt core-shell nanoparticles supported on multiwalled carbon nanotubes for methanol oxidation.</a> Catal. Commun. 13 (1), 54-58 (2011).</li><li>Baker, C. O., 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=Size+Control+of+Gold+Nanoparticles+Grown+on+Polyaniline+Nanofibers+for+Bistable+Memory+Devices.">Size Control of Gold Nanoparticles Grown on Polyaniline Nanofibers for Bistable Memory Devices.</a> ACS Nano. 5 (5), 3469-3474 (2011).</li><li>Wei, G. -. T., Yang, Z., Lee, C. Y., Yang, H. Y., Wang, C. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aqueous&#8722;Organic+Phase+Transfer+of+Gold+Nanoparticles+and+Gold+Nanorods+Using+an+Ionic+Liquid.">Aqueous&#8722;Organic Phase Transfer of Gold Nanoparticles and Gold Nanorods Using an Ionic Liquid.</a> J. Am. Chem. Soc. 126 (16), 5036-5037 (2004).</li><li>Gadenne, B., Hesemann, P., Moreau, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Supported+ionic+liquids:+ordered+mesoporous+silicas+containing+covalently+linked+ionic+species.">Supported ionic liquids: ordered mesoporous silicas containing covalently linked ionic species.</a> Chemical Communications. 15, 1768-1769 (2004).</li><li>Yang, J. H., 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=Understanding+preparation+variables+in+the+synthesis+of+Au/Al2O3+using+EXAFS+and+electron+microscopy.">Understanding preparation variables in the synthesis of Au/Al2O3 using EXAFS and electron microscopy.</a> Applied Catalysis A: General. 291 (1-2), 73-84 (2005).</li><li>Chen, L. F., 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=Intercalation+of+aggregation-free+and+well-dispersed+gold+nanoparticles+into+the+walls+of+mesoporous+silica+as+a+robust+&#8216;green&#8217;+catalyst+for+n-alkane+oxidation.">Intercalation of aggregation-free and well-dispersed gold nanoparticles into the walls of mesoporous silica as a robust &#8216;green&#8217; catalyst for n-alkane oxidation.</a> Journal of the American Chemical Society. 131, 914-915 (2009).</li><li>Wang, 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=Nanoscale+gold+intercalated+into+mesoporous+silica+as+a+highly+active+and+robust+catalyst.">Nanoscale gold intercalated into mesoporous silica as a highly active and robust catalyst.</a> Nanotechnology. 23, 294010-294018 (2012).</li><li>Chen, L. F., 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=Controlled+synthesis+of+nanoscale+icosahedral+gold+particles+at+room+temperature.">Controlled synthesis of nanoscale icosahedral gold particles at room temperature.</a> Chemcatchem. 4, 1662-1667 (2012).</li></ol>

The authors have nothing to disclose.

Dans le protocole de synthèse, l&#39;attention de concentration en tensioactif, pH de la solution et la température de réaction est essentielle à la formation réussie de GMS. Les étapes essentielles sont 1,2, 1,3, 1,4 et 1,6. Les paramètres mentionnés ci-dessus contrôlent le paramètre de tassement critique et la phase de micelles formées à partir de tensio-actif. La phase et la morphologie de micelle détermine l&#39;état final de la matrice de silice, qui sert de cadre pour GMS. Il est également important...

Comme une technologie émergente qui a un grand potentiel dans les applications de catalyse, matériaux nanométriques ont suscité l&#39;intérêt de recherches intensives dans les dernières décennies. Parmi les catalyseurs à l&#39;échelle nanométrique ont indiqué, les catalyseurs de métaux nobles tels que Au, Ag, Pd et Pt ont attiré l&#39;attention dans le monde entier de 1 à 3. Sélectionner des réactions catalytiques comprennent l&#39;oxydation des chercheurs de monoxyde de carbone sur Au, réaction de Heck sur des catalyseurs de Pd, et décomposition de l&#39;eau avec Pt. En dépit du potentiel prometteur catalytique, de l&#39;or à l&#39;échelle nanométrique est limité dans son application en raison de la désactivation de l&#39;empoisonnement, la cokéfaction, la dégradation thermique, et le frittage. Il a été rapporté que l&#39;or, en tant que représentant pour les métaux nobles, a une haute sélectivité et est moins sujette à la lixiviation des métaux, sur-oxydation, et l&#39;auto-empoisonnement 4. Cependant, la performance catalytique d&#39;or dépend fortement de la taille des particules. Haruta et al. A rapporté la relation entre la performance catalytique et allerdiamètre de la grappe ld, ce qui démontre la plus grande activité des catalyseurs de l&#39;or ayant une taille de particule de 2,7 ~ 5 nm. La taille des particules de métaux nobles peut être contrôlé par le procédé de préparation 6-9; Cependant, l&#39;obstacle majeur vers une large application reste agrégation et perte d&#39;activité. Pour résoudre le problème de frittage, une méthode courante consiste à immobiliser des particules nanométriques sur un matériau de support. Diverses matières de support ont été appliquées, y compris la silice poreuse 10 à 11, les oxydes métalliques semi-conducteurs 12 à 13, les polymères 14, 15 graphène et des nanotubes de carbone 16. Parmi les matériaux utilisés, la silice poreuse est un matériau intéressant en tant que support, car il est seulement légèrement acide, relativement inerte, thermiquement et chimiquement stable, et peut être préparé avec méso / micro-porosité très bien défini. La structure poreuse offre un bon soutien pour les particules métalliques, mais donne également un accès taille du substrat sélectifles catalyseurs à base de métal. Cette sélectivité est particulièrement prometteuse du fait de l&#39;accordabilité associée à ces matériaux poreux. Souvent, les particules d&#39;or se trouvent à être extrêmement mobile sur des surfaces de silice 17-18 et facilement former de très grandes (50 nm) particules non réactifs lorsqu&#39;ils sont exposés à des températures élevées, ce qui rend difficile de préparer des nanoparticules d&#39;or sur silice 19. Mukherjee et al. Immobilisation déclarés de nanoparticules d&#39;or monodispersés sur mésoporeux silice MCM-41 par le 3-aminopropyl-triméthoxysilane et le 3-mercaptopropyl-triéthoxysilane, et les nanoparticules d&#39;or supportés se sont révélés être très actif pour les réactions d&#39;hydrogénation et non lixiviation de l&#39;or a été trouvé 20 dans la réaction. Suite au rapport de la modification de surface de silice mésoporeuse, nous avons rapporté une méthode pour préparer l&#39;or intercalé dans la paroi de silice mésoporeuse (GMS). En outre, l&#39;approche silice mésoporeuse soutenue offre une ap évolutiveapproche potentiellement modifier indépendamment le catalyseur et milieu poreux. Depuis procédés catalytiques sont d&#39;une importance économique vitale, les avantages pourraient être considérables. La capacité à développer des catalyseurs &quot;verts&quot; aurait un impact positif considérable sur l&#39;environnement et améliorer la faisabilité et l&#39;efficacité des ressources économiques des processus industriels importants.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol)</td>
			<td>Aldrich</td>
			<td>435465-250ML</td>
			<td></td>
		</tr>
		<tr>
			<td>tetraethoxysilane</td>
			<td>TCI</td>
			<td>201-083-8</td>
			<td></td>
		</tr>
		<tr>
			<td>bis[3-(triethoxysilyl)propyl]-tetrasulfide</td>
			<td>GELEST</td>
			<td>SIB1825.0-100GM</td>
			<td></td>
		</tr>
		<tr>
			<td>chloroauric acid</td>
			<td>Aldrich</td>
			<td>520918-1G</td>
			<td></td>
		</tr>
		<tr>
			<td>benzyl alcohol</td>
			<td>Sigma-Aldrich</td>
			<td>305197-1L</td>
			<td></td>
		</tr>
		<tr>
			<td>nitrogen physisorption</td>
			<td>Micromeritics</td>
			<td>Tristar II</td>
			<td></td>
		</tr>
		<tr>
			<td>X-ray diffraction</td>
			<td>Philips</td>
			<td>X&#39;Pert Pro</td>
			<td></td>
		</tr>
		<tr>
			<td>transmission electron microscopy</td>
			<td>Philips</td>
			<td>CM200</td>
			<td></td>
		</tr>
		<tr>
			<td>gas chromatography</td>
			<td>Shimadzu</td>
			<td>GC-2010</td>
			<td></td>
		</tr>
	</tbody>
</table>

synthesis and catalytic performance of gold intercalated in the walls of mesoporous silica

En tant que réacteur de nano promettant catalytiquement actif, des nanoparticules d&#39;or intercalés en silice mésoporeuse (GMS) ont été synthétisés avec succès et les propriétés des matériaux ont été étudiés. Nous avons utilisé une approche sol-gel d&#39;un pot d&#39;intercaler des nano particules d&#39;or dans les murs de silice mésoporeuse. Pour commencer la synthèse, P123 a été utilisé comme matrice pour former des micelles. Puis TESPTS a été utilisé comme agent de modification de surface pour intercaler des nanoparticules d&#39;or. À la suite de ce processus, on a ajouté en TEOS en tant que source de silice qui a subi un procédé de polymérisation en milieu acide. Après le traitement hydrothermique et calcination, le produit final a été acquise. Plusieurs techniques ont été utilisées pour caractériser la porosité, de la morphologie et de la structure de la silice mésoporeuse intercalé d&#39;or. Les résultats ont montré une structure stable de silice mésoporeuse, après intercalation d&#39;or. Grâce à l&#39;oxydation de l&#39;alcool benzylique comme une réaction de référence, les matériaux de la GMS ont montré haute selectivité et la recyclabilité.

Cette méthode a été utilisée pour comparer les niveaux de synthèse de l&#39;hème dans la normale (HBEC30KT) vs. cancer (HCC4017) les cellules pulmonaires. La figure 2 montre un niveau plus élevé de la synthèse de l&#39;hème dans les cellules cancéreuses (de HCC4017) que les cellules pulmonaires normales (HBEC30KT). Le niveau de synthèse de l&#39;hème a également été mesurée dans les cellules normales et cancéreuses en présence de cyanure de carbonyle découpleur 3-chlorophénylhydrazo...

Watch this Scientific Journal Video about Synthesis and Catalytic Performance of Gold Intercalated in the Walls of Mesoporous Silica at JoVE.com

Synthesis and Catalytic Performance of Gold Intercalated in the Walls of Mesoporous Silica

Here, we present a protocol with a sol-gel process to synthesize gold intercalated in the walls of mesoporous materials (GMS), which is confirmed to possess a mesoporous matrix with gold intercalated in the walls imparting great stability and recyclability.

Synthèse et performance catalytique de l&#39;or intercalé dans les murs de silice mésoporeuse

As a promising catalytically active nano reactor, gold nanoparticles intercalated in mesoporous silica (GMS) were successfully synthesized and properties ...

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Chemistry

9.9K vues.  Colorado School of Mines. Here, we present a protocol with a sol-gel process to synthesize gold intercalated in the walls of mesoporous materials (GMS), which is confirmed to possess a mesoporous matrix with gold intercalated in the walls imparting great stability and recyclability.

Vidéo: Synthesis and Catalytic Performance of Gold Intercalated in the Walls of Mesoporous Silica

Isolation and Preparation of Bacterial Cell Walls for Compositional Analysis by Ultra Performance Liquid Chromatography

The bacterial cell wall is critical for the determination of cell shape during growth and division, and maintains the mechanical integrity of cells in the face of turgor pressures several atmospheres in magnitude. Across the diverse shapes and sizes of the bacterial kingdom, the cell wall is composed of peptidoglycan, a macromolecular network of sugar strands crosslinked by short peptides. Peptidoglycan&#8217;s central importance to bacterial physiology underlies its use as an antibiotic target and has motivated genetic, structural, and cell biological studies of how it is robustly assembled during growth and division. Nonetheless, extensive investigations are still required to fully characterize the key enzymatic activities in peptidoglycan synthesis and the chemical composition of bacterial cell walls. High Performance Liquid Chromatography (HPLC) is a powerful analytical method for quantifying differences in the chemical composition of the walls of bacteria grown under a variety of environmental and genetic conditions, but its throughput is often limited. Here, we present a straightforward procedure for the isolation and preparation of bacterial cell walls for biological analyses of peptidoglycan via HPLC and Ultra Performance Liquid Chromatography (UPLC), an extension of HPLC that utilizes pumps to deliver ultra-high pressures of up to 15,000 psi, compared with 6,000 psi for HPLC. In combination with the preparation of bacterial cell walls presented here, the low-volume sample injectors, detectors with high sampling rates, smaller sample volumes, and shorter run times of UPLC will enable high resolution and throughput for novel discoveries of peptidoglycan composition and fundamental bacterial cell biology in most biological laboratories with access to an ultracentrifuge and UPLC.

The bacterial cell wall is composed of peptidoglycan, a macromolecular network of sugar strands crosslinked by peptides. Ultra Performance Liquid Chromatography provides high resolution and throughput for novel discoveries of peptidoglycan composition. We present a procedure for the isolation of cell walls (sacculi) and their subsequent preparation for analysis via UPLC.

Isolement et préparation de parois cellulaires bactériennes pour l’analyse de composition par chromatographie liquide ultra-performante

The bacterial cell wall is critical for the determination of cell shape during growth and division, and maintains the mechanical integrity of cells in the ...

Recherche

Chimie

Sequencing of Plant Wall Heteroxylans Using Enzymic, Chemical (Methylation) and Physical (Mass Spectrometry, Nuclear Magnetic Resonance) Techniques

This protocol describes the specific techniques used for the characterization of reducing end (RE) and internal region glycosyl sequence(s) of heteroxylans. De-starched wheat endosperm cell walls were isolated as an alcohol-insoluble residue (AIR)1 and sequentially extracted with water (W-sol Fr) and 1 M KOH containing 1% NaBH4 (KOH-sol Fr) as described by Ratnayake et al. (2014)2. Two different approaches (see summary in Figure 1) are adopted. In the first, intact W-sol AXs are treated with 2AB to tag the original RE backbone chain sugar residue and then treated with an endoxylanase to generate a mixture of 2AB-labelled RE and internal region reducing oligosaccharides, respectively. In a second approach, the KOH-sol Fr is hydrolyzed with endoxylanase to first generate a mixture of oligosaccharides which are subsequently labelled with 2AB. The enzymically released ((un)tagged) oligosaccharides from both W- and KOH-sol Frs are then methylated and the detailed structural analysis of both the native and methylated oligosaccharides is performed using a combination of MALDI-TOF-MS, RP-HPLC-ESI-QTOF-MS and ESI-MSn. Endoxylanase digested KOH-sol AXs are also characterized by nuclear magnetic resonance (NMR) that also provides information on the anomeric configuration. These techniques can be applied to other classes of polysaccharides using the appropriate endo-hydrolases.

Sequencing of Plant Wall Heteroxylans Using Enzymic, Chemical Methylation and Physical Mass Spectrometry, Nuclear Magnetic Resonance Techniques

This protocol describes the specific techniques used for the structural characterization of reducing end (RE) and internal region glycosyl sequence(s) of heteroxylans by tagging the RE with 2 aminobenzamide prior to enzymatic (endoxylanase) hydrolysis and then analysis of the resultant oligosaccharides using mass spectrometry (MS) and nuclear magnetic resonance (NMR).

Le séquençage de l&#39;usine mur hétéroxylanes Utilisation enzymatique, chimique (méthylation) et physiques (spectrométrie de masse, résonance magnétique nucléaire) Techniques

This protocol describes the specific techniques used for the characterization of reducing end (RE) and internal region glycosyl sequence(s) of ...

Synthesis of Protein Bioconjugates via Cysteine-maleimide Chemistry

The chemical linking or bioconjugation of proteins to fluorescent dyes, drugs, polymers and other proteins has a broad range of applications, such as the development of antibody drug conjugates (ADCs) and nanomedicine, fluorescent microscopy and systems chemistry. For many of these applications, specificity of the bioconjugation method used is of prime concern. The Michael addition of maleimides with cysteine(s) on the target proteins is highly selective and proceeds rapidly under mild conditions, making it one of the most popular methods for protein bioconjugation.
We demonstrate here the modification of the only surface-accessible cysteine residue on yeast cytochrome c with a ruthenium(II) bisterpyridine maleimide. The protein bioconjugation is verified by gel electrophoresis and purified by aqueous-based fast protein liquid chromatography in 27% yield of isolated protein material. Structural characterization with MALDI-TOF MS and UV-Vis is then used to verify that the bioconjugation is successful. The protocol shown here is easily applicable to other cysteine - maleimide coupling of proteins to other proteins, dyes, drugs or polymers.

Synthesis of Protein Bioconjugates via Cysteine-maleimide Chemistry

This protocol details the important steps required for the bioconjugation of a cysteine containing protein to a maleimide, including reagent purification, reaction conditions, bioconjugate purification and bioconjugate characterization.

Synthèse des bioconjugués protéiques<em&gt; via</em&gt; Cystéine-maléimide Chemistry

The chemical linking or bioconjugation of proteins to fluorescent dyes, drugs, polymers and other proteins has a broad range of applications, such as the ...

Hydroquinone Based Synthesis of Gold Nanorods

Gold nanorods are an important kind of nanoparticles characterized by peculiar plasmonic properties. Despite their widespread use in nanotechnology, the synthetic methods for the preparation of gold nanorods are still not fully optimized. In this paper we describe a new, highly efficient, two-step protocol based on the use of hydroquinone as a mild reducing agent. Our approach allows the preparation of nanorods with a good control of size and aspect ratio (AR) simply by varying the amount of hexadecyl trimethylammonium bromide (CTAB) and silver ions (Ag+) present in the "growth solution". By using this method, it is possible to markedly reduce the amount of CTAB, an expensive and cytotoxic reagent, necessary to obtain the elongated shape. Gold nanorods with an aspect ratio of about 3 can be obtained in the presence of just 50 mM of CTAB (versus 100 mM used in the standard protocol based on the use of ascorbic acid), while shorter gold nanorods are obtained using a concentration as low as 10 mM.

This paper describes a protocol for the synthesis of gold nanorods, based on the use of hydroquinone as reducing agent, plus the different mechanisms for controlling their size and aspect ratio.

Hydroquinone Based Synthèse de l&#39;or nanorods

Gold nanorods are an important kind of nanoparticles characterized by peculiar plasmonic properties. Despite their widespread use in nanotechnology, the ...

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions

Detailed and generalized protocols are presented for the synthesis and subsequent purification of four palladium N-heterocyclic carbene complexes from benzimidazolium salts. Detailed and generalized protocols are also presented for testing the catalytic activity of such complexes in arylation and Suzuki-Miyaura cross-coupling reactions. Representative results are shown for the catalytic activity of the four complexes in arylation and Suzuki-Miyaura type reactions. For each of the reactions investigated, at least one of the four complexes successfully catalyzed the reaction, qualifying them as promising candidates for catalysis of many carbon-carbon bond-forming reactions. The protocols presented are general enough to be adapted for the synthesis, purification and catalytic activity testing of new palladium N-heterocyclic carbene complexes.

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions

Detailed and generalized protocols are presented for the synthesis and subsequent purification of four palladium N-heterocyclic carbene complexes from benzimidazolium salts. The complexes were tested for catalytic activity in arylation and Suzuki-Miyaura reactions. For each reaction investigated, at least one of the four complexes successfully catalyzed the reaction.

Palladium<em&gt; N</em&gt; - Complexes de carbène hétérocyclique: synthèse des sels de benzimidazolium et activité catalytique dans les réactions de formation de liaison carbone-carbone

Detailed and generalized protocols are presented for the synthesis and subsequent purification of four palladium N-heterocyclic carbene complexes from ...

Synthesis of Platinum-nickel Nanowires and Optimization for Oxygen Reduction Performance

Platinum-nickel (Pt-Ni) nanowires were developed as fuel cell electrocatalysts, and were optimized for the performance and durability in the oxygen reduction reaction. Spontaneous galvanic displacement was used to deposit Pt layers onto Ni nanowire substrates. The synthesis approach produced catalysts with high specific activities and high Pt surface areas. Hydrogen annealing improved Pt and Ni mixing and specific activity. Acid leaching was used to preferentially remove Ni near the nanowire surface, and oxygen annealing was used to stabilize near-surface Ni, improving durability and minimizing Ni dissolution. These protocols detail the optimization of each post-synthesis processing step, including hydrogen annealing to 250 &#176;C, exposure to 0.1 M nitric acid, and oxygen annealing to 175 &#176;C. Through these steps, Pt-Ni nanowires produced increased activities more than an order of magnitude than Pt nanoparticles, while offering significant durability improvements. The presented protocols are based on Pt-Ni systems in the development of fuel cell catalysts. These techniques have also been used for a variety of metal combinations, and can be applied to develop catalysts for a number of electrochemical processes.

&#160; The protocol describes the synthesis and electrochemical testing of platinum-nickel nanowires. Nanowires were synthesized by the galvanic displacement of a nickel nanowire template. Post-synthesis processing, including hydrogen annealing, acid leaching, and oxygen annealing were used to optimize nanowire performance and durability in the oxygen reduction reaction.

Synthèse de nanofils Platinum-nickel et optimisation des performances de réduction de l’oxygène

Platinum-nickel (Pt-Ni) nanowires were developed as fuel cell electrocatalysts, and were optimized for the performance and durability in the oxygen ...

Chemical Precipitation Method for the Synthesis of Nb2O5 Modified Bulk Nickel Catalysts with High Specific Surface Area

We demonstrate a method for the synthesis of NixNb1-xO catalysts with sponge-like and fold-like nanostructures. By varying the Nb:Ni ratio, a series of NixNb1-xO nanoparticles with different atomic compositions (x = 0.03, 0.08, 0.15, and 0.20) have been prepared by chemical precipitation. These NixNb1-xO catalysts are characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy. The study revealed the sponge-like and fold-like appearance of Ni0.97Nb0.03O and Ni0.92Nb0.08O on the NiO surface, and the larger surface area of these NixNb1-xO catalysts, compared with the bulk NiO. Maximum surface area of 173 m2/g can be obtained for Ni0.92Nb0.08O catalysts. In addition, the catalytic hydroconversion of lignin-derived compounds using the synthesized Ni0.92Nb0.08O catalysts have been investigated.

Chemical Precipitation Method for the Synthesis of Nb2O5 Modified Bulk Nickel Catalysts with High Specific Surface Area

A protocol for the synthesis of sponge-like and fold-like Ni1-xNbxO nanoparticles by chemical precipitation is presented.

Méthode de précipitation chimique pour la synthèse de Nb2O5 modifiée catalyseurs Nickel en vrac avec le haute surface spécifique

We demonstrate a method for the synthesis of NixNb1-xO catalysts with sponge-like and fold-like nanostructures. By varying the Nb:Ni ratio, a series of ...

Rapid Nanoprobe Signal Enhancement by In Situ Gold Nanoparticle Synthesis

The use of nanoprobes such as gold, silver, silica or iron-oxide nanoparticles as detection reagents in bioanalytical assays can enable high sensitivity and convenient colorimetric readout. However, high densities of nanoparticles are typically needed for detection. The available synthesis-based enhancement protocols are either limited to gold and silver nanoparticles or rely on precise enzymatic control and optimization. Here, we present a protocol to enhance the colorimetric readout of gold, silver, silica, and iron oxide nanoprobes. It was observed that the colorimetric signal can be improved by up to a 10000-fold factor. The basis for such signal enhancement strategies is the chemical reduction of Au3+ to Au0. There are several chemical reactions that enable the reduction of Au3+ to Au0. In the protocol, Good&#39;s buffers and H2O2 are used and it is possible to favor the deposition of Au0 onto the surface of existing nanoprobes, in detriment of the formation of new gold nanoparticles. The protocol consists of the incubation of the microarray with a solution consisting of chloroauric acid and H2O2 in 2-(N-morpholino)ethanesulfonic acid pH 6 buffer following the nanoprobe-based detection assay. The enhancement solution can be applied to paper and glass-based sensors. Moreover, it can be used in commercially available immunoassays as demonstrated by the application of the method to a commercial allergen microarray. The signal development requires less than 5 min of incubation with the enhancement solution and the readout can be assessed by naked eye or low-end image acquisition devices such as a table-top scanner or a digital camera.

Rapid Nanoprobe Signal Enhancement by In Situ Gold Nanoparticle Synthesis

In this work, a protocol for signal enhancement of nanoprobe-based biosensing is presented. The protocol is based on the reduction of chloroauric acid onto the surface of existing nanoprobes that consist of gold, silver, silica or iron-oxide nanoparticles.

Signal Nanoprobe rapide amélioration de la synthèse de nanoparticules or In Situ

The use of nanoprobes such as gold, silver, silica or iron-oxide nanoparticles as detection reagents in bioanalytical assays can enable high sensitivity ...

Synthesis and Characterization of Amphiphilic Gold Nanoparticles

Gold nanoparticles covered with a mixture of 1-octanethiol (OT) and 11-mercapto-1-undecane sulfonic acid (MUS) have been extensively studied because of their interactions with cell membranes, lipid bilayers, and viruses. The hydrophilic ligands make these particles colloidally stable in aqueous solutions and the combination with hydrophobic ligands creates an amphiphilic particle that can be loaded with hydrophobic drugs, fuse with the lipid membranes, and resist nonspecific protein adsorption. Many of these properties depend on nanoparticle size and the composition of the ligand shell. It is, therefore, crucial to have a reproducible synthetic method and reliable characterization techniques that allow the determination of nanoparticle properties and the ligand shell composition. Here, a one-phase chemical reduction, followed by a thorough purification to synthesize these nanoparticles with diameters below 5 nm, is presented. The ratio between the two ligands on the surface of the nanoparticle can be tuned through their stoichiometric ratio used during synthesis. We demonstrate how various routine techniques, such as transmission electron microscopy (TEM), nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), and ultraviolet-visible (UV-Vis) spectrometry, are combined to comprehensively characterize the physicochemical parameters of the nanoparticles.

Amphiphilic gold nanoparticles can be used in many biological applications. A protocol to synthesize gold nanoparticles coated by a binary mixture of ligands and a detailed characterization of these particles is presented.

Synthèse et caractérisation des nanoparticules d'or amphiphiles

Gold nanoparticles covered with a mixture of 1-octanethiol (OT) and 11-mercapto-1-undecane sulfonic acid (MUS) have been extensively studied because of ...

Gold Nanoparticle Synthesis

Gold nanoparticles (Au nanoparticles) that are ~12 nm in diameter were synthesized by rapidly injecting a solution of 150 mg (0.15 mmol) of tetrachloroauric acid in 3.0 g (3.7 mmol, 3.6 mL) of oleylamine (technical grade) and 3.0 mL of toluene into a boiling solution of 5.1 g (6.4 mmol, 8.7 mL) of oleylamine in 147 mL of toluene. While boiling and mixing the reaction solution for 2 hours, the color of the reaction mixture changed from clear, to light yellow, to light pink, and then slowly to dark red. The heat was then turned off, and the solution was allowed to gradually cool down to room temperature for 1 hour. The gold nanoparticles were then collected and separated from the solution using a centrifuge and washed three times; by vortexing and dispersing the gold nanoparticles in 10 mL portions of toluene, and then precipitating the gold nanoparticles by adding 40 mL portions of methanol and spinning them in a centrifuge. The solution was then decanted to remove any remaining byproducts and unreacted starting materials. Drying the gold nanoparticles in a vacuum environment produced a solid black pellet; which could be stored for long periods of time (up to one year) for later use, and then redissolved in organic solvents such as toluene.

A protocol for synthesizing ~12 nm diameter gold nanoparticles (Au nanoparticles) in an organic solvent is presented. The gold nanoparticles are capped with oleylamine ligands to prevent agglomeration. The gold nanoparticles are soluble in organic solvents such as toluene.