Noi riconosciamo il sostegno finanziario dall&#39;Istituto Zernike dei materiali avanzati, Università di Groningen.

1. Preparazione e caratterizzazione di PS-b-P4VP (PDP) Complessi con Double gyroid Morfologia <ol><li> Pesare polistirene-block-poli (4-vinilpiridina) (PS-b-P4VP) e pentadecylphenol (PDP, M r = 304,51 g / mol). Per avere la morfologia gyroid, selezionare accuratamente la quantità di PDP dovrebbe essere (la frazione in peso di blocco P4VP (PDP) (f P4VP (PDP)) dovrebbe essere ca. 0,6 secondo il diagramma di fase lineari AB copolimeri a due blocchi). Solitamente, 0,15-0,2 g di un PS-b-P4VP porta a PS-b-P4VP (PDP) film spessi 50-100 micron (dato che il diametro di un piatto Petri utilizzata nel passo 1.3 è 5-6 cm). Calcolare la quantità di PDP secondo le seguenti equazioni: <img alt="Equazione 1" src="/files/ftp_upload/50673/50673eq1.jpg" /> <img alt="Equazione 2" src="/files/ftp_upload/50673/50673eq2.jpg" /> <img alt="Equazione 3" src="/files/ftp_upload/50673/50673eq3.jpg" /><br/&gt; <img alt="Equazione 4" src="/files/ftp_upload/50673/50673eq4.jpg" /></li><li> Sciogliere PS-b-P4VP e PDP in cloroformio e mescolare per un paio d&#39;ore a temperatura ambiente. Mantenere la concentrazione del polimero inferiore al 2% in peso per assicurare la formazione del complesso omogeneo. </li><li> Versare la soluzione in una capsula Petri di vetro. </li><li> Porre la capsula in un&#39;atmosfera satura di cloroformio. </li><li> Dopo circa una settimana, togliere la piastra di Petri. Un film del complesso supramolecolare è formato. </li><li> Essiccare il film in vuoto a 30 ° C per una notte. </li><li> Posizionare la pellicola in un contenitore appositamente progettato, eliminare l&#39;aria dal contenitore e poi riempire con azoto. Ricuocere la pellicola per 4 giorni nel forno a 120 ° C sotto atmosfera di N 2 con 1 bar di sovrapressione. </li><li> Tagliare il piccolo pezzo del film, incorporare in resina epossidica e curare durante la notte a 40 ° C. </li><li> Microtomo il campione ad uno spessore di circa 80 nm, usando un coltello di diamante a temperatura ambiente. The la sezione microtomed galleggia sull&#39;acqua. Raccoglierli e posizionare sulle griglie Cu. </li><li> Mettere le griglie contenenti le sezioni microtomed in un vaso con iodio. Dopo 45 min campioni sono macchiati e pronto per la trasmissione microscopia elettronica. </li><li> Inserire le griglie Cu con sezioni colorate al microscopio elettronico a trasmissione utilizzato a una tensione di accelerazione di 120 kV e l&#39;immagine del campione. </li><li> Inserire il pezzo del film (ottenuto dopo passo 1.7) nel portacampione per piccolo angolo di diffusione di raggi X e fissare con un nastro Kapton. Collocare il supporto del campione preparato nella macchina per SAXS. Aprire l&#39;otturatore di raggi X e acquisire il modello di dispersione 2D. Integrare il modello 2D ottenuto e analizzare la posizione dei picchi in 1D pattern. </li></ol> 2. Generazione e caratterizzazione della struttura porosa <ol><li> Mettere il pezzo del film (ottenuto dopo passo 1.7) in etanolo e tenerlo per tre giorni. </li><li> Essiccare il campione. </li><li> Prepare i campioni per le misurazioni 1 H NMR. Sciogliere PDP polvere, PS-b-P4VP polvere, supramolecolare PS-b-P4VP (PDP) (dopo il passo 1.7), e porosa film complesso (dopo il passo 2.2) in CDCl 3. Record 1 H NMR a temperatura ambiente. </li><li> Analizzare PS-b-P4VP polvere, supramolecolare complesso PS-b-P4VP (PDP) (dopo il passo 1.7), e il film poroso (dopo il passo 2.2) mediante calorimetria differenziale a scansione. Utilizzare una modalità modulata con una velocità di riscaldamento / raffreddamento di 1 ° C / min, una ampiezza di oscillazione di 0,5 ° C, e un periodo di oscillazione di 60 sec. Equilibrare i campioni a -30 ° C, calore a 180 ° C, raffreddare a -30 ° C, e poi riscaldare nuovamente a 180 ° C. Utilizzare i dati del secondo ciclo di riscaldamento per l&#39;analisi. </li><li> Outgas campione poroso (dopo passo 2.2) per 8 ore a temperatura ambiente e per 18 ore a 70 ° C ed eseguire misure di adsorbimento di azoto a 77 K. </li><li> Utilizzare il software appropriato (per esempio, WinADP) e modelli per analizzare le isoterme ottenuti. </li><li> Essiccare il campione poroso (dopo passo 2.2) a 50 ° C per 8 ore e degassare a temperatura ambiente e pressione di 0,5 Pa per 2 h. </li><li> Eseguire porosimetria a mercurio. </li></ol> 3. Inserimento Nickel nel polimero Template <ol><li> Pesare cloruro di stagno (SnCl 2, M r = 189.60 g / mol) e preparare una soluzione acquosa (0,1 M SnCl 2 / 0,1 M HCl; 1.896 g SnCl 2, 0,8 ml di HCl e 100 ml di H 2 O). Mettere la soluzione su una notte shaker per garantire la completa dissoluzione di SnCl 2. </li><li> Pesare cloruro di palladio (PdCl 2, M r = 177.33 g / mol) e preparare una soluzione acquosa (0,0014 M PdCl 2 / HCl 0,25 M; 0,025 g PdCl 2, 2 ml di HCl e 100 ml di H 2 O). </li><li> Preparare parte 1 del bagno di nichelatura: pesare 6,78 g di solfato di nichel esaidrato (NISO 4 • 6H 2 O, M r = 262.85 G / mol) e 2 g di citrato di sodio (Na 3 C 6 H 5 O 7, M r = 258,06 g / mol) e sciogliere in 80 ml ​​di acqua. Aggiungere 828 microlitri 85% di acido lattico (C 3 H 6 O 3, M r = 90.08 g / mol). </li><li> Preparare parte 2 del bagno di nichelatura: di peso fuori 0,2 g complessa dimetilammina borano ((CH 3) 2 NHBH 3, M r = 58,92 g / mol) e scioglierlo in 20 ml di acqua. Complesso dimetilammina borano dovrebbe essere gestita in una cappa ben ventilata. </li><li> Immergere la pellicola porosa (dopo passo 2.2) nella soluzione acquosa di cloruro di stagno (passo 3.1) per 1 ora. </li><li> Sciacquare accuratamente la pellicola con acqua deionizzata. </li><li> Immergere la pellicola nella soluzione acquosa di cloruro di palladio (passo 3.2) per 1 ora. </li><li> Sciacquare accuratamente la pellicola con acqua deionizzata. </li><li> Miscelare parte 1 (3.3) e parte 2 (3.4) del bagno di placcatura di nichel. Regolare il pH a 7,0 con idrossido di ammonio. </li><li> Immergere la pellicola nel bagno di placcatura di nichel per 1 ora. </li><li> Sciacquare accuratamente la pellicola con acqua deionizzata. </li><li> Essiccare il campione. </li><li> Preparare il campione placcato per microscopia elettronica come descritto nei passaggi 1,8-1,9. </li><li> Immagine del campione come descritto nel passaggio 1.11. </li><li> Inserire griglie Cu contenenti le sezioni del campione placcato in alta risoluzione microscopio elettronico a trasmissione. Acquisire micrografie TEM ad alta risoluzione. Osservare il campione sotto il microscopio e scegli la zona per analisi elementare da EDX (Energy Dispersive Analisi dei raggi X). Eseguire l&#39;analisi EDX della zona prescelta e analizzare il modello ottenuto. </li></ol> 4. Esposizione della Inverse gyroid Nickel Foam <ol><li> Mettere il film nichelato (dopo passo 3.12) in un forno a 350 ° C e tenerlo da 1 ora fino a 4 giorni. </li><li> Fissare il campione nel porta-campioni utilizzando una pasta d&#39;argento. </li><li> Inserire il campione nel microfono elettronico a scansioneROSCOPE. Acquisire diverse immagini del campione. </li><li> Inserire il campione nel microscopio elettronico a scansione. Osservare il campione sotto il microscopio e scegli la zona per analisi elementare da EDX. Eseguire l&#39;analisi EDX della zona prescelta e analizzare il modello ottenuto. </li></ol>

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	<li>Erlebacher, J., Aziz, M. J., Karma, A., Dimitrov, N., Sieradzki, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evolution+of+nanoporosity+in+dealloying.">Evolution of nanoporosity in dealloying.</a> Nature. 410, 450-453 (2001).</li><li>Nyce, G. W., Hayes, J. R., Hamza, A. V., Satcher, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+and+Characterization+of+Hierarchical+Porous+Gold+Materials.">Synthesis and Characterization of Hierarchical Porous Gold Materials.</a> Chem. Mater. 19, 344-346 (2007).</li><li>Detsi, E., van de Schootbrugge, M., Punzhin, S., Onck, P. R., De Hosson, J. T. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+tuning+the+morphology+of+nanoporous+gold.">On tuning the morphology of nanoporous gold.</a> Scripta Mater. 64, 319-322 (2011).</li><li>Gacoin, T., Lahlil, K., Larregaray, P., Boilot, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transformation+of+CdS+Colloids:+Sols,+Gels,+and+Precipitates.">Transformation of CdS Colloids: Sols, Gels, and Precipitates.</a> J. Phys. Chem. B. 105, 10228-10235 (2001).</li><li>Tappan, B. C., Steiner, S. A., Luther, E. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanoporous+Metal+Foams.">Nanoporous Metal Foams.</a> Angew. Chem. Int. Ed. 49, 4544-4565 (2010).</li><li>Leventis, N., Chandrasekaran, N., Sadekar, A. G., Sotiriou-Leventis, C., Lu, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=One-Pot+Synthesis+of+Interpenetrating+Inorganic/Organic.">One-Pot Synthesis of Interpenetrating Inorganic/Organic.</a> Networks of CuO/Resorcinol-Formaldehyde Aerogels: Nanostructured Energetic Materials. J. Am. Chem. Soc. 131, 4576-4577 (2009).</li><li>Leventis, N., Chandrasekaran, N., Sotiriou-Leventis, C., Mumtaz, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Smelting+in+the+age+of+nano:+iron+aerogels.">Smelting in the age of nano: iron aerogels.</a> J. Mater. Chem. 19, 63-65 (2009).</li><li>Tappan, B. 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=Ultralow-Density+Nanostructured+Metal+Foams:+Combustion+Synthesis,+Morphology,+and+Composition.">Ultralow-Density Nanostructured Metal Foams: Combustion Synthesis, Morphology, and Composition.</a> J. Am. Chem. Soc. 128, 6589-6594 (2006).</li><li>Ashby, M. 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=Metal+Foams:+a+Design+Guide.">Metal Foams: a Design Guide.</a> Butterworth-Heinemann. , (2000).</li><li>Tekoglu, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Size+Effects+in+Cellular+Solids.">Size Effects in Cellular Solids.</a> , (2007).</li><li>Amsterdam, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+Performance+and+Failure+Analysis+of+Aluminium+Foams.">Structural Performance and Failure Analysis of Aluminium Foams.</a> , (2008).</li><li>Bates, F. S., Fredrickson, G. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Block+Copolymer+Thermodynamics:+Theory+and+Experiment.">Block Copolymer Thermodynamics: Theory and Experiment.</a> Annu. Rev. Phys. Chem. 41, 525-527 (1990).</li><li>Hamley, I. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Physics of Block Copolymers. , (1998).</li><li>Abetz, V., Simon, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Advances in Polymer Science. , (2005).</li><li>Hillmyer, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanoporous+Materials+from+Block+Copolymer+Precursors.">Nanoporous Materials from Block Copolymer Precursors.</a> Adv. Polym. Sci. 190, 137-181 (2005).</li><li>Mansky, P., Harrison, C. K., Chaikin, P. M., Register, R. A., Yao, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanolithographic+templates+from+diblock+copolymer+thin+films.">Nanolithographic templates from diblock copolymer thin films.</a> Appl. Phys. Lett. 68, 2586-2588 (1996).</li><li>Hashimoto, T., Tsutsumi, K., Funaki, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanoprocessing+Based+on+Bicontinuous+Microdomains+of+Block+Copolymers:+Nanochannels+Coated+with+Metals.">Nanoprocessing Based on Bicontinuous Microdomains of Block Copolymers: Nanochannels Coated with Metals.</a> Langmuir. 13, 6869-6872 (1997).</li><li>Chen, S. -. Y., Huang, Y., Tsiang, R. C. -. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ozonolysis+efficiency+of+PS-b-PI+block+copolymers+for+forming+nanoporous+polystyrene.">Ozonolysis efficiency of PS-b-PI block copolymers for forming nanoporous polystyrene.</a> J. Polym. Sci. A Polym. Chem. 46, 1964-1973 (2008).</li><li>Thurn-Albrecht, T., 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=Nanoscopic+Templates+from+Oriented+Block+Copolymer+Films.">Nanoscopic Templates from Oriented Block Copolymer Films.</a> Adv. Mater. 12, 787-791 (2000).</li><li>Park, M., Harrison, C., Chaikin, P. M., Register, R. A., Adamson, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Block+Copolymer+Lithography:+Periodic+Arrays+of+~1011+Holes+in+1+Square+Centimeter.">Block Copolymer Lithography: Periodic Arrays of ~1011 Holes in 1 Square Centimeter.</a> Science. 276, 1401-1404 (1997).</li><li>Cheng, J. Y., Ross, C. A., Thomas, E. L., Smith, H. I., Vancso, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+of+nanostructures+with+long-range+order+using+block+copolymer+lithography.">Fabrication of nanostructures with long-range order using block copolymer lithography.</a> Appl. Phys. Lett. 81, 3657-3659 (2002).</li><li>Voet, V. S. D., 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=Interface+Segregating+Fluoralkyl-Modified+Polymers+for+High-Fidelity+Block+Copolymer+Nanoimprint+Lithography.">Interface Segregating Fluoralkyl-Modified Polymers for High-Fidelity Block Copolymer Nanoimprint Lithography.</a> J. Am. Chem. Soc. 133, 2812-2815 (2011).</li><li>Zalusky, A. S., Olayo-Valles, R., Wolf, J. H., Hillmyer, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ordered+Nanoporous+Polymers+from+Polystyrene-Polylactide+Block+Copolymers.">Ordered Nanoporous Polymers from Polystyrene-Polylactide Block Copolymers.</a> J. Am. Chem. Soc. 124, 12761-12773 (2002).</li><li>Crossland, E. J. W., 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+Bicontinuous+Double+Gyroid+Hybrid+Solar+Cell.">A Bicontinuous Double Gyroid Hybrid Solar Cell.</a> Nano Lett. 9, 2807-2812 (2008).</li><li>Uehara, 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=Size-Selective+Diffusion+in+Nanoporous+but+Flexible+Membranes+for+Glucose+Sensors.">Size-Selective Diffusion in Nanoporous but Flexible Membranes for Glucose Sensors.</a> ACS Nano. 3, 924-932 (2009).</li><li>Voet, V. S. D., 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=Poly(vinylidene+fluoride)/nickel+nanocomposites+from+semicrystalline+block+copolymer+precursors.">Poly(vinylidene fluoride)/nickel nanocomposites from semicrystalline block copolymer precursors.</a> Nanoscale. 5, 184-192 (2013).</li><li>Brinker, C. J., Scherer, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Sol-Gel Science: The Physics and Chemistry of Sol-Gel Processing. , (1990).</li><li>Hsueh, H. -. 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=Inorganic+Gyroid+with+Exceptionally+Low+Refractive+Index+from+Block+Copolymer+Templating.">Inorganic Gyroid with Exceptionally Low Refractive Index from Block Copolymer Templating.</a> Nano Lett. 10, 4994-5000 (2010).</li><li>Hsueh, H. -. Y., Ho, R. -. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bicontinuous+Ceramics+with+High+Surface+Area+from+Block+Copolymer+Templates.">Bicontinuous Ceramics with High Surface Area from Block Copolymer Templates.</a> Langmuir. 28, 8518-8529 (2012).</li><li>Riedel, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Electroless Nickel Plating. , (1991).</li><li>Mallory, G. O., Hajdu, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electroless+Plating:+Fundamentals+and+Applications.">Electroless Plating: Fundamentals and Applications.</a> American Electroplaters and Surface Finishers Society. , (1992).</li><li>Djoki&#263;, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Modern Aspects of Electrochemistry. , (2002).</li><li>Djoki&#263;, S. S., Cavallotti, P. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Modern Aspects of Electrochemistry. , (2010).</li><li>Crossland, E. J. W., Ludwigs, S., Hillmyer, M. A., Steiner, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Control+of+gyroid+forming+block+copolymer+templates:+effects+of+an+electric+field+and+surface+topography.">Control of gyroid forming block copolymer templates: effects of an electric field and surface topography.</a> Soft Matter. 6, 670-676 (2010).</li><li>Hsueh, H. 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=Nanoporous+Gyroid+Nickel+from+Block+Copolymer+Templates+via+Electroless+Plating.">Nanoporous Gyroid Nickel from Block Copolymer Templates via Electroless Plating.</a> Adv. Mater. 23, 3041-3046 (2011).</li><li>Vukovic, 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=Supramolecular+Route+to+Well-Ordered+Metal+Nanofoams.">Supramolecular Route to Well-Ordered Metal Nanofoams.</a> ACS Nano. 5, 6339-6348 (2011).</li><li>Mao, H., Hillmyer, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Macroscopic+samples+of+polystyrene+with+ordered+three-dimensional+nanochannels.">Macroscopic samples of polystyrene with ordered three-dimensional nanochannels.</a> Soft Matter. 2, 57-59 (2006).</li><li>Kobayashi, Y., Tadaki, Y., Nagao, D., Konno, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deposition+of+Gold+Nanoparticles+on+Polystyrene+Spheres+by+Electroless+Metal+Plating+Technique.">Deposition of Gold Nanoparticles on Polystyrene Spheres by Electroless Metal Plating Technique.</a> J. Phys. Conf. Ser. 61, 582-586 (2007).</li><li>Finnefrock, A. C., Ulrich, R., Toombes, G. E., Gruner, S. M., Wiesner, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+plumber's+nightmare:+a+new+morphology+in+block+copolymer-ceramic+nanocomposites+and+mesoporous+aluminosilicates.">The plumber's nightmare: a new morphology in block copolymer-ceramic nanocomposites and mesoporous aluminosilicates.</a> J. Am. Chem. Soc. 125, 13084-13093 (2003).</li><li>Tyler, C. A., Morse, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Orthorhombic+Fddd+network+in+triblock+and+diblock+copolymer+melts.">Orthorhombic Fddd network in triblock and diblock copolymer melts.</a> Phys. Rev. Lett. 94, 208-302 (2005).</li><li>Ranjan, A., Morse, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Landau+theory+of+the+orthorhombic+Fddd+phase.">Landau theory of the orthorhombic Fddd phase.</a> Phys. Rev. E. 74, 011803 (2006).</li><li>Kim, M. 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=Stability+of+the+Fddd+Phase+in+Diblock+Copolymer+Melts.">Stability of the Fddd Phase in Diblock Copolymer Melts.</a> Macromolecules. 41, 7667-7670 (2008).</li></ol>

Gli autori dichiarano interessi finanziari concorrenti.

Complessi supramolecolari vengono applicate con successo come precursori per nanofoams metallo ben ordinate. In questo metodo, il passo fondamentale è quello di acquisire il modello appropriato, cioè un modello con morfologia gyroid. Nel diagramma di fase di copolimeri a blocchi della regione gyroid è molto piccola ed è piuttosto difficile bersaglio. Ciò significa che se copolimeri a blocchi convenzionali sono usati come materiali di partenza, la sintesi piuttosto elaborati deve essere ripetuta finché la ...

Ci sono diverse tecniche disponibili per la preparazione di nanofoams metallo: dealloying 1-3, sol-gel si avvicina 4,5, nanosmelting 6,7, e la sintesi di combustione 8. Nel processo dealloying, il materiale di partenza è di solito una lega binaria, per esempio, una lega di argento e oro. Il metallo meno nobile, argento in questo caso, può essere rimosso chimicamente o elettrochimicamente risultante in una schiuma porosa disordinato oro con legamenti dimensioni nanometriche. In sintesi combustione, il metallo è mescolato con un precursore energico che rilascia energia durante la sua decomposizione e guida la formazione di metallo nanofoam 8. Studi sul comportamento meccanico di schiume metalliche indicano che in architetture disordinati sollecitazioni non possono essere trasmessi in modo efficace dalla nanoscala alla macroscala legamento complessivo 9-11. Così nanofoams metallo ben ordinate dovrebbero avere proprietà meccaniche superiori rispetto allaquelle disordinate. L&#39;idea qui rappresentata è quella di impiegare copolimeri a blocchi che si auto-assemblano in nanostrutture ordinate come precursori di nanofoams metallo. A seconda della composizione di un copolimero a blocchi, il numero totale di unità monomeriche e la misura di repulsione tra i blocchi chimicamente collegati, varie morfologie appaiono come: sferica, cilindrica, lamellare, doppio gyroid, lamellare esagonale perforato, e altri 12-14 . Inoltre, blocchi polimerici possono essere degradati selettivamente portando a materiali nanoporosi 15. I metodi più comuni sono: ozonolisi 16-18, irraggiamento UV 19, reattiva agli ioni di incisione 20-22, 23-26 e dissoluzione. Le strutture porose generati possono essere recuperate le informazioni vari materiali inorganici. Ossidi metallici (ad esempio SiO 2, TiO2) sono solitamente introdotti tramite metodo sol-gel nei canali del modello 27-29. Elplaccatura ectrochemical e electroless sono comunemente usati per depositare metallo in o su modelli 30-33. Infine, il polimero residuo può essere rimosso dal polimero / nanoibridi inorganico tramite pirolisi 2, dissoluzione 34,35, 28,29 degradazione UV, ecc Nel nostro approccio, partiamo da un complesso supramolecolare di polistirene-block-poli (4-vinilpiridina) (PS-b-P4VP) copolimero diblock e pentadecylphenol anfifilico (PDP) molecole. Questo complesso è il risultato del legame idrogeno tra PDP e anelli piridinici (Figura 1A). La composizione del copolimero a blocchi di partenza e la quantità di aggiunta PDP sono scelti in modo tale che il sistema di auto-assembla ottenuti nel bicontinuous doppia morfologia gyroid con una rete PS e un P4VP (PDP) matrice (Figura 1b). Molecole PDP diventano selettivamente dissolto in etanolo e P4VP catene crollo sulla rete PS (Figura 1c). Successivamente, utilizzando il metodo di placcatura elettrolitica, nichel si deposita nei pori del modello (Figura 1d). Dopo la rimozione del polimero residuo tramite pirolisi, un nichel gyroid nanofoam ben ordinata è ottenuto (Figura 1e).

<table border="1">
 <tbody>
 <tr>
 <td>REAGENTS:</td>
 <td></td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>PS-b-P4VP, CAS: 26222-40-2</td>
 <td>Polymer Source Inc.</td>
 <td>P9009-S4VP 
 P136-S4VP 
 P5462-S4VP 
 P3912-S4VP</td>
 <td>additional information are provided in a separate table</td>
 </tr>
 <tr>
 <td>PDP</td>
 <td>Aldrich</td>
 <td>P4402-100G-A</td>
 <td>recrystallized twice from petroleum ether</td>
 </tr>
 <tr>
 <td>SnCl2</td>
 <td>Acros Organics</td>
 <td>196981000</td>
 <td></td>
 </tr>
 <tr>
 <td>PdCl2</td>
 <td>Aldrich</td>
 <td>76050</td>
 <td></td>
 </tr>
 <tr>
 <td>NiSO4 x H2O</td>
 <td>Sigma-Aldrich</td>
 <td>227676</td>
 <td></td>
 </tr>
 <tr>
 <td>lactic acid</td>
 <td>Aldrich</td>
 <td>W261106</td>
 <td></td>
 </tr>
 <tr>
 <td>citric acid trisodium salt</td>
 <td>Sigma-Aldrich</td>
 <td>C3674</td>
 <td></td>
 </tr>
 <tr>
 <td>borane dimethyl amine complex</td>
 <td>Aldrich</td>
 <td>180238</td>
 <td></td>
 </tr>
 <tr>
 <td>PS-b-P4VP catalogue number</td>
 <td>Mn (PS), g/mol</td>
 <td>Mn(P4VP), g/mol</td>
 <td>PDI</td>
 </tr>
 <tr>
 <td>P9009-S4VP</td>
 <td>24000</td>
 <td>9500</td>
 <td>1.1</td>
 </tr>
 <tr>
 <td>P136-S4VP</td>
 <td>31900</td>
 <td>13200</td>
 <td>1.08</td>
 </tr>
 <tr>
 <td>P5462-S4VP</td>
 <td>37500</td>
 <td>16000</td>
 <td>1.3</td>
 </tr>
 <tr>
 <td>P3912-S4VP</td>
 <td>41500</td>
 <td>17500</td>
 <td>1.07</td>
 </tr>
 </tbody>
</table>

gyroid nickel nanostructures from diblock copolymer supramolecules

Schiume metalliche nanoporous possiedono una combinazione unica di proprietà - sono cataliticamente attivo, termicamente ed elettricamente conduttivo, e, inoltre, hanno alta porosità, elevato rapporto superficie-volume e di forza-peso. Purtroppo, approcci comuni per la preparazione di nanostrutture metalliche rendono i materiali con un&#39;architettura altamente disordinata, che potrebbe avere un effetto negativo sulle loro proprietà meccaniche. Copolimeri a blocchi hanno la capacità di auto-assemblano in nanostrutture ordinate e possono essere applicate come modelli per la preparazione di nanofoams metallo ben ordinate. Qui si descrive l&#39;applicazione di un complesso a base di copolimero a blocchi-supramolecolare - polistirene-blocco-poli (4-vinilpiridina) (pentadecylphenol) PS-b-P4VP (PDP) - quanto precursore ordinata nanofoam nichel. I complessi supramolecolari mostrano un comportamento di fase simile a copolimeri a blocchi tradizionali e possono auto-assemblarsi in bicontinuous gyroid morfologia with due reti PS introdotti in una P4VP (PDP) matrice. PDP può essere sciolto in etanolo che porta alla formazione di una struttura porosa che può essere riempita con il metallo. Usando una tecnica placcatura elettrolitica, nichel può essere inserito nei canali del modello. Infine, il polimero residuo può essere rimosso tramite pirolisi del polimero / nanoibridi inorganico conseguente nanoporoso spugna di nickel con morfologia inversa gyroid.

La morfologia di complessi supramolecolari PS-b-P4VP (PDP) x viene esaminato mediante TEM e SAXS figure 2a e 2b visualizzare le forme gyroid tipici di un complesso supramolecolare rappresentativo:. Della doppia onda ed i modelli carro ruote che sono noti per rappresentare proiezioni attraverso la (211) e il piano (111) della cella unitaria gyroid rispettivamente. I domini blocco PS appaiono brillanti, mentre le (PDP) domini blocco x P4VP appaiono scure a causa di iodio colorazi...

Watch this Scientific Journal Video about Gyroid Nickel Nanostructures from Diblock Copolymer Supramolecules at JoVE.com

Gyroid Nickel Nanostructures from Diblock Copolymer Supramolecules

Questo articolo descrive la preparazione di nanofoams nichel ben ordinate tramite deposizione per elettrolisi metallo su modelli nanoporose ottenuti da supramolecole base di copolimero diblock auto-assemblati.

Gyroid Nickel Nanostrutture da diblock Copolimero supramolecole

Nanoporous metal foams possess a unique combination of properties - they are catalytically active, thermally and electrically conductive, and furthermore, ...

gyroid-nickel-nanostructures-from-diblock-copolymer-supramolecules

Research

JoVE Journal

Chemistry

12.3K Views.  University of Groningen.  Questo articolo descrive la preparazione di nanofoams nichel ben ordinate tramite deposizione per elettrolisi metallo su modelli nanoporose ottenuti da supramolecole base di copolimero diblock auto-assemblati. 

Video: Gyroid Nickel Nanostructures from Diblock Copolymer Supramolecules

Nucleoside Triphosphates - From Synthesis to Biochemical Characterization

The traditional strategy for the introduction of chemical functionalities is the use of solid-phase synthesis by appending suitably modified phosphoramidite precursors to the nascent chain. However, the conditions used during the synthesis and the restriction to rather short sequences hamper the applicability of this methodology. On the other hand, modified nucleoside triphosphates are activated building blocks that have been employed for the mild introduction of numerous functional groups into nucleic acids, a strategy that paves the way for the use of modified nucleic acids in a wide-ranging palette of practical applications such as functional tagging and generation of ribozymes and DNAzymes. One of the major challenges resides in the intricacy of the methodology leading to the isolation and characterization of these nucleoside analogues.
	
	In this video article, we present a detailed protocol for the synthesis of these modified analogues using phosphorous(III)-based reagents. In addition, the procedure for their biochemical characterization is divulged, with a special emphasis on primer extension reactions and TdT tailing polymerization. This detailed protocol will be of use for the crafting of modified dNTPs and their further use in chemical biology.

The protocol described herein aims to explain and abridge the numerous obstacles in the way of the intricate route leading to modified nucleoside triphosphates. Consequently, this protocol facilitates both the synthesis of these activated building-blocks and their availability for practical applications.

Nucleosidi trifosfati - Dalla sintesi di biochimica Caratterizzazione

The  traditional strategy for the introduction of chemical functionalities is the  use of solid-phase synthesis by appending suitably modified ...

Ricerca

Chimica

Synthesis of Ligand-free CdS Nanoparticles within a Sulfur Copolymer Matrix

Aliphatic ligands are typically used during the synthesis of nanoparticles to help mediate their growth in addition to operating as high-temperature solvents. These coordinating ligands help solubilize and stabilize the nanoparticles while in solution, and can influence the resulting size and reactivity of the nanoparticles during their formation. Despite the ubiquity of using ligands during synthesis, the presence of aliphatic ligands on the nanoparticle surface can result in a number of problems during the end use of the nanoparticles, necessitating further ligand stripping or ligand exchange procedures. We have developed a way to synthesize cadmium sulfide (CdS) nanoparticles using a unique sulfur copolymer. This sulfur copolymer is primarily composed of elemental sulfur, which is a cheap and abundant material. The sulfur copolymer has the advantages of operating both as a high temperature solvent and as a sulfur source, which can react with a cadmium precursor during nanoparticle synthesis, resulting in the generation of ligand free CdS. During the reaction, only some of the copolymer is consumed to produce CdS, while the rest remains in the polymeric state, thereby producing a nanocomposite material. Once the reaction is finished, the copolymer stabilizes the nanoparticles within a solid polymeric matrix. The copolymer can then be removed before the nanoparticles are used, which produces nanoparticles that do not have organic coordinating ligands. This nascent synthesis technique presents a method to produce metal-sulfide nanoparticles for a wide variety of applications where the presence of organic ligands is not desired.

Herein we present a method to synthesize ligand-free cadmium sulfide (CdS) nanoparticles based on a unique sulfur copolymer. The sulfur copolymer operates as a high temperature solvent and a sulfur source during the nanoparticle synthesis and stabilizes the nanoparticles after the reaction.

Sintesi di CdS nanoparticelle libera-ligando all&#39;interno di una matrice zolfo Copolimero

Aliphatic ligands are typically used during the synthesis of nanoparticles to help mediate their growth in addition to operating as high-temperature ...

Anionic Polymerization of an Amphiphilic Copolymer for Preparation of Block Copolymer Micelles Stabilized by &#960;-&#960; Stacking Interactions

In this study, an amphiphilic copolymer that includes a core-forming block with phenyl groups was synthesized by living anionic polymerization of phenyl glycidyl ether (PheGE) on methoxy-polyethylene glycol (mPEG-b-PPheGE). Characterization of the copolymer revealed a narrow molecular distribution (PDI &#60; 1.03) and confirmed the degree of polymerization of mPEG122-b-(PheGE)15. The critical micelle concentration of the copolymer was evaluated using an established fluorescence method with the aggregation behavior evaluated by dynamic light scattering and transmission electronic microscopy. The potential of the copolymer for use in drug delivery applications was evaluated in a preliminary manner including in vitro biocompatibility, loading and release of the hydrophobic anti-cancer drug doxorubicin (DOX). A stable micelle formulation of DOX was prepared with drug loading levels up to 14% (wt%), drug loading efficiencies &#62; 60% (w/w) and sustained release of drug over 4 days under physiologically relevant conditions (acidic and neutral pH, presence of albumin). The high drug loading level and sustained release is attributed to stabilizing &#960;-&#960; interactions between DOX and the core-forming block of the micelles.

Anionic Polymerization of an Amphiphilic Copolymer for Preparation of Block Copolymer Micelles Stabilized by &amp;#960;-&amp;#960; Stacking Interactions

The key steps of living anionic polymerization of phenyl glycidyl ether (PheGE) on methoxy-polyethylene glycol (mPEG-b-PPheGE) are described. The resulting block copolymer micelles (BCMs) were loaded with doxorubicin 14% (wt%) and sustained release of drug over 4 days under physiologically relevant conditions was obtained.

Anionico polimerizzazione di un copolimero Amphiphilic per la preparazione di copolimero a blocchi micelle stabilizzata da π-¸ Interazioni Stacking

In this study, an amphiphilic copolymer that includes a core-forming block with phenyl groups was synthesized by living anionic polymerization of phenyl ...

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

Here, we describe a protocol that allows for shape-anisotropic cadmium chalcogenide nanocrystals (NCs), such as nanorods (NRs) and tetrapods (TPs), to be covalently and site-specifically linked via their end facets, resulting in polymer-like linear or branched chains. The linking procedure begins with a cation-exchange process in which the end facets of the cadmium chalcogenide NCs are first converted to silver chalcogenide. This is followed by the selective removal of ligands at their surface. This results in cadmium chalcogenide NCs with highly reactive silver chalcogenide end facets that spontaneously fuse upon contact with each other, thereby establishing an interparticle facet-to-facet attachment. Through the judicious choice of precursor concentrations, an extensive network of linked NCs can be produced. Structural characterization of the linked NCs is carried out via low- and high-resolution transmission electron microscopy (TEM), as well as energy-dispersive X-ray spectroscopy, which confirm the presence of silver chalcogenide domains between chains of cadmium chalcogenide NCs.

A protocol detailing how shape-anisotropic colloidal cadmium chalcogenide nanocrystals can be covalently linked via their end facets is presented here.

Faccetta--sfaccettatura che collega di cadmio colloidale forma-anisotropo Chalcogenide nanostrutture

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

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.

Sintesi di nanofili di platino-nichel e ottimizzazione per le prestazioni di riduzione di ossigeno

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.

Modificare il metodo di precipitazione chimica per la sintesi di Nb2O5 catalizzatori di nichel Bulk con elevata superficie specifica

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 ...

Preparation and Characterization of C60/Graphene Hybrid Nanostructures

Physical thermal deposition in a high vacuum environment is a clean and controllable method for fabricating novel molecular nanostructures on graphene. We present methods for depositing and passively manipulating C60 molecules on rippled graphene that advance the pursuit of realizing applications involving 1D C60/graphene hybrid structures. The techniques applied in this exposition are geared towards high vacuum systems with preparation areas capable of supporting molecular deposition as well as thermal annealing of the samples. We focus on C60 deposition at low pressure using a homemade Knudsen cell connected to a scanning tunneling microscopy (STM) system. The number of molecules deposited is regulated by controlling the temperature of the Knudsen cell and the deposition time. One-dimensional (1D) C60 chain structures with widths of two to three molecules can be prepared via tuning of the experimental conditions. The surface mobility of the C60 molecules increases with annealing temperature allowing them to move within the periodic potential of the rippled graphene. Using this mechanism, it is possible to control the transition of 1D C60 chain structures to a hexagonal close packed quasi-1D stripe structure.

Preparation and Characterization of C60/Graphene Hybrid Nanostructures

Here we present a protocol for the fabrication of C60/graphene hybrid nanostructures by physical thermal evaporation. Particularly, the proper manipulation of deposition and annealing conditions allow the control over the creation of 1D and quasi 1D C60 structures on rippled graphene.

Preparazione e caratterizzazione di nanostrutture ibride C60/Graphene

Physical thermal deposition in a high vacuum environment is a clean and controllable method for fabricating novel molecular nanostructures on graphene. We ...

Disentangling High Strength Copolymer Aramid Fibers to Enable the Determination of Their Mechanical Properties

Traditionally, soft body armor has been made from poly(p-phenylene terephthalamide) (PPTA) and ultra-high molecular weight polyethylene. However, to diversify the fiber choices in the United States body armor market, copolymer fibers based on the combination of 5-amino-2-(p-aminophenyl) benzimidazole (PBIA) and the more conventional PPTA were introduced. Little is known regarding the long-term stability of these fibers, but as condensation polymers, they are expected to have potential sensitivity to moisture and humidity. Therefore, characterizing the strength of the materials and understanding their vulnerability to environmental conditions is important for evaluating their use lifetime in safety applications. Ballistic resistance and other critical structural properties of these fibers are predicated on their strength. To accurately determine the strength of the individual fibers, it is necessary to disentangle them from the yarn without introducing any damage. Three aramid-based copolymer fibers were selected for the study. The fibers were washed with acetone followed by methanol to remove an organic coating that held the individual fibers in each yarn bundle together. This coating makes it difficult to separate single fibers from the yarn bundle for mechanical testing without damaging the fibers and affecting their strength. After washing, fourier transform infrared (FTIR) spectroscopy was performed on both washed and unwashed samples and the results were compared. This experiment has shown that there are no significant variations in the spectra of poly(p-phenylene-benzimidazole-terephthalamide-co-p-phenylene terephthalamide) (PBIA-co-PPTA1) and PBIA-co-PPTA3 after washing, and only a small variation in intensity for PBIA. This indicates that the acetone and methanol rinses are not adversely affecting the fibers and causing chemical degradation. Additionally, single fiber tensile testing was performed on the washed fibers to characterize their initial tensile strength and strain to failure, and compare those to other reported values. Iterative procedural development was necessary to find a successful method for performing tensile testing on these fibers.

The primary goal of the study is to develop a protocol to prepare consistent specimens for accurate mechanical testing of high strength copolymer aramid fibers, by removing a coating and disentangling the individual fiber strands without introducing significant chemical or physical degradation.

Districante fibre di aramide copolimero ad alta resistenza per consentire la determinazione delle loro proprietà meccaniche

Traditionally, soft body armor has been made from poly(p-phenylene terephthalamide) (PPTA) and ultra-high molecular weight polyethylene. However, to ...

Stable DNA Motifs, 1D and 2D Nanostructures Constructed from Small Circular DNA Molecules

This article presents a detailed protocol for synthesis of small circular DNA molecules, annealing of circular DNA motifs, and construction of 1D and 2D DNA nanostructures. Over decades, the rapid development of DNA nanotechnology is attributed to the use of linear DNAs as the source materials. For example, the DAO (double crossover, antiparallel, odd half-turns) tile is well-known as a building block for construction of 2D DNA lattices; the core structure of DAO is made from two linear single-stranded (ss) oligonucleotides, like two ropes making a right hand granny&#160;knot. Herein, a new type of DNA tiles called cDAO (coupled DAO) are built using a small circular ss-DNA of c64nt or c84nt (circular 64 or 84 nucleotides) as the scaffold strand and several linear ss-DNAs as the staple strands. Perfect 1D and 2D nanostructures are assembled from cDAO tiles: infinite nanowires, nanospirals, nanotubes, nanoribbons; and finite nano-rectangles. Detailed protocols are described: 1) preparation by T4 ligase and purification by denaturing PAGE (polyacrylamide gel electrophoresis) of small circular oligonucleotides, 2) annealing of stable circular tiles, followed by native PAGE analysis, 3) assembling of infinite 1D nanowires, nanorings, nanospirals, infinite 2D lattices of nanotubes and nanoribbons, and finite 2D nano-rectangles, followed by AFM (Atomic Force Microscopy) imaging. The method is simple, robust, and affordable for most labs.

This article presents a detailed protocol for T4 ligation and denaturing PAGE purification of small circular DNA molecules, annealing and native PAGE analysis of circular tiles, assembling and AFM imaging of 1D and 2D DNA nanostructures, as well as agarose gel electrophoresis and centrifugation purification of finite DNA nanostructures.

Motivi di DNA stabile, 1D e 2D nanostrutture costruito da molecole di DNA circolare piccola

This article presents a detailed protocol for synthesis of small circular DNA molecules, annealing of circular DNA motifs, and construction of 1D and 2D ...

Gene-therapy Inspired Polycation Coating for Protection of DNA Origami Nanostructures

DNA origami nanostructures hold an immense potential to be used for biological and medical applications. However, low-salt conditions and nucleases in physiological fluids induce denaturation and degradation of self-assembled DNA nanostructures. In non-viral gene delivery, enzymatic degradation of DNA is overcome by the encapsulation of the negatively charged DNA in a cationic shell. Herein, inspired by gene delivery advancements, a simple, one-step and robust methodology is presented for the stabilization of DNA origami nanostructures by coating them with chitosan and linear polyethyleneimine. The polycation coating efficiently protects DNA origami nanostructures in Mg-depleted and nuclease-rich media. This method also preserves the full addressability of enzyme- and aptamer-based functionalization of DNA nanostructures.

Here, a protocol for the protection of DNA origami nanostructures in Mg-depleted and nuclease-rich media using natural cationic polysaccharide chitosan and synthetic linear polyethyleneimine (LPEI) coatings is presented.

Terapia genica ispirato Polycation rivestimento per la protezione di nanostrutture di DNA Origami

DNA origami nanostructures hold an immense potential to be used for biological and medical applications. However, low-salt conditions and nucleases in ...