Reconocemos el apoyo financiero del Instituto de Zernike de Materiales Avanzados de la Universidad de Groningen.

1. Preparación y Caracterización de PS-b-P4VP (PDP) Complejos con doble Gyroid Morfología <ol><li> Pesar de poliestireno de bloque de poli (4-vinilpiridina) (PS-b-P4VP) y pentadecilfenol (PDP, Mr = 304,51 g / mol). Con el fin de obtener la morfología giroide, seleccionar cuidadosamente la cantidad de PDP debe ser (la fracción en peso de P4VP (PDP) bloque (f P4VP (PDP)) debería ser de aprox. 0,6 de acuerdo con el diagrama de fases de copolímeros lineales dibloque AB). Por lo general, 0,15-0,2 g de un PS-b-P4VP conduce a PS-b-P4VP (PDP) películas de 50-100 m de espesor (dado que el diámetro de una placa de Petri utilizada en el paso 1,3 es de 5-6 cm). Calcular la cantidad de PDP de acuerdo con las siguientes ecuaciones: <img alt="Ecuación 1" src="/files/ftp_upload/50673/50673eq1.jpg" /> <img alt="Ecuación 2" src="/files/ftp_upload/50673/50673eq2.jpg" /> <img alt="Ecuación 3" src="/files/ftp_upload/50673/50673eq3.jpg" /><br/&gt; <img alt="Ecuación 4" src="/files/ftp_upload/50673/50673eq4.jpg" /></li><li> Disolver PS-b-P4VP y PDP en cloroformo y se remueve durante un par de horas a temperatura ambiente. Mantener la concentración de polímero por debajo de 2% en peso para asegurar la formación del complejo homogénea. </li><li> Vierta la solución en una placa de Petri de vidrio. </li><li> Coloque el plato en una atmósfera saturada de cloroformo. </li><li> Después de aproximadamente una semana, sacar la placa de Petri. Se forma una película del complejo supramolecular. </li><li> Seque la película en vacío a 30 º C durante la noche. </li><li> Coloque la película en un contenedor especialmente diseñado, extraer el aire del recipiente y luego llenarlo con nitrógeno. Recocer la película durante 4 días en el horno a 120 º C en atmósfera de N2 con 1 bar de sobrepresión. </li><li> Cortar el pequeño trozo de la película, incrustar en epoxi y curar durante la noche a 40 ° C. </li><li> Microtomo la muestra a un espesor de aproximadamente 80 nm utilizando un cuchillo de diamante a temperatura ambiente. The sección microtomed flotará en el agua. Recogerlos y colocarlos en rejillas de cobre. </li><li> Coloque las rejillas que contienen las secciones microtomed en un frasco con yodo. Después de 45 min muestras están manchadas y listo para microscopía electrónica de transmisión. </li><li> Insertar las rejillas de Cu con secciones teñidas en el microscopio electrónico de transmisión que operan a un voltaje de aceleración de 120 kV y la imagen de la muestra. </li><li> Inserte la pieza de la película (que se obtiene después del paso 1.7) en el soporte de la muestra para el pequeño ángulo de dispersión de rayos X y fijarla con una cinta Kapton. Coloque el soporte de la muestra preparada en la máquina para SAXS. Abra el obturador de rayos X y adquirir el patrón de dispersión 2D. Integrar el patrón 2D obtenida y analizar la posición de los picos en el patrón de 1D. </li></ol> 2. Generación y caracterización de la estructura porosa <ol><li> Coloque la pieza de la película (que se obtiene después del paso 1.7) en etanol y mantenerlo durante tres días. </li><li> Secar la muestra. </li><li> Precomparar las muestras para las mediciones de 1 H RMN. Disuelva el polvo PDP, polvo de PS-b-P4VP, PS-b-P4VP (PDP) (después del paso 1.7), y poroso film complejo supramolecular (después del paso 2.2) en CDCl3. Registro 1 H espectros RMN a temperatura ambiente. </li><li> Analizar polvo PS-b-P4VP, complejo supramolecular PS-b-P4VP (PDP) (después del paso 1.7), y la película porosa (después del paso 2.2) mediante calorimetría diferencial de barrido. Utilice un modo modulada con una velocidad de calentamiento / enfriamiento de 1 º C / min, una amplitud de oscilación de 0,5 º C, y un período de oscilación de 60 seg. Equilibrar las muestras a -30 ° C, el calor a 180 ° C, se enfría a -30 ° C, y luego calentar de nuevo a 180 ° C. Utilice los datos del segundo ciclo de calentamiento para el análisis. </li><li> Desgasificar la muestra porosa (después de la etapa 2.2) durante 8 horas a temperatura ambiente y durante 18 horas a 70 ° C y realizar mediciones de adsorción de nitrógeno a 77 K. </li><li> Utilice el software adecuado (por ejemplo, WinADP) y los modelos para analizar las isotermas obtenidas. </li><li> Secar la muestra porosa (después de la etapa 2.2) a 50 ° C durante 8 horas y se desgasifica a temperatura ambiente y presión de 0,5 Pa durante 2 horas. </li><li> Realice porosimetría de mercurio. </li></ol> 3. Inserción de níquel en la plantilla de Polímeros <ol><li> Pesar cloruro de estaño (SnCl2, Mr = 189,60 g / mol) y preparar una solución acuosa (SnCl2 / 0,1 HCl 0,1 M M; 1,896 g de SnCl2, 0,8 ml de HCl y 100 ml de H 2 O). Ponga la solución en un agitador durante la noche para asegurar la completa disolución de SnCl2. </li><li> Pesar cloruro de paladio (PdCl 2, M r = 177,33 g / mol) y preparar una solución acuosa (M PdCl M de HCl 0,0014 2 / 0,25; 0,025 g de PdCl 2, 2 ml de HCl y 100 ml de H2O). </li><li> Preparar la parte 1 del baño de niquelado: pesar 6,78 g sulfato de níquel hexahidratado (NiSO4 • 6H 2 O, M r = 2620.85 g / mol) y 2 g de citrato de sodio (Na 3 C 6 H 5 O 7, Mr = 258,06 g / mol) y se disuelven en 80 ml ​​de agua. Añadir 828 l 85% de ácido láctico (C 3 H 6 O 3, M r = 90,08 g / mol). </li><li> Preparar la parte 2 del baño de niquelado: peso por 0,2 g de complejo borano dimetilamina ((CH3) 2 NHBH 3, M r = 58,92 g / mol) y se disuelven en 20 ml de agua. Complejo borano dimetilamina debe manejarse en una campana extractora bien ventilada. </li><li> Sumergir la película porosa (después de la etapa 2.2) en la solución acuosa de cloruro de estaño (paso 3,1) durante 1 hora. </li><li> Enjuague la película a fondo con agua desionizada. </li><li> Sumergir la película en la solución acuosa de cloruro de paladio (paso 3,2) durante 1 hora. </li><li> Enjuague la película a fondo con agua desionizada. </li><li> Mezclar 1 parte (3.3) y parte 2 (3.4) del baño de niquelado. Ajustar el pH a 7,0 utilizando hidróxido de amonio. </li><li> Sumerja la película en el baño de niquelado durante 1 hora. </li><li> Enjuague la película a fondo con agua desionizada. </li><li> Secar la muestra. </li><li> Preparar la muestra chapado para microscopía electrónica, como se describe en los pasos 1.8 hasta 1.9. </li><li> Imagen de la muestra como se describe en el paso 1.11. </li><li> Inserte rejillas de Cu que contienen las secciones de la muestra en placas en el microscopio electrónico de transmisión de alta resolución. Adquirir micrografías TEM de alta resolución. Observa la muestra bajo el microscopio y elegir la zona para el análisis elemental por EDX (Energy Analysis dispersiva de rayos X). Efectuar el análisis EDX de la zona elegida y analizar el patrón obtenido. </li></ol> 4. Exposición del Inverse Gyroid Níquel Espuma <ol><li> Ponga la película niquelado (después del paso 3,12) en un horno a 350 ° C y evitar que 1 hora hasta 4 días. </li><li> Coloque la muestra en el soporte de la muestra utilizando una pasta de plata. </li><li> Introduzca la muestra en el micro electrónica de barridoroscope. Adquirir varias imágenes de la muestra. </li><li> Insertar la muestra en el microscopio electrónico de barrido. Observar la muestra bajo el microscopio y elegir el área para el análisis elemental por EDX. Efectuar el análisis EDX de la zona elegida y analizar el patrón obtenido. </li></ol>

<ol>
	<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>

Los autores declaran no tener intereses financieros en competencia.

Complejos supramoleculares se aplican con éxito como precursores para nanoespumas de metal bien ordenadas. En este método, el paso crucial es la adquisición de la plantilla adecuada, es decir, una plantilla con morfología giroide. En el diagrama de fase de copolímeros de bloques de la región giroide es muy pequeño y es bastante difícil para apuntar. Esto significa que si copolímeros de bloques convencionales se utilizan como materiales de partida, la síntesis bastante elaborado tiene que ser repetido ...

Hay varias técnicas disponibles para la preparación de nanoespumas de metal: dealloying 1-3, de sol-gel se acerca 4,5, nanosmelting 6,7, y la síntesis de combustión 8. En el proceso de dealloying, el material de partida es generalmente una aleación binaria, por ejemplo, una aleación de plata y oro. El metal menos noble, de plata en este caso, se puede eliminar ya sea químicamente o electroquímicamente resulta en una espuma de oro porosa desordenada con ligamentos de tamaño nanométrico. En la síntesis de combustión, de metal se mezcla con un precursor energético que libera energía durante su descomposición y impulsa la formación de nanoespuma de metal 8. Los estudios sobre el comportamiento mecánico de las espumas de metal indican que en arquitecturas desordenados tensiones no se pueden transmitir de manera efectiva desde la nanoescala ligamento a la macroescala general 9-11. Por lo tanto se espera que nanoespumas de metal bien ordenados que tienen propiedades mecánicas superiores en comparación con lalos desordenados. La idea representada aquí es el empleo de copolímeros de bloque que la auto-ensamblarse en nanoestructuras ordenadas como precursores de nanoespumas metal. Dependiendo de la composición de un copolímero de bloque, el número total de unidades de monómero y el grado de repulsión entre los bloques conectados químicamente, diversas morfologías parecen tales como: esférica, cilíndrica, lamelar, doble giroide, hexagonal laminar perforado, y otros 12-14 . Además, los bloques de polímero pueden ser degradados de manera selectiva conduce a materiales nanoporoso 15. Los métodos más comunes son: ozonólisis 16-18, la irradiación UV 19, grabado por iones reactivos 20-22, 23-26 y disolución. Las estructuras porosas generados pueden ser rellenados con diversos materiales inorgánicos. Los óxidos de metal (por ejemplo, SiO2, TiO2) son generalmente introducidos mediante el método sol-gel en los canales de la plantilla 27-29. Elchapado ectrochemical y no electrolíticos se utilizan comúnmente para depositar el metal en o sobre plantillas de 30-33. Finalmente, el polímero restante puede ser retirado de la nanohíbrido polímero / inorgánico a través de pirólisis 2, 34,35 disolución, la degradación UV 28,29, etc En nuestro enfoque, se parte de un complejo supramolecular de poliestireno en bloques de poli (4-vinilpiridina) (PS-b-P4VP) copolímero de dos bloques y pentadecilfenol anfifílico (PDP) moléculas. Este complejo es el resultado de la unión de hidrógeno entre PDP y anillos de piridina (Figura 1A). La composición del copolímero de bloque de partida y la cantidad de agregado de PDP se eligen de tal manera que el sistema se auto-ensambla obtenidos en la bicontinua morfología giroide doble con una red de PS y una P4VP (PDP) de la matriz (Figura 1b). Moléculas del PPD se disuelven selectivamente en etanol y P4VP cadenas colapso en la red PS (Figura 1c). Posteriormente, utilizando el método de revestimiento no electrolítico, de níquel se deposita en los poros de la plantilla (Figura 1d). Después de la eliminación del polímero restante a través de la pirólisis, un nanoespuma níquel giroide bien ordenada se obtiene (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

Espumas metálicas Nanoporous poseen una combinación única de propiedades - que son catalíticamente activo, térmica y eléctricamente conductora, y además, tienen una alta porosidad, alta relación de superficie a volumen y resistencia-peso. Desafortunadamente, los enfoques comunes para la preparación de nanoestructuras metálicas hacen que los materiales con una arquitectura altamente desordenada, lo que podría tener un efecto adverso en sus propiedades mecánicas. Los copolímeros de bloques tienen la capacidad de auto-ensamblarse en nanoestructuras ordenadas y se pueden aplicar como plantillas para la preparación de nanoespumas de metal bien ordenadas. Aquí se describe la aplicación de un complejo supramolecular basada en copolímero de bloque - poliestireno de bloque de poli (4-vinilpiridina) (pentadecilfenol) PS-b-P4VP (PDP) - como precursor para la bien ordenada nanoespuma níquel. Los complejos supramoleculares exhiben un comportamiento de fases similares a los copolímeros de bloques convencionales y pueden auto-ensamblarse en el bicontinuo ingenio morfología giroideh dos redes PS colocados en una P4VP (PDP) de la matriz. PDP puede ser disuelto en etanol conduce a la formación de una estructura porosa que puede ser rellenada con el metal. Utilizando la técnica de deposición sin corriente eléctrica, el níquel puede ser insertado en los canales de la plantilla. Por último, el polímero restante puede eliminarse a través de la pirólisis de la nanohíbrido polímero / inorgánico resultante en espuma de níquel nanoporoso con morfología giroide inversa.

La morfología de los complejos supramoleculares PS-b-P4VP (PDP) x se examinó por TEM y SAXS las figuras 2a y 2b muestran patrones Gyroid típicas de un complejo supramolecular representativo:. La onda doble y los patrones de la rueda del vagón que se sabe que representan proyecciones a través de la (211) y el plano (111) de la celda unidad giroide, respectivamente. Los dominios de bloque PS aparecen brillantes, mientras que los dominios (PDP) Bloque X P4VP aparecen oscuras ...

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

Gyroid Nickel Nanostructures from Diblock Copolymer Supramolecules

En este artículo se describe la preparación de nanoespumas níquel bien ordenados a través de la deposición no electrolítica de metal sobre las plantillas nanoporosas obtenidos de supramoléculas basadas copolímero dibloque autoensamblado.

Gyroid Níquel Nanoestructuras de copolímero de dibloques supramoléculas

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 vistas.  University of Groningen.  En este artículo se describe la preparación de nanoespumas níquel bien ordenados a través de la deposición no electrolítica de metal sobre las plantillas nanoporosas obtenidos de supramoléculas basadas copolímero dibloque autoensamblado. 

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.

Nucleósidos Trifosfatos - De la síntesis a la Caracterización bioquímica

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

Investigación

Química

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.

Síntesis del ligando libre de CdS nanopartículas dentro de una matriz de copolímero de azufre

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.

La polimerización aniónica de un copolímero anfífilo para la Preparación de micelas de copolímeros de bloques estabilizados por interacciones de apilamiento π-pi

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.

Faceta a faceta vincular de forma anisotrópica cadmio coloidal calcógeno nanoestructuras

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.

Síntesis de nanocables de platino y níquel y optimización de rendimiento de reducción de oxígeno

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.

Método de precipitación química para la síntesis de Nb2O5 modificado a granel catalizadores de níquel con alta superficie específica

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.

Preparación y caracterización de nanoestructuras de C60/Graphene híbrido

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.

Desenredar las fibras de aramida de copolímero de alta resistencia para permitir la determinación de sus propiedades mecánicas

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.

Motivos de ADN estable, 1D y 2D nanoestructuras construyen a partir de moléculas de ADN Circular pequeño

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 génica inspirado POLICATIÓN recubrimiento para protección de nanoestructuras de Origami de ADN

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