Storage of hydrogen in nanostructured carbon materials

Recent developments focusing on novel hydrogen storage media have helped to benchmark nanostructured carbon materials as one of the ongoing strategic research areas in science and technology. In particular, certain microporous carbon powders, carbon nanomaterials, and specifically carbon nanotubes stand to deliver unparalleled performance as the next generation of base materials for storing hydrogen. Accordingly, the main goal of this report is to overview the challenges, distinguishing traits, and apparent contradictions of carbon-based hydrogen storage technologies and to emphasize recently developed nanostructured carbon materials that show potential to store hydrogen by physisorption and/or chemisorption mechanisms. Specifically touched upon are newer material preparation methods as well as experimental and theoretical attempts to elucidate, improve or predict hydrogen storage capacities, sorption–desorption kinetics, microscopic uptake mechanisms and temperature–pressure–loading interrelations in nanostructured carbons, particularly microporous powders and carbon nanotubes

Carbon-Based Polymer Nanocomposites for High-Performance Applications II

In the field of science and technology, carbon-based nanomaterials, such as carbon nanotubes (CNTs), graphene, graphene oxide, graphene quantum dots (GQDs), fullerenes, and so forth, are becoming very attractive for a wide number of applications [...

Microwave heating of polymers: Influence of carbon nanotubes dispersion on the microwave susceptor effectiveness

"This is the peer reviewed version of the following article: Galindo, Begoña, Adolfo Benedito, Fernando Ramos, and Enrique Gimenez. 2016. Microwave Heating of Polymers: Influence of Carbon Nanotubes Dispersion on the Microwave Susceptor Effectiveness. Polymer Engineering & Science 56 (12). Wiley: 1321 29. doi:10.1002/pen.24365, which has been published in final form at https://doi.org/10.1002/pen.24365. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."[EN] Carbon nanotubes dispersion within the polymer matrix is a very important factor to take into account when developing new nanocomposites with optimized properties. In this article, dispersion studies have been carried out with polypropylene filled with 1% of multiwall carbon nanotubes. The nanocomposites were obtained by melt compounding in a corotative twin screw extruder. Processing parameters as screw speed, screw configuration and feeding technology were modified to analyse their effect onto carbon nanotubes dispersion. Developed nanocomposites were exposed to microwave heating (5.8 GHz, 700 W, 60 min) and heating temperature was monitored. The relation between dispersion level of carbon nanotubes and heating effectiveness was studied. Microwave heating efficiency of carbon nanotubes was increased as dispersion was improved. Electrical conductivity of nanocomposites was measured and used as indirect variable of microwave heating susceptor of carbon nanotubes nanocomposites. Higher electrical conductivity indicates a better microwave susceptor propertiy of the nanocomposite. (C) 2016 Society of Plastics EngineersGalindo-Galiana, B.; Benedito-Borrás, A.; Ramos, F.; Giménez Torres, E. (2016). Microwave heating of polymers: Influence of carbon nanotubes dispersion on the microwave susceptor effectiveness. Polymer Engineering & Science. 56(12):1321-1329. https://doi.org/10.1002/pen.24365S132113295612Ku, H. S., Siu, F., Siores, E., & Ball, J. A. R. (2003). Variable frequency microwave (VFM) processing facilities and application in processing thermoplastic matrix composites. Journal of Materials Processing Technology, 139(1-3), 291-295. doi:10.1016/s0924-0136(03)00238-3Ku, H. S., MacRobert, M., Siores, E., & Ball, J. A. R. (2000). Variable frequency microwave processing of thermoplastic composites. Plastics, Rubber and Composites, 29(6), 278-284. doi:10.1179/146580100101541076Williams, N. H. (1967). Curing Epoxy Resin Impregnates Pipe at 2450 Megahertz. Journal of Microwave Power, 2(4), 123-127. doi:10.1080/00222739.1967.11688661Antonio, C., & Deam, R. T. (2005). Comparison of linear and non-linear sweep rate regimes in variable frequency microwave technique for uniform heating in materials processing. Journal of Materials Processing Technology, 169(2), 234-241. doi:10.1016/j.jmatprotec.2005.03.024I. Gómez J. Aguilar Ciencia UANL 2005AGUILAR-GARIB, J. A., GARCÍA, F., & VALDEZ, Z. (2009). Estimating resistive and dielectric effects during microwave heating of Fe0.22Ni0.67Mn2.11O4. Journal of the Ceramic Society of Japan, 117(1367), 801-807. doi:10.2109/jcersj2.117.801Harper, J., Price, D., & Zhang, J. (2005). Use of Fillers to Enable the Microwave Processing of Polyethylene. Journal of Microwave Power and Electromagnetic Energy, 40(4), 219-227. doi:10.1080/08327823.2005.11688543Ling, Q., Sun, J., Zhao, Q., & Zhou, Q. (2009). Microwave absorbing properties of linear low density polyethylene/ethylene–octene copolymer composites filled with short carbon fiber. Materials Science and Engineering: B, 162(3), 162-166. doi:10.1016/j.mseb.2009.03.023Shim, H. C., Kwak, Y. K., Han, C.-S., & Kim, S. (2009). Enhancement of adhesion between carbon nanotubes and polymer substrates using microwave irradiation. Scripta Materialia, 61(1), 32-35. doi:10.1016/j.scriptamat.2009.02.060Xie, R., Wang, J., Yang, Y., Jiang, K., Li, Q., & Fan, S. (2011). Aligned carbon nanotube coating on polyethylene surface formed by microwave radiation. Composites Science and Technology, 72(1), 85-90. doi:10.1016/j.compscitech.2011.10.003Wadhawan, A., Garrett, D., & Perez, J. M. (2003). Nanoparticle-assisted microwave absorption by single-wall carbon nanotubes. Applied Physics Letters, 83(13), 2683-2685. doi:10.1063/1.1615679F. Naab M. Dhoubhadel O.W. Holland J.L. Duggan J. Roberts F.D. McDaniel Proceedings Of the International Conference on PIXE and its Analytical Applications Portoroz Slovenia 2004Mack, C., Sathyanarayana, S., Weiss, P., Mikonsaari, I., Hübner, C., Henning, F., & Elsner, P. (2012). Twin-screw extrusion of multi walled carbon nanotubes reinforced polycarbonate composites: Investigation of electrical and mechanical properties. IOP Conference Series: Materials Science and Engineering, 40, 012020. doi:10.1088/1757-899x/40/1/012020Castillo, F. Y., Socher, R., Krause, B., Headrick, R., Grady, B. P., Prada-Silvy, R., & Pötschke, P. (2011). Electrical, mechanical, and glass transition behavior of polycarbonate-based nanocomposites with different multi-walled carbon nanotubes. Polymer, 52(17), 3835-3845. doi:10.1016/j.polymer.2011.06.018Coleman, J. N., Cadek, M., Blake, R., Nicolosi, V., Ryan, K. P., Belton, C., … Blau, W. J. (2004). High Performance Nanotube-Reinforced Plastics: Understanding the Mechanism of Strength Increase. Advanced Functional Materials, 14(8), 791-798. doi:10.1002/adfm.200305200Krause, B., Pötschke, P., & Häußler, L. (2009). Influence of small scale melt mixing conditions on electrical resistivity of carbon nanotube-polyamide composites. Composites Science and Technology, 69(10), 1505-1515. doi:10.1016/j.compscitech.2008.07.007Prashantha, K., Soulestin, J., Lacrampe, M. F., Claes, M., Dupin, G., & Krawczak, P. (2008). Multi-walled carbon nanotube filled polypropylene nanocomposites based on masterbatch route: Improvement of dispersion and mechanical properties through PP-g-MA addition. Express Polymer Letters, 2(10), 735-745. doi:10.3144/expresspolymlett.2008.87Benedito, A., Buezas, I., Giménez, E., Galindo, B., & Ortega, A. (2011). Dispersion and characterization of thermoplastic polyurethane/multiwalled carbon nanotubes by melt mixing. Journal of Applied Polymer Science, 122(6), 3744-3750. doi:10.1002/app.34788Villmow, T., Pötschke, P., Pegel, S., Häussler, L., & Kretzschmar, B. (2008). Influence of twin-screw extrusion conditions on the dispersion of multi-walled carbon nanotubes in a poly(lactic acid) matrix. Polymer, 49(16), 3500-3509. doi:10.1016/j.polymer.2008.06.010Kasaliwal, G. R., Göldel, A., Pötschke, P., & Heinrich, G. (2011). Influences of polymer matrix melt viscosity and molecular weight on MWCNT agglomerate dispersion. Polymer, 52(4), 1027-1036. doi:10.1016/j.polymer.2011.01.007Krause, B., Boldt, R., & Pötschke, P. (2011). A method for determination of length distributions of multiwalled carbon nanotubes before and after melt processing. Carbon, 49(4), 1243-1247. doi:10.1016/j.carbon.2010.11.04

Urea functionalized multiwalled carbon nanotubes as efficient nitrogen delivery system for rice

This paper utilized urea functionalized multiwalled carbon nanotubes fertilizer as plant nutrition for rice to understand fully their mechanism of interaction. Surface modification of multiwalled carbon nanotubes was treated by nitric acid at different reflux times. The individual and interaction effects between the design factors of functionalized multiwalled carbon nanotube amount and functionalization reflux time with the corresponding responses of nitrogen uptake and nitrogen use efficiency were structured via the Response Surface Methodology based on five-level central composite design. The urea functionalized multiwalled carbon nanotubes fertilizer with optimized 0.5 weight% functionalized multiwalled carbon nanotubes treated at 21 h of reflux time achieve tremendous nitrogen uptake at 1180 mg/pot and NUE up to 96%. The FT-IR results confirm the formation of acidic functional groups of functionalized MWCNTs and UF-MWCNTs. The morphological observation of transmission electron microscopy shows extracellular regions to be the preferred localization of functionalized multiwalled carbon nanotubes in fresh plant root cells independent of their size and geometry. Penetration into the plant cell results in breaching of graphitic tubular structure of functionalized multiwalled carbon nanotubes with their length being shortened until ∼50 nm and diameters becoming thinner until less than 10 nm. The capability to agglomerate after translocation into the plant cells alarms potential cytotoxicity effect of functionalized multiwalled carbon nanotubes in agriculture. These work findings have suggested using urea functionalized multiwalled carbon nanotubes for effective nutrient delivery systems in rice plant. © 2019 Vietnam Academy of Science & Technology

Controlling and mapping interfacial stress transfer in fragmented hybrid carbon fibre-carbon nanotube composites

Copyright © 2014 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Composites Science and Technology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Composites Science and Technology Vol. 100 (2014), DOI: 10.1016/j.compscitech.2014.05.034Raman spectroscopy was used to map the stress transfer at the interface between high and low modulus carbon fibres in model composites when undergoing fragmentation. Both fibre surfaces were coated with two types of single wall carbon nanotubes (HiPCO and carboxylated nanotubes) in order to enhance the interfacial shear strength with an epoxy resin. For the low modulus carbon fibre this coating also enabled stress mapping at the interface. In both cases single fibres embedded in a dumbbell shaped model composite were deformed to cause fragmentation. When no further fragmentation took place the critical fibre length was calculated and converted to interfacial shear stress using classical Kelly–Tyson theory. These values were compared to data obtained using a Raman spectroscopic approach where the rate of change of stress with respect to distance along the fibre was measured directly. These data were then shown to fit a shear lag model. Two forms of single-wall carbon nanotubes were compared; namely unmodified and COOH modified. It was shown that only the COOH modified single wall carbon nanotubes increase the maximum interfacial shear stress significantly. Evidence of matrix yielding at the fibre ends is also presented and the possibility of the enhancement of the shear yield stress of the resin by the presence of the nanotubes is also discussed

Continuous process of carbon nanotubes synthesis by decomposition of methane using an arc-jet plasma

Author's version; The Joint Meeting of 7th APCPST (Asia Pacific Conference on Plasma Science and Technology) and 17th SPSM (Symposium on Plasma Science for Materials) - 7th APCPST/17th SPSMWe present a method of producing carbon nanotubes by means of the thermal plasma decomposition of methane in an arc-jet plasma of high temperature (5000–20,000 K). Carbon nanotubes are produced under a floating condition by introducing methane and a mixture of Ni–Y powders into the arc-jet plasma flame generated by a non-transferred plasma torch. Material evaluations of the synthesized product by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) reveal that the growth rate of carbon nanotubes is very high, and that the multi-walled carbon nanotubes of high purity are mainly produced. Since this process is continuously operable and easily scalable, it is expected to be a promising technique for large-scale commercial production of carbon nanotubes.Korea Institute of Science and Technology Evaluation and Planning (KISTEP

Electronic friction and liquid-flow-induced voltage in nanotubes

A recent exciting experiment by Ghosh et al. reported that the flow of an ion-containing liquid such as water through bundles of single-walled carbon nanotubes induces a voltage in the nanotubes that grows logarithmically with the flow velocity v0. We propose an explanation for this observation. Assuming that the liquid molecules nearest the nanotube form a 2D solid-like monolayer pinned through the adsorbed ions to the nanotubes, the monolayer sliding will occur by elastic loading followed by local yield (stick-slip). The drifting adsorbed ions produce a voltage in the nanotube through electronic friction against free electrons inside the nanotube. Thermally excited jumps over force-biased barriers, well-known in stick-slip, can explain the logarithmic voltage growth with flow velocity. We estimate the short circuit current and the internal resistance of the nanotube voltage generator.Comment: 8 pages, 3 figures; published on PRB (http://link.aps.org/abstract/PRB/v69/e235410) and on the Virtual Journal of Nanoscale Science and Technology (http://www.vjnano.org, July 14, 2002, Vol. 10, Iss. 2

Functionalized carbon nanotubes as a filler for dielectric elastomer composites with improved actuation performance

Among the broad class of electro-active polymers, dielectric elastomer actuators represent a rapidly growing technology for electromechanical transduction. In order to further develop this applied science, the high driving voltages currently needed must be reduced. For this purpose, one of the most widely considered approaches is based on making elastomeric composites with highly polarizable fillers in order to increase the dielectric constant while maintaining both low dielectric losses and high-mechanical compliance. In this work, multi-wall carbon nanotubes were first functionalized by grafting either acrylonitrile or diurethane monoacrylate oligomers, and then dispersed into a polyurethane matrix to make dielectric elastomer composites. The procedures for the chemical functionalization of carbon nanotubes and proper characterizations of the obtained products are provided in detail. The consequences of the use of chemically modified carbon nanotubes as a filler, in comparison to using unmodified ones, were studied in terms of dielectric, mechanical and electromechanical response. In particular, an increment of the dielectric constant was observed for all composites throughout the investigated frequency spectrum, but only in the cases of modified carbon nanotubes did the loss factor remain almost unchanged with respect to the simple matrix, indicating that conductive percolation paths did not arise in such systems. An effective improvement in the actuation strain was observed for samples loaded with functionalized carbon nanotubes

Dispersion and Characterization of Thermoplastic Polyurethane/Multiwalled Carbon Nanotubes by Melt Mixing

[EN] The dispersion of multiwalled carbon nanotubes (MWCNT) in thermoplastic polyurethanes (TPUs) was evaluated in a corotative twin-screw extruder through a melt-blending process. A specific experimental design was prepared with different parameters, such as screw speed, screw design, and carbon nanotube loading, taken into account. The obtained samples were characterized by thermogravimetric analysis, light transmission microscopy, field emission scanning electron microscopy, dynamic rheometry, dynamic mechanical analysis, and electrical conductivity. This work focuses on the influence of the compounding parameters in the dispersion quality of MWCNTs in a TPU matrix to optimize them for an industrial scaleup. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122: 3745-3751, 2011Benedito, A.; Buezas, I.; Giménez Torres, E.; Galindo, B.; Ortega, A. (2011). Dispersion and Characterization of Thermoplastic Polyurethane/Multiwalled Carbon Nanotubes by Melt Mixing. Journal of Applied Polymer Science. 122(6):3745-3751. https://doi.org/10.1002/app.34788S374537511226Coleman, J. N., Khan, U., Blau, W. J., & Gun’ko, Y. K. (2006). Small but strong: A review of the mechanical properties of carbon nanotube–polymer composites. Carbon, 44(9), 1624-1652. doi:10.1016/j.carbon.2006.02.038Manchado, M. A. L., Valentini, L., Biagiotti, J., & Kenny, J. M. (2005). Thermal and mechanical properties of single-walled carbon nanotubes–polypropylene composites prepared by melt processing. Carbon, 43(7), 1499-1505. doi:10.1016/j.carbon.2005.01.031Ramaratnam, A., & Jalili, N. (2006). Reinforcement of Piezoelectric Polymers with Carbon Nanotubes: Pathway to Next-generation Sensors. Journal of Intelligent Material Systems and Structures, 17(3), 199-208. doi:10.1177/1045389x06055282Xu , T. Wang , Z. Miao , J. Nanoelectron Conf 2008 INEC 2008 2nd IEEE Int 2008 555Zhang, R., Dowden, A., Deng, H., Baxendale, M., & Peijs, T. (2009). Conductive network formation in the melt of carbon nanotube/thermoplastic polyurethane composite. Composites Science and Technology, 69(10), 1499-1504. doi:10.1016/j.compscitech.2008.11.039Xia, H., & Song, M. (2005). Preparation and characterization of polyurethane–carbon nanotube composites. Soft Matter, 1(5), 386. doi:10.1039/b509038eKoerner, H., Liu, W., Alexander, M., Mirau, P., Dowty, H., & Vaia, R. A. (2005). Deformation–morphology correlations in electrically conductive carbon nanotube—thermoplastic polyurethane nanocomposites. Polymer, 46(12), 4405-4420. doi:10.1016/j.polymer.2005.02.025Yeo, L. Y., & Friend, J. R. (2006). Electrospinning carbon nanotube polymer composite nanofibers. Journal of Experimental Nanoscience, 1(2), 177-209. doi:10.1080/17458080600670015Chen, W., Tao, X., & Liu, Y. (2006). Carbon nanotube-reinforced polyurethane composite fibers. Composites Science and Technology, 66(15), 3029-3034. doi:10.1016/j.compscitech.2006.01.024Villmow, T., Pötschke, P., Pegel, S., Häussler, L., & Kretzschmar, B. (2008). Influence of twin-screw extrusion conditions on the dispersion of multi-walled carbon nanotubes in a poly(lactic acid) matrix. Polymer, 49(16), 3500-3509. doi:10.1016/j.polymer.2008.06.010Prashantha, K., Soulestin, J., Lacrampe, M. F., Krawczak, P., Dupin, G., & Claes, M. (2009). Masterbatch-based multi-walled carbon nanotube filled polypropylene nanocomposites: Assessment of rheological and mechanical properties. Composites Science and Technology, 69(11-12), 1756-1763. doi:10.1016/j.compscitech.2008.10.005Raja, M., Shanmugharaj, A. M., & Ryu, S. H. (2008). Influence of Surface Functionalized Carbon Nanotubes on the Properties of Polyurethane Nanocomposites. Soft Materials, 6(2), 65-74. doi:10.1080/15394450802046895Fernández, M., Landa, M., Muñoz, M. E., & Santamaría, A. (2010). Tackiness of an electrically conducting polyurethane–nanotube nanocomposite. International Journal of Adhesion and Adhesives, 30(7), 609-614. doi:10.1016/j.ijadhadh.2010.05.011Lee, C.-H., Liu, J.-Y., Chen, S.-L., & Wang, Y.-Z. (2006). Miscibility and Properties of Acid-Treated Multi-Walled Carbon Nanotubes/Polyurethane Nanocomposites. Polymer Journal, 39(2), 138-146. doi:10.1295/polymj.pj2006121McClory, C., Pötschke, P., & McNally, T. (2010). Influence of Screw Speed on Electrical and Rheological Percolation of Melt-Mixed High-Impact Polystyrene/MWCNT Nanocomposites. Macromolecular Materials and Engineering, 296(1), 59-69. doi:10.1002/mame.201000220Alig, I., Skipa, T., Engel, M., Lellinger, D., Pegel, S., & Pötschke, P. (2007). Electrical conductivity recovery in carbon nanotube–polymer composites after transient shear. physica status solidi (b), 244(11), 4223-4226. doi:10.1002/pssb.200776138Alig, I., Lellinger, D., Engel, M., Skipa, T., & Pötschke, P. (2008). Destruction and formation of a conductive carbon nanotube network in polymer melts: In-line experiments. Polymer, 49(7), 1902-1909. doi:10.1016/j.polymer.2008.01.073Radhakrishnan, V. K., Davis, E. W., & Davis, V. A. (2010). Influence of initial mixing methods on melt-extruded single-walled carbon nanotube-polypropylene nanocomposites. Polymer Engineering & Science, 50(9), 1831-1842. doi:10.1002/pen.21696Seo, M.-K., Lee, J.-R., & Park, S.-J. (2005). Crystallization kinetics and interfacial behaviors of polypropylene composites reinforced with multi-walled carbon nanotubes. Materials Science and Engineering: A, 404(1-2), 79-84. doi:10.1016/j.msea.2005.05.065Reyes-de Vaaben, S., Aguilar, A., Avalos, F., & Ramos-de Valle, L. F. (2008). Carbon nanoparticles as effective nucleating agents for polypropylene. Journal of Thermal Analysis and Calorimetry, 93(3), 947-952. doi:10.1007/s10973-007-8591-

Carbon nanotube applications for CMOS back-end processing

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, February 2005.Includes bibliographical references (p. 73-75).Carbon nanotubes are a recently discovered material with excellent mechanical, thermal, and electronic properties. In particular, they are potential ballistic transporters and are theorized to have thermal conductivities greater than any other material currently known. In this thesis, we will examine two possible applications of carbon nanotubes in CMOS back-end processing. The first application is as a replacement for copper interconnects. As interconnect line widths shrink, the electrical resistivity of copper will rise dramatically due to surface scattering effects. Carbon nanotube ballistic transporters may be able to overcome this obstacle, as well as being able to withstand current densities much greater than copper. The second application is an enhanced thermal conductivity dielectric for thermal management purposes. Carbon nanotube-oxide composites demonstrate improved thermal characteristics, and integration into CMOS technology may be able to alleviate some of the heat-removal and distribution problems future integrated circuits will face. We will also examine some of the processing techniques that will be necessary for carbon nanotube commercial deployment. Some of the issues we will discuss are nanotube growth, purification, and separation. In addition, we will consider some of the specific issues that need to be addressed for carbon nanotube integration into CMOS back-end technology, such as in situ growth and self-assembly.by Tan Mau Wu.S.M