Carbon nanotubes adsorption properties

Striolo, A., Chialvo, A.A., Gubbins, K.E., and Cummings, P.T. (2005). Water in carbon nanotubes adsorption isotherms and thermodynamic properties from molecular simulation. J. Chem. Phys. 122, 234712. 

Adsorption significant adsorption and interaction phenomena occur between carbon nanotubes and gases. There are two possible applications for this sector. The first is characterized by the molecular adsorption, which is related to carbon nanotube electrical properties and, then, with the possibility of developing chemical sensors. The second includes gas storage and separation due to the high surface area of carbon nanotubes. 

The amount of theoretical and experimental research focused on the interaction, equilibrium and dynamical properties of noble, simple and polyatomic gases within quasi-one-dimensional nanotubes is still limited [6-13]. Experimental adsorption isotherms have been reported for simple gases (Ar,N2) and alkanes (methane [11], ethane [12], propane-butane-pentane [13]) in monodisperse nanotubes of aluminophosphates. It is expected that similar experiment could be carried out soon in bundles of monodispersed carbon nanotubes. 

S.S. Han, H.M. Lee, Adsorption properties of hydrogen on (10, 0) single-walled carbon nanotube through density functional theory. Carbon 42, 2169 (2004)... 

Generally, a carbon nanotube FET device is constructed by a substrate (gate), two microelectrodes (source and drain), and bridging material between the electrodes, which is typically an individual SWNT or a SWNT network. A SWNT FET is usually fabricated by casting a dispersion of bulk SWNTs or directly growing nanotubes on the substrate by chemical vapor deposition (C VD) either before or after the electrodes are patterned.64 Due to the diffusive electron transport properties of semiconducting SWNTs, the current flow in SWNT FET is extremely sensitive to the substance adsorption or other related events on which the sensing is based. 

VII. Other Sorbents and Their Unique Adsorption Properties Carbon Nanotubes, Heteropoly Compounds, and Pillared Clays 118... 

Active carbon has exceptional adsorption properties because of its high surface area, its developed porosity, the wide variety of functional groups in its surface, and its relatively high mechanical strength [77-79], As a result, active carbons are usually applied in numerous industrial procedures for the elimination of impurities from gases and liquids [77], In this section, two examples of carbon-related adsorbents, that is, a Fisher powdered active carbon and a single-walled carbon nanotube (SWCNT), are presented [80],... 

Rekoske and Barteau (68) used TEOM in scaling-up to higher pressure surface-science results dealing with solid reactions related to redox cycles. These authors investigated reduction kinetics and reaction on titanium oxide (69,70). Recent applications also include the investigation of carbon nanofibers (9) and hydrogen adsorption properties of single-walled carbon nanotubes (71). 

The activation of char, obtained from the pyrolysis of post-consumer PET bottles, with carbon dioxide at 925°C leads to highly porous materials. After a burn-off of 76% a BET area of 2500 m is reached. This material shows similar or better hydrogen adsorption properties than high-tech carbon materials such as nanotubes [40]. It was possible to charge the carbon with 2.3 wt% hydrogen at — 196°C. This fact opens the way for the use of this low-cost material as hydrogen storage. 

Davydov, V.Y., Kalashnikova, E.V., Kamatsevich, V.L., and Kirillow, A.L. (2004). Adsorption properties of multi-wall carbon nanotubes. Fullerenes Nanotubes Carbon Nanostruct., 12, 513-18. 

Darkrim, F. and Levesque, D. (2000). High adsorptive property of opened carbon nanotubes at 17K.J. Phys. Chem. B, 104, 6773—6. 

Such a difference in terms of product selectivity was attributed to the complete absence of any acidic sites on the carbon nanotubes sur ce and also to the absence of micropores which could induce re-adsorption and consecutive reaction [16]. The presence of micropores could artificially increase the contact time and as a consequence, modify the hydrogenation pathway. The influence of the support nature on the electronic properties of the metallic phase eould also be put forward to explain these results. Depending on the metal-support interaction, the metal particles could exhibit different exposed faces and as a consequence, significantly modify the chemisorption of the reactant on their surface. According to the interaction between the C=C bond and the laces exposed by the palladium particles, the residence time and the desorption of the intermediate could be different and thus, lead to a different selectivity. The presence of palladium aggregates on the activated charcoal as compared to the individual palladium dispersion on the CNTs could be the illustration of this difference in exposed crystalline feces. 

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