| 查看: 3953 | 回复: 20 | ||
| 当前主题已经存档。 | ||
| 【有奖交流】积极回复本帖子，参与交流，就有机会分得作者 lingyun79 的 10 个金币 | ||
| 当前只显示满足指定条件的回帖，点击这里查看本话题的所有回帖 | ||
lingyun79木虫 (著名写手)
|
[交流]
07ACS-National Meeting论文Abstract_Inorganic(有Nano的)
|
|
|
INOR 21 Synthesis and characterization of covalently attached polyethyleneimine functionalized single-wall carbon nanotubes Christopher A. Crouse, Eoghan Dillon, Ramon Colorado Jr., and Andrew R. Barron, Department of Chemistry, Smalley Institute for Nanoscale Science and Technology, Rice University, Houston, TX 77005, crous1ca@rice.edu The solubility of single-wall carbon nanotubes (SWNTs) in aqueous and organic solvents is a difficult barrier that must be overcome to allow for potential applications in the biomedical and material sciences. Previous work involving the addition of polymers towards the dissolution of SWNTs has focused on the covalent attachment of polymers to the carboxylic acid moieties found at the open ends of SWNTs or the physical adsorption of polymers or surfactants on the sidewalls. In this work the reaction between branched-polyethyleneimine (PEI) and uncut, fluorinated-SWNTs (F-SWNTs) was performed yielding the covalent attachment of the polymer to the sidewalls of the nanotubes. These results were confirmed through solid state NMR, Raman spectroscopy, X-ray photoelectron spectroscopy, UV-vis spectroscopy and thermal gravimetric analysis studies. The resulting PEI functionalized SWNTs (PEI-SWNTs) are shown to have an increased solubility in aqueous media of up to 0.4 mg/mL. The synthesis, characterization, and possible biomedical applications of the newly formed PEI-SWNTs will be discussed. INOR 22 Synthesis of aligned single-walled carbon nanotube networks Chris Papadopoulos and Badr Omrane, Department of Electrical and Computer Engineering, University of Victoria, Victoria, BC V8W 3P6, Canada, papadop@uvic.ca With their excellent combination of mechanical, thermal, chemical and electrical properties, single-walled carbon nanotubes (SWNTs) have emerged as one of the most important materials in nanoscale science and technology. However, the controlled synthesis of SWNTs remains a key challenge for their practical implementation. In particular, controlling the type, size, positioning and orientation of nanotubes will be crucial for translating their fundamental properties into useful structures. Here we employ catalytic chemical vapor deposition coupled with precise nanoscale patterning to promote the alignment of lateral SWNT networks grown on silicon wafers. Results of growth trials and characterization of the networks via electron microscopy and scanning probe methods will be presented. The electronic properties and potential applications of the aligned SWNT networks will also be discussed. INOR 23 Substrate effects on the growth of single-walled carbon nanotubes (SWNTs) from iron complexes, clusters, and colloids on surfaces Ramon Colorado Jr., Christopher A. Crouse, Clayton C. Gallaway, Alvin Orbaek, and Andrew R. Barron, Department of Chemistry, Smalley Institute for Nanoscale Science and Technology, Rice University, 6100 Main Street, Houston, TX 77005, colorado@rice.edu Our investigations of the vapor-solid-liquid (VLS) growth of single-walled carbon nanotubes (SWNTs) from metallic catalysts on solid substrates (e.g. iron nanoparticles on silicon wafers) have suggested that there is a correlation between the nature of the substrate and the activity of the growth catalyst. An understanding of potential catalyst activation and deactivation pathways is essential in developing methods for increasing the total yield of grown SWNTs from catalyst precursors. To this end, we have studied the VLS growth of SWNTs from iron oxide catalyst precursors on various substrates (Si, Spin-on-glass, HOPG, Al2O3) under different growth conditions (i.e. varying growth temperatures and gases). In addition, we have examined how changes in the roughness and morphology of the substrates affect nanotube growth with respect to both the catalyst activity and the orientation of the grown nanotubes. Characterization of the SWNTs by AFM, SEM, and Raman spectroscopy will be presented. INOR 26 Synthesis of small diameter carbon nanotubes by catalytic decomposition of methane Xiang-ju Xu and Shao-ming Huang, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325027, China, daisyxxj2003@yahoo.com.cn Small diameter carbon nanotubes(CNTs) have been synthesized over Fe/Mo/MgO catalyst by catalytic decomposition of methane at 1000°C. The produced carbon material primarily consists of a CNTs bundle with a small amount of individual CNTs. The diameter of an individual CNTs is in the range of 5-10 nm. The as-synthesized CNTs have a yield of over 100% relative to the weight of supplied catalyst. Critical issues for synthesis of small diameter CNTs were further discussed in terms of procedure of catalyst preparation, growth time, and temperature. Our results show that methane can be a very ideal carbon source for the synthesis of small diameter CNTs. We suggest that catalytic decomposition of methane over Fe/Mo/MgO catalyst can promise a large-scale production of small diameter CNTs. INOR 27 “Green” approach for fabrication of conducting polymer nanocomposite: The catalytic role of carbon nanotubes Yufeng Ma, Pui Lam Chiu, Arnaldo Serrano, Alex Chen, and Huixin He, Chemistry Department, Rutgers University, 73 Warren Street, Newark, NJ 07102, Fax: 973-353-1264, huixinhe@newark.rutgers.edu The catalytic behavior of carbon nanotubes (CNTs) just aroused a hot debate. For a long time people believed that the electrocatalytic properties of CNTs can be exploited for a wide variety of applications. However, very recently, Compton and coworkers challenged these general beliefs and demonstrated that the origin of the electrocatalytic behavior of CNTs observed previously is the metal catalyst residues, such as iron oxide particles, that remain in the batch after the fabrication of nanotube and the purification process. In this report, we will present the intrinsic catalytic capability of the single-walled carbon nanotubes (SWNTs). This catalytic capability is not only chirally selective, but also depends on the dispersion methods and dispersion agents used to disperse them into aqueous solutions. Due to the remarkable catalytic capability of the SWNTs, conducting polymer nanocomposites are fabricated by a “greener” process. INOR 28 Photocatalytic nanofibers and nanotubes made by atomic layer deposition Markku Leskela, Marianna Kemell, Viljami Pore, Eero Santala, and Mikko Ritala, Department of Chemistry, University of Helsinki, P.O. Box 55, Helsinki FIN-00014, Finland, Fax: +358 9 191 50198, markku.leskela@helsinki.fi Because of the self-limiting growth principle Atomic Layer Deposition (ALD) suits very well for depositing thin films on nonplanar surfaces. Neither the size of the substrates nor the size of the structural features has any clear threshold value in ALD. ALD suits very well for making and modifying of nanomaterials. In this presentation the use of ALD for depositing conformal TiO2 films on nonplanar nanostructured surfaces is exemplified by three ways: deposition of thin films on porous alumina, deposition of films on nanofibers made with a porous alumina template, deposition of thin films on nanofibers either on natural fibers like cellulose or electrospun polymer nanofibers. The oxide nanotubes are obtained by annealing in air the TiO2 coated nanofibers and thereby removing the carbohydrate kernel. Photocatalytic activity of the nanomaterials were studied by decomposing methylene blue. The photocatalytic activity could be enhanced by coating the material with noble metal nanoparticles. Reusable magnetic nanofibers were obtained by coating electrospun iron acetate composite fibers with ALD TiO2. INOR 29 Carbon dioxide as a carbon source for synthesis of carbon nanotubes by chemical vapor deposition Xiang-ju Xu, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325027, China, daisyxxj2003@yahoo.com.cn Carbon dioxide was successfully used as carbon source in synthesis of carbon nanotubes(CNTs) by chemical vapour deposition(CVD) over Fe/CaO catalyst. The influence of some reaction parameters, including carbon source, furnace temperature, and types of support media is discussed in this paper. The product was evaluated using both Transmission electron microscopy(TEM) and Raman spectroscopy. Straight, crooked and branching structures of multi-walled carbon nanotubes(MCNTs) were discovered from the TEM micrographs of product. Their average diameters are about 50 nm. Raman spectrum results show that the nanotubes grew perfectly. The formation mechanism of MCNTs in this process was also studied. INOR 308 Thiol group sidewall functionalization of single walled carbon nanotubes Heather L. Rhoads1, Christopher N. Brammer2, Donna J. Nelson1, and Ruibo Li1. (1) Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrington Oval, Norman, OK 73019, Fax: 405-325-6111, hrhoads@ou.edu, (2) Department of Chemical, Biological, and Materials Engineering, University of Oklahoma Since their discovery, there has been an intense effort to characterize single walled carbon nanotubes (SWNTs) and to understand their properties. This information will allow researchers to develop SWNTs for applications intended to improve all aspects of life from medical to electrical and mechanical technology. Several characterization techniques, such as Raman, near-IR, UV-Vis, and TGA have been employed for years to characterize SWNTs, but more recently, NMR was found to be useful for determining both type and degree of functionalization. Such information will enable more direct syntheses for precise control of nanomaterial applications. To our knowledge, we report the first NMR spectra demonstrating thiol group sidewall functionalization; NMR data are analyzed in conjunction with Raman, FTIR, UV-Vis, and TGA data. In addition, a brief discussion of planned applications for our product's photoelectric properties will be presented. INOR 339 Potassium intercalation of graphitic nanofibers Jason A. Michel and Charles M. Lukehart, Department of Chemistry, Vanderbilt University, 1822 VU Station B, Nashville, TN 37212, Fax: 615-343-1234, j.michel@vanderbilt.edu Graphitic nanofibers (GNFs), grown by catalytic decomposition of carbonaceous gases, were reacted with potassium metal to form intercalation compounds. Three types of graphitic nanofiber were employed, namely platelet, herringbone, and narrow tubular herringbone, each with unique morphology. The air-sensitive stage 1 and stage 2 intercalation compounds were characterized by powder XRD. Thermionic electron energy distributions (TEED) show that the stage 1 intercalation compound has a work function of φ=2.2 eV, as compared to φ=4.7 eV for pristine GNFs, a reduction of 2.5 eV. The intercalation compounds have also been shown to initiate the polymerization of olefins such as isoprene and styrene to form GNF-polymer composites. INOR 350 Palladium nanoclusters on carbon nanotubes for flexible hydrogen sensors Yugang Sun, Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, ygsun@anl.gov, H. Hau Wang, Materials Science Division, Argonne National Laboratory, Qing Cao, Department of Chemistry, University of Illinois at Urbana-Champaign, and John A. Rogers, Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign Hydrogen sensing represents an important technique in a wide range of applications for ‘hydrogen economy' such as industrial processing, fuel cells, hydrogen storage and separation, etc. Conventional hydrogen sensors are fabricated, in general, on rigid substrates (e.g., glass, quartz, silicon wafers) by using continuous as well as discontinuous palladium films (or wires) with lateral dimensions on the nanometer scales. The rigidity (and/or fragility) of these devices somehow limits their application in systems with curvilinear surfaces that require conformal lamination and mechanical shock-resistance. In contrast, hydrogen sensing devices fabricated on flexible polymeric substrates can find applications complementary to that of the conventional sensors on rigid substrates. We have recently found that nanoclusters of palladium deposited on the support of networks of single-walled carbon nanotubes significantly change the transport property of carbon nanotubes when the composites are exposed to hydrogen. Printing thin films of the Pd/nanotube composites on poly(ethylene terephthalate) (PET) sheets generates light-weight, shock-resistive, flexible hydrogen sensors. The as-fabricated devices have excellent performance which is comparable (even higher) to the conventional sensors. For example, these sensors can detect hydrogen with concentration as low as 30 ppm in air. The response time is as short as 7.5 second when the devices are exposed to 0.1% hydrogen in air at room temperature. [ Last edited by lingyun79 on 2007-3-25 at 14:26 ] |
回复此楼
feifei19810812
金虫 (职业作家)
- 应助: 2 (幼儿园)
- 金币: 802.6
- 散金: 67
- 红花: 1
- 帖子: 3470
- 在线: 576.9小时
- 虫号: 78710
- 注册: 2005-07-06
- 性别: GG
- 专业: 胶体与界面化学
15楼2007-03-25 21:39:19