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Carbon Nanotubes (carbon + nanotube)
Kinds of Carbon Nanotubes Terms modified by Carbon Nanotubes Selected AbstractsThe biocompatibility microorganisms-carbon nanostructures for applications in microbial fuel cellsPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 6 2007A. Morozan Abstract Bionanocomposites Staphylococcus aureus /carbon nanotubes were prepared and their biocompatibility with different species of carbon nanotubes (CNTs) evaluated in terms of their incorporation into a microbial fuel cell (MFC) anodic design. Multi wall carbon nanotubes (MWNTs) with various morphologies and structures, as received, and synthesized by the pyrolysis of novolac with ferrocene addition were used. MWNTs were characterized by TEM and FT-IR spectroscopy. Optical microscopy with fluorescent quantum dots (QDs) have been used for bio-labeling, microorganisms-CNTs biocompatibility and rapid identification of the colonies developed. Designed BNCs are good culture cells media and the electrodes based on synthesized CNTs could be used with good effects in MFCs, from the point of view of bacteria biocompatibility. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Tris(2,2,-bipyridyl)ruthenium(II) Electrogenerated Chemiluminescence Sensor Based on Platinized Carbon Nanotube,Zirconia,Nafion Composite FilmsELECTROANALYSIS, Issue 12 2010Hyun Yoon Abstract Mesoporous films of platinized carbon nanotube,zirconia,Nafion composite have been used for the immobilization of tris(2,2,-bipyridyl)ruthenium (II) (Ru(bpy)32+) on an electrode surface to yield a solid-state electrogenerated chemiluminescence (ECL) sensor. The composite films of Pt,CNT,zirconia,Nafion exhibit much larger pore diameter (3.55,nm) than that of Nafion (2.82,nm) and thus leading to much larger ECL response for tripropylamine (TPA) because of the fast diffusion of the analyte within the films. Due to the conducting and electrocatalytic features of CNTs and Pt nanoparticles, their incorporation into the zirconia,Nafion composite films resulted in the decreased electron transfer resistance within the films. The present ECL sensor based on the Pt,CNT,zirconia,Nafion gave a linear response (R2=0.999) for TPA concentration from 3.0,nM to 1.0,mM with a remarkable detection limit (S/N=3) of 1.0,nM, which is much lower compared to those obtained with the ECL sensors based on other types of sol-gel ceramic,Nafion composite films such as silica,Nafion and titania,Nafion. [source] Improved Detection Limit and Stability of Amperometric Carbon Nanotube-Based Immunosensors by Crosslinking Antibodies with PolylysineELECTROANALYSIS, Issue 2 2008Vito Cataldo Abstract Amperometric immunosensor configurations featuring covalently bound anti-biotin antibodies (Ab) embedded into a polylysine (PLL)-single walled carbon nanotube (SWCNT) composite layer were evaluated. Assemblies were made by first oxidizing pyrolytic graphite (PG) electrodes to form surface carboxylic acid groups, to which PLL, SWCNTs and anti-biotin were covalently linked. Incorporating SWCNT into PLL-antibody assemblies improved the amperometric detection limit for biotin (Ag) labeled with horseradish peroxidase to 10,fmol mL,1. Anti-biotin embedded into the PLL matrix had improved thermal stability and retained its binding ability for biotin after exposure to temperatures of 42,°C for up to 3 hours, while the noncrosslinked antibody was inactivated at this temperature in several minutes. [source] Micropatterned Carbon Nanotube,Gel Composite as Photothermal MaterialADVANCED MATERIALS, Issue 27 2009Eijiro Miyako Micropatterned carbon nanotube (CNT),gel composites are prepared using a new and simple method. A micropatterned CNT,gel composite is capable of fast thermal control in microspaces of this composite by an NIR laser. [source] A Combined Process of In Situ Functionalization and Microwave Treatment to Achieve Ultrasmall Thermal Expansion of Aligned Carbon Nanotube,Polymer Nanocomposites: Toward Applications as Thermal Interface MaterialsADVANCED MATERIALS, Issue 23 2009Wei Lin Ultrasmall thermal expansion of aligned carbon nanotube,epoxy composites at temperatures below and above the glass transition is achieved by a novel combined process of in situ functionalization and microwave treatment. Carbon nanotube,polymer interfacial bonding is the key to the reduced thermal expansion, enhanced storage modulus, and improved thermal conductivity. [source] Reversible Infrared Actuation of Carbon Nanotube,Liquid Crystalline Elastomer Nanocomposites,ADVANCED MATERIALS, Issue 12 2008Liqiang Yang Nanocomposite films comprising polymer-functionalized single-walled carbon-nanotubes (SWNTs) and liquid crystal elastomers (LCEs) show a reversible IR-induced strain (,,30%) at very low SWNT loading levels (,0.2 wt%). SWNTs can efficiently transform absorbed IR light into thermal energy, thereby serving as a nanoscale heat-source and thermal- conduction pathway. The absorbed thermal-energy induced a nematic, isotropic phase-transition, generating a shape change in the nanocomposite film. [source] Actuating Single Wall Carbon Nanotube,Polymer Composites: Intrinsic Unimorphs,ADVANCED MATERIALS, Issue 11 2008Cheol Park A novel actuating single wall carbon nanotube (SWNT)/polymer composite is reported. It exhibits a large strain (2.6%) at a low driving voltage (<1 MV m,1) while possessing excellent mechanical and thermal properties. The strain energy density is at least an order of magnitude greater than any state-of-the-art polymeric materials reported. The actuating characteristic mainly originates from the electrostrictive contribution, presumably due to interfacial polarization. [source] A Catalytic Reaction Inside a Single-Walled Carbon Nanotube,ADVANCED MATERIALS, Issue 8 2008Hidetsugu Shiozawa A catalytic reaction inside a single-walled carbon nanotube is demonstrated by using encapsulated ferrocene molecules as precursors. A combined spectroscopic and microscopic study unravels the mechanism of catalytic inner tube growth. This confined process provides for the controlled iron growing of double-walled carbon nanotubes and represents a new route for materials design. [source] Enhanced Sensitivity of a Gas Sensor Incorporating Single-Walled Carbon Nanotube,Polypyrrole Nanocomposites,ADVANCED MATERIALS, Issue 12 2004H. An A nanocomposite of polypyrrole/carbon nanotubes prepared by in situ chemical polymerization shows improved conductivity of the polypyrrole as compared with its pure form. Its application as a chemical sensor, made using a simple spin-casting technique, shows a drastically increased sensitivity. The Figure shows a field-emission scanning electron microscopy (FE-SEM) image of the SWNT/Ppy nanocomposite. [source] Modification of Electronic Structures of a Carbon Nanotube by Hydrogen FunctionalizationADVANCED MATERIALS, Issue 24 2002K.S. Kim A rigorous method to engineer the electronic structure of carbon nanotubes from metallic to semiconducting is reported (see inside front cover). An intramolecular junction in carbon nanotube is fabricated, where half of the nanotube is masked by a silicon oxide thin film. Functionalization of the nanotube by atomic hydrogen leads to the formation of an intramolecular junction, resulting in clear rectifying behavior at room temperature. This represents an important step towards the practical realization of nanotube-based nanotransistors. [source] Reinforcement of Calcium Phosphate Cement by Bio-Mineralized Carbon NanotubeJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 3 2007Xiupeng Wang Bio-mineralized carbon natotubes (CNTs) were prepared by soaking carboxyl functionalized CNTs in a simulating body fluid (SBF). A uniform hydroxyapatite layer was precipitated on the outer walls of CNTs after 7 days of soaking. The results showed that, by addition of the as-received CNTs and bio-mineralized CNTs, the compressive strength of the calcium phosphate cement (CPC) increased by 24% and 120%, respectively. The modified interfacial bonding between the bio-mineralized CNTs and CPC accounted for the significant improvement in the mechanical property by addition of the bio-mineralized CNTs as compared with the as-received CNTs. [source] Crack Toughness Behaviour of Multiwalled Carbon Nanotube (MWNT)/Polycarbonate NanocompositesMACROMOLECULAR RAPID COMMUNICATIONS, Issue 15 2005Bhabani K. Satapathy Abstract Summary: The morphology and fracture behaviour of polycarbonate (PC)/multiwalled carbon nanotube (MWNT) composites have been studied by AFM and post-yield fracture mechanics. The essential work of fracture (EWF) method has been used to distinguish between two terms representing the resistance to crack initiation and crack propagation. A maximum in the non-essential work of fracture was observed at 2 wt.-% MWNT, demonstrating enhanced resistance to crack propagation compared to pure PC. At 4 wt.-% MWNT, a tough-to-brittle transition has been observed. The time-resolved in-situ strain field analysis revealed that the onset of crack initiation was shifted to a shorter time for nanocomposites with 4 wt.-% MWNT compared to that with 2 wt.-%, and thus explained the existence of a tough-to-brittle transition in these nanocomposites. [source] Glass Transition Temperature Depression at the Percolation Threshold in Carbon Nanotube,Epoxy Resin and Polypyrrole,Epoxy Resin CompositesMACROMOLECULAR RAPID COMMUNICATIONS, Issue 5 2005Sophie Barrau Abstract Summary: The glass transition temperatures of conducting composites, obtained by blending carbon nanotubes (CNTs) or polypyrrole (PPy) particles with epoxy resin, were investigated by using both differential scanning calorimetry (DSC) and dynamical mechanical thermal analysis (DMTA). For both composites, dc and ac conductivity measurements revealed an electrical percolation threshold at which the glass transition temperature and mechanical modulus of the composites pass through a minimum. DC conductivity, ,dc, as a function of the conducting filler concentration of the CNT, (,) and PPy, (,) epoxy resin composites. [source] Isolation of a Small Carbon Nanotube: The Surprising Appearance of D5h(1)-C90,ANGEWANDTE CHEMIE, Issue 5 2010Hua Yang Vollkommen röhrenförmig: Das bislang nicht nachgewiesene höhere Fulleren D5h(1)-C90 (siehe Struktur) wurde als Haupt-C90 -Isomer isoliert, wenn von Sm2O3 -dotierten Graphitstäbchen ausgegangen wurde, und durch eine Röntgenstrukturanalyse charakterisiert. [source] Innentitelbild: 1,1,8,8-Tetramethyl[8](2,11)teropyrenophane: Half of an Aromatic Belt and a Segment of an (8,8) Single-Walled Carbon Nanotube (Angew. Chem.ANGEWANDTE CHEMIE, Issue 30 200930/2009) Große, nichtplanare PAHs (polycyclische aromatische Kohlenwasserstoffe) können als diskrete Teilstrukturen der neueren Allotrope von Kohlenstoffnanoröhren betrachtet werden. G.,J. Bodwell et,al. beschreiben in ihrer Zuschrift auf S.,5595,ff. eine kurze Syntheseroute zu einem (2,11)Teropyrenophan mit einem mehrkernigen aromatischen System aus 36 Kohlenstoffatomen, dessen Struktur einem Segment einer einwandigen (8,8)-Kohlenstoffnanoröhre ähnelt. [source] Carbon Nanotube and Gold-Based Materials: A SymbiosisCHEMISTRY - A EUROPEAN JOURNAL, Issue 6 2010Rajpal Singh Dr. Abstract Carbon nanotubes constitute a novel class of nanomaterials with potential applications in many areas. The attachment of metal nanoparticles to carbon nanotubes is new way to obtain novel hybrid materials with interesting properties for various applications such as catalysts and gas sensors as well as electronic and magnetic devices. Their unique properties such as excellent electronic properties, a good chemical stability, and a large surface area make carbon nanotubes very useful as a support for gold nanoparticles in many potential applications, ranging from advanced catalytic systems through very sensitive electrochemical sensors and biosensors to highly efficient fuel cells. Here we give an overview on the recent progress in this area by exploring the various synthesis approaches and types of assemblies, in which nanotubes can be decorated with gold nanoparticles and explore the diverse applications of the resulting composites. [source] Carbon Nanotube,Acridine Nanohybrids: Spectroscopic Characterization of Photoinduced Electron TransferCHEMISTRY - A EUROPEAN JOURNAL, Issue 15 2009Nicolas Mackiewicz Dr. Abstract Change happens: Acridine,carbon nanotube nanohybrids were built (see figure) and their photoinduced electron-transfer properties investigated, showing variable behaviour depending on the acridine partner. Single-walled carbon nanotubes (NT) were covalently functionalized with either 9-phenyl acridine (PhA) or 10-methyl-9-phenyl acridinium (PhMeA+). Absorption and fluorescence properties of acridine derivatives tethered to the nanotubes were studied in homogeneous dispersions. Exciplex emission was observed for NT functionalized with 9-phenylacridine. This phenomenon was attributed to an "intramolecular" interaction between excited phenyl acridine and carbon nanotubes. Interestingly, reverse photoinduced electron transfer from the nanotube to 10-methyl-9-phenylacridinium was detected for the NT-PhMeA+ nanohybrid. This electron transfer led to a strong quenching of the acridinium fluorescence and to the formation of a metastable acridine radical. Evidence for the formation of this radical was obtained by ESR studies. [source] Light-Driven Thermoelectric Conversion Based on a Carbon Nanotube,Ionic Liquid Gel CompositeCHEMSUSCHEM CHEMISTRY AND SUSTAINABILITY, ENERGY & MATERIALS, Issue 8 2009Eijiro Miyako Dr. A photoinduced thermoelectric conversion system based on single-walled carbon nanotube,room temperature ionic liquid composite gels is reported. These new types of gel-based near-infrared laser-driven thermoelectric convertors generate high electrical energy. [source] Amino Acids Analysis by MALDI Mass Spectrometry Using Carbon Nanotube as MatrixCHINESE JOURNAL OF CHEMISTRY, Issue 2 2005Zhang Jing Abstract Twenty common amino acids have been analyzed successfully by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) using carbon nanotubes as matrix. From the spectra, little or no background interference or fragmentation of the analytes has been observed. This method was also applied to the analysis of amino acid mixture successfully. Carbon nanotubes have some features such as large surface area to disperse the analyte molecules sufficiently and prevent the sample aggregation and strong ultraviolet absorption to transfer energy easily to the analyte molecules. The present method has potential application for the rapid and sensitive analysis of amino acids and their mixture [source] A Combined Process of In Situ Functionalization and Microwave Treatment to Achieve Ultrasmall Thermal Expansion of Aligned Carbon Nanotube,Polymer Nanocomposites: Toward Applications as Thermal Interface MaterialsADVANCED MATERIALS, Issue 23 2009Wei Lin Ultrasmall thermal expansion of aligned carbon nanotube,epoxy composites at temperatures below and above the glass transition is achieved by a novel combined process of in situ functionalization and microwave treatment. Carbon nanotube,polymer interfacial bonding is the key to the reduced thermal expansion, enhanced storage modulus, and improved thermal conductivity. [source] Carbon Nanotube Monolayer Patterns for Directed Growth of Mesenchymal Stem Cells,ADVANCED MATERIALS, Issue 18 2007Y. Park Carbon nanotube (CNT) monolayer patterns are utilized to control the growth of mesenchymal stem cells (MSCs) (see figure). MSCs exhibit preferential growth on CNT patterns, suggesting that the CNT monolayer does not have a harmful effect on the MSCs. Furthermore, the growth of MSCs on swCNT patterns between electrodes is demonstrated. These results show that CNT patterns have enormous potential as a new platform for basic research and applications using stem cells. [source] Carbon nanotube based composites for electronic applications: CNT,conducting polymers, CNT,CuPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 6 2006N. Ferrer-Anglada Abstract We performed two different types of composites using single wall carbon nanotubes: 1) transparent electrodes, using a thin network of carbon nanotubes as electrode on which we can grow a conducting polymer electrochemically on it, polyaniline or polypirrole, CNT,CP; the obtained thin films are both transparent (transmission coefficient T from 70% to 95%) and electrically conducting. The samples were observed by AFM, optical and Raman spectroscopy, room temperature electrical conductivity were performed. 2) CNT with a metal, copper in our case (CNT,Cu), as a material with high electrical and thermal conductivity and low coefficient of thermal expansion (CTE), to be used in electronic packaging. We observed the samples by AFM and SEM. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Carbon nanotube , molecular resonant tunneling diodePHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 2 2006Rajeev R. Pandey Abstract Carbon nanotube (CNT) molecular resonant tunnel diodes (RTDs) are proposed to complement bio-assembled CNT field effect transistors (CNTFETs). A model CNT,pseudopeptide,CNT device is shown to exhibit the current,voltage response of an RTD. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Fabrication of carbon nanotube-based field-effect transistors for studies of their memory effectsPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 11 2007M. Y. Zavodchikova Abstract Carbon nanotube-based field-effect transistors (CNTFETs) have been fabricated using nanometer thin dielectric material as the gate insulator film. The demonstrated fabrication technique is highly suitable for preparing devices with low contact resistances between the electrodes and the carbon nanotube, down to 14 k,. Electronic transport measurements of the fabricated devices have been conducted on more than 70 FETs. Hysteretic behavior in the transfer characteristics of some CNTFETs was observed. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Comparison of the Electrochemical Reactivity of Carbon Nanotubes Paste Electrodes with Different Types of Multiwalled Carbon NanotubesELECTROANALYSIS, Issue 17 2008Xueling Li Abstract Carbon nanotubes (CNTs) are widely used in electrochemical studies. It is reported that CNTs with different source and dispersed in different agents [1] yield significant difference of electrochemical reactivity. Here we report on the electrochemical performance of CNTs paste electrodes (CNTPEs) prepared by multiwalled carbon nanotubes (MWNTs) with different diameters, lengths and functional groups. The resulting electrodes exhibit remarkable different electrochemical reactivity towards redox molecules such as NADH and K3[Fe(CN)6]. It is found that CNTPEs prepared by MWNTs with 20,30,nm diameter show highest catalysis to NADH oxidation, while CNTPEs prepared by MWNTs with carboxylate groups have best electron-transfer rate (The peak-peak separation (,Ep) is +0.108,V for MWNTs with carboxylate groups, +0.155,V for normal MWNTs, and +0.174,V for short MWNTs) but weak catalysis towards oxidation of NADH owing to the hydrophilicity of carboxylate groups. The electrochemical reactivity depends on the lengths of CNTs to some extent. The ,long' CNTs perform better in our study (The oxidation signals of NADH appear below +0.39,V for ,long' CNTs and above +0.46,V for the ,short' one totally). Readers may get some directions from this article while choose CNTs for electrochemical study. [source] Electrochemical Sensors Based on Carbon NanotubesELECTROANALYSIS, Issue 23 2002Qiang Zhao Abstract Carbon nanotubes are attractive new materials. It has been about a decade since carbon nanotubes were discovered. Carbon nanotubes have many outstanding properties and have many practical or potential applications. In this short review we introduce recent advances in carbon nanotubes as potential material for electrochemical sensors. The advantages of carbon nanotubes as sensors are discussed along with future prospects. [source] Factors influencing the partitioning and toxicity of nanotubes in the aquatic environment,,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2008Alan J. Kennedy Abstract Carbon nanotubes (NTs) may be among the most useful engineered nanomaterials for structural applications but could be difficult to study in ecotoxicological evaluations using existing tools relative to nanomaterials with a lower aspect ratio. Whereas the hydrophobicity and van der Waals interactions of NTs may suggest aggregation and sedimentation in aquatic systems, consideration regarding how engineered surface modifications influence their environmental fate and toxicology is needed. Surface modifications (e.g., functional groups and coatings) are intended to create conditions to make NTs dispersible in aqueous suspension, as required for some applications. In the present study, column stability and settling experiments indicated that raw, multiwalled NTs (MWNTs) settled more rapidly than carbon black and activated carbon particles, suggesting sediment as the ultimate repository. The presence of functional groups, however, slowed the settling of MWNTs (increasing order of stability: hydroxyl > carboxyl > raw), especially in combination with natural organic matter (NOM). Stabilized MWNTs in high concentrations of NOM provided relevance for water transport and toxicity studies. Aqueous exposures to raw MWNTs decreased Ceriodaphnia dubia viability, but such effects were not observed during exposure to functionalized MWNTs (>80 mg/L). Sediment exposures of the amphipods Leptocheirus plumulosus and Hyalella azteca to different sizes of sediment-borne carbon particles at high concentration indicated mortality increased as particle size decreased, although raw MWNTs induced lower mortality (median lethal concentration [LC50], 50 to >264 g/kg) than carbon black (LC50, 18,40 g/kg) and activated carbon (LC50, 12,29 g/kg). Our findings stress that it may be inappropriate to classify all NTs into one category in terms of their environmental regulation. [source] Neurite Outgrowth on Nanocomposite Scaffolds Synthesized from PLGA and Carboxylated Carbon Nanotubes,ADVANCED ENGINEERING MATERIALS, Issue 12 2009Hyun Jung Lee Abstract Carbon nanotubes (CNTs) have been suggested as suitable materials for biomedical applications, especially in the neural area. It is essential not only to investigate the biocompatibility of CNTs with the neural system but also to determine proper methods for applying CNTs to neuronal growth. This work represents the first application of CNTs by electrospun poly(D,L -lactic-co-glycolic acid) (PLGA) scaffolds for a neural system. We synthesized electrospun nanocomposites of PLGA and single-walled carbon nanotubes functionalized by carboxylic acid groups (c- SWNTs), and investigated neurite outgrowth from SH-SY5Y cells on these nanocomposites as compared to that on fibrous PLGA alone. Cells on our PLGA/c -SWNT nanocomposite showed significantly enhanced mitochondrial function and neurite outgrowth compared to cells on PLGA alone. We concluded that c -SWNTs incorporated into fibrous PLGA scaffolds exerted a positive role on the health of neural cells. [source] Carbon Nanotubes on Polymeric Microcapsules: Free-Standing Structures and Point-Wise Laser OpeningsADVANCED FUNCTIONAL MATERIALS, Issue 18 2010Alexey M. Yashchenok Abstract Single-wall carbon nanotubes modified by anionic polyelectrolyte molecules are embedded into the shells of microcapsules. Carbon nanotubes serve as rigid rods in a softer polymeric capsule, which forms a free-standing shell upon treatment with glutaraldehyde and subsequent drying. The embedded carbon nanotubes exhibit a broad absorption in the UV,near-infrared part of the spectrum, and that allows point-wise activation and opening of the microcapsules by laser. Raman signal analysis shows changes of carbon-nanotube-specific lines after high-power laser irradiation, which is characteristic of the formation of disordered carbonlike structures. These polyelectrolyte/carbon nanotube composite capsules represent a novel light-addressable type of microcontainers. [source] Long-Cycle Electrochemical Behavior of Multiwall Carbon Nanotubes Synthesized on Stainless Steel in Li Ion BatteriesADVANCED FUNCTIONAL MATERIALS, Issue 7 2009Charan Masarapu Abstract Carbon nanotubes (CNTs) are considered to be excellent candidates for high performance electrode materials in Li ion batteries. The nanometer-sized pore structures of CNTs can provide the hosting sites for storing large numbers of Li ions. A short diffusion distance for the Li ions may bring about a high discharge rate. The long-cycle performance of aligned multiwalled carbon nanotubes (MWNTs) directly synthesized on stainless-steel foil as an anode material in lithium battery is demonstrated. An increase in the specific capacity with an increase in the cycle number is observed. Starting at a value of 132,mA hg,1 in the first cycle at a current rate of 1,C, the specific capacity increased about 250% to a value of 460,mA hg,1 after 1,200 cycles. This is an unusual but a welcoming behavior for battery applications. It is found that the morphology of the MWNTs with structural and surface defects and the stainless-steel substrate play an important role in enhancing the capacity during the cycling process. [source] | |||||||||||||||||||||||||||||||||||||