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Carbon Nanotube Networks (carbon + nanotube_network)
Selected AbstractsSensors: Glass Fibers with Carbon Nanotube Networks as Multifunctional Sensors (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 12 2010Mater. A semiconductive interphase between a glass fi ber and an epoxy matrix is achieved by coating carbon nanotubes on the glass fiber, as reported by S.-L. Gao, E. Mäder, et al. on page 1885. The interphase at the nanoscale provides multifunctional sensibility, which can be observed by electric force microscopy. The resulting composites with an ultra-high anisotropic electrical property are capable of detecting piezoresistive effects as well as the local glass transition temperature. [source] Glass Fibers with Carbon Nanotube Networks as Multifunctional SensorsADVANCED FUNCTIONAL MATERIALS, Issue 12 2010Shang-lin Gao Abstract A simple approach to deposit multiwalled carbon nanotube (MWNT) networks onto glass fiber surfaces achieving semiconductive MWNT,glass fibers is reported, along with application of fiber/polymer interphases as in-situ multifunctional sensors. This approach demonstrates for the first time that the techniques of conducting electrical resistance measurements could be applicable to glass fibers for in situ sensing of strain and damage; the techniques were previously limited to conductive and semiconductive materials. The electrical properties of the single MWNT,glass fiber and the "unidirectional" fiber/epoxy composite show linear or nonlinear stress/strain, temperature, and relative humidity dependencies, which are capable of detecting piezoresistive effects as well as the local glass transition temperature. The unidirectional composites containing MWNT,glass fibers exhibit ultrahigh anisotropic electrical properties and an ultralow electrical percolation threshold. Based on this approach, the glass fiber,the most widely used reinforcement in composites globally,along with the surface electrical conductivity of MWNTs will stimulate and realize a broad range of multifunctional applications. [source] A Promising Approach to Enhanced Thermoelectric Properties Using Carbon Nanotube NetworksADVANCED MATERIALS, Issue 4 2010Chuizhou Meng Enhanced Seebeck coefficients and power factors , important for the conversion of heat to electrical energy , are obtained in polyaniline/carbon nanotube (PANI/CNT) composites in which PANI coats CNT networks (see figure). The values are several times larger than those of either of the individual components. This new approach has potential for synthesizing high-performance thermoelectric materials. [source] Carbon Nanotube Networks: Sensing of Distributed Strain and Damage for Life Prediction and Self Healing,ADVANCED MATERIALS, Issue 21 2006T. Thostenson Conducting carbon nanotube networks formed in an epoxy polymer matrix can be utilized as highly sensitive in,situ sensors for detecting the onset, nature, and evolution of damage in advanced polymer-based composites using direct-current measurements (see figure). These results hold promise for evaluation of autonomic self-healing approaches for polymers and for the development of enhanced life-prediction methodologies. [source] Electrical transport properties of a single wall carbon nanotube networkPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 4 2009J. S. Hwang Abstract A single wall carbon nanotube (SWCNT) network is fabricated and its electronic transport properties are investigated. It shows a typical p-type field-effect-transistor (FET) behavior and nonlinearities in the source current-source bias characteristics. The network also exhibits incomplete turn-off and a small mobility. These characteristics are explained by the fact that the network is a mixture of metallic and semiconducting SWCNTs connecting with one another. Various cross junctions such as SWCNT (semiconducting)-SWCNT (semiconducting), SWCNT (semiconducting)-SWCNT (metallic) are the source of nonlinearities and the small mobility. Incomplete turn-off can be explained by the parallel conduction paths consisting of metallic SWCNTs which are insensitive to the gate bias. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Carbon Nanotube Networks: Sensing of Distributed Strain and Damage for Life Prediction and Self Healing,ADVANCED MATERIALS, Issue 21 2006T. Thostenson Conducting carbon nanotube networks formed in an epoxy polymer matrix can be utilized as highly sensitive in,situ sensors for detecting the onset, nature, and evolution of damage in advanced polymer-based composites using direct-current measurements (see figure). These results hold promise for evaluation of autonomic self-healing approaches for polymers and for the development of enhanced life-prediction methodologies. [source] Highly Bendable, Transparent Thin-Film Transistors That Use Carbon-Nanotube-Based Conductors and Semiconductors with Elastomeric Dielectrics,ADVANCED MATERIALS, Issue 3 2006Q. Cao Transparent flexible thin-film transistors (see Figure) have been made using single-walled carbon nanotube networks of high and moderate coverages as the conducting and semiconducting layers. Electrical (e.g., good performance on plastic), optical (e.g. transparency to visible wavelengths), and mechanical (e.g. extreme flexibility) characteristics that would be difficult, or impossible, to achieve with conventional materials are reported. [source] In-situ synthesis of transparent and conductive carbon nanotube networksPHYSICA STATUS SOLIDI - RAPID RESEARCH LETTERS, Issue 4 2007Márcio D. Lima Abstract A method for the production of transparent carbon nanotube networks (CNTNs) over transparent substrates was developed. In this method, CNTNs were grown directly in the target surface by applying the catalyst in specific zones of the substrate through lithographic techniques. The networks can be also transferred from the original substrate to other surfaces. The newly grown carbon nanotubes have a very high aspect ratio (>50000). Thus far, networks with an optical transmittance of 94% at 550 nm and a surface resistivity of 3.6 k,/sq have been produced. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Shear-stimulated formation of multi-wall carbon nanotube networks in polymer meltsPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 11-12 2009T. Skipa Abstract We report on shear-induced nanotube network formation in multi-wall nanotubes/polycarbonate (MWNT/PC) composite melts which was directly monitored by the time-resolved DC-conductivity measurements during steady shear. A small steady shear applied for 1,h to a non-conductive composite with initially well-dispersed nanotubes was found to induce the insulator-to-conductor transition resulting in a conductivity increase by about six orders of magnitude. Similar composite melt annealed without steady shear demonstrates much slower process of the network formation what can be attributed to an agglomeration of attractively interacting nanotubes in polymer melts. The rheologic properties were also measured for shear-stimulated agglomeration. Unexpected difference between the electrical and mechanical networks in MWNT/PC composites was found. For the modeling of the network formation a shear-dependent kinetic equation for the nanotube agglomeration was coupled with empirical formula for insulator-to-conductor transition. Electric DC-conductivity and shear modulus (G, and G,) of MWNT/PC melt (230,°C) measured simultaneously during shear-stimulated network formation. [source] Polarization-dependent optical reflectivity in magnetically oriented carbon nanotube networksPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 13 2006K. Kamarás Abstract We have observed marked anisotropy in the optical reflectivity of magnetically oriented nanotube networks: for light polarized along the orientation direction, the reflectivity is much higher than for the perpendicular polarization. However, the spectrum in the perpendicular direction is also structured, similar to the parallel polarization but with a shift in frequency. We emphasize the importance of surface scattering corrections when investigating carbon nanotubes by reflectance spectroscopy. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Direct Simultaneous Determination of ,- and ,-Naphthol Isomers at GC-Electrode Modified with CNTs Network Joined by Pt Nanoparticles Through Derivative VoltammetryELECTROANALYSIS, Issue 5 2006Xiao-Gang Wang Abstract The semi-derivative technique was adopted to improve the resolution and surfactant was added to sample solution to enhance the sensitivity, , - and , -naphthol isomers could be determined directly and simultaneously at glassy carbon electrode modified with carbon nanotubes network joined by Pt nanoparticles. In 0.1,mol,L,1 HAc-NaAc buffer solution (pH,5.8), the linear calibration ranges were 1.0×10,6 to 8.0×10,4 mol,L,1 for both , - and , -naphthols, with detection limits of 5.0×10,7 for , - and 6.0×10,7,mol,L,1 for , -naphthol. The amount of naphthol isomers in artificial wastewater has been tested with above method, and the recovery was from 98% to 103%. [source] | |||||||||||||