WorldWideScience

Sample records for single nanotube devices

  1. Photovoltaic device using single wall carbon nanotubes and method of fabricating the same

    Science.gov (United States)

    Biris, Alexandru S.; Li, Zhongrui

    2012-11-06

    A photovoltaic device and methods for forming the same. In one embodiment, the photovoltaic device has a silicon substrate, and a film comprising a plurality of single wall carbon nanotubes disposed on the silicon substrate, wherein the plurality of single wall carbon nanotubes forms a plurality of heterojunctions with the silicon in the substrate.

  2. A Single-Walled Carbon Nanotube Network Gas Sensing Device

    Directory of Open Access Journals (Sweden)

    I-Ju Teng

    2011-08-01

    Full Text Available The goal of this research was to develop a chemical gas sensing device based on single-walled carbon nanotube (SWCNT networks. The SWCNT networks are synthesized on Al2O3-deposted SiO2/Si substrates with 10 nm-thick Fe as the catalyst precursor layer using microwave plasma chemical vapor deposition (MPCVD. The development of interconnected SWCNT networks can be exploited to recognize the identities of different chemical gases by the strength of their particular surface adsorptive and desorptive responses to various types of chemical vapors. The physical responses on the surface of the SWCNT networks cause superficial changes in the electric charge that can be converted into electronic signals for identification. In this study, we tested NO2 and NH3 vapors at ppm levels at room temperature with our self-made gas sensing device, which was able to obtain responses to sensitivity changes with a concentration of 10 ppm for NO2 and 24 ppm for NH3.

  3. Formation of single-walled carbon nanotube thin films enriched with semiconducting nanotubes and their application in photoelectrochemical devices.

    Science.gov (United States)

    Wei, Li; Tezuka, Noriyasu; Umeyama, Tomokazu; Imahori, Hiroshi; Chen, Yuan

    2011-04-01

    Single-walled carbon nanotube (SWCNT) thin films, containing a high-density of semiconducting nanotubes, were obtained by a gel-centrifugation method. The agarose gel concentration and centrifugation force were optimized to achieve high semiconducting and metallic nanotube separation efficiency at 0.1 wt% agarose gel and 18,000g. The thickness of SWCNT films can be precisely controlled from 65 to 260 nm with adjustable transparency. These SWCNT films were applied in photoelectrochemical devices. Photocurrents generated by semiconducting SWCNT enriched films are 15-35% higher than those by unsorted SWCNT films. This is because of reducing exciton recombination channels as a result of the removal of metallic nanotubes. Thinner films generate higher photocurrents because charge carriers have less chances going in metallic nanotubes for recombination, before they can reach electrodes. Developing more scalable and selective methods for high purity semiconducting SWCNTs is important to further improve the photocurrent generation efficiency by using SWCNT-based photoelectrochemical devices.

  4. Fabrication of spintronics device by direct synthesis of single-walled carbon nanotubes from ferromagnetic electrodes

    Directory of Open Access Journals (Sweden)

    Mohd Ambri Mohamed, Nobuhito Inami, Eiji Shikoh, Yoshiyuki Yamamoto, Hidenobu Hori and Akihiko Fujiwara

    2008-01-01

    Full Text Available We describe an alternative method for realizing a carbon nanotube spin field-effect transistor device by the direct synthesis of single-walled carbon nanotubes (SWNTs on substrates by alcohol catalytic chemical vapor deposition. We observed hysteretic magnetoresistance (MR at low temperatures due to spin-dependent transport. In these devices, the maximum ratio in resistance variation of MR was found to be 1.8%.

  5. Nanotube resonator devices

    Science.gov (United States)

    Jensen, Kenneth J; Zettl, Alexander K; Weldon, Jeffrey A

    2014-05-06

    A fully-functional radio receiver fabricated from a single nanotube is being disclosed. Simultaneously, a single nanotube can perform the functions of all major components of a radio: antenna, tunable band-pass filter, amplifier, and demodulator. A DC voltage source, as supplied by a battery, can power the radio. Using carrier waves in the commercially relevant 40-400 MHz range and both frequency and amplitude modulation techniques, successful music and voice reception has been demonstrated. Also disclosed are a radio transmitter and a mass sensor using a nanotube resonator device.

  6. Effect of single walled carbon nanotubes on the threshold voltage of dye based photovoltaic devices

    International Nuclear Information System (INIS)

    Chakraborty, S.; Manik, N.B.

    2016-01-01

    Carbon nanotubes are being widely used in organic photovoltaic (OPV) devices as their usage has been reported to enhance the device efficiency along with other related parameters. In this work we have studied the energy (E c ) effect of single walled carbon nanotubes (SWCNT) on the threshold voltage (V th ) and also on the trap states of dye based photovoltaic devices. SWCNT is added in a series of dyes such as Rose Bengal (RB), Methyl Red (MR), Malachite Green (MG) and Crystal Violet (CV). By analysing the steady state dark current–voltage (I–V) characteristics V th and E c is estimated for the different devices with and without addition of SWCNT. It is observed that on an average for all the dyes V th is reduced by about 30% in presence of SWCNT. The trap energy E c also reduces in case of all the dyes. The relation between V th , E c and total trap density is discussed. From the photovoltaic measurements it is seen that the different photovoltaic parameters change with addition of SWCNT to the dye based devices. Both the short circuit current density and fill factor are found to increase for all the dye based devices in presence of SWCNT.

  7. Growth of single-wall carbon nanotubes by chemical vapor deposition for electrical devices

    OpenAIRE

    Furer, Jürg

    2006-01-01

    Carbon emerges in di®erent forms. Diamond and graphite have been well known mate- rials for centuries. Moreover fullerenes and nanotubes were discovered only a few years ago. H. W. Kroto et al. depicted the fullerenes in 1985 [1]. A few years later, in 1991, S. Iijima described carbon nanotubes (CNTs) for the ¯rst time [2] (Figure 1.1). CNTs have a close relation to graphite, since a single-wall carbon nanotube is like a rolled-up graphite mono layer. However a nanotube has wi...

  8. Single walled carbon nanotube-based stochastic resonance device with molecular self-noise source

    Science.gov (United States)

    Fujii, Hayato; Setiadi, Agung; Kuwahara, Yuji; Akai-Kasaya, Megumi

    2017-09-01

    Stochastic resonance (SR) is an intrinsic noise usage system for small-signal sensing found in various living creatures. The noise-enhanced signal transmission and detection system, which is probabilistic but consumes low power, has not been used in modern electronics. We demonstrated SR in a summing network based on a single-walled carbon nanotube (SWNT) device that detects small subthreshold signals with very low current flow. The nonlinear current-voltage characteristics of this SWNT device, which incorporated Cr electrodes, were used as the threshold level of signal detection. The adsorption of redox-active polyoxometalate molecules on SWNTs generated additional noise, which was utilized as a self-noise source. To form a summing network SR device, a large number of SWNTs were aligned parallel to each other between the electrodes, which increased the signal detection ability. The functional capabilities of the present small-size summing network SR device, which rely on dense nanomaterials and exploit intrinsic spontaneous noise at room temperature, offer a glimpse of future bio-inspired electronic devices.

  9. Chemiresistor Devices for Chemical Warfare Agent Detection Based on Polymer Wrapped Single-Walled Carbon Nanotubes

    Science.gov (United States)

    Fennell, John F.; Hamaguchi, Hitoshi; Yoon, Bora; Swager, Timothy M.

    2017-01-01

    Chemical warfare agents (CWA) continue to present a threat to civilian populations and military personnel in operational areas all over the world. Reliable measurements of CWAs are critical to contamination detection, avoidance, and remediation. The current deployed systems in United States and foreign militaries, as well as those in the private sector offer accurate detection of CWAs, but are still limited by size, portability and fabrication cost. Herein, we report a chemiresistive CWA sensor using single-walled carbon nanotubes (SWCNTs) wrapped with poly(3,4-ethylenedioxythiophene) (PEDOT) derivatives. We demonstrate that a pendant hexafluoroisopropanol group on the polymer that enhances sensitivity to a nerve agent mimic, dimethyl methylphosphonate, in both nitrogen and air environments to concentrations as low as 5 ppm and 11 ppm, respectively. Additionally, these PEDOT/SWCNT derivative sensor systems experience negligible device performance over the course of two weeks under ambient conditions. PMID:28452929

  10. Non-Contact Stiffness Measurement of a Suspended Single Walled Carbon Nanotube Device

    Science.gov (United States)

    Zheng, Yun; Su, Chanmin; Getty, Stephanie

    2010-01-01

    A new nanoscale electric field sensor was developed for studying triboelectric charging in terrestrial and Martian dust devils. This sensor is capable to measure the large electric fields for large dust devils without saturation. However, to quantify the electric charges and the field strength it is critical to calibrate the mechanical stiffness of the sensor devices. We performed a technical feasibility study of the Nano E-field Sensor stiffness by a non-contact stiffness measurement method. The measurement is based on laser Doppler vibrometer measurement of the thermal noise due to energy flunctuations in the devices. The experiment method provides a novel approach to acquire data that is essential in analyzing the quantitative performance of the E-field Nano Sensor. To carry out the non-contact stiffness measurement, we fabricated a new Single-Walled Carbon Nanotube (SWCNT) E-field sensor with different SWCNTs suspension conditions. The power spectra of the thermal induced displacement in the nano E-field sensor were measured at the accuracy of picometer. The power spectra were then used to derive the mechanical stiffness of the sensors. Effect of suspension conditions on stiffness and sensor sensitivty was discussed. After combined deformation and resistivity measurement, we can compare with our laboratory testing and field testing results. This new non-contact measurement technology can also help to explore to other nano and MEMS devices in the future.

  11. Photovoltaic devices based on high density boron-doped single-walled carbon nanotube/n-Si heterojunctions

    International Nuclear Information System (INIS)

    Saini, Viney; Li, Zhongrui; Bourdo, Shawn; Kunets, Vasyl P.; Trigwell, Steven; Couraud, Arthur; Rioux, Julien; Boyer, Cyril; Nteziyaremye, Valens; Dervishi, Enkeleda; Biris, Alexandru R.; Salamo, Gregory J.; Viswanathan, Tito; Biris, Alexandru S.

    2011-01-01

    A simple and easily processible photovoltaic device has been developed based on borondoped single-walled carbon nanotubes (B-SWNTs) and n-type silicon (n-Si) heterojunctions. The single-walled carbon nanotubes (SWNTs) were substitutionally doped with boron atoms by thermal annealing, in the presence of B 2 O 3 . The samples used for these studies were characterized by Raman spectroscopy, thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), and x-ray photoelectron spectroscopy (XPS). The fully functional solar cell devices were fabricated by airbrush deposition that generated uniform B-SWNT films on top of the n-Si substrates. The carbon nanotube films acted as exciton-generation sites, charge collection and transportation, while the heterojunctions formed between B-SWNTs and n-Si acted as charge dissociation centers. The current-voltage characteristics in the absence of light and under illumination, as well as optical transmittance spectrum are reported here. It should be noted that the device fabrication process can be made amenable to scalability by depositing direct and uniform films using airbrushing, inkjet printing, or spin-coating techniques

  12. Two-bit memory devices based on single-wall carbon nanotubes: demonstration and mechanism

    International Nuclear Information System (INIS)

    Guo Ao; Fu Yunyi; Wang Chuan; Guan Lunhui; Liu Jia; Shi Zujin; Gu Zhennan; Huang Ru; Zhang Xing

    2007-01-01

    Two-bit memory devices of SWNTs, based on the hysteresis effect, have been demonstrated for the first time. The pertinent memory behaviours seem to originate from the capacitive effect due to polarization of molecules, especially the surface-bound water molecules on SiO 2 in close proximity to carbon nanotubes. Our investigations are intimately linked with ultrahigh-density memory applications, and possibly go a long way in broadening the memory applications of SWNTs, for example from nonvolatile to volatile cells

  13. Carbon nanotube junctions and devices

    NARCIS (Netherlands)

    Postma, H.W.Ch.

    2001-01-01

    In this thesis Postma presents transport experiments performed on individual single-wall carbon nanotubes. Carbon nanotubes are molecules entirely made of carbon atoms. The electronic properties are determined by the exact symmetry of the nanotube lattice, resulting in either metallic or

  14. Modification of single-walled carbon nanotube electrodes by layer-by-layer assembly for electrochromic devices

    OpenAIRE

    Jain, Vaibhav; Yochum, Henry M.; Montazami, Reza; Heflin, James R.; Hu, Liangbing; Gruner, George

    2008-01-01

    We have studied the morphological properties and electrochromic (EC) performance of polythiophene multilayer films on single wall carbon nanotube (SWCNT) conductive electrodes. The morphology for different numbers of layer-by-layer (LbL) bilayer on the SWCNT electrode has been characterized with atomic force microscopy and scanning electron microscope, and it was found that the LbL multilayers significantly decrease the surface roughness of the nanoporous nanotube films. The controlled surfac...

  15. Optimizing the e-beam profile of a single carbon nanotube field emission device for electric propulsion systems

    Directory of Open Access Journals (Sweden)

    Juliano Fujioka Mologni

    2010-04-01

    Full Text Available Preliminary studies on field emission (FE arrays comprised of carbon nanotubes (CNT as an electron source for electric propulsion system show remarkably promising results. Design parameters for a carbon nanotube (CNT field-emission device operating on triode configuration were numerically simulated and optimized in order to enhance the e-beam focusing quality. An additional focus gate (FG was integrated to the device to control the profile of the emitted e-beam. An axisymmetric finite element model was developed to calculate the electric field distribution on the vacuum region and a modified Fowler-Nordheim (FN equation was used to evaluate the current density emission and the effective emitter area. Afterward, a FE simulation was employed in order to calculate the trajectory of the emitted electrons and define the electron-optical properties of the e-beam. The integration of the FG was fully investigated via computational intelligence techniques. The best performance device according to our simulations presents a collimated e-beam profile that suits well for field emission displays, magnetic field detection and electron microscopy. The automated computational design tool presented in this study strongly benefits the robust design of integrated electron-optical systems for vacuum field emission applications, including electrodynamic tethering and electric propulsion systems.

  16. Single walled carbon nanotubes functionally adsorbed to biopolymers for use as chemical sensors

    Science.gov (United States)

    Johnson, Jr., Alan T.; Gelperin, Alan [Princeton, NJ; Staii, Cristian [Madison, WI

    2011-07-12

    Chemical field effect sensors comprising nanotube field effect devices having biopolymers such as single stranded DNA functionally adsorbed to the nanotubes are provided. Also included are arrays comprising the sensors and methods of using the devices to detect volatile compounds.

  17. Effect of different substitution position on the switching behavior in single-molecule device with carbon nanotube electrodes

    Science.gov (United States)

    Yang, Jingjuan; Han, Xiaoxiao; Yuan, Peipei; Bian, Baoan; Wang, Yixiang

    2018-01-01

    We investigate the electronic transport properties of dihydroazulene (DHA) and vinylheptafulvene (VHF) molecule sandwiched between two carbon nanotubes using density functional theory and non-equilibrium Green's function. The device displays significantly switching behavior between DHA and VHF isomerizations. It is found the different substitution position of F in the molecule influences the switching ratio of device, which is analyzed by transmission spectra and molecular projected self-consistent Hamiltonian. The observed negative differential resistance effect is explained by transmission spectra and transmission eigenstates of transmission peak in the bias window. The observed reverse of current in VHF form in which two H atoms on the right side of the benzene ring of the molecule are replaced by F is explained by transmission spectra and molecule-electrode coupling with the varied bias. The results suggest that the reasonable substitution position of molecule may improve the switching ratio, displaying a potential application in future molecular circuit.

  18. Electrostatic sensing and electrochemistry with single carbon nanotubes

    NARCIS (Netherlands)

    Heller, I.

    2009-01-01

    This thesis describes the experimental study of devices based on single carbon nanotubes in the context of (bio)sensing in aqueous solutions. Carbon nanotubes are cylindrical molecules of sp2- carbon, about one nanometer in diameter and typically several micrometers long, which have semiconducting

  19. Graphene oxide as a multi-functional p-dopant of transparent single-walled carbon nanotube films for optoelectronic devices

    Science.gov (United States)

    Han, Joong Tark; Kim, Jun Suk; Jo, Sae Byeok; Kim, Sung Hun; Kim, Jong Soo; Kang, Boseok; Jeong, Hee Jin; Jeong, Seung Yol; Lee, Geon-Woong; Cho, Kilwon

    2012-11-01

    Modulation of electronic structures and surface properties of transparent carbon nanotube films is a challenging issue for their application in optoelectronic devices. Here, we report, for the first time, that graphene oxide (GO) nanosheets play the role of a p-doping agent and surface energy modifier of single-walled carbon nanotube (SWCNT)-based transparent conducting electrodes (TCEs). The deposition of highly oxidized, small-sized (i.e., diameter of less than 500 nm) GO nanosheets onto a SWCNT network film reduces the sheet resistance of the pristine film to 60% of its original value by p-doping. The modified TCEs exhibit an outstanding optoelectronic feature of high conductivity with high transparency. Moreover, the wettability of the electrode surface was also noticeably increased, which is advantageous for the solution-based processing of organic electronics. Furthermore, the organic photovoltaic (OPV) cells with the GO-doped SWCNT anodes on flexible substrates were successfully demonstrated. In stark contrast to a power conversion efficiency of 0.44% for pristine SWCNT anodes, GO-doped SWCNT anodes show a drastically enhanced power conversion efficiency of 2.7%.Modulation of electronic structures and surface properties of transparent carbon nanotube films is a challenging issue for their application in optoelectronic devices. Here, we report, for the first time, that graphene oxide (GO) nanosheets play the role of a p-doping agent and surface energy modifier of single-walled carbon nanotube (SWCNT)-based transparent conducting electrodes (TCEs). The deposition of highly oxidized, small-sized (i.e., diameter of less than 500 nm) GO nanosheets onto a SWCNT network film reduces the sheet resistance of the pristine film to 60% of its original value by p-doping. The modified TCEs exhibit an outstanding optoelectronic feature of high conductivity with high transparency. Moreover, the wettability of the electrode surface was also noticeably increased, which is

  20. Low-power-consumption flat-panel light-emitting device driven by field-emission electron source using high-crystallinity single-walled carbon nanotubes

    Science.gov (United States)

    Shimoi, Norihiro; Abe, Daisuke; Matsumoto, Kazuyuki; Sato, Yoshinori; Tohji, Kazuyuki

    2017-06-01

    Thin electrode films assembled through a wet process using single-walled carbon nanotubes (SWCNTs) are expected to play a role in reducing power consumption and saving energy in field-emission electron sources. The flat-panel light-emitting device for this study featured a line-sequential-scanning-type electrode structure equipped with electrodes for on-and-off controls of electron emissions, on which high-crystallinity SWCNTs were uniformly distributed. The device successfully emitted electrons on the flat panel in a stable manner. A technology for amplifying the luminance output by controlling the persistence characteristics of a fluorescent screen was also successfully developed. By combining such elemental technologies, a flat-panel light-emission device, as a stand-alone planar lighting device, which achieves a high-luminance efficiency of 87 lm/W and energy-conserved driving, was assembled for the first time in the world. The creation of field-emission electron sources driven with ultralow power consumption, along with applications that utilize such devices, is expected in the future.

  1. High-Throughput Processes and Structural Characterization of Single-Nanotube Based Devices for 3D Electronics

    Science.gov (United States)

    Kaul, A. B.; Megerian, K. G.; Baron, R. L.; Jennings, A. T.; Jang, D.; Greer, J. R.

    2011-01-01

    We have developed manufacturable approaches to form single, vertically aligned carbon nanotubes, where the tubes are centered precisely, and placed within a few hundred nm of 1-1.5 micron deep trenches. These wafer-scale approaches were enabled by chemically amplified resists and inductively coupled Cryo-etchers to form the 3D nanoscale architectures. The tube growth was performed using dc plasmaenhanced chemical vapor deposition (PECVD), and the materials used for the pre-fabricated 3D architectures were chemically and structurally compatible with the high temperature (700 C) PECVD synthesis of our tubes, in an ammonia and acetylene ambient. The TEM analysis of our tubes revealed graphitic basal planes inclined to the central or fiber axis, with cone angles up to 30 deg. for the particular growth conditions used. In addition, bending tests performed using a custom nanoindentor, suggest that the tubes are well adhered to the Si substrate. Tube characteristics were also engineered to some extent, by adjusting growth parameters, such as Ni catalyst thickness, pressure and plasma power during growth.

  2. Dielectrophoretic assembly of carbon nanotube devices

    DEFF Research Database (Denmark)

    Dimaki, Maria

    The purpose of this project has been to assemble single-walled carbon nanotubes on electrodes at the tip of a biocompatible cantilever and use these for chemical species sensing in air and liquid, for example in order to measure the local activity from ion channels in the cell membrane....... The electrical resistance of carbon nanotubes has been shown to be extremely sensitive to gas molecules. Dielectrophoresis is a method capable of quickly attracting nanotubes on microelectrodes by using an electric field, thus enabling nanotube integration in microsystems. Dielectrophoresis offers also...... the potential of distinguishing between nanotubes of different electrical properties, which is very important for the optimisation of the properties of the carbon nanotube sensors. Various cantilever and planar structures were designed, fabricated and tested both with multi-walled and single-walled carbon...

  3. Telescopic nanotube device for hot nanolithography

    Science.gov (United States)

    Popescu, Adrian; Woods, Lilia M

    2014-12-30

    A device for maintaining a constant tip-surface distance for producing nanolithography patterns on a surface using a telescopic nanotube for hot nanolithography. An outer nanotube is attached to an AFM cantilever opposite a support end. An inner nanotube is telescopically disposed within the outer nanotube. The tip of the inner nanotube is heated to a sufficiently high temperature and brought in the vicinity of the surface. Heat is transmitted to the surface for thermal imprinting. Because the inner tube moves telescopically along the outer nanotube axis, a tip-surface distance is maintained constant due to the vdW force interaction, which in turn eliminates the need of an active feedback loop.

  4. One-step fabrication of single-crystalline ZnS nanotubes with a novel hollow structure and large surface area for photodetector devices

    Science.gov (United States)

    An, Qinwei; Meng, Xianquan; Xiong, Ke; Qiu, Yunlei; Lin, Weihua

    2017-03-01

    ZnS nanotubes (NTs) were successfully prepared via a one-step thermal evaporation process without using any templates. The resulting NTs were single crystalline and structurally uniform. Based on experimental analysis, a tube-growth vapor-liquid-solid process was proposed as the growth mechanism of ZnS NTs. A metal-semiconductor-metal full-nanostructured ultraviolet (UV) photodetector with ZnS NTs as the active layer, and Ag nanowires of low resistivity and high transmissivity as electrodes, was fabricated and characterized. The ZnS NT-based device displayed a high I on/I off ratio of up to ˜1.56 × 105 with a high response to UV incident light at low operation voltage. This work is a meaningful exploration for preparing other one-dimensional semiconductor NTs, and developing a high-performance and power-saving UV sensor.

  5. Carbon nanotube polymer composition and devices

    Science.gov (United States)

    Liu, Gao [Oakland, CA; Johnson, Stephen [Richmond, CA; Kerr, John B [Oakland, CA; Minor, Andrew M [El Cerrito, CA; Mao, Samuel S [Castro Valley, CA

    2011-06-14

    A thin film device and compound having an anode, a cathode, and at least one light emitting layer between the anode and cathode, the at least one light emitting layer having at least one carbon nanotube and a conductive polymer.

  6. Electrical device fabrication from nanotube formations

    Science.gov (United States)

    Nicholas, Nolan Walker; Kittrell, W. Carter; Kim, Myung Jong; Schmidt, Howard K.

    2013-03-12

    A method for forming nanotube electrical devices, arrays of nanotube electrical devices, and device structures and arrays of device structures formed by the methods. Various methods of the present invention allow creation of semiconducting and/or conducting devices from readily grown SWNT carpets rather than requiring the preparation of a patterned growth channel and takes advantage of the self-controlling nature of these carpet heights to ensure a known and controlled channel length for reliable electronic properties as compared to the prior methods.

  7. Physical removal of metallic carbon nanotubes from nanotube network devices using a thermal and fluidic process

    International Nuclear Information System (INIS)

    Ford, Alexandra C; Shaughnessy, Michael; Wong, Bryan M; Kane, Alexander A; Krafcik, Karen L; Léonard, François; Kuznetsov, Oleksandr V; Billups, W Edward; Hauge, Robert H

    2013-01-01

    Electronic and optoelectronic devices based on thin films of carbon nanotubes are currently limited by the presence of metallic nanotubes. Here we present a novel approach based on nanotube alkyl functionalization to physically remove the metallic nanotubes from such network devices. The process relies on preferential thermal desorption of the alkyls from the semiconducting nanotubes and the subsequent dissolution and selective removal of the metallic nanotubes in chloroform. The approach is versatile and is applied to devices post-fabrication. (paper)

  8. Synthesis, assembly, and applications of single-walled carbon nanotube

    Science.gov (United States)

    Ryu, Koungmin

    This dissertation presents the synthesis and assembly of aligned carbon nanotubes, and their applications in both nano-electronics such as transistor and integrated circuits and macro-electronics in energy conversion devices as transparent conducting electrodes. Also, the high performance chemical sensor using metal oxide nanowire has been demonstrated. Chapter 1 presents a brief introduction of carbon nanotube, followed by discussion of a new synthesis technique using nanosphere lithography to grow highly aligned single-walled carbon nanotubes atop quartz and sapphire substrates. This method offers great potential to produce carbon nanotube arrays with simultaneous control over the nanotube orientation, position, density, diameter and even chirality. Chapter 3 introduces the wafer-scale integration and assembly of aligned carbon nanotubes, including full-wafer scale synthesis and transfer of massively aligned carbon nanotube arrays, and nanotube device fabrication on 4 inch Si/SiO2 wafer to yield submicron channel transistors with high on-current density ˜ 20 muA/mum and good on/off ratio and CMOS integrated circuits. In addition, various chemical doping methods for n-type nanotube transistors are studied to fabricate CMOS integrated nanotube circuits such as inverter, NAND and NOR logic devices. Furthermore, defect-tolerant circuit design for NAND and NOR is proposed and demonstrated to guarantee the correct operation of logic circuit, regardless of the presence of mis-aligned or mis-positioned nanotubes. Carbon nanotube flexible electronics and smart textiles for ubiquitous computing and sensing are demonstrated in chapter 4. A facile transfer printing technique has been introduced to transfer massively aligned single-walled carbon nanotubes from the original sapphire/quartz substrates to virtually any other substrates, including glass, silicon, polymer sheets, and even fabrics. The characterization of transferred nanotubes reveals that the transferred

  9. Titania nanotube arrays: Interfaces for implantable devices

    Science.gov (United States)

    Smith, Barbara Symie

    For the 8--10% of Americans (20--25 million people) that have implanted biomedical devices, biomaterial failure and the need for revision surgery are critical concerns. The major causes for failure in implantable biomedical devices promoting a need for re-implantation and revision surgery include thrombosis, post-operative infection, immune driven fibrosis and biomechanical failure. The successful integration of long-term implantable devices is highly dependent on the early events of tissue/biomaterial interaction, promoting either implant rejection or a wound healing response (extracellular matrix production and vasculature). Favorable interactions between the implant surface and the respective tissue are critical for the long-term success of any implantable device. Recent studies have shown that material surfaces which mimic the natural physiological hierarchy of in vivo tissue may provide a possible solution for enhancing biomaterial integration, thus preventing infection and biomaterial rejection. Titania nanotube arrays, fabricated using a simple anodization technique, provide a template capable of promoting altered cellular functionality at a hierarchy similar to that of natural tissue. This work focuses on the fabrication of immobilized, vertically oriented and highly uniform titania nanotube arrays to determine how this specific nano-architecture affects skin cell functionality, hemocompatibility, thrombogenicity and the immune response. The results in this work identify enhanced dermal matrix production, altered hemocompatibility, reduced thrombogenicity and a deterred immune response on titania nanotube arrays. This evidences promising implications with respect to the use of titania nanotube arrays as beneficial interfaces for the successful implantation of biomedical devices.

  10. Single walled carbon nanotubes with functionally adsorbed biopolymers for use as chemical sensors

    Science.gov (United States)

    Johnson, Jr., Alan T

    2013-12-17

    Chemical field effect sensors comprising nanotube field effect devices having biopolymers such as single stranded DNA or RNA functionally adsorbed to the nanotubes are provided. Also included are arrays comprising the sensors and methods of using the devices to detect volatile compounds.

  11. Nanotube Production Devices Expand Research Capabilities

    Science.gov (United States)

    2012-01-01

    In order for the Hubble Space Telescope to take incredible, never-seen-before shots of celestial bodies and then send them back to Earth, the spacecraft needs power. While in orbit, Hubble cannot plug into an electrical outlet or stop at a store for some batteries. One of the ways NASA supplies power aboard a spacecraft is by harnessing energy from the most powerful entity in the solar system: the Sun. Since the 1960s, photovoltaic technology, or technology that converts sunlight into electricity, has been instrumental in the exploration of space. To build upon existing photovoltaic technology, NASA s Glenn Research Center has worked on a variety of innovative designs and materials to incorporate into photovoltaic cells, the building blocks of solar power systems. One of these materials is the carbon nanotube - a tiny structure about 50,000 times finer than the average human hair, with notably high electrical and thermal conductivity and an extreme amount of mechanical strength. Such properties give carbon nanotubes great potential to enhance the reliability of power generation and storage devices in space and on Earth. Dennis J. Flood, the branch chief of the photovoltaic division at Glenn in the 1990s, was looking into using carbon nanotubes to improve the efficiency of solar cells when he ran into a major roadblock - high-quality carbon nanotubes were not readily available. To address this problem, one of the chemists in Flood s group came up with a process and system for growing them. A senior chemist at Glenn, Aloysius F. Hepp, devised an injection chemical vapor deposition process using a specific organometallic catalyst in a two-zone furnace. Hepp's group found the unique process produced high-quality carbon nanotubes with less than 5 percent metal impurity. In addition, the process was more efficient than existing techniques, as it eliminated pre-patterning of the substrate used for growing the nanotubes, a timely and cost-prohibitive step.

  12. Carbon Nanotube Paper-Based Electroanalytical Devices

    Directory of Open Access Journals (Sweden)

    Youngmi Koo

    2016-04-01

    Full Text Available Here, we report on carbon nanotube paper-based electroanalytical devices. A highly aligned-carbon nanotube (HA-CNT array, grown using chemical vapor deposition (CVD, was processed to form bi-layered paper with an integrated cellulose-based Origami-chip as the electroanalytical device. We used an inverse-ordered fabrication method from a thick carbon nanotube (CNT sheet to a thin CNT sheet. A 200-layered HA-CNT sheet and a 100-layered HA-CNT sheet are explored as a working electrode. The device was fabricated using the following methods: (1 cellulose-based paper was patterned using a wax printer, (2 electrical connection was made using a silver ink-based circuit printer, and (3 three electrodes were stacked on a 2D Origami cell. Electrochemical behavior was evaluated using electrochemical impedance spectroscopy (EIS and cyclic voltammetry (CV. We believe that this platform could attract a great deal of interest for use in various chemical and biomedical applications.

  13. Detection of multiple tumor markers using ultra-long carbon nanotube devices

    Science.gov (United States)

    So, Hye-Mi; Park, Dong-Won; Kim, Beom Soo; Kong, Ki-Jeong; Buh, Gyoung-Ho; Chang, Hyunju; Lee, Jeong-O.; Kong, Jing

    2008-03-01

    For the simultaneous detection of multiple tumor markers, we have fabricated ultra-long carbon nanotube sensors that can detect carcinoembryonic antigen (CEA) and prostate specific antigen (PSA), simultaneously. Ultra-long carbon nanotubes, several millimeters long, were grown by ethanol CVD, and fabricated as FET sensors by using conventional photolithography. To functionalize each segment of a single ultra-long nanotube device with multiple-tumor markers, we first functionalize the entire device with CDI-Tween 20 linking molecules, and then immobilized CEA and PSA antibodies using the microfluidic channel. The electrical conductance from CEA-antibody functionalized and PSA-antibody functionalized segment of a ultra-long carbon nanotube device was monitored simultaneously with Ag/AgCl reference electrode as a liquid gate. We will discuss the advantages of long-nanotube device in detail.

  14. Carbon-Nanotube-Based Thermoelectric Materials and Devices.

    Science.gov (United States)

    Blackburn, Jeffrey L; Ferguson, Andrew J; Cho, Chungyeon; Grunlan, Jaime C

    2018-01-22

    Conversion of waste heat to voltage has the potential to significantly reduce the carbon footprint of a number of critical energy sectors, such as the transportation and electricity-generation sectors, and manufacturing processes. Thermal energy is also an abundant low-flux source that can be harnessed to power portable/wearable electronic devices and critical components in remote off-grid locations. As such, a number of different inorganic and organic materials are being explored for their potential in thermoelectric-energy-harvesting devices. Carbon-based thermoelectric materials are particularly attractive due to their use of nontoxic, abundant source-materials, their amenability to high-throughput solution-phase fabrication routes, and the high specific energy (i.e., W g -1 ) enabled by their low mass. Single-walled carbon nanotubes (SWCNTs) represent a unique 1D carbon allotrope with structural, electrical, and thermal properties that enable efficient thermoelectric-energy conversion. Here, the progress made toward understanding the fundamental thermoelectric properties of SWCNTs, nanotube-based composites, and thermoelectric devices prepared from these materials is reviewed in detail. This progress illuminates the tremendous potential that carbon-nanotube-based materials and composites have for producing high-performance next-generation devices for thermoelectric-energy harvesting. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Carbon-Nanotube-Based Thermoelectric Materials and Devices

    Energy Technology Data Exchange (ETDEWEB)

    Blackburn, Jeffrey L. [Chemistry and Nanoscience Center, National Renewable Energy Laboratory, Golden CO 80401-3305 USA; Ferguson, Andrew J. [Chemistry and Nanoscience Center, National Renewable Energy Laboratory, Golden CO 80401-3305 USA; Cho, Chungyeon [Department of Mechanical Engineering, Texas A& M University, College Station TX 77843-3003 USA; Grunlan, Jaime C. [Department of Mechanical Engineering, Texas A& M University, College Station TX 77843-3003 USA

    2018-01-22

    Conversion of waste heat to voltage has the potential to significantly reduce the carbon footprint of a number of critical energy sectors, such as the transportation and electricity-generation sectors, and manufacturing processes. Thermal energy is also an abundant low-flux source that can be harnessed to power portable/wearable electronic devices and critical components in remote off-grid locations. As such, a number of different inorganic and organic materials are being explored for their potential in thermoelectric-energy-harvesting devices. Carbon-based thermoelectric materials are particularly attractive due to their use of nontoxic, abundant source-materials, their amenability to high-throughput solution-phase fabrication routes, and the high specific energy (i.e., W g-1) enabled by their low mass. Single-walled carbon nanotubes (SWCNTs) represent a unique 1D carbon allotrope with structural, electrical, and thermal properties that enable efficient thermoelectric-energy conversion. Here, the progress made toward understanding the fundamental thermoelectric properties of SWCNTs, nanotube-based composites, and thermoelectric devices prepared from these materials is reviewed in detail. This progress illuminates the tremendous potential that carbon-nanotube-based materials and composites have for producing high-performance next-generation devices for thermoelectric-energy harvesting.

  16. Single electron-ics with carbon nanotubes

    NARCIS (Netherlands)

    Götz, G.T.J.

    2010-01-01

    We experimentally investigate Quantum Dots, formed in Carbon Nanotubes. The first part of this thesis deals with charge sensing on such quantum dots. The charge sensor is a metallic Single-electron-transistor, sensitive to the charge of a single electron on the quantum dot. We use this technique for

  17. Carbon nanotubes for gas detection: materials preparation and device assembly

    International Nuclear Information System (INIS)

    Terranova, M L; Lucci, M; Orlanducci, S; Tamburri, E; Sessa, V; Reale, A; Carlo, A Di

    2007-01-01

    An efficient sensing device for NH 3 and NO x detection has been realized using ordered arrays of single-walled C nanotubes deposited onto an interdigitated electrode platform operating at room temperature. The sensing material has been prepared using several chemical-physical techniques for purification and positioning of the nanotubes inside the electrode gaps. In particular, both DC and AC fields have been applied in order to move and to align the nanostructures by electrophoresis and dielectrophoresis processes. We investigated the effects of different voltages applied to a gate contact on the back side of the substrate on the performances of the device and found that for different gas species (NH 3 , NO x ) a constant gate bias increases the sensitivity for gas detection. Moreover, in this paper we demonstrate that a pulsed bias applied to the gate contact facilitates the gas interaction with the nanotubes, either reducing the absorption times or accelerating the desorption times, thus providing a fast acceleration and a dramatic improvement of the time dependent behaviour of the device

  18. Single Value Devices

    NARCIS (Netherlands)

    Mader, Angelika H.; Dertien, Edwin Christian; Reidsma, Dennis

    2011-01-01

    We live in a world of continuous information overflow, but the quality of information and communication is suffering. Single value devices contribute to the information and communication quality by fo- cussing on one explicit, relevant piece of information. The information is decoupled from a

  19. Single Value Devices

    NARCIS (Netherlands)

    Mader, Angelika H.; Dertien, Edwin Christian; Reidsma, Dennis; Camurri, Antonio; Costa, Cristina

    We live in a world of continuous information overflow, but the quality of information and communication is suffering. Single value devices contribute to information and communication quality by focussing on one explicit, relevant piece of information. The information is decoupled from a computer and

  20. Single Value Devices

    NARCIS (Netherlands)

    Mader, Angelika H.; Reidsma, Dennis; Dertien, Edwin Christian; Volpe, G; Kolkmeier, Jan; Camurri, A.; Kolkmeier, Jan; Nijholt, Antinus

    2015-01-01

    We live in a world of continuous information overflow, but the quality of information and communication is suffering. Single value devices contribute to the information and communication quality by focussing on one explicit, relevant piece of information. The information is decoupled from a computer

  1. Conjugated Polymer-Assisted Dispersion of Single-Wall Carbon Nanotubes : The Power of Polymer Wrapping

    NARCIS (Netherlands)

    Samanta, Suman Kalyan; Fritsch, Martin; Scherf, Ullrich; Gomulya, Widianta; Bisri, Satria Zulkarnaen; Loi, Maria Antonietta

    CONSPECTUS: The future application of single-walled carbon nanotubes (SWNTs) in electronic (nano)devices is closely coupled to the availability of pure, semiconducting SWNTs and preferably, their defined positioning on suited substrates. Commercial carbon nanotube raw mixtures contain metallic as

  2. Synthesis of PbI(2) single-layered inorganic nanotubes encapsulated within carbon nanotubes.

    Science.gov (United States)

    Cabana, Laura; Ballesteros, Belén; Batista, Eudar; Magén, César; Arenal, Raúl; Oró-Solé, Judith; Rurali, Riccardo; Tobias, Gerard

    2014-04-02

    The template assisted growth of single-layered inorganic nanotubes is reported. Single-crystalline lead iodide single-layered nanotubes have been prepared using the inner cavities of carbon nanotubes as hosting templates. The diameter of the resulting inorganic nanotubes is merely dependent on the diameter of the host. This facile method is highly versatile opening up new horizons in the preparation of single-layered nanostructures. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Dysprosium Acetylacetonato Single-Molecule Magnet Encapsulated in Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Ryo Nakanishi

    2016-12-01

    Full Text Available Dy single-molecule magnets (SMMs, which have several potential uses in a variety of applications, such as quantum computing, were encapsulated in multi-walled carbon nanotubes (MWCNTs by using a capillary method. Encapsulation was confirmed by using transmission electron microscopy (TEM. In alternating current magnetic measurements, the magnetic susceptibilities of the Dy acetylacetonato complexes showed clear frequency dependence even inside the MWCNTs, meaning that this hybrid can be used as magnetic materials in devices.

  4. Conductivity of single-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Gets, A. V.; Krainov, V. P., E-mail: vpkrainov@mail.ru [Moscow Institute of Physics and Technology (Russian Federation)

    2016-12-15

    The conductivity of single-walled carbon nanotubes at low temperatures is calculated. It is shown that it is much higher than the well-known conductivity of a model 1D Fermi system. This is a purely quantum-mechanical effect.

  5. Carbon nanotube oscillator surface profiling device and method of use

    Science.gov (United States)

    Popescu, Adrian [Tampa, FL; Woods, Lilia M [Tampa, FL; Bondarev, Igor V [Fuquay Varina, NC

    2011-11-15

    The proposed device is based on a carbon nanotube oscillator consisting of a finite length outer stationary nanotube and a finite length inner oscillating nanotube. Its main function is to measure changes in the characteristics of the motion of the carbon nanotube oscillating near a sample surface, and profile the roughness of this surface. The device operates in a non-contact mode, thus it can be virtually non-wear and non-fatigued system. It is an alternative to the existing atomic force microscope (AFM) tips used to scan surfaces to determine their roughness.

  6. Methods for Gas Sensing with Single-Walled Carbon Nanotubes

    Science.gov (United States)

    Kaul, Anupama B. (Inventor)

    2013-01-01

    Methods for gas sensing with single-walled carbon nanotubes are described. The methods comprise biasing at least one carbon nanotube and exposing to a gas environment to detect variation in temperature as an electrical response.

  7. A study on electromechanical carbon nanotube memory devices

    International Nuclear Information System (INIS)

    Kang, Jeong Won; Hwang, Ho Jung

    2005-01-01

    Electromechanical operations of carbon-nanotube (CNT) bridge memory device were investigated by using atomistic simulations based on empirical potentials. The nanotube-bridge memory device was operated by the electrostatic and the van der Waals forces acting on the nanotube-bridge. For the CNT bridge memory device, the van der Waals interactions between the CNT bridge and the oxide were very important. As the distance between the CNT bridge and the oxide decreased and the van der Waals interaction energy increased, the pull-in bias of the CNT-bridge decreased and the nonvolatility of the nanotube-bridge memory device increased, while the pull-out voltages increased. When the materials composed of the oxide film are different, since the van der Waals interactions must be also different, the oxide materials must be carefully selected for the CNT-bridge memory device to work as a nonvolatile memory.

  8. Selective Deposition and Alignment of Single-Walled Carbon Nanotubes Assisted by Dielectrophoresis: From Thin Films to Individual Nanotubes

    Science.gov (United States)

    Li, Pengfei; Xue, Wei

    2010-06-01

    Dielectrophoresis has been used in the controlled deposition of single-walled carbon nanotubes (SWNTs) with the focus on the alignment of nanotube thin films and their applications in the last decade. In this paper, we extend the research from the selective deposition of SWNT thin films to the alignment of small nanotube bundles and individual nanotubes. Electrodes with “teeth”-like patterns are fabricated to study the influence of the electrode width on the deposition and alignment of SWNTs. The entire fabrication process is compatible with optical lithography-based techniques. Therefore, the fabrication cost is low, and the resulting devices are inexpensive. A series of SWNT solutions is prepared with concentrations ranging from 0.0125 to 0.2 mg/ml. The alignment of SWNT thin films, small bundles, and individual nanotubes is achieved under the optimized experimental conditions. The electrical properties of these samples are characterized; the linear current-voltage plots prove that the aligned SWNTs are mainly metallic nanotubes. The microscopy inspection of the samples demonstrates that the alignment of small nanotube bundles and individual nanotubes can only be achieved using narrow electrodes and low-concentration solutions. Our investigation shows that it is possible to deposit a controlled amount of SWNTs in desirable locations using dielectrophoresis.

  9. Selective Deposition and Alignment of Single-Walled Carbon Nanotubes Assisted by Dielectrophoresis: From Thin Films to Individual Nanotubes

    Directory of Open Access Journals (Sweden)

    Li Pengfei

    2010-01-01

    Full Text Available Abstract Dielectrophoresis has been used in the controlled deposition of single-walled carbon nanotubes (SWNTs with the focus on the alignment of nanotube thin films and their applications in the last decade. In this paper, we extend the research from the selective deposition of SWNT thin films to the alignment of small nanotube bundles and individual nanotubes. Electrodes with “teeth”-like patterns are fabricated to study the influence of the electrode width on the deposition and alignment of SWNTs. The entire fabrication process is compatible with optical lithography-based techniques. Therefore, the fabrication cost is low, and the resulting devices are inexpensive. A series of SWNT solutions is prepared with concentrations ranging from 0.0125 to 0.2 mg/ml. The alignment of SWNT thin films, small bundles, and individual nanotubes is achieved under the optimized experimental conditions. The electrical properties of these samples are characterized; the linear current–voltage plots prove that the aligned SWNTs are mainly metallic nanotubes. The microscopy inspection of the samples demonstrates that the alignment of small nanotube bundles and individual nanotubes can only be achieved using narrow electrodes and low-concentration solutions. Our investigation shows that it is possible to deposit a controlled amount of SWNTs in desirable locations using dielectrophoresis.

  10. Nanotechnology with Carbon Nanotubes: Mechanics, Chemistry, and Electronics

    Science.gov (United States)

    Srivastava, Deepak

    2003-01-01

    This viewgraph presentation reviews the Nanotechnology of carbon nanotubes. The contents include: 1) Nanomechanics examples; 2) Experimental validation of nanotubes in composites; 3) Anisotropic plastic collapse; 4) Spatio-temporal scales, yielding single-wall nanotubes; 5) Side-wall functionalization of nanotubes; 6) multi-wall Y junction carbon nanotubes; 7) Molecular electronics with Nanotube junctions; 8) Single-wall carbon nanotube junctions; welding; 9) biomimetic dendritic neurons: Carbon nanotube, nanotube electronics (basics), and nanotube junctions for Devices,

  11. Conjugates between photosystem I and a carbon nanotube for a photoresponse device.

    Science.gov (United States)

    Nii, Daisuke; Miyachi, Mariko; Shimada, Yuichiro; Nozawa, Yosuke; Ito, Masahiro; Homma, Yoshikazu; Ikehira, Shu; Yamanoi, Yoshinori; Nishihara, Hiroshi; Tomo, Tatsuya

    2017-09-01

    Photosystem I (PS I) is a large pigment-protein complex embedded in the thylakoid membranes that performs light-driven electron transfer across the thylakoid membrane. Carbon nanotubes exhibit excellent electrical conductivities and excellent strength and stiffness. In this study, we generated PSI-carbon nanotube conjugates dispersed in a solution aimed at application in artificial photosynthesis. PS I complexes in which a carbon nanotube binding peptide was introduced into the middle of the PsaE subunit were conjugated on a single-walled carbon nanotube, orienting the electron acceptor side to the nanotube. Spectral and photoluminescence analysis showed that the PS I is bound to a single-walled carbon nanotube, which was confirmed by transmission electron microscopy. Photocurrent observation proved that the photoexcited electron originated from PSI and transferred to the carbon nanotube with light irradiation, which also confirmed its orientated conjugation. The PS I-carbon nanotube conjugate will be a useful nano-optoelectronic device for the development of artificial systems.

  12. Synthesis of single wall carbon nanotubes from a lamellar type ...

    Indian Academy of Sciences (India)

    Wintec

    These nanotubes are applicable to store more hydrogen. Keywords. AlPO4-L; single wall carbon nanotubes. 1. Introduction. Carbon nanotubes (Iijima 1991) are nano-scale structures formed by self assembly. They possess excellent chemical and physical properties (Rodney and Donald 1995; Chen et al 1998) that make ...

  13. Printable Thin Film Supercapacitors Using Single-Walled Carbon Nanotubes

    KAUST Repository

    Kaempgen, Martti

    2009-05-13

    Thin film supercapacitors were fabricated using printable materials to make flexible devices on plastic. The active electrodes were made from sprayed networks of single-walled carbon nanotubes (SWCNTs) serving as both electrodes and charge collectors. Using a printable aqueous gel electrolyte as well as an organic liquid electrolyte, the performances of the devices show very high energy and power densities (6 W h/kg for both electrolytes and 23 and 70 kW/kg for aqueous gel electrolyte and organic electrolyte, respectively) which is comparable to performance in other SWCNT-based supercapacitor devices fabricated using different methods. The results underline the potential of printable thin film supercapacitors. The simplified architecture and the sole use of printable materials may lead to a new class of entirely printable charge storage devices allowing for full integration with the emerging field of printed electronics. © 2009 American Chemical Society.

  14. Translocation events in a single-walled carbon nanotube

    Energy Technology Data Exchange (ETDEWEB)

    He Jin; Lindsay, Stuart [Biodesign Institute, Arizona State University, Tempe, AZ 85287 (United States); Liu Hao [Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287 (United States); Pang Pei; Cao Di, E-mail: jinhe@asu.ed [Department of Physics, Arizona State University, Tempe, AZ 85287 (United States)

    2010-11-17

    Translocation of DNA oligomers through a single-walled carbon nanotube was demonstrated recently. Translocation events are accompanied by giant current pulses, the origin of which remains obscure. Here, we show that the introduction of a nucleotide, guanosine triphosphate, alone into the input reservoir of a carbon nanotube nanofluidic device also gives giant current pulses. Taken together with data on oligomer translocation, these new results suggest that the pulse width has a nonlinear, power-law dependence on the number of nucleotides in a DNA molecule. We have also measured the time for the onset of DNA translocation pulses after bias reversal, finding that the time for the onset of translocation is directly proportional to the period of the bias reversal.

  15. Translocation events in a single-walled carbon nanotube

    International Nuclear Information System (INIS)

    He Jin; Lindsay, Stuart; Liu Hao; Pang Pei; Cao Di

    2010-01-01

    Translocation of DNA oligomers through a single-walled carbon nanotube was demonstrated recently. Translocation events are accompanied by giant current pulses, the origin of which remains obscure. Here, we show that the introduction of a nucleotide, guanosine triphosphate, alone into the input reservoir of a carbon nanotube nanofluidic device also gives giant current pulses. Taken together with data on oligomer translocation, these new results suggest that the pulse width has a nonlinear, power-law dependence on the number of nucleotides in a DNA molecule. We have also measured the time for the onset of DNA translocation pulses after bias reversal, finding that the time for the onset of translocation is directly proportional to the period of the bias reversal.

  16. Single-cavity SLED device

    International Nuclear Information System (INIS)

    Lippmann, B.A.

    1984-09-01

    The conventional SLED device used at SLAC requires two cavities. However, the same effect can be obtained with a single cavity; the theory and operation of the device is the same, only the hardware is changed. The single-cavity device is described here

  17. Investigation of Chirality Selection Mechanism of Single Walled Carbon Nanotube

    Science.gov (United States)

    2016-12-13

    AFRL-AFOSR-JP-TR-2017-0007 Investigation of Chirality Selection Mechanism of Single -Walled Carbon Nanotube Seun Min Kim KOREA INSTITUTE OF SCIENCE...Selection Mechanism of Single -Walled Carbon Nanotube 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA2386-15-1-4099 5c.  PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR...research involved investigation of two fundamental mechanisms of carbon nanotube (CNT) growth: chirality selection of single -walled CNT (SWCNT) and

  18. X-ray irradiation-induced structural changes on Single Wall Carbon Nanotubes

    Science.gov (United States)

    Bardi, N.; Jurewicz, I.; King, A. K.; Alkhorayef, M. A.; Bradley, D.; Dalton, A. B.

    2017-11-01

    Dosimetry devices based on Carbon Nanotubes are a promising new technology. In particular using devices based on single wall Carbon Nanotubes may offer a tissue equivalent response with the possibility for device miniaturisation, high scale manufacturing and low cost. An important precursor to device fabrication requires a quantitative study of the effects of X-ray radiation on the physical and chemical properties of the individual nanotubes. In this study, we concentrate on the effects of relatively low doses, 20 cGy and 45 cGy , respectively. We use a range of characterization techniques including scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy to quantify the effects of the radiation dose on inherent properties of the nanotubes. Specifically we find that the radiation exposure results in a reduction in the sp2 nature of the nanotube bond structure. Moreover, our analysis indicates that the exposure results in nanotubes that have an increased defect density which ultimately effects the electrical properties of the nanotubes.

  19. Towards parallel fabrication of single electron transistors using carbon nanotubes.

    Science.gov (United States)

    Islam, Muhammad R; Joung, Daeha; Khondaker, Saiful I

    2015-06-07

    Single electron transistors (SETs) are considered to be promising building blocks for post CMOS era electronic devices, however, a major bottleneck for practical realization of SET based devices is a lack of a parallel fabrication approach. Here, we have demonstrated a technique for the scalable fabrication of SETs using single-walled carbon nanotubes (SWNTs). The approach is based on the integration of solution processed individual SWNTs via dielectrophoresis (DEP) at the selected position of the circuit with a 100 nm channel length, where the metal-SWNT Schottky contact works as a tunnel barrier. Measurements carried out at a low temperature (4.2 K) show that the majority of the devices with a contact resistance (RT) > 100 kΩ display SET behavior. For the devices with 100 kΩ 1 MΩ) multiple QD behavior was observed. From the transport study of 50 SWNT devices, a total of 38 devices show SET behavior giving a yield of 76%. The results presented here are a significant step forward for the practical realization of SET based devices.

  20. Superconductivity in single wall carbon nanotubes

    Directory of Open Access Journals (Sweden)

    H Yavari

    2009-08-01

    Full Text Available   By using Greens function method we first show that the effective interaction between two electrons mediated by plasmon exchange can become attractive which in turn can lead to superconductivity at a high critical temperature in a singl wall carbon nanotubes (SWCNT. The superconducting transition temperature Tc for the SWCNT (3,3 obtained by this mechanism agrees with the recent experimental result. We also show as the radius of SWCNT increases, plasmon frequency becomes lower and leads to lower Tc.

  1. Symmetry Properties of Single-Walled BC2N Nanotubes

    Directory of Open Access Journals (Sweden)

    Lin Jianyi

    2009-01-01

    Full Text Available Abstract The symmetry properties of the single-walled BC2N nanotubes were investigated. All the BC2N nanotubes possess nonsymmorphic line groups. In contrast with the carbon and boron nitride nanotubes, armchair and zigzag BC2N nanotubes belong to different line groups, depending on the index n (even or odd and the vector chosen. The number of Raman- active phonon modes is almost twice that of the infrared-active phonon modes for all kinds of BC2N nanotubes.

  2. Selective formation and efficient photocurrent generation of [70]fullerene-single-walled carbon nanotube composites

    NARCIS (Netherlands)

    Umeyama, Tomokazu; Tezuka, Noriyasu; Seki, Shu; Matano, Yoshihiro; Nishi, Masayuki; Hirao, Kazuyuki; Lehtivuori, Heli; Tkachenko, Nikolai V.; Lemmetyinen, Helge; Nakao, Yoshihide; Sakaki, Shigeyoshi; Imahori, Hiroshi

    2010-01-01

    For the first time nanocarbon composites with C 70 molecules aligned on the sidewall of single-walled carbon nanotubes (SWNTs) are demonstrated. The C70-SWNT photoelectrochemical devices exhibit efficient photocurrent generation properties that result from selective formation of a single composite

  3. Observation of Fermi Arc Surface States Induced by Organic Memristive/Memcapacitive Devices with a Double-Helical Polarized Single-Wall Nanotube Membrane for Direct Chelating with Matrix Matelloproteinase-2

    Directory of Open Access Journals (Sweden)

    E. T. CHEN

    2017-07-01

    Full Text Available Matrix Matelloproteinase-2 (MMP-2 plays a key role in many diseases. A new type of dual-functioning device was developed for fast, direct ultrasensitive detection of MMP-2. We report a memristive/memcapacitive device with vertex double-helical polarized biomimetic protein nanotubules forming double membranes with potential gradient mimicking mitochondria’s inner double membrane has developed. We also report Fermi arcs with nodes on the surface of the nanostructured membrane was observed at the first time by using a 3D real-time - energy-current dynamic mapping method based on data obtained from the Cyclic Voltammetry (CV method. The memristive/memcapacitive device comprises a cross- linked organic polymer having single-wall cross-bar polarized nanotube self-assembling membrane (SAM on a gold chip, under an applied potential, a pair of vertex double- helical circular current flow induced the Fermi arcs states occurrence and these Fermi arcs promoted a direct chelating with zinc ions of the MMP-2 to become possible without any antibody, tracer, or reagent used at room temperature was accomplished. We observed the pair of Dirac Cones became alignment and strengthened with each other in the presence of MMP-2 compared without MMP-2. The MMP-2 can be detected with ag/mL level sensitivity and the value of Detection of Limits (DOL reached orders of magnitude lower than published reports with simplified procedures by a Chronoamperometry (CA method and a Double Step Chronopotentiometry (DSCPO method using NIST SRM 965A standard human serum, respectively. The results show a feasible application for developing the commercial fast and real-time MMP monitoring devices for various diseases.

  4. Influence of the contact geometry on single-walled carbon nanotube/Si photodetector response

    Science.gov (United States)

    Scagliotti, Mattia; Salvato, Matteo; De Crescenzi, Maurizio; Boscardin, Maurizio; Castrucci, Paola

    2018-03-01

    A systematic study of the optical response of photodetectors based on carbon nanotube/Si heterojunctions is performed by measuring the responsivity, the detectivity and the time response of the devices with different contact configurations. The sensors are obtained by dry transferring single-walled carbon nanotube films on the surface of n-doped Si substrate provided with a multifinger contact geometry. The experimental data show a consistent improvement of the photodetector parameters with the increase of the number of fingers without affecting the carbon nanotube film thickness for increase its optical transmittance as in previous experiments. The role of the electrical resistance of the carbon nanotube film is discussed. The obtained results confirm the method and suggest new perspectives in the use of nanostructured materials as part of semiconducting optical devices.

  5. Excitons in single-walled carbon nanotubes: environmental effect

    International Nuclear Information System (INIS)

    Smyrnov, O.A.

    2010-01-01

    The properties of excitons in semiconducting single-walled carbon nanotubes (SWCNTs) isolated in vacuum or a medium and their contributions to the optical spectra of nanotubes are studied within the elementary potential model, in which an exciton is represented as a bound state of two oppositely charged quasiparticles confined to the nanotube surface. The emphasis is given on the influence of the dielectric environment surrounding a nanotube on the exciton spectra. For nanotubes in the environment with a permittivity less than ∼ 1:8; the ground-state exciton binding energies exceed the respective energy gaps, whereas the obtained binding energies of excitons in nanotubes in a medium with permittivity greater than ∼ 4 are in good accordance with the corresponding experimental data and consistent with the known scaling relation for the environmental effect. The stabilization of a single-electron spectrum in SWCNTs in media with rather low permittivities is discussed.

  6. Nanotube Film Electrode and an Electroactive Device Fabricated with the Nanotube Film Electrode and Methods for Making Same

    Science.gov (United States)

    Kang, Jin Ho (Inventor); Park, Cheol (Inventor); Harrison, Joycelyn S. (Inventor)

    2017-01-01

    Disclosed is a single wall carbon nanotube (SWCNT) film electrode (FE), all-organic electroactive device systems fabricated with the SWNT-FE, and methods for making same. The SWCNT can be replaced by other types of nanotubes. The SWCNT film can be obtained by filtering SWCNT solution onto the surface of an anodized alumina membrane. A freestanding flexible SWCNT film can be collected by breaking up this brittle membrane. The conductivity of this SWCNT film can advantageously be higher than 280 S/cm. An electroactive polymer (EAP) actuator layered with the SWNT-FE shows a higher electric field-induced strain than an EAP layered with metal electrodes because the flexible SWNT-FE relieves the restraint of the displacement of the polymeric active layer as compared to the metal electrode. In addition, if thin enough, the SWNT-FE is transparent in the visible light range, thus making it suitable for use in actuators used in optical devices.

  7. Thermogravimetric Analysis of Single-Wall Carbon Nanotubes

    Science.gov (United States)

    Arepalli, Sivram; Nikolaev, Pavel; Gorelik, Olga

    2010-01-01

    An improved protocol for thermogravimetric analysis (TGA) of samples of single-wall carbon nanotube (SWCNT) material has been developed to increase the degree of consistency among results so that meaningful comparisons can be made among different samples. This improved TGA protocol is suitable for incorporation into the protocol for characterization of carbon nanotube material. In most cases, TGA of carbon nanotube materials is performed in gas mixtures that contain oxygen at various concentrations. The improved protocol is summarized.

  8. Peptide aptamer-assisted immobilization of green fluorescent protein for creating biomolecule-complexed carbon nanotube device

    Science.gov (United States)

    Nii, Daisuke; Nozawa, Yosuke; Miyachi, Mariko; Yamanoi, Yoshinori; Nishihara, Hiroshi; Tomo, Tatsuya; Shimada, Yuichiro

    2017-10-01

    Carbon nanotubes are a novel material for next-generation applications. In this study, we generated carbon nanotube and green fluorescent protein (GFP) conjugates using affinity binding peptides. The carbon nanotube-binding motif was introduced into the N-terminus of the GFP through molecular biology methods. Multiple GFPs were successfully aligned on a single-walled carbon nanotube via the molecular recognition function of the peptide aptamer, which was confirmed through transmission electron microscopy and optical analysis. Fluorescence spectral analysis results also suggested that the carbon nanotube-GFP complex was autonomously formed with orientation and without causing protein denaturation during immobilization. This simple process has a widespread potential for fabricating carbon nanotube-biomolecule hybrid devices.

  9. Laser-Assisted Simultaneous Transfer and Patterning of Vertically Aligned Carbon Nanotube Arrays on Polymer Substrates for Flexible Devices

    KAUST Repository

    In, Jung Bin

    2012-09-25

    We demonstrate a laser-assisted dry transfer technique for assembling patterns of vertically aligned carbon nanotube arrays on a flexible polymeric substrate. A laser beam is applied to the interface of a nanotube array and a polycarbonate sheet in contact with one another. The absorbed laser heat promotes nanotube adhesion to the polymer in the irradiated regions and enables selective pattern transfer. A combination of the thermal transfer mechanism with rapid direct writing capability of focused laser beam irradiation allows us to achieve simultaneous material transfer and direct micropatterning in a single processing step. Furthermore, we demonstrate that malleability of the nanotube arrays transferred onto a flexible substrate enables post-transfer tailoring of electric conductance by collapsing the aligned nanotubes in different directions. This work suggests that the laser-assisted transfer technique provides an efficient route to using vertically aligned nanotubes as conductive elements in flexible device applications. © 2012 American Chemical Society.

  10. Single-Walled Carbon Nanotubes in Solar Cells.

    Science.gov (United States)

    Jeon, Il; Matsuo, Yutaka; Maruyama, Shigeo

    2018-01-22

    Photovoltaics, more generally known as solar cells, are made from semiconducting materials that convert light into electricity. Solar cells have received much attention in recent years due to their promise as clean and efficient light-harvesting devices. Single-walled carbon nanotubes (SWNTs) could play a crucial role in these devices and have been the subject of much research, which continues to this day. SWNTs are known to outperform multi-walled carbon nanotubes (MWNTs) at low densities, because of the difference in their optical transmittance for the same current density, which is the most important parameter in comparing SWNTs and MWNTs. SWNT films show semiconducting features, which make SWNTs function as active or charge-transporting materials. This chapter, consisting of two sections, focuses on the use of SWNTs in solar cells. In the first section, we discuss SWNTs as a light harvester and charge transporter in the photoactive layer, which are reviewed chronologically to show the history of the research progress. In the second section, we discuss SWNTs as a transparent conductive layer outside of the photoactive layer, which is relatively more actively researched. This section introduces SWNT applications in silicon solar cells, organic solar cells, and perovskite solar cells each, from their prototypes to recent results. As we go along, the science and prospects of the application of solar cells will be discussed.

  11. Nanotube devices based crossbar architecture: toward neuromorphic computing

    International Nuclear Information System (INIS)

    Zhao, W S; Gamrat, C; Agnus, G; Derycke, V; Filoramo, A; Bourgoin, J-P

    2010-01-01

    Nanoscale devices such as carbon nanotube and nanowires based transistors, memristors and molecular devices are expected to play an important role in the development of new computing architectures. While their size represents a decisive advantage in terms of integration density, it also raises the critical question of how to efficiently address large numbers of densely integrated nanodevices without the need for complex multi-layer interconnection topologies similar to those used in CMOS technology. Two-terminal programmable devices in crossbar geometry seem particularly attractive, but suffer from severe addressing difficulties due to cross-talk, which implies complex programming procedures. Three-terminal devices can be easily addressed individually, but with limited gain in terms of interconnect integration. We show how optically gated carbon nanotube devices enable efficient individual addressing when arranged in a crossbar geometry with shared gate electrodes. This topology is particularly well suited for parallel programming or learning in the context of neuromorphic computing architectures.

  12. Frontiers of graphene and carbon nanotubes devices and applications

    CERN Document Server

    2015-01-01

    This book focuses on carbon nanotubes and graphene as representatives of nano-carbon materials, and describes the growth of new technology and applications of new devices. As new devices and as new materials, nano-carbon materials are expected to be world pioneers that could not have been realized with conventional semiconductor materials, and as those that extend the limits of conventional semiconductor performance. This book introduces the latest achievements of nano-carbon devices, processes, and technology growth. It is anticipated that these studies will also be pioneers in the development of future research of nano-carbon devices and materials. This book consists of 18 chapters. Chapters 1 to 8 describe new device applications and new growth methods of graphene, and Chapters 9 to 18, those of carbon nanotubes. It is expected that by increasing the advantages and overcoming the weak points of nanocarbon materials, a new world that cannot be achieved with conventional materials will be greatly expanded. W...

  13. A Computational Experiment on Single-Walled Carbon Nanotubes

    Science.gov (United States)

    Simpson, Scott; Lonie, David C.; Chen, Jiechen; Zurek, Eva

    2013-01-01

    A computational experiment that investigates single-walled carbon nanotubes (SWNTs) has been developed and employed in an upper-level undergraduate physical chemistry laboratory course. Computations were carried out to determine the electronic structure, radial breathing modes, and the influence of the nanotube's diameter on the…

  14. Network single-walled carbon nanotube biosensors for fast and highly sensitive detection of proteins.

    Science.gov (United States)

    Hu, Pingán; Zhang, Jia; Wen, Zhenzhong; Zhang, Can

    2011-08-19

    Detection of proteins is powerfully assayed in the diagnosis of diseases. A strategy for the development of an ultrahigh sensitivity biosensor based on a network single-walled carbon nanotube (SWNT) field-effect transistor (FET) has been demonstrated. Metallic SWNTs (m-SWNTs) in the network nanotube FET were selectively removed or cut via a carefully controlled procedure of electrical break-down (BD), and left non-conducting m-SWNTs which magnified the Schottky barrier (SB) area. This nanotube FET exhibited ultrahigh sensitivity and fast response to biomolecules. The lowest detection limit of 0.5 pM was achieved by exploiting streptavidin (SA) or a biotin/SA pair as the research model, and BD-treated nanotube biosensors had a 2 × 10(4)-fold lower minimum detectable concentration than the device without BD treatment. The response time is in the range of 0.3-3 min.

  15. Estimation of mechanical properties of single wall carbon nanotubes ...

    Indian Academy of Sciences (India)

    - rent work to evaluate the mechanical properties of Zigzag, Armchair and Chiral Single wall Carbon Nanotubes (SWCNT) of different diameters and chiralities. Three dif- ferent types of atomic bonds, that is Carbon–Carbon covalent bond and ...

  16. Molecular mechanics applied to single-walled carbon nanotubes

    OpenAIRE

    Ávila,Antonio Ferreira; Lacerda,Guilherme Silveira Rachid

    2008-01-01

    Single-walled carbon nanotubes, with stiffness of 1.0 TPa and strength of 60 GPa, are a natural choice for high strength materials. A problem, however, arises when experimental data are compiled. The large variability of experimental data leads to the development of numerical models denominated molecular mechanics, which is a "symbiotic" association of molecular dynamics and solid mechanics. This paper deals with molecular mechanics simulations of single-walled carbon nanotubes. To be able to...

  17. Noncovalent functionalization of single-walled carbon nanotubes.

    Science.gov (United States)

    Zhao, Yan-Li; Stoddart, J Fraser

    2009-08-18

    Single-walled carbon nanotubes (SWNTs) have attracted much attention on account of their potential to be transformed into new materials that can be employed to address a wide range of applications. The insolubility of the SWNTs in most solvents and the difficulties of handling these highly intractable carbon nanostructures, however, are restricting their real-life applications at the present time. To improve upon the properties of the SWNTs, low-cost and industrially feasible approaches to their modifications are constantly being sought by chemists and materials scientists. Together, they have shown that noncovalent functionalization of the SWNTs can do much to preserve the desired properties of the SWNTs while remarkably improving their solubilities. This Account describes recent advances in the design, synthesis, and characterization of SWNT hybrids and evaluates applications of these new hybrid materials based on noncovalently functionalized SWNTs. Their solubilization enables the characterization of these hybrids as well as the investigation of the properties of the SWNTs using solution-based techniques. Cognizant of the structural properties of the functional molecules on the SWNTs, we present some of the recent work carried out by ourselves and others under the umbrella of the following three subtopics: (i) aromatic small-molecule-based noncovalent functionalization, (ii) biomacromolecule-based noncovalent functionalization, and (iii) polymer-based noncovalent functionalization. Several examples for the applications of noncovalently functionalized SWNT hybrids in the fabrication of field-effect transistor (FET) devices, chemical sensors, molecular switch tunnel junctions (MSTJs), and photovoltaic devices are highlighted and discussed. The blossoming of new methods for the noncovalent functionalization of the SWNTs promises a new generation of SWNT hybrid-based integrated multifunctional sensors and devices, an outcome which is essential for the development of

  18. Coarse-grained potentials of single-walled carbon nanotubes

    Science.gov (United States)

    Zhao, Junhua; Jiang, Jin-Wu; Wang, Lifeng; Guo, Wanlin; Rabczuk, Timon

    2014-11-01

    We develop the coarse-grained (CG) potentials of single-walled carbon nanotubes (SWCNTs) in CNT bundles and buckypaper for the study of the static and dynamic behaviors. The explicit expressions of the CG stretching, bending and torsion potentials for the nanotubes are obtained by the stick-spiral and the beam models, respectively. The non-bonded CG potentials between two different CG beads are derived from analytical results based on the cohesive energy between two parallel and crossing SWCNTs from the van der Waals interactions. We show that the CG model is applicable to large deformations of complex CNT systems by combining the bonded potentials with non-bonded potentials. Checking against full atom molecular dynamics calculations and our analytical results shows that the present CG potentials have high accuracy. The established CG potentials are used to study the mechanical properties of the CNT bundles and buckypaper efficiently at minor computational cost, which shows great potential for the design of micro- and nanomechanical devices and systems.

  19. Optical Characterization and Applications of Single Walled Carbon Nanotubes

    Science.gov (United States)

    Strano, Michael S.

    2005-03-01

    Recent advances in the dispersion and separation of single walled carbon nanotubes have led to new methods of optical characterization and some novel applications. We find that Raman spectroscopy can be used to probe the aggregation state of single-walled carbon nanotubes in solution or as solids with a range of varying morphologies. Carbon nanotubes experience an orthogonal electronic dispersion when in electrical contact that broadens (from 40 meV to roughly 80 meV) and shifts the interband transition to lower energy (by 60 meV). We show that the magnitude of this shift is dependent on the extent of bundle organization and the inter-nanotube contact area. In the Raman spectrum, aggregation shifts the effective excitation profile and causes peaks to increase or decrease, depending on where the transition lies, relative to the excitation wavelength. The findings are particularly relevant for evaluating nanotube separation processes, where relative peak changes in the Raman spectrum can be confused for selective enrichment. We have also used gel electrophoresis and column chromatography conducted on individually dispersed, ultrasonicated single-walled carbon nanotubes to yield simultaneous separation by tube length and diameter. Electroelution after electrophoresis is shown to produce highly resolved fractions of nanotubes with average lengths between 92 and 435 nm. Separation by diameter is concomitant with length fractionation, and nanotubes that have been cut shortest also possess the greatest relative enrichments of large-diameter species. The relative quantum yield decreases nonlinearly as the nanotube length becomes shorter. These findings enable new applications of nanotubes as sensors and biomarkers. Particularly, molecular detection using near infrared (n-IR) light between 0.9 and 1.3 eV has important biomedical applications because of greater tissue penetration and reduced auto-fluorescent background in thick tissue or whole blood media. Carbon nanotubes

  20. Crystallization and mechanical properties of functionalized single-walled carbon nanotubes/polyvinylidene fluoride composites

    DEFF Research Database (Denmark)

    Ma, Jing; Iftekharul Haque, Rubaiyet; Larsen, Mikael

    2012-01-01

    Single-walled carbon nanotubes were purified and functionalized by nitric acid and octadecylamine. Raman and Fourier transform infrared spectroscopy were used to characterize the functionalization of the single-walled carbon nanotubes. Polyvinylidene flouride nanocomposites containing 1 wt......% purified or functionalized single-walled carbon nanotubes were prepared by solution blending and injection molding. The dispersion of different carbon nanotubes in dimethylformamide and in polyvinylidene flouride has been investigated. Mechanical properties show that adding single-walled carbon nanotubes...

  1. Electrostatically telescoping nanotube nonvolatile memory device

    International Nuclear Information System (INIS)

    Kang, Jeong Won; Jiang Qing

    2007-01-01

    We propose a nonvolatile memory based on carbon nanotubes (CNTs) serving as the key building blocks for molecular-scale computers and investigate the dynamic operations of a double-walled CNT memory element by classical molecular dynamics simulations. The localized potential energy wells achieved from both the interwall van der Waals energy and CNT-metal binding energy make the bistability of the CNT positions and the electrostatic attractive forces induced by the voltage differences lead to the reversibility of this CNT memory. The material for the electrodes should be carefully chosen to achieve the nonvolatility of this memory. The kinetic energy of the CNT shuttle experiences several rebounds induced by the collisions of the CNT onto the metal electrodes, and this is critically important to the performance of such an electrostatically telescoping CNT memory because the collision time is sufficiently long to cause a delay of the state transition

  2. Generalizing thermodynamic properties of bulk single-walled carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Kenneth R. Rodriguez

    2014-12-01

    Full Text Available The enthalpy and Gibbs free energy thermodynamical potentials of single walled carbon nanotubes were studied of all types (armchairs, zig-zags, chirals (n>m, and chiral (nnanotube. Results of this study led to the proposal of a single equation for the thermodynamical potential of Δ H AB 298   K or Δ G AB 298   K (assembly of nanotubes from atoms versus the chiral vector indexes n and m for any given nanotube. The equations show a good level of accuracy in predicting thermodynamic potentials for practical applications.

  3. Production of single-walled carbon nanotube grids

    Science.gov (United States)

    Hauge, Robert H; Xu, Ya-Qiong; Pheasant, Sean

    2013-12-03

    A method of forming a nanotube grid includes placing a plurality of catalyst nanoparticles on a grid framework, contacting the catalyst nanoparticles with a gas mixture that includes hydrogen and a carbon source in a reaction chamber, forming an activated gas from the gas mixture, heating the grid framework and activated gas, and controlling a growth time to generate a single-wall carbon nanotube array radially about the grid framework. A filter membrane may be produced by this method.

  4. Single-walled carbon nanotube-induced mitotic disruption⋆

    OpenAIRE

    Sargent, L.M.; Hubbs, A.F.; Young, S.-H.; Kashon, M.L.; Dinu, C.Z.; Salisbury, J.L.; Benkovic, S.A.; Lowry, D.T.; Murray, A.R.; Kisin, E.R.; Siegrist, K.J.; Battelli, L.; Mastovich, J.; Sturgeon, J.L.; Bunker, K.L.

    2011-01-01

    Carbon nanotubes were among the earliest products of nanotechnology and have many potential applications in medicine, electronics, and manufacturing. The low density, small size, and biological persistence of carbon nanotubes create challenges for exposure control and monitoring and make respiratory exposures to workers likely. We have previously shown mitotic spindle aberrations in cultured primary and immortalized human airway epithelial cells exposed to 24, 48 and 96 μg/cm2 single-walled c...

  5. Recent developments in the selective dispersion of single-walled carbon nanotubes using conjugated polymers.

    Science.gov (United States)

    Fong, Darryl; Adronov, Alex

    2017-11-01

    A significant barrier that impedes the commercialization of single-walled carbon nanotube-related applications is that all known synthetic methods produce a complicated mixture of semiconducting and metallic species. For device applications, pure semiconducting or pure metallic samples are desirable. Thus far, the purification methods that have been identified are capable of separating individual carbon nanotube species on a microgram scale, but purification on a large scale has remained elusive. The use of conjugated polymers to selectively disperse specific nanotube species is a promising approach to resolve the scalability issue, but a comprehensive understanding of the selectivity mechanism has not yet been achieved. Here, several of the trends reported in the literature are outlined to further the rational design of conjugated polymers for nanotube sorting. Numerous variables influence dispersion selectivity, including polymer structure and molecular weight, nanotube type used, sonication temperature, amount of polymer relative to nanotube, and solvent. We have organized these seemingly disparate parameters into two simple categories: conjugated polymer structure, and dispersion preparation conditions. Most importantly, we consider the mechanistic arguments that have been proposed, and provide additional insights based on the observations in the literature.

  6. Applied Physics of Carbon Nanotubes Fundamentals of Theory, Optics and Transport Devices

    CERN Document Server

    Rotkin, Slava V

    2005-01-01

    The book describes the state-of-the-art in fundamental, applied and device physics of nanotubes, including fabrication, manipulation and characterization for device applications; optics of nanotubes; transport and electromechanical devices and fundamentals of theory for applications. This information is critical to the field of nanoscience since nanotubes have the potential to become a very significant electronic material for decades to come. The book will benefit all all readers interested in the application of nanotubes, either in their theoretical foundations or in newly developed characterization tools that may enable practical device fabrication.

  7. Electric moulding of dispersed lipid nanotubes into a nanofluidic device.

    Science.gov (United States)

    Frusawa, Hiroshi; Manabe, Tatsuhiko; Kagiyama, Eri; Hirano, Ken; Kameta, Naohiro; Masuda, Mitsutoshi; Shimizu, Toshimi

    2013-01-01

    Hydrophilic nanotubes formed by lipid molecules have potential applications as platforms for chemical or biological events occurring in an attolitre volume inside a hollow cylinder. Here, we have integrated the lipid nanotubes (LNTs) by applying an AC electric field via plug-in electrode needles placed above a substrate. The off-chip assembly method has the on-demand adjustability of an electrode configuration, enabling the dispersed LNT to be electrically moulded into a separate film of parallel LNT arrays in one-step. The fluorescence resonance energy transfer technique as well as the digital microscopy visualised the overall filling of gold nanoparticles up to the inner capacity of an LNT film by capillary action, thereby showing the potential of this flexible film for use as a high-throughput nanofluidic device where not only is the endo-signalling and product in each LNT multiplied but also the encapsulated objects are efficiently transported and reacted.

  8. Flexible electroluminescent device with inkjet-printed carbon nanotube electrodes

    Science.gov (United States)

    Azoubel, Suzanna; Shemesh, Shay; Magdassi, Shlomo

    2012-08-01

    Carbon nanotube (CNTs) inks may provide an effective route for producing flexible electronic devices by digital printing. In this paper we report on the formulation of highly concentrated aqueous CNT inks and demonstrate the fabrication of flexible electroluminescent (EL) devices by inkjet printing combined with wet coating. We also report, for the first time, on the formation of flexible EL devices in which all the electrodes are formed by inkjet printing of low-cost multi-walled carbon nanotubes (MWCNTs). Several flexible EL devices were fabricated by using different materials for the production of back and counter electrodes: ITO/MWCNT and MWCNT/MWCNT. Transparent electrodes were obtained either by coating a thin layer of the CNTs or by inkjet printing a grid which is composed of empty cells surrounded by MWCNTs. It was found that the conductivity and transparency of the electrodes are mainly controlled by the MWCNT film thickness, and that the dominant factor in the luminance intensity is the transparency of the electrode.

  9. Electronic properties of single-walled chiral carbon nanotube

    International Nuclear Information System (INIS)

    Mensah, S.Y.; Allotey, F.K.A.; Mensah, N.G.; Nkrumah, G.

    2001-09-01

    The electronic properties of single-walled chiral carbon nanotube has been studied using the model based on infinitely long carbon atoms wrapped along a base helix of single-walled carbon nanotubes(SWNTs). The problem is solved semiclassically, and current density J, resistivity ρ, thermopower α z , and electrical power factor P calculated. It is noted that the current density j displays negative differential conductivity, whiles the resistivity ρ increases with increasing electrical field. ρ also slowly increases at low temperatures and then gradually increases with increasing temperature. The thermopower α z shows interesting behaviour. Very intriguing is the electrical power factor which shows relatively large values. (author)

  10. Quantum dot-like excitonic behavior in individual single walled-carbon nanotubes

    Science.gov (United States)

    Wang, Xu; Alexander-Webber, Jack A.; Jia, Wei; Reid, Benjamin P. L.; Stranks, Samuel D.; Holmes, Mark J.; Chan, Christopher C. S.; Deng, Chaoyong; Nicholas, Robin J.; Taylor, Robert A.

    2016-11-01

    Semiconducting single-walled carbon nanotubes are one-dimensional materials with great prospects for applications such as optoelectronic and quantum information devices. Yet, their optical performance is hindered by low fluorescent yield. Highly mobile excitons interacting with quenching sites are attributed to be one of the main non-radiative decay mechanisms that shortens the exciton lifetime. In this paper we report on time-integrated photoluminescence measurements on individual polymer wrapped semiconducting carbon nanotubes. An ultra narrow linewidth we observed demonstrates intrinsic exciton dynamics. Furthermore, we identify a state filling effect in individual carbon nanotubes at cryogenic temperatures as previously observed in quantum dots. We propose that each of the CNTs is segmented into a chain of zero-dimensional states confined by a varying local potential along the CNT, determined by local environmental factors such as the amount of polymer wrapping. Spectral diffusion is also observed, which is consistent with the tunneling of excitons between these confined states.

  11. Spontaneous and controlled-diameter synthesis of single-walled and few-walled carbon nanotubes

    Science.gov (United States)

    Inoue, Shuhei; Lojindarat, Supanat; Kawamoto, Takahiro; Matsumura, Yukihiko; Charinpanitkul, Tawatchai

    2018-05-01

    In this study, we explored the spontaneous and controlled-diameter growth of carbon nanotubes. We evaluated the effects of catalyst density, reduction time, and a number of catalyst coating on the substrate (for multi-walled carbon nanotubes) on the diameter of single-walled carbon nanotubes and the number of layers in few-walled carbon nanotubes. Increasing the catalyst density and reduction time increased the diameters of the carbon nanotubes, with the average diameter increasing from 1.05 nm to 1.86 nm for single-walled carbon nanotubes. Finally, we succeeded in synthesizing a significant double-walled carbon nanotube population of 24%.

  12. Single Molecule Electronics and Devices

    Science.gov (United States)

    Tsutsui, Makusu; Taniguchi, Masateru

    2012-01-01

    The manufacture of integrated circuits with single-molecule building blocks is a goal of molecular electronics. While research in the past has been limited to bulk experiments on self-assembled monolayers, advances in technology have now enabled us to fabricate single-molecule junctions. This has led to significant progress in understanding electron transport in molecular systems at the single-molecule level and the concomitant emergence of new device concepts. Here, we review recent developments in this field. We summarize the methods currently used to form metal-molecule-metal structures and some single-molecule techniques essential for characterizing molecular junctions such as inelastic electron tunnelling spectroscopy. We then highlight several important achievements, including demonstration of single-molecule diodes, transistors, and switches that make use of electrical, photo, and mechanical stimulation to control the electron transport. We also discuss intriguing issues to be addressed further in the future such as heat and thermoelectric transport in an individual molecule. PMID:22969345

  13. Dipole induced conductance modulation in chromophore-functionalized single-walled carbon nanotubes

    Science.gov (United States)

    Zhao, Yuanchun; Huang, Changshui; Kim, Myungwoong; Gopalan, Padma; Eriksson, Mark

    2013-03-01

    Single-walled carbon nanotubes (SWNTs) are highly sensitive to local electrostatic environments, making SWNT field-effect transistors (FETs) of interest for a number of sensor applications and optoelectronic devices. Here we demonstrate a direct correlation between the conduction of SWNTs and their surrounding dipolar environments. We use azobenzene-based dipolar chromophores, Disperse Red 1 (DR1) and its derivatives to functionalize the sidewalls of SWNTs. The chromophores are coupled with a pyrenebutyric group for realizing noncovalent attachment and to attempt to direct their dipole moments. The functionalizing chromophores produce a dipole field that shifts the threshold voltage (Vth) of the nanotube FET. Under light illumination, these molecules isomerize from the ground trans state to the excited cis state, leading to a decrease of their dipole moments. This dipole moment change acts as an additional gate, causing a shift in Vth. Our results provide a new insight into the photogating mechanisms of the nanotube-chromophore hybrid devices, and they reveal the possibility to modulate optoelectronic properties of nanotube-hybrid devices by designing chromophores with required photosensitive features.

  14. Silicon spectral response extension through single wall carbon nanotubes in hybrid solar cells

    KAUST Repository

    Del Gobbo, Silvano

    2013-01-01

    Photovoltaic devices based on single wall carbon nanotubes (SWCNTs) and n-silicon multiple heterojunctions have been fabricated by a SWCNT film transferring process. We report on the ability of the carbon nanotubes to extend the Si spectral range towards the near ultraviolet (UV) and the near infrared regions. Semiconducting and about metallic SWCNT networks have been studied as a function of the film sheet resistance, Rsh. Optical absorbance and Raman spectroscopy have been used to assign nanotube chirality and electronic character. This gave us hints of evidence of the participation of the metal nanotubes in the photocurrent generation. Moreover, we provide evidence that the external quantum efficiency spectral range can be modulated as a function of the SWCNT network sheet resistance in a hybrid SWCNT/Si solar cell. This result will be very useful to further design/optimize devices with improved performance in spectral regions generally not covered by conventional Si p-n devices. © 2013 The Royal Society of Chemistry.

  15. Synthesis of single walled carbon nanotubes by dual laser vaporization

    CSIR Research Space (South Africa)

    Moodley, MK et al.

    2006-02-27

    Full Text Available Single-walled carbon nanotubes were synthesised by the laser vaporisation of graphite composite targets in a tube furnace. Two pulsed Nd:YAG lasers operating at fundamental (1 064 nm) and 2nd harmonic (532 nm) were combined, focused and evaporated...

  16. Hydrogen adsorption on N-decorated single wall carbon nanotubes

    International Nuclear Information System (INIS)

    Rangel, Eduardo; Ruiz-Chavarria, Gregorio; Magana, L.F.; Arellano, J.S.

    2009-01-01

    Using density functional theory and molecular dynamics we found that N-decorated single walled (8,0) carbon nanotubes are potential high capacity hydrogen storage media. This system could store up to 6.0 wt% hydrogen at 300 K and ambient pressure, with average adsorption energy of -80 meV/(H 2 ). Nitrogen coverage was C 8 N.

  17. A new method of preparing single-walled carbon nanotubes

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 115; Issue 5-6. A new method of preparing single-walled carbon nanotubes ... Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur PO, Bangalore 560 064, India; Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, ...

  18. A new method of preparing single-walled carbon nanotubes

    Indian Academy of Sciences (India)

    Unknown

    A new method of preparing single-walled carbon nanotubes. ¶. S R C VIVEKCHAND1 and A GOVINDARAJ1,2,*. 1Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for. Advanced Scientific Research, Jakkur PO, Bangalore 560 064, India. 2Solid State and Structural Chemistry Unit, Indian Institute of Science ...

  19. Estimation of mechanical properties of single wall carbon nanotubes ...

    Indian Academy of Sciences (India)

    40, Part 4, June 2015, pp. 1301–1311. c Indian Academy of Sciences. Estimation of mechanical properties of single wall carbon nanotubes using molecular mechanics approach. P SUBBA RAO1,2,∗, SUNIL ANANDATHEERTHA3,. G NARAYANA NAIK1 and S GOPALAKRISHNAN1. 1Department of Aerospace Engineering ...

  20. Estimation of mechanical properties of single wall carbon nanotubes ...

    Indian Academy of Sciences (India)

    Molecular mechanics based finite element analysis is adopted in the current work to evaluate the mechanical properties of Zigzag, Armchair and Chiral Single wall Carbon Nanotubes (SWCNT) of different diameters and chiralities. Three different types of atomic bonds, that is Carbon–Carbon covalent bond and two types of ...

  1. A new method of preparing single-walled carbon nanotubes

    Indian Academy of Sciences (India)

    A novel method of purification for single-walled carbon nanotubes, prepared by an arc-discharge method, is described. The method involves a combination of acid washing followed by high temperature hydrogen treatment to remove the metal nanoparticles and amorphous carbon present in the as-synthesized singlewalled ...

  2. Functionalization of oxidized single-walled carbon nanotubes with 4 ...

    Indian Academy of Sciences (India)

    The low-dimension and remarkable physical proper- ties of single-walled carbon nanotubes (SWCNTs) ren- der them unique material properties with a wide range of potential applications.1,2 However, the lack of sol- ubility in solvents presents a considerable impediment toward harnessing of their applications.

  3. Single-Walled Carbon-Nanotubes-Based Organic Memory Structures

    Directory of Open Access Journals (Sweden)

    Sundes Fakher

    2016-09-01

    Full Text Available The electrical behaviour of organic memory structures, based on single-walled carbon-nanotubes (SWCNTs, metal–insulator–semiconductor (MIS and thin film transistor (TFT structures, using poly(methyl methacrylate (PMMA as the gate dielectric, are reported. The drain and source electrodes were fabricated by evaporating 50 nm gold, and the gate electrode was made from 50 nm-evaporated aluminium on a clean glass substrate. Thin films of SWCNTs, embedded within the insulating layer, were used as the floating gate. SWCNTs-based memory devices exhibited clear hysteresis in their electrical characteristics (capacitance–voltage (C–V for MIS structures, as well as output and transfer characteristics for transistors. Both structures were shown to produce reliable and large memory windows by virtue of high capacity and reduced charge leakage. The hysteresis in the output and transfer characteristics, the shifts in the threshold voltage of the transfer characteristics, and the flat-band voltage shift in the MIS structures were attributed to the charging and discharging of the SWCNTs floating gate. Under an appropriate gate bias (1 s pulses, the floating gate is charged and discharged, resulting in significant threshold voltage shifts. Pulses as low as 1 V resulted in clear write and erase states.

  4. Single-Walled Carbon-Nanotubes-Based Organic Memory Structures.

    Science.gov (United States)

    Fakher, Sundes; Nejm, Razan; Ayesh, Ahmad; Al-Ghaferi, Amal; Zeze, Dagou; Mabrook, Mohammed

    2016-09-02

    The electrical behaviour of organic memory structures, based on single-walled carbon-nanotubes (SWCNTs), metal-insulator-semiconductor (MIS) and thin film transistor (TFT) structures, using poly(methyl methacrylate) (PMMA) as the gate dielectric, are reported. The drain and source electrodes were fabricated by evaporating 50 nm gold, and the gate electrode was made from 50 nm-evaporated aluminium on a clean glass substrate. Thin films of SWCNTs, embedded within the insulating layer, were used as the floating gate. SWCNTs-based memory devices exhibited clear hysteresis in their electrical characteristics (capacitance-voltage (C-V) for MIS structures, as well as output and transfer characteristics for transistors). Both structures were shown to produce reliable and large memory windows by virtue of high capacity and reduced charge leakage. The hysteresis in the output and transfer characteristics, the shifts in the threshold voltage of the transfer characteristics, and the flat-band voltage shift in the MIS structures were attributed to the charging and discharging of the SWCNTs floating gate. Under an appropriate gate bias (1 s pulses), the floating gate is charged and discharged, resulting in significant threshold voltage shifts. Pulses as low as 1 V resulted in clear write and erase states.

  5. Immunosuppressive agent leflunomide: a SWNTs-immobilized dihydroortate dehydrogenase inhibitory effect and computational study of its adsorption properties on zigzag single walled (6,0) carbon and boron nitride nanotubes as controlled drug delivery devices.

    Science.gov (United States)

    Raissi, Heidar; Mollania, Fariba

    2014-06-02

    Leflunomide [HWA 486 or RS-34821, 5-methyl-N-(4trifluoromethylphenyl)-4-isoxazole carboximide] is an immunosuppressive agent effective in the treatment of rheumatoid arthritis. Dihydroortate dehydrogenase (DHODH, EC 1.3.3.1) immobilization on the nanotubes was carried out and biochemical characterization of free and immobilized enzyme was determined. In comparison with free enzyme, the immobilized DHODH showed improved stability and reusability for investigation of inhibition pattern of drugs such as leflunomide. The experimental data showed that, DHODH was inhibited by the active metabolite of leflunomide (RS-61980) with a Ki and KI of 0.82 and 0.06 mM, respectively. Results exhibited mixed-type inhibition kinetics towards dihydroorotate as a substrate in the free and immobilized enzyme. Furthermore, the behavior of anticancer drug leflunomide adsorbed on the external surface of zigzag single walled (6,0) carbon and boron nitride nanotubes (SWCNT and SWBNNT) was studied by means of DFT calculations at the B3LYP/6-31G(*) level of theory. The larger adsorption energies and charges transfer showed that the adsorption of leflunomide onto SWBNNT is more stable than that the adsorption of leflunomide onto SWCNT. Frontier molecular orbitals (HOMO and LUMO) suggest that adsorption of leflunomide onto SWBNNT behave as charge transfer compounds with leflunomide as an electron donor and SWBNNT as an electron acceptor. Thus, nanotubes (NTs) have been proposed and actively explored as multipurpose innovative carriers for drug delivery and diagnostic application. The AIM theory has been also applied to analyze the properties of the bond critical points: their electron densities and their laplacians. Also, the natural bond orbital (NBO) calculations were performed to derive natural atomic orbital occupancies, and partial charges of the interacting atoms in the equilibrium tube-molecule distance. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Fluorescent single walled nanotube/silica composite materials

    Science.gov (United States)

    Dattelbaum, Andrew M.; Gupta, Gautam; Duque, Juan G.; Doorn, Stephen K.; Hamilton, Christopher E.; DeFriend Obrey, Kimberly A.

    2013-03-12

    Fluorescent composites of surfactant-wrapped single-walled carbon nanotubes (SWNTs) were prepared by exposing suspensions of surfactant-wrapped carbon nanotubes to tetramethylorthosilicate (TMOS) vapor. Sodium deoxycholate (DOC) and sodium dodecylsulphate (SDS) were the surfactants. No loss in emission intensity was observed when the suspension of DOC-wrapped SWNTs were exposed to the TMOS vapors, but about a 50% decrease in the emission signal was observed from the SDS-wrapped SWNTs nanotubes. The decrease in emission was minimal by buffering the SDS/SWNT suspension prior to forming the composite. Fluorescent xerogels were prepared by adding glycerol to the SWNT suspensions prior to TMOS vapor exposure, followed by drying the gels. Fluorescent aerogels were prepared by replacing water in the gels with methanol and then exposing them to supercritical fluid drying conditions. The aerogels can be used for gas sensing.

  7. Center for Applications of Single-Walled Carbon Nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Resasco, Daniel E

    2008-02-21

    This report describes the activities conducted under a Congressional Direction project whose goal was to develop applications for Single-walled carbon nanotubes, under the Carbon Nanotube Technology Center (CANTEC), a multi-investigator program that capitalizes on OU’s advantageous position of having available high quality carbon nanotubes. During the first phase of CANTEC, 11 faculty members and their students from the College of Engineering developed applications for carbon nanotubes by applying their expertise in a number of areas: Catalysis, Reaction Engineering, Nanotube synthesis, Surfactants, Colloid Chemistry, Polymer Chemistry, Spectroscopy, Tissue Engineering, Biosensors, Biochemical Engineering, Cell Biology, Thermal Transport, Composite Materials, Protein synthesis and purification, Molecular Modeling, Computational Simulations. In particular, during this phase, the different research groups involved in CANTEC made advances in the tailoring of Single-Walled Carbon Nanotubes (SWNT) of controlled diameter and chirality by Modifying Reaction Conditions and the Nature of the catalyst; developed kinetic models that quantitatively describe the SWNT growth, created vertically oriented forests of SWNT by varying the density of metal nanoparticles catalyst particles, and developed novel nanostructured SWNT towers that exhibit superhydrophobic behavior. They also developed molecular simulations of the growth of Metal Nanoparticles on the surface of SWNT, which may have applications in the field of fuell cells. In the area of biomedical applications, CANTEC researchers fabricated SWNT Biosensors by a novel electrostatic layer-by-layer (LBL) deposition method, which may have an impact in the control of diabetes. They also functionalized SWNT with proteins that retained the protein’s biological activity and also retained the near-infrared light absorbance, which finds applications in the treatment of cancer.

  8. Bipolar single-wall carbon nanotube field-effect transistor

    OpenAIRE

    Babic, Bakir; Iqbal, Mahdi; Schonenberger, Christian

    2002-01-01

    We use a simultaneous flow of ethylene and hydrogen gases to grow single wall carbon nanotubes by chemical vapor deposition. Strong coupling to the gate is inferred from transport measurements for both metallic and semiconducting tubes. At low-temperatures, our samples act as single-electron transistors where the transport mechanism is mainly governed by Coulomb blockade. The measurements reveal very rich quantized energy level spectra spanning from valence to conduction band. The Coulomb dia...

  9. Giant osmotic energy conversion measured in a single transmembrane boron nitride nanotube.

    Science.gov (United States)

    Siria, Alessandro; Poncharal, Philippe; Biance, Anne-Laure; Fulcrand, Rémy; Blase, Xavier; Purcell, Stephen T; Bocquet, Lydéric

    2013-02-28

    New models of fluid transport are expected to emerge from the confinement of liquids at the nanoscale, with potential applications in ultrafiltration, desalination and energy conversion. Nevertheless, advancing our fundamental understanding of fluid transport on the smallest scales requires mass and ion dynamics to be ultimately characterized across an individual channel to avoid averaging over many pores. A major challenge for nanofluidics thus lies in building distinct and well-controlled nanochannels, amenable to the systematic exploration of their properties. Here we describe the fabrication and use of a hierarchical nanofluidic device made of a boron nitride nanotube that pierces an ultrathin membrane and connects two fluid reservoirs. Such a transmembrane geometry allows the detailed study of fluidic transport through a single nanotube under diverse forces, including electric fields, pressure drops and chemical gradients. Using this device, we discover very large, osmotically induced electric currents generated by salinity gradients, exceeding by two orders of magnitude their pressure-driven counterpart. We show that this result originates in the anomalously high surface charge carried by the nanotube's internal surface in water at large pH, which we independently quantify in conductance measurements. The nano-assembly route using nanostructures as building blocks opens the way to studying fluid, ionic and molecule transport on the nanoscale, and may lead to biomimetic functionalities. Our results furthermore suggest that boron nitride nanotubes could be used as membranes for osmotic power harvesting under salinity gradients.

  10. Quenching of Single-Walled Carbon Nanotube Fluorescence by Dissolved Oxygen Reveals Selective Single-Stranded DNA Affinities.

    Science.gov (United States)

    Zheng, Yu; Bachilo, Sergei M; Weisman, R Bruce

    2017-05-04

    The selective interactions between short oligomers of single-stranded DNA (ssDNA) and specific structures of single-walled carbon nanotubes have been exploited in powerful methods for nanotube sorting. We report here that nanotubes coated with ssDNA also display selective interactions through the selective quenching of nanotube fluorescence by dissolved oxygen. In aqueous solutions equilibrated under 1 atm of O 2 , emission intensity from semiconducting nanotubes is reduced by between 9 and 40%, varying with the combination of ssDNA sequence and nanotube structure. This quenching reverses promptly and completely on the removal of dissolved O 2 and may be due to physisorption on nanotube surfaces. Fluorescence quenching offers a simple, nondestructive approach for studying the structure-selective interactions of ssDNA with single-walled carbon nanotubes and identifying recognition sequences.

  11. CMOS-analogous wafer-scale nanotube-on-insulator approach for submicrometer devices and integrated circuits using aligned nanotubes.

    Science.gov (United States)

    Ryu, Koungmin; Badmaev, Alexander; Wang, Chuan; Lin, Albert; Patil, Nishant; Gomez, Lewis; Kumar, Akshay; Mitra, Subhasish; Wong, H-S Philip; Zhou, Chongwu

    2009-01-01

    Massive aligned carbon nanotubes hold great potential but also face significant integration/assembly challenges for future beyond-silicon nanoelectronics. We report a wafer-scale processing of aligned nanotube devices and integrated circuits, including progress on essential technological components such as wafer-scale synthesis of aligned nanotubes, wafer-scale transfer of nanotubes to silicon wafers, metallic nanotube removal and chemical doping, and defect-tolerant integrated nanotube circuits. We have achieved synthesis of massive aligned nanotubes on complete 4 in. quartz and sapphire substrates, which were then transferred to 4 in. Si/SiO(2) wafers. CMOS analogous fabrication was performed to yield transistors and circuits with features down to 0.5 mum, with high current density approximately 20 muA/mum and good on/off ratios. In addition, chemical doping has been used to build fully integrated complementary inverter with a gain approximately 5, and a defect-tolerant design has been employed for NAND and NOR gates. This full-wafer approach could serve as a critical foundation for future integrated nanotube circuits.

  12. Giant electrical power factor in single-walled chiral carbon nanotube

    International Nuclear Information System (INIS)

    Mensah, S.Y.; Allotey, F.K.A.; Mensah, N.G.; Nkrumah, G.

    2001-10-01

    Using the semiclassical approach we studied the thermoelectrical properties of single-walled chiral carbon nanotubes (SWNTs). We predict a giant electrical power factor and hence proposed the use of carbon nanotubes as thermoelements for refrigeration. (author)

  13. Visualizing the growth dynamics of individual single-wall carbon nanotubes

    DEFF Research Database (Denmark)

    Wagner, Jakob Birkedal; Zhang, Lili; He, Maoshuai

    In order to meet the increasing demand of faster and more flexible electronics and optical devices and at the same time decrease the use of the critical metals, carbon based devices are in fast development. Single walled carbon nanotube (SWCNT) based electronics is a way of addressing...... around the studied sample at elevated temperature gives a unique way of monitoring gas-solid interactions such as CNT growth. Here we show the direct experimental evidence on the growth dynamics of SW-CNTs from Co/MgO catalysts using CO as carbon source inside the environmental TEM. The evolution...

  14. Improvements in Production of Single-Walled Carbon Nanotubes

    Science.gov (United States)

    Balzano, Leandro; Resasco, Daniel E.

    2009-01-01

    A continuing program of research and development has been directed toward improvement of a prior batch process in which single-walled carbon nanotubes are formed by catalytic disproportionation of carbon monoxide in a fluidized-bed reactor. The overall effect of the improvements has been to make progress toward converting the process from a batch mode to a continuous mode and to scaling of production to larger quantities. Efforts have also been made to optimize associated purification and dispersion post processes to make them effective at large scales and to investigate means of incorporating the purified products into composite materials. The ultimate purpose of the program is to enable the production of high-quality single-walled carbon nanotubes in quantities large enough and at costs low enough to foster the further development of practical applications. The fluidized bed used in this process contains mixed-metal catalyst particles. The choice of the catalyst and the operating conditions is such that the yield of single-walled carbon nanotubes, relative to all forms of carbon (including carbon fibers, multi-walled carbon nanotubes, and graphite) produced in the disproportionation reaction is more than 90 weight percent. After the reaction, the nanotubes are dispersed in various solvents in preparation for end use, which typically involves blending into a plastic, ceramic, or other matrix to form a composite material. Notwithstanding the batch nature of the unmodified prior fluidized-bed process, the fluidized-bed reactor operates in a continuous mode during the process. The operation is almost entirely automated, utilizing mass flow controllers, a control computer running software specific to the process, and other equipment. Moreover, an important inherent advantage of fluidized- bed reactors in general is that solid particles can be added to and removed from fluidized beds during operation. For these reasons, the process and equipment were amenable to

  15. Carbon nanotube field-effect devices with asymmetric electrode configuration by contact geometry

    Science.gov (United States)

    Yotprayoonsak, P.; Talukdar, D.; Ahlskog, M.

    2014-06-01

    We have studied experimentally the conductive properties of single walled carbon nanotube (SWNT) based field-effect type devices, with different contact geometries at the connecting electrode. The device designs are asymmetric with one end of the SWNT having the metal electrode deposited on top and immersing it, while at the other end, the SWNT is on top of the electrode. The devices were made with either gold or palladium as electrode materials, of which the latter resulted in different behavior of the different contact types. This is argued to be caused by the existence of a thin insulating layer of surface adsorbents on the palladium, possibly Pd5O4, the effect of which is enhanced by the 1D nature of the contact area in the configuration with SWNT on top of electrode.

  16. Quantum optics with single quantum dot devices

    International Nuclear Information System (INIS)

    Zwiller, Valery; Aichele, Thomas; Benson, Oliver

    2004-01-01

    A single radiative transition in a single-quantum emitter results in the emission of a single photon. Single quantum dots are single-quantum emitters with all the requirements to generate single photons at visible and near-infrared wavelengths. It is also possible to generate more than single photons with single quantum dots. In this paper we show that single quantum dots can be used to generate non-classical states of light, from single photons to photon triplets. Advanced solid state structures can be fabricated with single quantum dots as their active region. We also show results obtained on devices based on single quantum dots

  17. High-performance partially aligned semiconductive single-walled carbon nanotube transistors achieved with a parallel technique.

    Science.gov (United States)

    Wang, Yilei; Pillai, Suresh Kumar Raman; Chan-Park, Mary B

    2013-09-09

    Single-walled carbon nanotubes (SWNTs) are widely thought to be a strong contender for next-generation printed electronic transistor materials. However, large-scale solution-based parallel assembly of SWNTs to obtain high-performance transistor devices is challenging. SWNTs have anisotropic properties and, although partial alignment of the nanotubes has been theoretically predicted to achieve optimum transistor device performance, thus far no parallel solution-based technique can achieve this. Herein a novel solution-based technique, the immersion-cum-shake method, is reported to achieve partially aligned SWNT networks using semiconductive (99% enriched) SWNTs (s-SWNTs). By immersing an aminosilane-treated wafer into a solution of nanotubes placed on a rotary shaker, the repetitive flow of the nanotube solution over the wafer surface during the deposition process orients the nanotubes toward the fluid flow direction. By adjusting the nanotube concentration in the solution, the nanotube density of the partially aligned network can be controlled; linear densities ranging from 5 to 45 SWNTs/μm are observed. Through control of the linear SWNT density and channel length, the optimum SWNT-based field-effect transistor devices achieve outstanding performance metrics (with an on/off ratio of ~3.2 × 10(4) and mobility 46.5 cm(2) /Vs). Atomic force microscopy shows that the partial alignment is uniform over an area of 20 × 20 mm(2) and confirms that the orientation of the nanotubes is mostly along the fluid flow direction, with a narrow orientation scatter characterized by a full width at half maximum (FWHM) of parallel process is large-scale applicable and exploits the anisotropic properties of the SWNTs, presenting a viable path forward for industrial adoption of SWNTs in printed, flexible, and large-area electronics. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Selective etching of thin single-walled carbon nanotubes.

    Science.gov (United States)

    Kalbác, Martin; Kavan, Ladislav; Dunsch, Lothar

    2009-04-01

    Raman spectroscopy and in situ Raman spectroelectrochemistry were applied to study the selective etching of thin tubes by lithium vapor in doped single-walled carbon nanotubes (SWCNTs). A strong doping of SWCNTs after the reaction with Li vapor was confirmed by the vanishing of the radial breathing mode (RBM) and by a strong attenuation of the tangential displacement (TG) band in the Raman spectra. The Raman spectra of the Li-vapor-treated SWCNTs after subsequent reaction with water showed changes in the diameter distribution compared with that of a pristine sample (nanotubes with diameters of <1 nm disappeared from the Raman spectra). The samples were tested by the Raman pattern with five different laser lines, and a removal of narrower tubes was confirmed. The remaining wider tubes were not significantly damaged by the treatment with Li, as indicated by the D line in the Raman spectra. Furthermore, the small-diameter tubes are converted not into amorphous carbon but into lithium carbide, which could easily be removed by hydrolysis. The treated samples were further charged electrochemically. It was shown by spectroelectrochemistry that anodic charging may lead to removal of the residual chemical doping from the thicker nanotubes in the sample, but the thin nanotubes did not appear in the spectra. This is a further confirmation of the removal of the small-diameter tubes.

  19. Broadband photodetector based on carbon nanotube thin film/single layer graphene Schottky junction

    Science.gov (United States)

    Zhang, Teng-Fei; Li, Zhi-Peng; Wang, Jiu-Zhen; Kong, Wei-Yu; Wu, Guo-An; Zheng, Yu-Zhen; Zhao, Yuan-Wei; Yao, En-Xu; Zhuang, Nai-Xi; Luo, Lin-Bao

    2016-12-01

    In this study, we present a broadband nano-photodetector based on single-layer graphene (SLG)-carbon nanotube thin film (CNTF) Schottky junction. It was found that the as-fabricated device exhibited obvious sensitivity to a wide range of illumination, with peak sensitivity at 600 and 920 nm. In addition, the SLG-CNTF device had a fast response speed (τr = 68 μs, τf = 78 μs) and good reproducibility in a wide range of switching frequencies (50-5400 Hz). The on-off ratio, responsivity, and detectivity of the device were estimated to be 1 × 102, 209 mAW-1 and 4.87 × 1010 cm Hz1/2 W-1, respectively. What is more, other device parameters including linear performance θ and linear dynamic range (LDR) were calculated to be 0.99 and 58.8 dB, respectively, which were relatively better than other carbon nanotube based devices. The totality of the above study signifies that the present SLG-CNTF Schottky junction broadband nano-photodetector may have promising application in future nano-optoelectronic devices and systems.

  20. Light Induced Aggregation of Specific Single Walled Carbon Nanotubes

    OpenAIRE

    Gopannagari, Madhusudana; Chaturvedi, Harsh

    2015-01-01

    We report optically induced aggregation and consequent separation of specific diameter of pristine single walled carbon nanotubes (SWNT) from stable solution. Well dispersed solution of pristine SWNTs, without any surfactant or functionalization, show rapid aggregation by uniform exposure to UV, visible and NIR illumination. Optically induced aggregation linearly increases with consequent increase in the intensity of light. Aggregated SWNTs were separated from the dispersed supernatant and ch...

  1. Titanium dioxide, single-walled carbon nanotube composites

    Science.gov (United States)

    Yao, Yuan; Li, Gonghu; Gray, Kimberly; Lueptow, Richard M.

    2015-07-14

    The present invention provides titanium dioxide/single-walled carbon nanotube composites (TiO.sub.2/SWCNTs), articles of manufacture, and methods of making and using such composites. In certain embodiments, the present invention provides membrane filters and ceramic articles that are coated with TiO.sub.2/SWCNT composite material. In other embodiments, the present invention provides methods of using TiO.sub.2/SWCNT composite material to purify a sample, such as a water or air sample.

  2. Applications of Nanotubes in Electronic and Nanomechanical Devices

    National Research Council Canada - National Science Library

    Tomanek, David

    2002-01-01

    ... as their potential for energy storage. Our research helps to better understand nanotube properties in case of chemically and structurally modified nanotubes consisting of carbon and boron nitride, including multi-wall systems and peapods...

  3. AC-driven organic light emission devices with carbon nanotubes

    Science.gov (United States)

    Jeon, So-Yeon; Yu, SeGi

    2017-02-01

    We have investigated alternating current (AC)-driven organic light-emitting devices (OLEDs), with carbon nanotubes (CNTs) incorporated within the emission layer. With CNT incorporation, the brightness of the OLEDs was substantially improved, and the turn-on voltage was reduced by at least a factor of five. Furthermore, the current levels of the CNT-incorporated OLEDs were lower than that of the reference device. A roughly 70% decrease in the current level was obtained for a CNT concentration of 0.03 wt%. This was accomplished by keeping the concentration of CNTs low and the length of CNTs short, which helped to suppress the percolation networking of CNTs within the emitting layer. Strong local electric fields near the end-tips of CNTs and micro-capacitors formed by dispersed CNTs might have caused this high brightness and these low currents. CNT incorporation in the emitting layer can improve the characteristics of AC-driven OLEDs, which are considered to be one of the candidates for flat panel displays and lightning devices.

  4. Direct observation of spin-injection in tyrosinate-functionalized single-wall carbon nanotubes

    NARCIS (Netherlands)

    Tsoufis, Theodoros; Ampoumogli, Asem; Gournis, Dimitrios; Georgakilas, Vasilios; Jankovic, Lubos; Christoforidis, Konstantinos C.; Deligiannakis, Yiannis; Mavrandonakis, Andreas; Froudakis, George E.; Maccallini, Enrico; Rudolf, Petra; Mateo-Alonso, Aurelio; Prato, Maurizio

    In this work, we report on the interaction of a tyrosinate radical with single wall carbon nanotubes (CNT). The tyrosinate radical was formed from tyrosine (ester) by Fenton's reagent and, reacted in situ with carbon nanotubes resulting in novel tyrosinated carbon nanotube derivatives. The covalent

  5. Raman study on single-walled carbon nanotubes with different laser ...

    Indian Academy of Sciences (India)

    TECS

    Abstract. The industrial use of carbon nanotubes is increasing day by day; therefore, it is very important to identify the nature of carbon nanotubes in a bundle. In this study, we have used the Raman spectroscopic analysis on vertically aligned single-walled carbon nanotubes (SWCNTs) grown by the chemical vapour depo-.

  6. Ultraclean single, double, and triple carbon nanotube quantum dots with recessed Re bottom gates

    Science.gov (United States)

    Jung, Minkyung; Schindele, Jens; Nau, Stefan; Weiss, Markus; Baumgartner, Andreas; Schoenenberger, Christian

    2014-03-01

    Ultraclean carbon nanotubes (CNTs) that are free from disorder provide a promising platform to manipulate single electron or hole spins for quantum information. Here, we demonstrate that ultraclean single, double, and triple quantum dots (QDs) can be formed reliably in a CNT by a straightforward fabrication technique. The QDs are electrostatically defined in the CNT by closely spaced metallic bottom gates deposited in trenches in Silicon dioxide by sputter deposition of Re. The carbon nanotubes are then grown by chemical vapor deposition (CVD) across the trenches and contacted using conventional electron beam lithography. The devices exhibit reproducibly the characteristics of ultraclean QDs behavior even after the subsequent electron beam lithography and chemical processing steps. We demonstrate the high quality using CNT devices with two narrow bottom gates and one global back gate. Tunable by the gate voltages, the device can be operated in four different regimes: i) fully p-type with ballistic transport between the outermost contacts (over a length of 700 nm), ii) clean n-type single QD behavior where a QD can be induced by either the left or the right bottom gate, iii) n-type double QD and iv) triple bipolar QD where the middle QD has opposite doping (p-type). Research at Basel is supported by the NCCR-Nano, NCCR-QIST, ERC project QUEST, and FP7 project SE2ND.

  7. Sequestration of Single-Walled Carbon Nanotubes in a Polymer

    Science.gov (United States)

    Bley, Richard A.

    2007-01-01

    Sequestration of single-walled carbon nanotubes (SWCNs) in a suitably chosen polymer is under investigation as a means of promoting the dissolution of the nanotubes into epoxies. The purpose of this investigation is to make it possible to utilize SWCNs as the reinforcing fibers in strong, lightweight epoxy-matrix/carbon-fiber composite materials. SWCNs are especially attractive for use as reinforcing fibers because of their stiffness and strength-to-weight ratio: Their Young s modulus has been calculated to be 1.2 TPa, their strength has been calculated to be as much as 100 times that of steel, and their mass density is only one-sixth that of steel. Bare SWCNs cannot be incorporated directly into composite materials of the types envisioned because they are not soluble in epoxies. Heretofore, SWCNS have been rendered soluble by chemically attaching various molecular chains to them, but such chemical attachments compromise their structural integrity. In the method now under investigation, carbon nanotubes are sequestered in molecules of poly(m-phenylenevinylene-co-2,5-dioctyloxy-p-phenylenevinylene) [PmPV]. The strength of the carbon nanotubes is preserved because they are not chemically bonded to the PmPV. This method exploits the tendency of PmPV molecules to wrap themselves around carbon nanotubes: the wrapping occurs partly because there exists a favorable interface between the conjugated face of a nanotube and the conjugated backbone of the polymer and partly because of the helical molecular structure of PmPV. The constituents attached to the polymer backbones (the side chains) render the PmPV-wrapped carbon nanotubes PmPV soluble in organic materials that, in turn, could be used to suspend the carbon nanotubes in epoxy precursors. At present, this method is being optimized: The side chains on the currently available form of PmPV are very nonpolar and unable to react with the epoxy resins and/or hardeners; as a consequence, SWCN/PmPV composites have been

  8. Finite single wall capped carbon nanotubes under hydrostatic pressure

    International Nuclear Information System (INIS)

    Baltazar, S E; Romero, A H; RodrIguez-Lopez, J L; Martonak, R

    2006-01-01

    We report a classical molecular dynamics isothermal-isobaric ensemble (NPT) implementation for the simulation of pressure effects on finite systems. The method is based on calculating the enclosed surface area by means of the Delauney triangulation method, which results in a fairly accurate description of the surface and the system volume. The external pressure is applied to the system by external forces acting on the triangulated surface covering the nanostructure. Pressure is exerted perpendicularly to every one of the Delauney triangles, by equally distributing the force to every corner of a triangle. We applied the method to finite single wall capped carbon nanotubes (SWCNTs) with different chiralities and different tube lengths ranging from 4 nm up to 30 nm. Pressure effects are studied as a function of the radii and the nanotube length, as well as as a function of temperature. Our results are in very good agreement when compared with both experimental and other theoretical results

  9. The electrochemical properties of bundles of single-walled nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Zawodzinski, T.A. Jr.; Haridoss, P.; Uribe, F.A.

    1998-12-31

    This is the final report of a Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The authors studied electrochemical properties of single-walled fullerene nanotube bundles. The materials exhibited a highly anisotropic conductivity. Electrochemical cycling in solutions of alkyl ammonium salts in propylene carbonate revealed that the nanotubes are stable to at least {+-}1.5 V and have a fairly high accessible surface area. Double-layer charging currents of approximately 30 farads per gram were observed. This is on the same order of magnitude, though somewhat lower, than state-of-the-art values for ultra-capacitor materials. Electrochemical insertion of lithium was attempted. Though several features were observed in a slow cyclic voltammetric scan, these features were not reversible, indicating little reversible insertion. Several possible reasons for this behavior are discussed.

  10. Synthesis and Cytotoxicity of POSS Modified Single Walled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Yuhua Xue

    2015-01-01

    Full Text Available Single walled carbon nanotubes (SWNTs decorated with polyhedral oligomeric silsesquioxane (POSS were synthesized via the amide linkages between the acid treated SWNTs and amine-functionalized POSS. The successful modification of SWNTs with POSS was confirmed by Fourier transform infrared spectroscopy (FTIR, X-ray photoelectron spectroscopy (XPS, and UV-Vis spectra. The resulting SWNTs-POSS can be dispersed in both water and organic solutions. The biocompatibility and cytotoxicity of the SWNTs and SWNTs-POSS were evaluated by CCK-8 viability assays, which indicated that SWNTs-POSS exhibit very extremely low toxicity. The low toxicity of the POSS modified SWNTs leads to more opportunities for using carbon nanotubes in biomedical fields.

  11. Systems and Methods for Fabricating Carbon Nanotube-Based Vacuum Electronic Devices

    Science.gov (United States)

    Manohara, Harish (Inventor); Toda, Risaku (Inventor); Del Castillo, Linda Y. (Inventor); Murthy, Rakesh (Inventor)

    2015-01-01

    Systems and methods in accordance with embodiments of the invention proficiently produce carbon nanotube-based vacuum electronic devices. In one embodiment a method of fabricating a carbon nanotube-based vacuum electronic device includes: growing carbon nanotubes onto a substrate to form a cathode; assembling a stack that includes the cathode, an anode, and a first layer that includes an alignment slot; disposing a microsphere partially into the alignment slot during the assembling of the stack such that the microsphere protrudes from the alignment slot and can thereby separate the first layer from an adjacent layer; and encasing the stack in a vacuum sealed container.

  12. Shape-engineerable and highly densely packed single-walled carbon nanotubes and their application as super-capacitor electrodes.

    Science.gov (United States)

    Futaba, Don N; Hata, Kenji; Yamada, Takeo; Hiraoka, Tatsuki; Hayamizu, Yuhei; Kakudate, Yozo; Tanaike, Osamu; Hatori, Hiroaki; Yumura, Motoo; Iijima, Sumio

    2006-12-01

    We present a rational and general method to fabricate a high-densely packed and aligned single-walled carbon-nanotube (SWNT) material by using the zipping effect of liquids to draw tubes together. This bulk carbon-nanotube material retains the intrinsic properties of individual SWNTs, such as high surface area, flexibility and electrical conductivity. By controlling the fabrication process, it is possible to fabricate a wide range of solids in numerous shapes and structures. This dense SWNT material is advantageous for numerous applications, and here we demonstrate its use as flexible heaters as well as supercapacitor electrodes for compact energy-storage devices.

  13. Viscosity and Morphology Modification of Length Sorted Single Walled Carbon Nanotubes in Pib Matrices

    Science.gov (United States)

    Huang, Hanxiao

    In this work, Single Walled Carbon Nanotubes (SWNT) were separated by length and chirality using an ultracentrifuge technique. The influence of length-separation on the composites' viscosity and crystallinity behavior was studied. We found that the composites' viscosity does not increase monotonously with weight fractions. Specifically, in relatively small nanotube weight fractions, the dynamic viscosity of the composites was found to be smaller than that of the pure Polyisotublyene (PIB) matrix. The dimension of nanotube bundles and polymer radius of gyration were compared to further study the mechanism of such a viscosity change. It was observed that nanotubes with shorter lengths successfully initiated polymer crystallization. In further studies conducted on, both length and chirality separated SWNTs were used to fabricate nanotube based semi-conducting devices, the 1/f noise characteristics of all samples were measured and compared. It was experimentally observed that both length and chirality separation could effectively reduce the level of noise in these homogenous samples. Finally, in coordinating the effects of nanoparticulate inclusions, with highly spe-cific dimensional, and dispersion characteristics the study of the extrusion processing of Polytetrafluoroethylene (PTFE)/ Styrene-Acrylonitrile Copolymer (SAN) nanocomposites is presented. As with the dimensional control observed with regards to the nanoparticulates in SWNT-polymer composites, which serves as a first order system model which has led to predictable structure-property relationships, the control of the dimension and morphology of nanofribrils produced in processing PTFE/SAN nanocomposites will decisively alter the overall properties and behavior of the whole composite. In this study, the degree of nano-fibrillaiton is quantified, and its relationship to increased mechanical properties of the composite is assessed. The accelerating pattern of fibrillation increase was identified, and the

  14. Polyvinylchloride-Single-Walled Carbon Nanotube Composites: Thermal and Spectroscopic Properties

    Directory of Open Access Journals (Sweden)

    Mircea Chipara

    2012-01-01

    Full Text Available Nanocomposites of single-walled carbon nanotubes dispersed within polyvinylchloride have been obtained by using the solution path. High-power sonication was utilized to achieve a good dispersion of carbon nanotubes. Thermogravimetric analysis revealed that during the synthesis, processing, or thermal analysis of these nanocomposites the released chlorine is functionalizing the single-walled carbon nanotubes. The loading of polyvinylchloride by single-walled carbon nanotubes increases the glass transition temperature of the polymeric matrix, demonstrating the interactions between macromolecular chains and filler. Wide Angle X-Ray Scattering data suggested a drop of the crystallite size and of the degree of crystallinity as the concentration of single-walled carbon nanotubes is increased. The in situ chlorination and amorphization of nanotube during the synthesis (sonication step is confirmed by Raman spectroscopy.

  15. Synthesis of carbon and zinc oxide nanotubes and their applications in electronic devices

    Science.gov (United States)

    Yang, Kaikun

    Nanostructured materials, including single and multiwalled carbon nanotubes (SWCNTs and MWCNTs), zinc oxide (ZnO) nanotubes (NTs) and graphene, have been successfully synthesized using chemical vapor deposition (CVD) or wet chemistry routines, and used to fabricate nanoelectronic and optoelectronic devices, including field effect transistors (FETs) and heterojunction solar cells. Both nanomaterials properties and devices performances have been characterized. Vertically aligned multiwalled carbon nanotubes (VACNTs) have been synthesized using both the pre-deposited iron films and the continuous supply of catalytic species via gas flow in pyrolytic decomposition of hydrocarbons by CVD. High quality VACNTs have been obtained after the optimization of synthesis parameters. Using metal nanoparticles as catalysts, centimeter-long SWCNTs have been synthesized on a silicon wafer with a thin thermal oxide layer. A series of FETs have been fabricated directly on a single SWCNT by inkjet printing of Pd nanoparticles to form both source and drain electrodes. The devices exhibit typical Schottky barrier p-type conductance characteristics. The line density and field mobility of charge carriers, as well as the effect of gate field modulation have been shown to strongly depend on thermal treatment of the SWCNT-FETs, implying the effect of carrier doping and interfacial reconstruction. ZnO NTs have been synthesized in an aqueous solution of zinc nitrate at 60ºC. A novel core-shell growth mechanism was hypothesized to explain the synthesis of ZnO NTs. The crystalline microstructures and optical properties of ZnO NTs upon thermal annealing in air at various temperatures have been examined. Ultraviolet-Visible (UV-Vis) absorption spectra reveal a slightly redshift of the direct band gap upon annealing. Solution structure of regioregular poly(3-hexylthiophene) (RR-P3HT) in toluene has been examined using optical spectroscopy in situ and atomic force microscopy upon casting films on a

  16. Electrochemical Charging of Individual Single-Walled Carbon Nanotubes

    Czech Academy of Sciences Publication Activity Database

    Kalbáč, Martin; Farhat, H.; Kavan, Ladislav; Kong, J.; Sasaki, K.; Saito, R.; Dresselhaus, M. S.

    2009-01-01

    Roč. 3, č. 8 (2009), s. 2320-2328 ISSN 1936-0851 R&D Projects: GA ČR GC203/07/J067; GA AV ČR IAA400400804; GA AV ČR IAA400400911; GA AV ČR KAN200100801; GA MŠk ME09060 Institutional research plan: CEZ:AV0Z40400503 Keywords : single-walled carbon nanotubes * Raman spectroscopy * electrochemical gating * spectroelectrochemistry Subject RIV: CG - Electrochemistry Impact factor: 7.493, year: 2009

  17. Induced Magnetic Moment in Defected Single-Walled Carbon Nanotubes

    International Nuclear Information System (INIS)

    Liu Hong

    2006-01-01

    The existence of a large induced magnetic moment in defect single-walled carbon nanotube(SWNT) is predicted using the Green's function method. Specific to this magnetic moment of defect SWNT is its magnitude which is several orders of magnitude larger than that of perfect SWNT. The induced magnetic moment also shows certain remarkable features. Therefore, we suggest that two pair-defect orientations in SWNT can be distinguished in experiment through the direction of the induced magnetic moment at some Specific energy points

  18. Capillary electrophoresis of covalently functionalized single-chirality carbon nanotubes.

    Science.gov (United States)

    He, Pingli; Meany, Brendan; Wang, Chunyan; Piao, Yanmei; Kwon, Hyejin; Deng, Shunliu; Wang, YuHuang

    2017-07-01

    We demonstrate the separation of chirality-enriched single-walled carbon nanotubes (SWCNTs) by degree of surface functionalization using high-performance CE. Controlled amounts of negatively charged and positively charged functional groups were attached to the sidewall of chirality-enriched SWCNTs through covalent functionalization using 4-carboxybenzenediazonium tetrafluoroborate or 4-diazo-N,N-diethylaniline tetrafluoroborate, respectively. Surfactant- and pH-dependent studies confirmed that under conditions that minimized ionic screening effects, separation of these functionalized SWCNTs was strongly dependent on the surface charge density introduced through covalent surface chemistry. For both heterogeneous mixtures and single-chirality-enriched samples, covalently functionalized SWCNTs showed substantially increased peak width in electropherogram spectra compared to nonfunctionalized SWCNTs, which can be attributed to a distribution of surface charges along the functionalized nanotubes. Successful separation of functionalized single-chirality SWCNTs by functional density was confirmed with UV-Vis-NIR absorption and Raman scattering spectroscopies of fraction collected samples. These results suggest a high degree of structural heterogeneity in covalently functionalized SWCNTs, even for chirality-enriched samples, and show the feasibility of applying CE for high-performance separation of nanomaterials based on differences in surface functional density. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Single Nucleotide Polymorphism Detection Using Au-Decorated Single-Walled Carbon Nanotube Field Effect Transistors

    Directory of Open Access Journals (Sweden)

    Keum-Ju Lee

    2011-01-01

    Full Text Available We demonstrate that Au-cluster-decorated single-walled carbon nanotubes (SWNTs may be used to discriminate single nucleotide polymorphism (SNP. Nanoscale Au clusters were formed on the side walls of carbon nanotubes in a transistor geometry using electrochemical deposition. The effect of Au cluster decoration appeared as hole doping when electrical transport characteristics were examined. Thiolated single-stranded probe peptide nucleic acid (PNA was successfully immobilized on Au clusters decorating single-walled carbon nanotube field-effect transistors (SWNT-FETs, resulting in a conductance decrease that could be explained by a decrease in Au work function upon adsorption of thiolated PNA. Although a target single-stranded DNA (ssDNA with a single mismatch did not cause any change in electrical conductance, a clear decrease in conductance was observed with matched ssDNA, thereby showing the possibility of SNP (single nucleotide polymorphism detection using Au-cluster-decorated SWNT-FETs. However, a power to discriminate SNP target is lost in high ionic environment. We can conclude that observed SNP discrimination in low ionic environment is due to the hampered binding of SNP target on nanoscale surfaces in low ionic conditions.

  20. Study on the Microwave Permittivity of Single-Walled Carbon Nanotube

    Science.gov (United States)

    Liu, Xiaolai; Zhao, Donglin

    2009-01-01

    In this article, we studied the microwave permittivity of the complex of the single-walled carbon nanotube and paraffin in 2-18GHz. In the range, the dielectric loss of single-walled carbon nanotube is higher, and the real part and the imaginary part of the dielectric constant decrease with the increase of frequency, and the dielectric constant…

  1. Single-walled carbon nanotubes as near-infrared optical biosensors for life sciences and biomedicine.

    Science.gov (United States)

    Jain, Astha; Homayoun, Aida; Bannister, Christopher W; Yum, Kyungsuk

    2015-03-01

    Single-walled carbon nanotubes that emit photostable near-infrared fluorescence have emerged as near-infrared optical biosensors for life sciences and biomedicine. Since the discovery of their near-infrared fluorescence, researchers have engineered single-walled carbon nanotubes to function as an optical biosensor that selectively modulates its fluorescence upon binding of target molecules. Here we review the recent advances in the single-walled carbon nanotube-based optical sensing technology for life sciences and biomedicine. We discuss the structure and optical properties of single-walled carbon nanotubes, the mechanisms for molecular recognition and signal transduction in single-walled carbon nanotube complexes, and the recent development of various single-walled carbon nanotube-based optical biosensors. We also discuss the opportunities and challenges to translate this emerging technology into biomedical research and clinical use, including the biological safety of single-walled carbon nanotubes. The advances in single-walled carbon nanotube-based near-infrared optical sensing technology open up a new avenue for in vitro and in vivo biosensing with high sensitivity and high spatial resolution, beneficial for many areas of life sciences and biomedicine. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Photophysics of covalently functionalized single wall carbon nanotubes with verteporfin

    Science.gov (United States)

    Staicu, Angela; Smarandache, Adriana; Pascu, Alexandru; Pascu, Mihail Lucian

    2017-09-01

    Covalently functionalized single wall carbon nanotubes (SWCNT) with the photosensitizer verteporfin (VP) were synthesized and studied. Photophysical properties of the obtained compounds like optical absorption, laser-induced fluorescence and generated singlet oxygen were investigated. In order to highlight the features of the conjugated compound, its photophysical characteristics were compared with those of the mixtures of the initial components. The optical absorption data evidenced a compound that combines features of the primary SWCNTs and VP. This is the also the case of the laser induced fluorescence of the synthesized product. Moreover, fluorescence quantum yield (Φf) of the compound (Φf = 2.4%) is smaller than for the mixture of SWCNT and VP in (Φf = 3.2%). The behavior is expected, because linked VP (carrying the fluorescent moiety) transfers easier a part of its excitation energy to the SWCNT in the covalent structure. Relative to the quantum yield of singlet oxygen generation (ΦΔ) by Methylene Blue, it was found that the ΦΔ for the conjugated VP-SWCNT is 51% while for the mixture ΦΔ is 23%. The results indicate covalently functionalized single walled carbon nanotubes with verteporfin as potential compounds of interest in targeted drug delivery and photodynamic therapy.

  3. Surface chemical functionalization of single walled carbon nanotubes with a bacteriorhodopsin mutant.

    Science.gov (United States)

    Ingrosso, Chiara; Bianco, Giuseppe Valerio; Lopalco, Patrizia; Tamborra, Michela; Curri, Maria Lucia; Corcelli, Angela; Bruno, Giovanni; Agostiano, Angela; Siciliano, Pietro; Striccoli, Marinella

    2012-10-21

    In this work, single walled carbon nanotubes (SWNTs) have been chemically functionalized at their walls with a membrane protein, namely the mutated bacteriorhodopsin D96N, integrated in its native archaeal lipid membrane. The modification of the SWNT walls with the mutant has been carried out in different buffer solutions, at pH 5, 7.5 and 9, to investigate the anchoring process, the typical chemical and physical properties of the component materials being dependent on the pH. The SWNTs modified by interactions with bacteriorhodopsin membrane patches have been characterized by UV-vis steady state, Raman and attenuated total reflection Fourier transform infrared spectroscopy and by atomic force and transmission electron microscopy. The investigation shows that the membrane protein patches wrap the carbon walls by tight chemical interactions undergoing a conformational change; such chemical interactions increase the mechanical strength of the SWNTs and promote charge transfers which p-dope the nano-objects. The functionalization, as well as the SWNT doping, is favoured in acid and basic buffer conditions; such buffers make the nanotube walls more reactive, thus catalysing the anchoring of the membrane protein. The direct electron communication among the materials can be exploited for effectively interfacing the transport properties of carbon nanotubes with both molecular recognition capability and photoactivity of the cell membrane for sensing and photoconversion applications upon integration of the achieved hybrid materials in sensors or photovoltaic devices.

  4. Industrial-scale separation of high-purity single-chirality single-wall carbon nanotubes for biological imaging

    Science.gov (United States)

    Yomogida, Yohei; Tanaka, Takeshi; Zhang, Minfang; Yudasaka, Masako; Wei, Xiaojun; Kataura, Hiromichi

    2016-06-01

    Single-chirality, single-wall carbon nanotubes are desired due to their inherent physical properties and performance characteristics. Here, we demonstrate a chromatographic separation method based on a newly discovered chirality-selective affinity between carbon nanotubes and a gel containing a mixture of the surfactants. In this system, two different selectivities are found: chiral-angle selectivity and diameter selectivity. Since the chirality of nanotubes is determined by the chiral angle and diameter, combining these independent selectivities leads to high-resolution single-chirality separation with milligram-scale throughput and high purity. Furthermore, we present efficient vascular imaging of mice using separated single-chirality (9,4) nanotubes. Due to efficient absorption and emission, blood vessels can be recognized even with the use of ~100-fold lower injected dose than the reported value for pristine nanotubes. Thus, 1 day of separation provides material for up to 15,000 imaging experiments, which is acceptable for industrial use.

  5. Recent progress on the structure separation of single-wall carbon nanotubes

    Science.gov (United States)

    Cui, Jiaming; Yang, Dehua; Zeng, Xiang; Zhou, Naigen; Liu, Huaping

    2017-11-01

    The mass production of single-structure, single-wall carbon nanotubes (SWCNTs) with identical properties is critical for their basic research and technical applications in the fields of electronics, optics and optoelectronics. Great efforts have been made to control the structures of SWCNTs since their discovery. Recently, the structure separation of SWCNTs has been making great progress. Various solution-sorting methods have been developed to achieve not only the separation of metallic and semiconducting species, but also the sorting of distinct (n, m) single-chirality species and even their enantiomers. This progress would dramatically accelerate the application of SWCNTs in the next-generation electronic devices. Here, we review the recent progress in the structure sorting of SWCNTs and outline the challenges and prospects of the structure separation of SWCNTs.

  6. Ultrashort single-walled carbon nanotubes in a lipid bilayer as a new nanopore sensor

    Science.gov (United States)

    Liu, Lei; Yang, Chun; Zhao, Kai; Li, Jingyuan; Wu, Hai-Chen

    2013-01-01

    An important issue in nanopore sensing is to construct stable and versatile sensors that can discriminate analytes with minute differences. Here we report a means of creating nanopores that comprise ultrashort single-walled carbon nanotubes inserted into a lipid bilayer. We investigate the ion transport and DNA translocation through single-walled carbon nanotube nanopores and find that our results are fundamentally different from previous studies using much longer single-walled carbon nanotubes. Furthermore, we utilize the new single-walled carbon nanotube nanopores to selectively detect modified 5-hydroxymethylcytosine in single-stranded DNA, which may have implications in screening specific genomic DNA sequences. This new nanopore platform can be integrated with many unique properties of carbon nanotubes and might be useful in molecular sensing such as DNA-damage detection, nanopore DNA sequencing and other nanopore-based applications. PMID:24352224

  7. New Method Developed To Purify Single Wall Carbon Nanotubes for Aerospace Applications

    Science.gov (United States)

    Lebron, Marisabel; Meador, Michael A.

    2003-01-01

    Single wall carbon nanotubes have attracted considerable attention because of their remarkable mechanical properties and electrical and thermal conductivities. Use of these materials as primary or secondary reinforcements in polymers or ceramics could lead to new materials with significantly enhanced mechanical strength and electrical and thermal conductivity. Use of carbon-nanotube-reinforced materials in aerospace components will enable substantial reductions in component weight and improvements in durability and safety. Potential applications for single wall carbon nanotubes include lightweight components for vehicle structures and propulsion systems, fuel cell components (bipolar plates and electrodes) and battery electrodes, and ultra-lightweight materials for use in solar sails. A major barrier to the successful use of carbon nanotubes in these components is the need for methods to economically produce pure carbon nanotubes in large enough quantities to not only evaluate their suitability for certain applications but also produce actual components. Most carbon nanotube synthesis methods, including the HiPCO (high pressure carbon monoxide) method developed by Smalley and others, employ metal catalysts that remain trapped in the final product. These catalyst impurities can affect nanotube properties and accelerate their decomposition. The development of techniques to remove most, if not all, of these impurities is essential to their successful use in practical applications. A new method has been developed at the NASA Glenn Research Center to purify gram-scale quantities of single wall carbon nanotubes. This method, a modification of a gas phase purification technique previously reported by Smalley and others, uses a combination of high-temperature oxidations and repeated extractions with nitric and hydrochloric acid. This improved procedure significantly reduces the amount of impurities (catalyst and nonnanotube forms of carbon) within the nanotubes, increasing

  8. Asymmetric devices based on carbon nanotubes for terahertz-range radiation detection

    Energy Technology Data Exchange (ETDEWEB)

    Fedorov, G. E., E-mail: gefedorov@mail.ru; Stepanova, T. S.; Gazaliev, A. Sh.; Gaiduchenko, I. A.; Kaurova, N. S.; Voronov, B. M.; Goltzman, G. N. [Moscow State Pedagogical University (Russian Federation)

    2016-12-15

    Various asymmetric detecting devices based on carbon nanotubes (CNTs) are studied. The asymmetry is understood as inhomogeneous properties along the conducting channel. In the first type of devices, an inhomogeneous morphology of the CNT grid is used. In the second type of devices, metals with highly varying work functions are used as the contact material. The relation between the sensitivity and detector configuration is analyzed. Based on the data obtained, approaches to the development of an efficient detector of terahertz radiation, based on carbon nanotubes are proposed.

  9. Chemical detection with nano/bio hybrid devices based on carbon nanotubes and graphene

    Science.gov (United States)

    Lerner, Mitchell Bryant

    Carbon nanotube field-effect transistors (NT-FETs) and graphene field effect transistors (GFETs) provide a unique transduction platform for chemical and biomolecular detection. The work presented in this thesis describes the fabrication, characterization, and investigation of operational mechanisms of carbon-based biosensors. In the first set of experiments, we used carbon nanotubes as fast, all-electronic readout elements in novel vapor sensors, suitable for applications in environmental monitoring and medicine. Molecules bound to the hybrid alter the electrical properties of the NT-FET via several mechanisms, allowing direct detection as a change in the transistor conduction properties. Vapor sensors suitable for more complex system architectures characteristic of mammalian olfaction were demonstrated using NT-FETs functionalized with mouse olfactory receptor (mOR) proteins or single stranded DNA (ssDNA). Substitution of graphene as the channel material enabled production of hundreds of electronically similar devices with high yield. Etching large scale chemical vapor deposition (CVD)-grown graphene into small channels is itself a challenging problem, and we have developed novel fabrication methods to this end without sacrificing the inherent electrical quality that makes graphene such an attractive material. Large arrays of such devices have potential utility for understanding the physics of ligand-receptor interactions and contributing to the development of a new generation of devices for electronic olfaction. Tailored and specific detection was accomplished by chemically functionalizing the NT-FET or GFET with biomolecules, such as proteins or small molecules, to create a hybrid nanostructures. Targets for detection were widely varied, indicating the utility of these techniques, such as 1) live Salmonella cells in nutrient broth, 2) a biomarker protein indicative of prostate cancer, 3) antigen protein from the bacterium that causes Lyme disease, and 4) glucose

  10. Relationships among the structural topology, bond strength, and mechanical properties of single-walled aluminosilicate nanotubes.

    Science.gov (United States)

    Liou, Kai-Hsin; Tsou, Nien-Ti; Kang, Dun-Yen

    2015-10-21

    Carbon nanotubes (CNTs) are regarded as small but strong due to their nanoscale microstructure and high mechanical strength (Young's modulus exceeds 1000 GPa). A longstanding question has been whether there exist other nanotube materials with mechanical properties as good as those of CNTs. In this study, we investigated the mechanical properties of single-walled aluminosilicate nanotubes (AlSiNTs) using a multiscale computational method and then conducted a comparison with single-walled carbon nanotubes (SWCNTs). By comparing the potential energy estimated from molecular and macroscopic material mechanics, we were able to model the chemical bonds as beam elements for the nanoscale continuum modeling. This method allowed for simulated mechanical tests (tensile, bending, and torsion) with minimum computational resources for deducing their Young's modulus and shear modulus. The proposed approach also enabled the creation of hypothetical nanotubes to elucidate the relative contributions of bond strength and nanotube structural topology to overall nanotube mechanical strength. Our results indicated that it is the structural topology rather than bond strength that dominates the mechanical properties of the nanotubes. Finally, we investigated the relationship between the structural topology and the mechanical properties by analyzing the von Mises stress distribution in the nanotubes. The proposed methodology proved effective in rationalizing differences in the mechanical properties of AlSiNTs and SWCNTs. Furthermore, this approach could be applied to the exploration of new high-strength nanotube materials.

  11. Ultraclean individual suspended single-walled carbon nanotube field effect transistor

    Science.gov (United States)

    Liu, Siyu; Zhang, Jian; Nshimiyimana, Jean Pierre; Chi, Xiannian; Hu, Xiao; Wu, Pei; Liu, Jia; Wang, Gongtang; Sun, Lianfeng

    2018-04-01

    In this work, we report an effective technique of fabricating ultraclean individual suspended single-walled carbon nanotube (SWNT) transistors. The surface tension of molten silver is utilized to suspend an individual SWNT between a pair of Pd electrodes during annealing treatment. This approach avoids the usage and the residues of organic resist attached to SWNTs, resulting ultraclean SWNT devices. And the resistance per micrometer of suspended SWNTs is found to be smaller than that of non-suspended SWNTs, indicating the effect of the substrate on the electrical properties of SWNTs. The ON-state resistance (˜50 kΩ), mobility of 8600 cm2 V-1 s-1 and large on/off ratio (˜105) of semiconducting suspended SWNT devices indicate its advantages and potential applications.

  12. Modification of single wall carbon nanotubes (SWNT) for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Rashidi, A.M.; Nouralishahi, A.; Karimi, A.; Kashefi, K. [Nanotechnology Research Center, Research Institute of petroleum industry (RIPI), Tehran (Iran); Khodadadi, A.A.; Mortazavi, Y. [Chemical engineering Department, University of Tehran, Tehran (Iran)

    2010-09-15

    Due to unique structural, mechanical and electrical properties of single wall carbon nanotubes, SWNTs, they have been proposed as promising hydrogen storage materials especially in automotive industries. This research deals with investing of CNT's and some activated carbons hydrogen storage capacity. The CNT's were prepared through natural gas decomposition at a temperature of 900 C over cobalt-molybdenum nanoparticles supported by nanoporous magnesium oxide (Co-Mo/MgO) during a chemical vapor deposition (CVD) process. The effects of purity of CNT (80-95%wt.) on hydrogen storage were investigated here. The results showed an improvement in the hydrogen adsorption capacity with increasing the purity of CNT's. Maximum adsorption capacity was 0.8%wt. in case of CNT's with 95% purity and it may be raised up with some purification to 1%wt. which was far less than the target specified by DOE (6.5%wt.). Also some activated carbons were manufactured and the results compared to CNTs. There were no considerable H{sub 2}-storage for carbon nanotubes and activated carbons at room-temperature due to insufficient binding between H{sub 2} molecules carbon nanostructures. Therefore, hydrogen must be adsorbed via interaction of atomic hydrogen with the storage environment in order to achieve DOE target, because the H atoms have a very stronger interaction with carbon nanostructures. (author)

  13. Broadband Spectroscopic Thermoacoustic Characterization of Single-Walled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Daniel R. Bauer

    2015-01-01

    Full Text Available Carbon nanotubes have attracted interest as contrast agents for biomedical imaging because they strongly absorb electromagnetic radiation in the optical and microwave regions. This study applies thermoacoustic (TA imaging and spectroscopy to measure the frequency-dependent absorption profile of single-walled carbon nanotubes (SWNT in the ranges of 2.7–3.1 GHz and 7–9 GHz using two tunable microwave sources. Between 7 and 9 GHz, the peak TA signal for solutions containing semiconducting and metallic SWNTs increased monotonically with a slope of 1.75 AU/GHz (R2=0.95 and 2.8 AU/GHz (R2=0.93, respectively, relative to a water baseline. However, after compensating for the background signal from water, it was revealed that the TA signal from metallic SWNTs increased exponentially within this frequency band. Results suggest that TA imaging and spectroscopy could be a powerful tool for quantifying the absorption properties of SWNTs and optimizing their performance as contrast agents for imaging or heat sources for thermal therapy.

  14. Electronic sensitivity of a single-walled carbon nanotube to internal electrolyte composition

    International Nuclear Information System (INIS)

    Cao, D; Pang, P; Lindsay, S M; Liu, H; He, J

    2012-01-01

    Carbon nanotubes (CNTs) are well known as materials for nanoelectronics and show great potential to be used as the sensing elements in chemical and biological sensors. Recently, CNTs have been shown to be effective nanofluidic channels and the transport of substances through small diameter CNTs is intrinsically fast, selective, and operates at the single molecule level. It has been shown that the transport characteristics of semiconducting single-walled CNT (SWCNT) field effect transistors (FETs) are sensitive to internal water wetting. We report here that the characteristics of semiconducting SWCNT FETs are also sensitive to the concentration, pH and ion type of the ionic solution when the electrolyte is inside the CNT. Such sensitivity is not observed at the outside surface of a semiconducting SWCNT. This opens a new avenue for building new types of CNT sensor devices in which the SWCNT concurrently functions as a nanochannel and an electronic detector. (paper)

  15. Electronic sensitivity of single-walled carbon nanotube to internal electrolyte composition

    Science.gov (United States)

    Cao, D; Pang, P; Liu, H; He, J; Lindsay, SM

    2012-01-01

    Carbon nanotubes (CNTs) are well-known as materials for nanoelectronics and show great potential to be used as the sensing element in chemical and biological sensors. Recently, CNTs have been shown to be effective nanofluidic channels and the transport of substances through small diameter CNTs is intrinsically fast, selective, and operates at the single molecule level. It has been shown that the transport characteristics of semiconducting single-walled CNT (SWCNT) field effect transistor (FET) are sensitive to internal water wetting. We report here that the characteristics of semiconducting SWCNT FETs are also sensitive to the concentration, pH and ion type of ionic solution when the electrolytes are inside the CNT. Such sensitivity is not observed at the outside surface of a semiconducting SWCNT. This opens a new avenue for building new types of CNT sensor devices in which the SWCNT concurrently functions as a nanochannel and an electronic detector. PMID:22293518

  16. On the elastic properties of single-walled carbon nanotubes/poly(ethylene oxide) nanocomposites using molecular dynamics simulations.

    Science.gov (United States)

    Rouhi, S; Alizadeh, Y; Ansari, R

    2016-01-01

    Molecular dynamics simulations are used to study the physical and mechanical properties of single-walled carbon nanotubes/poly(ethylene oxide) nanocomposites. The effects of nanotube atomic structure, diameter, and volume fraction on the polymer density distribution, polymer atom distribution, stress-strain curves of nanocomposites and Young's, and shear moduli of single-walled carbon nanotubes/poly(ethylene oxide) nanocomposites are explored. It is shown that the density of polymer, surrounding the nanotube surface, has a peak near the nanotube surface. However, increasing distance leads to dropping it to the value near the density of pure polymer. It is seen that for armchair nanotubes, the average polymer atoms distances from the single-walled carbon nanotubes are larger than the polymer atom distance from zigzag nanotubes. It further is shown that zigzag nanotubes are better candidates to reinforce poly (ethylene oxide) than their armchair counterparts.

  17. The synthesis and filling of single-walled carbon nanotubes

    CERN Document Server

    Friedrichs, S

    2002-01-01

    This thesis is concerned with the synthesis, properties and application of single-walled carbon nanotubes (SWNTs). The two main objectives of the work were the development of a continuous-flow synthesis of SWNTs, using chemical vapour deposition (CVD) techniques, and the application of the hollow SWNTs as moulds for the study of the crystallisation behaviour of inorganic materials in the confined space of their inner cavity. The latter study was mainly performed by interpreting high-resolution transmission electron microscopy (HRTEM) images of the filled SWNTs. A so-called focal series restoration approach, which enhances the resolution of the images and thereby increases the information content, was employed where possible. Chapter I reviews the previous work in the field of SWNTs and introduces their basic structure, symmetry, physical and mechanical properties and the common methods of SWNT synthesis. The chapter ends with an overview of the techniques used in the present work for the characterisation of c...

  18. Radiation Protection Using Single-Wall Carbon Nanotube Derivatives

    Science.gov (United States)

    Tour, James M.; Lu, Meng; Lucente-Schultz, Rebecca; Leonard, Ashley; Doyle, Condell Dewayne; Kosynkin, Dimitry V.; Price, Brandi Katherine

    2011-01-01

    This invention is a means of radiation protection, or cellular oxidative stress mitigation, via a sequence of quenching radical species using nano-engineered scaffolds, specifically single-wall carbon nanotubes (SWNTs) and their derivatives. The material can be used as a means of radiation protection by reducing the number of free radicals within, or nearby, organelles, cells, tissue, organs, or living organisms, thereby reducing the risk of damage to DNA and other cellular components (i.e., RNA, mitochondria, membranes, etc.) that can lead to chronic and/or acute pathologies, including but not limited to cancer, cardiovascular disease, immuno-suppression, and disorders of the central nervous system. In addition, this innovation could be used as a prophylactic or antidote for accidental radiation exposure, during high-altitude or space travel where exposure to radiation is anticipated, or to protect from exposure from deliberate terrorist or wartime use of radiation- containing weapons.

  19. Review of Electronics Based on Single-Walled Carbon Nanotubes.

    Science.gov (United States)

    Cao, Yu; Cong, Sen; Cao, Xuan; Wu, Fanqi; Liu, Qingzhou; Amer, Moh R; Zhou, Chongwu

    2017-08-14

    Single-walled carbon nanotubes (SWNTs) are extremely promising materials for building next-generation electronics due to their unique physical and electronic properties. In this article, we will review the research efforts and achievements of SWNTs in three electronic fields, namely analog radio-frequency electronics, digital electronics, and macroelectronics. In each SWNT-based electronic field, we will present the major challenges, the evolutions of the methods to overcome these challenges, and the state-of-the-art of the achievements. At last, we will discuss future directions which could lead to the broad applications of SWNTs. We hope this review could inspire more research on SWNT-based electronics, and accelerate the applications of SWNTs.

  20. Determination of moisture content of single-wall carbon nanotubes.

    Science.gov (United States)

    Sturgeon, Ralph E; Lam, Joseph W; Windust, Anthony; Grinberg, Patricia; Zeisler, Rolf; Oflaz, Rabia; Paul, Rick L; Lang, Brian E; Fagan, Jeffrey A; Simard, Benoit; Kingston, Christopher T

    2012-01-01

    Several techniques were evaluated for the establishment of reliable water/moisture content of single-wall carbon nanotubes. Karl Fischer titration (KF) provides a direct measure of the water content and was used for benchmarking against results obtained by conventional oven drying, desiccation over anhydrous magnesium perchlorate as well as by thermogravimetry and prompt gamma-ray activation analysis. Agreement amongst results was satisfactory with the exception of thermogravimetry, although care must be taken with oven drying as it is possible to register mass gain after an initial moisture loss if prolonged drying time or elevated temperatures (120 °C) are used. Thermogravimetric data were precise but a bias was evident that could be accounted for by considering the non-selective loss of mass as volatile carbonaceous components. Simple drying over anhydrous magnesium perchlorate for a minimum period of 8-10 days is recommended if KF is not available for this measurement.

  1. Device-independent randomness amplification with a single device

    International Nuclear Information System (INIS)

    Plesch, Martin; Pivoluska, Matej

    2014-01-01

    Expansion and amplification of weak randomness with untrusted quantum devices has recently become a very fruitful topic of research. Here we contribute with a procedure for amplifying a single weak random source using tri-partite GHZ-type entangled states. If the quality of the source reaches a fixed threshold R=log 2 ⁡(10), perfect random bits can be produced. This technique can be used to extract randomness from sources that can't be extracted neither classically, nor by existing procedures developed for Santha–Vazirani sources. Our protocol works with a single fault-free device decomposable into three non-communicating parts, that is repeatedly reused throughout the amplification process. - Highlights: • We propose a protocol for device independent randomness amplification. • Our protocol repeatedly re-uses a single device decomposable into three parts. • Weak random sources with min-entropy rate greater than 1/4 log 2 ⁡(10) can be amplified. • Security against all-quantum adversaries is achieved

  2. Signal Integrity Analysis in Single and Bundled Carbon Nanotube Interconnects

    International Nuclear Information System (INIS)

    Majumder, M.K.; Pandya, N.D.; Kaushik, B.K.; Manhas, S.K.

    2013-01-01

    Carbon nanotube (CN T) can be considered as an emerging interconnect material in current nano scale regime. They are more promising than other interconnect materials such as Al or Cu because of their robustness to electromigration. This research paper aims to address the crosstalk-related issues (signal integrity) in interconnect lines. Different analytical models of single- (SWCNT), double- (DWCNT), and multiwalled CNTs (MWCNT) are studied to analyze the crosstalk delay at global interconnect lengths. A capacitively coupled three-line bus architecture employing CMOS driver is used for accurate estimation of crosstalk delay. Each line in bus architecture is represented with the equivalent RLC models of single and bundled SWCNT, DWCNT, and MWCNT interconnects. Crosstalk delay is observed at middle line (victim) when it switches in opposite direction with respect to the other two lines (aggressors). Using the data predicted by ITRS 2012, a comparative analysis on the basis of crosstalk delay is performed for bundled SWCNT/DWCNT and single MWCNT interconnects. It is observed that the overall crosstalk delay is improved by 40.92% and 21.37% for single MWCNT in comparison to bundled SWCNT and bundled DWCNT interconnects, respectively.

  3. Resonant ablation of single-wall carbon nanotubes by femtosecond laser pulses

    International Nuclear Information System (INIS)

    Arutyunyan, N R; Komlenok, M S; Kononenko, V V; Pashinin, V P; Pozharov, A S; Konov, V I; Obraztsova, E D

    2015-01-01

    The thin 50 nm film of bundled arc-discharge single-wall carbon nanotubes was irradiated by femtosecond laser pulses with wavelengths 675, 1350 and 1745 nm corresponding to the absorption band of metallic nanotubes E 11 M , to the background absorption and to the absorption band of semiconducting nanotubes E 11 S , respectively. The aim was to induce a selective removal of nanotubes of specific type from the bundled material. Similar to conducted thermal heating experiments, the effect of laser irradiation results in suppression of all radial breathing modes in the Raman spectra, with preferential destruction of the metallic nanotubes with diameters less than 1.26 nm and of the semiconducting nanotubes with diameters 1.36 nm. However, the etching rate of different nanotubes depends on the wavelength of the laser irradiation. It is demonstrated that the relative content of nanotubes of different chiralities can be tuned by a resonant laser ablation of undesired nanotube fraction. The preferential etching of the resonant nanotubes has been shown for laser wavelengths 675 nm (E 11 M ) and 1745 nm (E 11 S ). (paper)

  4. Effect of tubular chiralities of single-walled ZnO nanotubes on electronic transport

    Science.gov (United States)

    Han, Qin; Liu, Zhenghui; Zhou, Liping; Yu, Yiqing; Wu, Xuemei

    2017-04-01

    The electronic transport properties of single-walled ZnO nanotubes with different chiralities are investigated by nonequilibrium Green's function combined with density functional theory. In this paper we consider three representative ZnO nanotubes, namely (3, 3) armchair, (5, 0) zigzag, and (4, 2) chiral, with a similar diameter of about 5.4 Å. Short nanotubes exhibit good conductance behavior. As the tube length increases, the conductance decreases at low bias and the nanotubes indicate semiconducting behavior. The current-voltage characteristics of the nanotubes longer than 3 nm depend weakly on the length of the tubes. The armchair and chiral ZnO nanotubes with the same length and diameter have almost overlapped current-voltage curves. The electron transport behaviors are analyzed in terms of the transmission spectra, density of states and charge population of these nanotubes. The results indicate that the resonant peaks above the Fermi level are responsible for electric currents. However, the zigzag ZnO nanotubes exhibit asymmetric current-voltage curves attributed to the built-in polarization field and give larger current than the armchair and chiral nanotubes at the same bias. The features explored here strongly suggest that the ZnO nanotubes are stable, flexible structures, which are valuable in Nano-Electromechanical System.

  5. Spin transport properties of single metallocene molecules attached to single-walled carbon nanotubes via nickel adatoms

    Science.gov (United States)

    Wei, Peng; Sun, Lili; Benassi, Enrico; Shen, Ziyong; Sanvito, Stefano; Hou, Shimin

    2011-06-01

    The spin-dependent transport properties of single ferrocene, cobaltocene, and nickelocene molecules attached to the sidewall of a (4,4) armchair single-walled carbon nanotube via a Ni adatom are investigated by using a self-consistent ab initio approach that combines the non-equilibrium Green's function formalism with the spin density functional theory. Our calculations show that the Ni adatom not only binds strongly to the sidewall of the nanotube, but also maintains the spin degeneracy and affects little the transmission around the Fermi level. When the Ni adatom further binds to a metallocene molecule, its density of states is modulated by that of the molecule and electron scattering takes place in the nanotube. In particular, we find that for both cobaltocene and nickelocene the transport across the nanotube becomes spin-polarized. This demonstrates that metallocene molecules and carbon nanotubes can become a promising materials platform for applications in molecular spintronics.

  6. Vibrational Analysis of Curved Single-Walled Carbon Nanotube on a Pasternak Elastic Foundation

    DEFF Research Database (Denmark)

    Mehdipour, I.; Barari, Amin; Kimiaeifar, Amin

    2012-01-01

    Continuum mechanics and an elastic beam model were employed in the nonlinear force vibrational analysis of an embedded, curved, single-walled carbon nanotube. The analysis considered the effects of the curvature or waviness and midplane stretching of the nanotube on the nonlinear frequency....... By utilizing He’s Energy Balance Method (HEBM), the relationships of the nonlinear amplitude and frequency were expressed for a curved, single-walled carbon nanotube. The amplitude frequency response curves of the nonlinear free vibration were obtained for a curved, single-walled carbon nanotube embedded...... in a Pasternak elastic foundation. Finally, the influence of the amplitude of the waviness, midplane stretching nonlinearity, shear foundation modulus, surrounding elastic medium, radius, and length of the curved carbon nanotube on the amplitude frequency response characteristics are discussed. As a result...

  7. Single-Walled Carbon Nanotubes as Fluorescence Biosensors for Pathogen Recognition in Water Systems

    Directory of Open Access Journals (Sweden)

    Venkata K. K. Upadhyayula

    2008-01-01

    Full Text Available The possibility of using single-walled carbon nanotubes (SWCNTs aggregates as fluorescence sensors for pathogen recognition in drinking water treatment applications has been studied. Batch adsorption study is conducted to adsorb large concentrations of Staphylococcus aureus aureus SH 1000 and Escherichia coli pKV-11 on single-walled carbon nanotubes. Subsequently the immobilized bacteria are detected with confocal microscopy by coating the nanotubes with fluorescence emitting antibodies. The Freundlich adsorption equilibrium constant (k for S.aureus and E.coli determined from batch adsorption study was found to be 9×108 and 2×108 ml/g, respectively. The visualization of bacterial cells adsorbed on fluorescently modified carbon nanotubes is also clearly seen. The results indicate that hydrophobic single-walled carbon nanotubes have excellent bacterial adsorption capacity and fluorescent detection capability. This is an important advancement in designing fluorescence biosensors for pathogen recognition in water systems.

  8. Raman study of bromine-doped single-walled carbon nanotubes under high pressure

    CERN Document Server

    Liu Bing Bing; Yu Miao; Zou Guang Tian; Carlsten, J; Wagberg, T; Sundqvist, B

    2002-01-01

    Raman results for different single-walled carbon nanotube bundles doped with Br sub 2 were studied both at ambient pressure and under high pressure up to 6 GPa. Our study indicates that bromine resides in the interstitial channel of nanotube bundles as a form of polymer.

  9. Raman study on single-walled carbon nanotubes with different laser ...

    Indian Academy of Sciences (India)

    TECS

    identify the nature of carbon nanotubes in a bundle. In this study, we have used the Raman spectroscopic analysis on vertically aligned single-walled carbon nanotubes (SWCNTs) grown by the chemical vapour depo- sition (CVD) technique. The grown sample is excited with two laser excitation wavelengths, 633 nm from ...

  10. Production of vertical arrays of small diameter single-walled carbon nanotubes

    Science.gov (United States)

    Hauge, Robert H; Xu, Ya-Qiong

    2013-08-13

    A hot filament chemical vapor deposition method has been developed to grow at least one vertical single-walled carbon nanotube (SWNT). In general, various embodiments of the present invention disclose novel processes for growing and/or producing enhanced nanotube carpets with decreased diameters as compared to the prior art.

  11. Chirality-Dependent Vapor-Phase Epitaxial Growth and Termination of Single-Wall Carbon Nanotubes

    Science.gov (United States)

    Liu, Bilu; Liu, Jia; Zhou, Chongwu; USC nanolab Team

    2014-03-01

    Chirality-pure single-wall carbon nanotubes are highly desired for both fundamental study and many of their technological applications. Recently, we have shown that chirality-pure short nanotubes can be used as seeds for vapor-phase epitaxial cloning growth, opening up a new route toward chirality-controlled carbon nanotube synthesis. Nevertheless, the yield of vapor-phase epitaxial growth is rather limited at the present stage, due to the lack of mechanistic understanding of the process. Here we report chirality-dependent growth kinetics and termination mechanism for the vapor-phase epitaxial growth of seven single- chirality nanotubes of (9, 1), (6, 5), (8, 3), (7, 6), (10, 2), (6, 6), and (7, 7), covering near zigzag, medium chiral angle, and near armchair semiconductors, as well as armchair metallic nanotubes. Our results reveal that the growth rates of nanotubes increase with their chiral angles while the active lifetimes of the growth hold opposite trend. Consequently, the chirality distribution of a nanotube ensemble is jointly determined by both growth rates and lifetimes. These results correlate nanotube structures and properties with their growth behaviors and deepen our understanding of chirality-controlled growth of nanotubes.

  12. Robust neurite extension following exogenous electrical stimulation within single walled carbon nanotube-composite hydrogels.

    Science.gov (United States)

    Koppes, A N; Keating, K W; McGregor, A L; Koppes, R A; Kearns, K R; Ziemba, A M; McKay, C A; Zuidema, J M; Rivet, C J; Gilbert, R J; Thompson, D M

    2016-07-15

    The use of exogenous electrical stimulation to promote nerve regeneration has achieved only limited success. Conditions impeding optimized outgrowth may arise from inadequate stimulus presentation due to differences in injury geometry or signal attenuation. Implantation of an electrically-conductive biomaterial may mitigate this attenuation and provide a more reproducible signal. In this study, a conductive nanofiller (single-walled carbon nanotubes [SWCNT]) was selected as one possible material to manipulate the bulk electrical properties of a collagen type I-10% Matrigel™ composite hydrogel. Neurite outgrowth within hydrogels (SWCNT or nanofiller-free controls) was characterized to determine if: (1) nanofillers influence neurite extension and (2) electrical stimulation of the nanofiller composite hydrogel enhances neurite outgrowth. Increased SWCNT loading (10-100-μg/mL) resulted in greater bulk conductivity (up to 1.7-fold) with no significant changes to elastic modulus. Neurite outgrowth increased 3.3-fold in 20-μg/mL SWCNT loaded biomaterials relative to the nanofiller-free control. Electrical stimulation promoted greater outgrowth (2.9-fold) within SWCNT-free control. The concurrent presentation of electrical stimulation and SWCNT-loaded biomaterials resulted in a 7.0-fold increase in outgrowth relative to the unstimulated, nanofiller-free controls. Local glia residing within the DRG likely contribute, in part, to the observed increases in outgrowth; but it is unknown which specific nanofiller properties influence neurite extension. Characterization of neuronal behavior in model systems, such as those described here, will aid the rational development of biomaterials as well as the appropriate delivery of electrical stimuli to support nerve repair. Novel biomedical devices delivering electrical stimulation are being developed to mitigate symptoms of Parkinson's, treat drug-resistant depression, control movement or enhance verve regeneration. Carbon

  13. Polypyrrole-Functionalized Single-Walled Carbon Nanotube Gas Sensor Arrays

    Science.gov (United States)

    Kakoullis, James, Jr.

    The overall objective of this work is to fabricate and evaluate polypyrrole-single-walled carbon nanotubes hybrid structures based chemiresistive sensor arrays for sensitive, selective and discriminative sensing at room temperature of emissions from automobiles and industrial manufacturing. To conceive the sensor arrays single-walled carbon nanotubes (SWNTs) networks were aligned to bridge a 3 mum gap between a pair of prefabricated microelectrodes followed by coating with polypyrrole (PPY) with different dopants by electrochemical polymerization. Initially, the sensor¡¦s synthesis conditions in terms of PPY thickness on SWNTs networks by varying the electropolymerization charge of the monomer pyrrole in presence of LiClO4 dopant for the sensing of NH3 was optimized. Using the optimized polymerization charge of 1 muC determined previously, arrays of SWNTs-PPY hybrid sensors were fabricated by replacing dopant LiClO4 by L-camphor sulfonic acid, D-camphor sulfonic acid, p-toluene sulfonic acid and sodium dodecyl sulfonate. Room temperature gas sensing performance of the PPY coated SWNTs network arrays to gases of environmental significance such as NH3, NO 2, H2S, SO2, CO and CO2 and volatile organic compounds such as benzene, toluene, ethyl benzene, p-xylene, methanol, n-hexane and acetone and humidity, was evaluated. Several folds enhancement in sensing performance was observed towards all the tested analytesfor hybrid devices when compared to bare SWNTs network devices. Differences in sensing performance were noticed for PPY coating with different dopants demonstrating the potential of using the array for discrimination of the tested analytes in a mixture by using chemometric techniques. The underlying sensing mechanism was also investigated by using the devices in chemFET mode configuration.

  14. Environmental Impacts from Photovoltaic Solar Cells Made with Single Walled Carbon Nanotubes.

    Science.gov (United States)

    Celik, Ilke; Mason, Brooke E; Phillips, Adam B; Heben, Michael J; Apul, Defne

    2017-04-18

    An ex-ante life cycle inventory was developed for single walled carbon nanotube (SWCNT) PV cells, including a laboratory-made 1% efficient device and an aspirational 28% efficient four-cell tandem device. The environmental impact of unit energy generation from the mono-Si PV technology was used as a reference point. Compared to monocrystalline Si (mono-Si), the environmental impacts from 1% SWCNT was ∼18 times higher due mainly to the short lifetime of three years. However, even with the same short lifetime, the 28% cell had lower environmental impacts than mono-Si. The effects of lifetime and efficiency on the environmental impacts were further examined. This analysis showed that if the SWCNT device efficiency had the same value as the best efficiency of the material under comparison, to match the total normalized impacts of the mono- and poly-Si, CIGS, CdTe, and a-Si devices, the SWCNT devices would need a lifetime of 2.8, 3.5, 5.3, 5.1, and 10.8 years, respectively. It was also found that if the SWCNT PV has an efficiency of 4.5% or higher, its energy payback time would be lower than other existing and emerging PV technologies. The major impacts of SWCNT PV came from the cell's materials synthesis.

  15. Carbon Nanotube Oscillator Surface Profiling Device and Method of Use

    Science.gov (United States)

    2011-11-15

    system. The carbon nanotube oscillator in accor- dance with the present invention can achieve in-plane reso- lution -1 nm as compared to 20-30 nm in...following phenomenologi - cal expression: (13) where m is the mass of the moving tube and y is the appro- priate friction coefficient. E>(z) is the

  16. Single Particle Transport Through Carbon Nanotube Wires: Effect of Defects and Polyhedral Cap

    Science.gov (United States)

    Anantram, M. P.; Govidan, T. R.

    1999-01-01

    The ability to manipulate carbon nanotubes with increasing precision has enabled a large number of successful electron transport experiments. These studies have primarily focussed on characterizing transport through both metallic and semiconducting wires. Tans et al. demonstrated ballistic transport in single-wall nanotubes for the first time, although the experimental configuration incurred large contact resistance. Subsequently, methods of producing low contact resistances have been developed and two terminal conductances smaller than 50 k-ohms have been repeatably demonstrated in single-wall and multi-wall nanotubes. In multi-wall nanotubes, Frank et al. demonstrated a resistance of approximately h/2e(exp 2) in a configuration where the outermost layer made contact to a liquid metal. This was followed by the work of de Pablo et al. where a resistance of h(bar)/27e(exp 2) (approximately 478 ohms) was measured in a configuration where electrical contact was made to many layers of a multi-wall nanotube. Frank et al. and Pablo et al. note that each conducting layer contributes a conductance of only 2e(exp 2)/h, instead of the 4e(exp 2)/h that a single particle mode counting picture yields. These small resistances have been obtained in microns long nanotubes, making them the best conducting molecular wires to date. The large conductance of nanotube wires stems from the fact that the crossing bands of nanotubes are robust to defect scattering.

  17. Stable single helical C- and I-chains inside single-walled carbon nanotubes

    International Nuclear Information System (INIS)

    Yao Z; Li Y; Jing X D; Meng F S; Zhao X; Li J H; Qiu Z Y; Yuan Q; Wang W X; Bi L; Liu H; Zhang Y P; Liu C J; Zheng S P; Liu B B

    2016-01-01

    The helicity of stable single helical carbon chains and iodine chains inside single-walled carbon nanotubes (SWCNTs) is studied by calculating the systematic van der Waals interaction energy. The results show that the optimal helical radius increases linearly with increasing tube radius, which produces a constant separation between the chain structure and the tube wall. The helical angle exhibits a ladder-like decrease with increasing tube radius, indicating that a large tube can produce a small helicity in the helical structures. (paper)

  18. Semi-Crystalline Polymer based Single Walled Carbon Nanotube Nanocomposites

    Science.gov (United States)

    Mitchell, Cynthia; Krishnamoorti, Ramanan

    2004-03-01

    The reinforcement of polymers with nanometer scale inorganic materials has stimulated much scientific and technological interest because, when compared to traditional composites, nanocomposites exhibit improved thermal, mechanical and physical properties at much lower particle loading. Development of single walled carbon nanotube (SWNT) based polymer nanocomposites is attractive because of the possibility of combining the extraordinary array of properties of SWNTs with the light-weight character of polymers to develop unique and tailorable materials. Important areas of concern in the development of SWNT composites are ensuring homogeneity of dispersion, good interfacial compatibility with the polymeric matrix and the exfoliation of the ropes and bundles. Several strategies for developing well-dispersed SWNT polymer nanocomposites have been undertaken in the current research and we demonstrate the development of well dispersed SWNT nanocomposites with poly(e-caprolactone) (PCL). PCL is a model, low melting analog of nylon-6, an important commercial material, and additionally is a biocompatible and biodegradable crystalline polymer. Compatibility between PCL and SWNT is anticipated based on the fact that the monomer e-caprolactone disperses SWNTs effectively. Preparation of the composites was accomplished by in-situ polymerization and also by solution blending a model polymer with functionalized or unfunctionalized SWNTs. Composites were characterized extensively utilizing UV- Vis - NearIR spectroscopy, FTIR, DSC, X-ray scattering and diffraction, AFM, melt state rheology and electrical conductivity. Controlling the interactions by covalently linking the polymer to the nanotube or by use of a dispersing aid before the introduction of the polymer and the extensive characterization of the resulting system could lead to the development of structure property relationships that would be beneficial to the tailoring of ultra lightweight materials with exceptional mechanical

  19. Production and characterization of polymer nanocomposite with aligned single wall carbon nanotubes

    International Nuclear Information System (INIS)

    Chen Wei; Tao Xiaoming

    2006-01-01

    We reported a simple method to fabricate polymer nanocomposites with single-walled carbon nanotubes (SWNTs) having exceptional alignment and improved mechanical properties. The composite films were fabricated by casting a suspension of single walled carbon nanotubes in a solution of thermoplastic polyurethane and tetrahydrofuran. The orientation as well as dispersion of nanotubes was determined by scanning electron microscopy, transmission electron microscopy and polarized Raman spectroscopy. The macroscopic alignment probably results from solvent-polymer interaction induced orientation of soft segment chain during swelling and moisture curing. The tensile behavior of the aligned nanotube composite film was also studied. At a 0.5 wt.% nanotube loading, a 1.9-fold increase in Young's modulus was achieved

  20. Nanopattern formation using localized plasma for growth of single-standing carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Javadi, Mohammad; Abdi, Yaser, E-mail: y.abdi@ut.ac.ir [University of Tehran, Nanophysics Research Laboratory, Department of Physics (Iran, Islamic Republic of)

    2017-01-15

    We report a novel method for formation of self-organized single-standing carbon nanotubes by customizing a plasma-based process. The growth of carbon nanotubes by plasma-enhanced chemical vapor deposition provides suitable grounds to utilize plasma–solid interactions for nanopatterning. The bulk plasma is utilized to fabricate carbon nanotubes on the prepatterned Ni catalyst which in turn can confine the plasma to the growth region. The plasma localization leads to a dielectrophoretic force exerted on Ni atoms and can be engineered in order to grow a specific pattern of self-organized single-standing carbon nanotubes. Numerical simulations based on the plasma localization and dielectrophoretic force confirmed the experimental results. This method provides a simple and cost-effective approach to obtain nanopatterned arrays of carbon nanotubes which can be used for fabrication of photonic and phononic crystals, self-gated field emission-based transistors and displays.

  1. Coupled Cluster Studies of Ionization Potentials and Electron Affinities of Single-Walled Carbon Nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Bo; Govind, Niranjan; Apra, Edoardo; Klemm, Michael; Hammond, Jeff R.; Kowalski, Karol

    2017-02-03

    In this paper we apply equation-of-motion coupled cluster (EOMCC) methods in studies of vertical ionization potentials (IP) and electron affinities (EA) for sin- gled walled carbon nanotubes. EOMCC formulations for ionization potentials and electron affinities employing excitation manifolds spanned by single and double ex- citations (IP/EA-EOMCCSD) are used to study IPs and EAs of nanotubes as a function of nanotube length. Several armchair nanotubes corresponding to C20nH20 models with n = 2 - 6 have been used in benchmark calculations. In agreement with previous studies, we demonstrate that the electronegativity of C20nH20 systems remains, to a large extent, independent of nanotube length. We also compare IP/EA- EOMCCSD results with those obtained with the coupled cluster models with single and double excitations corrected by perturbative triples, CCSD(T), and density func- tional theory (DFT) using global and range-separated hybrid exchange-correlation functionals.

  2. Evaluation of Different Single-Walled Carbon Nanotube Surface Coatings for Single-Particle Tracking Applications in Biological Environments.

    Science.gov (United States)

    Gao, Zhenghong; Danné, Noémie; Godin, Antoine Guillaume; Lounis, Brahim; Cognet, Laurent

    2017-11-16

    Fluorescence imaging of biological systems down to the single-molecule level has generated many advances in cellular biology. For applications within intact tissue, single-walled carbon nanotubes (SWCNTs) are emerging as distinctive single-molecule nanoprobes, due to their near-infrared photoluminescence properties. For this, SWCNT surfaces must be coated using adequate molecular moieties. Yet, the choice of the suspension agent is critical since it influences both the chemical and emission properties of the SWCNTs within their environment. Here, we compare the most commonly used surface coatings for encapsulating photoluminescent SWCNTs in the context of bio-imaging applications. To be applied as single-molecule nanoprobes, encapsulated nanotubes should display low cytotoxicity, and minimal unspecific interactions with cells while still being highly luminescent so as to be imaged and tracked down to the single nanotube level for long periods of time. We tested the cell proliferation and cellular viability of each surface coating and evaluated the impact of the biocompatible surface coatings on nanotube photoluminescence brightness. Our study establishes that phospholipid-polyethylene glycol-coated carbon nanotube is the best current choice for single nanotube tracking experiments in live biological samples.

  3. Effects of Two Purification Pretreatments on Electroless Copper Coating over Single-Walled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Zhong Zheng

    2014-01-01

    Full Text Available To achieve the reinforcement of copper matrix composite by single-walled carbon nanotubes, a three-step-refluxing purification of carbon nanotubes sample with HNO3-NaOH-HCl was proposed and demonstrated. A previously reported purification process using an electromagnetic stirring with H2O2/HCl mixture was also repeated. Then, the purified carbon nanotubes were coated with copper by the same electroless plating process. At the end, the effects of the method on carbon nanotubes themselves and on copper coating were determined by transmission electron microscope spectroscopy, scanning electron microscope spectroscopy, X-ray diffractometry, thermogravimetric analysis, Fourier transformed infrared spectroscopy, and energy dispersive spectrometry. It was clearly confirmed that both of the two processes could remove most of iron catalyst particles and carbonaceous impurities without significant damage to carbon nanotubes. The thermal stability of the sample purified by H2O2/HCl treatment was slightly higher than that purified by HNO3-NaOH-HCl treatment. Nevertheless, the purification by HNO3-NaOH-HCl treatment was more effective for carboxyl functionalization on nanotubes than that by H2O2/HCl treatment. The Cu-coating on carbon nanotubes purified by both purification processes was complete, homogenous, and continuous. However, the Cu-coating on carbon nanotubes purified by H2O2/HCl was oxidized more seriously than those on carbon nanotubes purified by HNO3-NaOH-HCl treatment.

  4. Nanotubes oxidation temperature controls the height of single-walled carbon nanotube forests on gold micropatterned thin layers.

    Science.gov (United States)

    Lamberti, Francesco; Agnoli, Stefano; Meneghetti, Moreno; Elvassore, Nicola

    2010-07-06

    We developed a simple methodology for a direct control of the height of carboxylated single-walled carbon nanotube (SWNT) forests. We found that the important step is a good control of the oxidation temperature of the nanotubes. SWNTs oxidation at different temperature was followed by Raman and X-ray photoelectron spectroscopies. Atomic force microscopy images showed that micropatterned self-assembled monolayers forests have average height from 20 to 80 nm using SWNTs oxidized in the temperature ranging from 323 to 303 K, respectively.

  5. Optical Detection of Paraoxon Using Single-Walled Carbon Nanotube Films with Attached Organophosphorus Hydrolase-Expressed Escherichia coli

    Directory of Open Access Journals (Sweden)

    Intae Kim

    2015-05-01

    Full Text Available In whole-cell based biosensors, spectrophotometry is one of the most commonly used methods for detecting organophosphates due to its simplicity and reliability. The sensor performance is directly affected by the cell immobilization method because it determines the amount of cells, the mass transfer rate, and the stability. In this study, we demonstrated that our previously-reported microbe immobilization method, a microbe-attached single-walled carbon nanotube film, can be applied to whole-cell-based organophosphate sensors. This method has many advantages over other whole-cell organophosphate sensors, including high specific activity, quick cell immobilization, and excellent stability. A device with circular electrodes was fabricated for an enlarged cell-immobilization area. Escherichia coli expressing organophosphorus hydrolase in the periplasmic space and single-walled carbon nanotubes were attached to the device by our method. Paraoxon was hydrolyzed using this device, and detected by measuring the concentration of the enzymatic reaction product, p-nitrophenol. The specific activity of our device was calculated, and was shown to be over 2.5 times that reported previously for other whole-cell organophosphate sensors. Thus, this method for generation of whole-cell-based OP biosensors might be optimal, as it overcomes many of the caveats that prevent the widespread use of other such devices.

  6. Conjugated polymer-assisted dispersion of single-wall carbon nanotubes: the power of polymer wrapping.

    Science.gov (United States)

    Samanta, Suman Kalyan; Fritsch, Martin; Scherf, Ullrich; Gomulya, Widianta; Bisri, Satria Zulkarnaen; Loi, Maria Antonietta

    2014-08-19

    The future application of single-walled carbon nanotubes (SWNTs) in electronic (nano)devices is closely coupled to the availability of pure, semiconducting SWNTs and preferably, their defined positioning on suited substrates. Commercial carbon nanotube raw mixtures contain metallic as well as semiconducting tubes of different diameter and chirality. Although many techniques such as density gradient ultracentrifugation, dielectrophoresis, and dispersion by surfactants or polar biopolymers have been developed, so-called conjugated polymer wrapping is one of the most promising and powerful purification and discrimination strategies. The procedure involves debundling and dispersion of SWNTs by wrapping semiflexible conjugated polymers, such as poly(9,9-dialkylfluorene)s (PFx) or regioregular poly(3-alkylthiophene)s (P3AT), around the SWNTs, and is accompanied by SWNT discrimination by diameter and chirality. Thereby, the π-conjugated backbone of the conjugated polymers interacts with the two-dimensional, graphene-like π-electron surface of the nanotubes and the solubilizing alkyl side chains of optimal length support debundling and dispersion in organic solvents. Careful structural design of the conjugated polymers allows for a selective and preferential dispersion of both small and large diameter SWNTs or SWNTs of specific chirality. As an example, with polyfluorenes as dispersing agents, it was shown that alkyl chain length of eight carbons are favored for the dispersion of SWNTs with diameters of 0.8-1.2 nm and longer alkyls with 12-15 carbons can efficiently interact with nanotubes of increased diameter up to 1.5 nm. Polar side chains at the PF backbone produce dispersions with increased SWNT concentration but, unfortunately, cause reduction in selectivity. The selectivity of the dispersion process can be monitored by a combination of absorption, photoluminescence, and photoluminescence excitation spectroscopy, allowing identification of nanotubes with specific

  7. Phototransformation-Induced Aggregation of Functionalized Single-Walled Carbon Nanotubes: The Importance of Amorphous Carbon

    Science.gov (United States)

    Single-walled carbon nanotubes (SWCNTs) with proper functionalization are desirable for applications that require dispersion in aqueous and biological environments, and functionalized SWCNTs also serve as building blocks for conjugation with specific molecules in these applicatio...

  8. Vertical Alignment of Single-Walled Carbon Nanotubes on Nanostructure Fabricated by Atomic Force Microscope

    National Research Council Canada - National Science Library

    Lee, Haiwon

    2007-01-01

    This project focused on the behavior of single-wall carbon nanotubes (SWCNTs) in the electrophoresis cells and aligned growth of SWCNTs by thermal chemical vapor deposition on selectively deposited metallic nanoparticle...

  9. A one-step single source route to carbon nanotubes

    Indian Academy of Sciences (India)

    Abstract. Carbon nanotubes (CNTs) have been synthesized via directly pyrolyzing ferrocene in the autoclave. The nanotubes with several micrometers in length have outer and inner diameters in the range of 40–100 nm and 20–40 nm, respectively. An yield of ~70% of CNTs can be obtained without any accessorial ...

  10. A one-step single source route to carbon nanotubes

    Indian Academy of Sciences (India)

    Carbon nanotubes (CNTs) have been synthesized via directly pyrolyzing ferrocene in the autoclave. The nanotubes with several micrometers in length have outer and inner diameters in the range of 40–100 nm and 20–40 nm, respectively. An yield of ∼70% of CNTs can be obtained without any accessorial solvents and ...

  11. Adsorption of triclosan on single wall carbon nanotubes: A first principle approach

    Science.gov (United States)

    Castro, S. M.; Araújo, A. B.; Nogueira, R. F. P.; Guerini, S.

    2017-05-01

    The interaction of triclosan on (8,0) and (5,5) single wall carbon nanotube (SWCNT) was investigated using density functional calculations. The results show that the adsorption of triclosan modifies the electronic properties of pristine (8,0) and (5,5) SWCNT and induced changes in the electronic properties are dependent on the triclosan adsorption site. It was observed through binding energy that triclosan molecule interacts mainly via chemical process in parallel configuration to (8,0) SWCNT, while interaction via physical process was observed with both (8,0) and (5,5) SWCNT. It is proposed that these SWCNTs are a potential filter device due to reasonable physical interaction with triclosan molecule. Furthermore, this type of filter could be reusable, therefore after the filtering, the SWCNTs could be separated from triclosan molecule.

  12. Dysprosium-Catalyzed Growth of Single-Walled Carbon Nanotube Arrays on Substrates

    Directory of Open Access Journals (Sweden)

    Qian Yong

    2009-01-01

    Full Text Available Abstract In this letter, we report that dysprosium is an effective catalyst for single-walled carbon nanotubes (SWNTs growth via a chemical vapor deposition (CVD process for the first time. Horizontally superlong well-oriented SWNT arrays on SiO2/Si wafer can be fabricated by EtOH-CVD under suitable conditions. The structure and properties are characterized by scanning electron microscopy, transition electron microscopy, Raman spectroscopy and atomic force microscopy. The results show that the SWNTs from dysprosium have better structural uniformity and better conductivity with fewer defects. This rare earth metal provides not only an alternative catalyst for SWNTs growth, but also a possible method to generate high percentage of superlong semiconducting SWNT arrays for various applications of nanoelectronic device.

  13. Antenna-coupled terahertz radiation from joule-heated single-wall carbon nanotubes

    Directory of Open Access Journals (Sweden)

    M. Muthee

    2011-12-01

    Full Text Available In this letter an experimental method is introduced that allows detection of terahertz (THz radiation from arrays of joule-heated Single-Walled Carbon Nanotubes (SWCNTs, by coupling this radiation through integrated antennas and a silicon lens. The radiation forms a diffraction-limited beam with a total maximum radiated power of 450 nW, significantly greater than the power estimated from Nyquist thermal noise (8 nW. The physical radiation process is unknown at this stage, but possible explanations for the high radiated power are discussed briefly. The emission has a typical bandwidth of 1.2 THz and can be tuned to different frequencies by changing the dimensions of the antennas. Arrays of the devices could be integrated in CMOS integrated circuits, and find application in THz systems, such as in near-range medical imaging.

  14. In situ Raman studies of single-walled carbon nanotubes grown by local catalyst heating

    Science.gov (United States)

    Dittmer, S.; Olofsson, N.; Ek Weis, J.; Nerushev, O. A.; Gromov, A. V.; Campbell, E. E. B.

    2008-05-01

    Using in situ Raman spectroscopy we investigate single wall carbon nanotube growth on Mo electrodes, using a highly localized resistive heating technique. Small diameter semiconducting single wall nanotubes grow very rapidly when the catalyst support is heated to a temperature of 800 °C. The G/D ratio shows an interesting time-dependent behaviour. It first decreases, indicating the presence of amorphous carbon and then significantly increases again after ca. 5 min growth while retaining the position and shape expected for predominantly semiconducting carbon nanotubes.

  15. Activated carbon and single-walled carbon nanotube based electrochemical capacitor in 1 M LiPF{sub 6} electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Azam, M.A., E-mail: asyadi@utem.edu.my [Carbon Research Technology Research Group, Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Melaka (Malaysia); Jantan, N.H.; Dorah, N.; Seman, R.N.A.R.; Manaf, N.S.A. [Carbon Research Technology Research Group, Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Melaka (Malaysia); Kudin, T.I.T. [Ionics Materials & Devices Research Laboratory, Faculty of Applied Sciences, Universiti Teknologi MARA, Shah Alam, Selangor (Malaysia); Yahya, M.Z.A. [Ionics Materials & Devices Research Laboratory, Faculty of Applied Sciences, Universiti Teknologi MARA, Shah Alam, Selangor (Malaysia); National Defence University of Malaysia, Kem Sungai Besi, 57000 Kuala Lumpur (Malaysia)

    2015-09-15

    Highlights: • Activated carbon and single-walled CNT based electrochemical capacitor. • Electrochemical analysis by means of CV, charge/discharge and impedance. • 1 M LiPF{sub 6} non-aqueous solution as an electrolyte. • AC/SWCNT electrode exhibits a maximum capacitance of 60.97 F g{sup −1}. - Abstract: Carbon nanotubes have been extensively studied because of their wide range of potential application such as in nanoscale electric circuits, textiles, transportation, health, and the environment. Carbon nanotubes feature extraordinary properties, such as electrical conductivities higher than those of copper, hardness and thermal conductivity higher than those of diamond, and strength surpassing that of steel, among others. This research focuses on the fabrication of an energy storage device, namely, an electrochemical capacitor, by using carbon materials, i.e., activated carbon and single-walled carbon nanotubes, of a specific weight ratio as electrode materials. The electrolyte functioning as an ion carrier is 1 M lithium hexafluorophosphate. Variations in the electrochemical performance of the device, including its capacitance, charge/discharge characteristics, and impedance, are reported in this paper. The electrode proposed in this work exhibits a maximum capacitance of 60.97 F g{sup −1} at a scan rate of 1 mV s{sup −1}.

  16. Microbiological quality control of single-walled carbon-nanotubes-coated surfaces experimentally contaminated

    International Nuclear Information System (INIS)

    Natalizi, T.; Frioni, A.; Passeri, D.; Pantanella, F.

    2013-01-01

    The emergence of new nanotechnologies involves the spreading of nanoparticles in various fields of human life. Nanoparticles in general and, more specifically, carbon nanotubes have been adopted for many practical approaches i.e.: coatings for medical devices, food process industry and drug delivery. Humans will be increasingly exposed to nanoparticles but the susceptibility of nanostructured materials to microbial colonization in process of manufacturing and storage has not been thoroughly considered. Therefore, the microbiological quality control of nanoparticles plays a pivotal role. Different analytical methods have been attempted for detecting bacterial population contaminating a surface, but no one can be considered fully appropriate. Here, BioTimer Assay (BTA) and conventional sonication followed by colony forming units method (S-CFU) were applied for microbiological quality control of single-walled carbon nanotubes (SWCNTs)-coated surfaces experimentally contaminated with Streptococcus mutans and Pseudomonas aeruginosa. Our results demonstrated that S-CFU is unreliable to actually determine the number of bacteria, contaminating abiotic surfaces, as it does not detach all adherent bacteria and kills part of the bacterial population. Instead, BTA is a reliable method to enumerate bacteria colonizing SWCNTs-coated surfaces and can be considered a useful tool for microbiological quality control of nanomaterials for human use.

  17. Enhanced mechanical properties of single-walled carbon nanotubes due to chemical functionalization.

    Science.gov (United States)

    He, X Q; Kuang, Y D; Chen, C Y; Li, G Q

    2009-05-27

    Recent studies have shown that the chemical functionalization of carbon nanotubes weakens most of their mechanical properties such as the critical buckling force under compression and the critical buckling moment under torsion. However, the mechanical properties including the critical bending curvature and the critical bending moment of single-walled carbon nanotubes can be improved after functionalization as shown in this paper. The molecular mechanics simulations reveal that there exists an optimum functionalization degree at which the critical curvatures of the functionalized carbon nanotubes reaches its maximum value. The critical curvatures of the carbon nanotubes increase with increasing functionalization degree below the optimum value, while the critical curvatures change little as the functionalization degree is beyond the optimum value. The influences of the bending directions and the aspect ratios of the functionalized carbon nanotubes are also examined via molecular mechanics simulations.

  18. Rapid prototyping of nanotube-based devices using topology-optimized microgrippers

    DEFF Research Database (Denmark)

    Sardan, Özlem; Eichhorn, Volkmar; Petersen, D.H.

    2008-01-01

    Nanorobotic handling of carbon nanotubes (CNTs) using microgrippers is one of the most promising approaches for the rapid characterization of the CNTs and also for the assembly of prototypic nanotube-based devices. In this paper, we present pick-and-place nanomanipulation of multi-walled CNTs...... in a rapid and a reproducible manner. We placed CNTs on copper TEM grids for structural analysis and on AFM probes for the assembly of AFM super-tips. We used electrothermally actuated polysilicon microgrippers designed using topology optimization in the experiments. The microgrippers are able to open...

  19. Shape transition of unstrained flattest single-walled carbon nanotubes under pressure

    Energy Technology Data Exchange (ETDEWEB)

    Mu, Weihua, E-mail: whmu@mit.edu, E-mail: muwh@itp.ac.cn [Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, The Chinese Academy of Sciences, P. O. Box 2735 Beijing 100190 (China); Kavli Institute for Theoretical Physics China, The Chinese Academy of Sciences, P. O. Box 2735 Beijing 100190 (China); Cao, Jianshu, E-mail: jianshu@mit.edu [Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Singapore-MIT Alliance for Research and Technology (SMART), Singapore 138602 (Singapore); Ou-Yang, Zhong-can [State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, The Chinese Academy of Sciences, P. O. Box 2735 Beijing 100190 (China); Kavli Institute for Theoretical Physics China, The Chinese Academy of Sciences, P. O. Box 2735 Beijing 100190 (China); Singapore-MIT Alliance for Research and Technology (SMART), Singapore 138602 (Singapore); Center for Advanced Study, Tsinghua University, Beijing 100084 (China)

    2014-01-28

    Single walled carbon nanotube's (SWCNT's) cross section can be flattened under hydrostatic pressure. One example is the cross section of a single walled carbon nanotube successively deforms from the original round shape to oval shape, then to peanut-like shape. At the transition point of reversible deformation between convex shape and concave shape, the side wall of nanotube is flattest. This flattest tube has many attractive properties. In the present work, an approximate approach is developed to determine the equilibrium shape of this unstrained flattest tube and the curvature distribution of this tube. Our results are in good agreement with recent numerical results, and can be applied to the study of pressure controlled electric properties of single walled carbon nanotubes. The present method can also be used to study other deformed inorganic and organic tube-like structures.

  20. Synergistic Impacts of Electrolyte Adsorption on the Thermoelectric Properties of Single-Walled Carbon Nanotubes.

    Science.gov (United States)

    Nakano, Motohiro; Nakashima, Takuya; Kawai, Tsuyoshi; Nonoguchi, Yoshiyuki

    2017-08-01

    Single-walled carbon nanotubes are promising candidates for light-weight and flexible energy materials. Recently, the thermoelectric properties of single-walled carbon nanotubes have been dramatically improved by ionic liquid addition; however, controlling factors remain unsolved. Here the thermoelectric properties of single-walled carbon nanotubes enhanced by electrolytes are investigated. Complementary characterization with absorption, Raman, and X-ray photoelectron spectroscopy reveals that shallow hole doping plays a partial role in the enhanced electrical conductivity. The molecular factors controlling the thermoelectric properties of carbon nanotubes are systematically investigated in terms of the ionic functionalities of ionic liquids. It is revealed that appropriate ionic liquids show a synergistic enhancement in conductivity and the Seebeck coefficient. The discovery of significantly precise doping enables the generation of thermoelectric power factor exceeding 460 µW m - 1 K -2 . © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Raman imaging and spectroscopy of individual single-wall carbon nanotubes

    Science.gov (United States)

    Zhang, Li

    Single-wall carbon nanotubes (SWNT) are unique one-dimensional materials that are promising for many potential applications in various important areas. Their vibrational properties reflect the electron and phonon confinement as well as the structures of the tubes. Resonant Raman spectroscopy has been proven to be an exceedingly powerful tool for the characterization of the vibrational and electronic properties of SWNTs. This thesis focuses on the study of Raman spectroscopy of individual single carbon nanotubes. Single tube spectroscopy allows probing the structure dependent properties of SWNTs. A beam-scanning confocal Raman microscope system capable of large-area Raman imaging is first developed for characterizing SWNTs at the single tube level. Raman images and first-order Raman spectra of nanotubes, consisting of both semicoducting and metallic nanotubes, are systemically studied at room temperature in ambient air. The diameter of the nanotubes is determined from their radial breathing mode (RBM) frequency. A broad diameter distribution is observed for nanotubes synthesized by chemical vapor deposition. The tangential G mode Raman spectra of individual metallic nanotubes are found to exhibit a broad distribution of line shapes, which is attributed to shift of the Fermi level due to O2 adsorption. The doping dependence of Raman spectra of metallic tubes is further studied by both electrostatic gating and electrochemical gating. Significant changes in the G band Raman spectra of nanotubes are observed, suggesting the effect of doping on electron-phonon interaction. The observation of a gradual evolution of G band spectrum from a semiconducting type to the broad BWF type reveals evidence of phonon interaction between two G band modes. Raman imaging and Raman spectra of isolated SWNTs and single-layer graphenen are investigated at both room temperature and low temperature. The temperature-induced Raman spectral change of individual nanotubes is observed to be tube

  2. Reinforced Thermoplastic Polyimide with Dispersed Functionalized Single Wall Carbon Nanotubes

    Science.gov (United States)

    Lebron-Colon, Marisabel; Meador, Michael A.; Gaier, James R.; Sola, Francisco; Scheiman, Daniel A.; McCorkle, Linda S.

    2010-01-01

    Molecular pi-complexes were formed from pristine HiPCO single-wall carbon nanotubes (SWCNTs) and 1-pyrene- N-(4- N'-(5-norbornene-2,3-dicarboxyimido)phenyl butanamide, 1. Polyimide films were prepared with these complexes as well as uncomplexed SWCNTs and the effects of nanoadditive addition on mechanical, thermal, and electrical properties of these films were evaluated. Although these properties were enhanced by both nanoadditives, larger increases in tensile strength and thermal and electrical conductivities were obtained when the SWCNT/1 complexes were used. At a loading level of 5.5 wt %, the Tg of the polyimide increased from 169 to 197 C and the storage modulus increased 20-fold (from 142 to 3045 MPa). The addition of 3.5 wt % SWCNT/1 complexes increased the tensile strength of the polyimide from 61.4 to 129 MPa; higher loading levels led to embrittlement and lower tensile strengths. The electrical conductivities (DC surface) of the polyimides increased to 1 x 10(exp -4) Scm(exp -1) (SWCNT/1 complexes loading level of 9 wt %). Details of the preparation of these complexes and their effects on polyimide film properties are discussed.

  3. Offset configurations for single- and double-strand DNA inside single-walled carbon nanotubes.

    Science.gov (United States)

    Alshehri, Mansoor H; Cox, Barry J; Hill, James M

    2014-01-01

    Nanotechnology is a rapidly expanding research area, and it is believed that the unique properties of molecules at the nano-scale will prove to be of substantial benefit to mankind, especially so in medicine and electronics. Here we use applied mathematical modelling exploiting the basic principles of mechanics and the 6-12 Lennard-Jones potential function together with the continuum approximation, which assumes that intermolecular interactions can be approximated by average atomic surface densities. We consider the equilibrium offset positions for both single-strand and double-strand DNA molecules inside a single-walled carbon nanotube, and we predict offset positions with reference to the cross-section of the carbon nanotube. For the double-strand DNA, the potential energy is determined for the general case for any helical phase angle ϕ, but we also consider a special case when ϕ = π, which leads to a substantial simplification in the analytical expression for the energy. As might be expected, our results confirm that the global minimum energy positions for a single-strand DNA molecule and a double-strand DNA molecule will lie off axis and they become closer to the tube wall as the radius of the tube increases.

  4. Synthesis of single walled carbon nanotubes by dual laser vaporization

    CSIR Research Space (South Africa)

    Moodley, MK

    2006-07-01

    Full Text Available ., Fujita M., Dresselhaus G. and Dresselhaus M.S. (1992). Electronic structure of graphene tubules based C60. Phys. Rev B. 46, 1804–1811. 5. Ajayan P.M, Stephan O., Colliex C. and Trauth D. (1994). Aligned carbon nanotube arrays formed by cutting a... and nanoropes. Phys. Rev. Lett. 79(7), 1297–1300. 8. Harris P.J.F. (1999). Carbon Nanotubes and Related Structures. Cambridge University Press, Cambridge. 9. Dresselhaus M.S., Dresselhaus G. and Avouris Ph. (eds) (2000). Carbon Nanotubes: Synthesis...

  5. Study on electroactive and electrocatalytic surfaces of single walled carbon nanotube-modified electrodes

    International Nuclear Information System (INIS)

    Salinas-Torres, David; Huerta, Francisco; Montilla, Francisco; Morallon, Emilia

    2011-01-01

    An investigation of the electrocatalysis of single-walled carbon nanotubes modified electrodes has been performed in this work. Nanotube-modified electrodes present a surface area much higher than the bare glassy carbon surfaces as determined by capacitance measurements. Several redox probes were selected for checking the reactivity of specific sites at the carbon nanotube surface. The presence of carbon nanotubes on the electrode improves the kinetics for all the reactions studied compared with the bare glassy carbon electrode with variations of the heterogeneous electron transfer rate constant up to 5 orders of magnitude. The most important effects are observed for the benzoquinone/hydroquinone and ferrocene/ferricinium redox couples, which show a remarkable improvement of their electron transfer kinetics on SWCNT-modified electrodes, probably due to strong π-π interaction between the organic molecules and the walls of the carbon nanotubes. For many of the reactions studied, less than 1% of the nanotube-modified electrode surface is transferring charge to species in solution. This result suggests that only nanotube tips are active sites for the electron transfer in such cases. On the contrary, the electroactive surface for the reactions of ferrocene and quinone is higher indicating that the electron transfer is produced also from the nanotube walls.

  6. Simultaneous shunt protection and back contact formation for CdTe solar cells with single wall carbon nanotube layers

    Science.gov (United States)

    Phillips, Adam B.; Khanal, Rajendra R.; Song, Zhaoning; Watthage, Suneth C.; Kormanyos, Kenneth R.; Heben, Michael J.

    2015-12-01

    Thin film photovoltaic (PV) devices and modules prepared by commercial processes can be severely compromised by through-device low resistance electrical pathways. The defects can be due to thin or missing semiconductor material, metal diffusion along grain boundaries, or areas containing diodes with low turn-on potentials. We report the use of single wall carbon nanotube (SWCNT) layers to enable both protection against these defects and back contact formation for CdTe PV devices. Samples prepared with a SWCNT back contact exhibited good efficiency and did not require shunt protection, while devices prepared without shunt protection using a standard metal back contact performed poorly. We describe the mechanism by which the SWCNT layer functions. In addition to avoiding the need for shunt protection by other means, the SWCNT film also provides a route to higher short circuit currents.

  7. Nanoparticle/nanotube-based nanoelectronic devices and chemically-directed assembly thereof

    Science.gov (United States)

    Schmidt, Howard K [Cypress, TX

    2011-02-22

    According to some embodiments, the present invention provides a nanoelectronic device based on a nanostructure that may include a nanotube with first and second ends, a metallic nanoparticle attached to the first end, and an insulating nanoparticle attached to the second end. The nanoelectronic device may include additional nanostructures so a to form a plurality of nanostructures comprising the first nanostructure and the additional nanostructures. The plurality of nanostructures may arranged in a network comprising a plurality of edges and a plurality of vertices, wherein each edge comprises a nanotube and each vertex comprises at least one insulating nanoparticle and at least one metallic nanoparticle adjacent the insulating nanoparticle. The combination of at least one edge and at least one vertex comprises a diode. The device may be an optical rectenna.

  8. The electronic fine structure of 4-nitrophenyl functionalized single-walled carbon nanotubes

    International Nuclear Information System (INIS)

    Chakraborty, Amit K; Coleman, Karl S; Dhanak, Vinod R

    2009-01-01

    Controlling the electronic structure of carbon nanotubes (CNTs) is of great importance to various CNT based applications. Herein the electronic fine structure of single-walled carbon nanotube films modified with 4-nitrophenyl groups, produced following reaction with 4-nitrobenzenediazonium tetrafluoroborate, was investigated for the first time. Various techniques such as x-ray and ultra-violet photoelectron spectroscopy, and near edge x-ray absorption fine structure studies were used to explore the electronic structure, and the results were compared with the measured electrical resistances. A reduction in number of the π electronic states in the valence band consistent with the increased resistance of the functionalized nanotube films was observed.

  9. Energy loss of the electron system in individual single-walled carbon nanotubes.

    Science.gov (United States)

    Santavicca, Daniel F; Chudow, Joel D; Prober, Daniel E; Purewal, Meninder S; Kim, Philip

    2010-11-10

    We characterize the energy loss of the nonequilibrium electron system in individual metallic single-walled carbon nanotubes at low temperature. Using Johnson noise thermometry, we demonstrate that, for a nanotube with Ohmic contacts, the dc resistance at finite bias current directly reflects the average electron temperature. This enables a straightforward determination of the thermal conductance associated with cooling of the nanotube electron system. In analyzing the temperature- and length-dependence of the thermal conductance, we consider contributions from acoustic phonon emission, optical phonon emission, and hot electron outdiffusion.

  10. Effective permittivity of single-walled carbon nanotube composites: Two-fluid model

    Energy Technology Data Exchange (ETDEWEB)

    Moradi, Afshin, E-mail: a.moradi@kut.ac.ir [Department of Engineering Physics, Kermanshah University of Technology, Kermanshah (Iran, Islamic Republic of); Department of Nano Sciences, Institute for Studies in Theoretical Physics and Mathematics (IPM), Tehran (Iran, Islamic Republic of); Zangeneh, Hamid Reza; Moghadam, Firoozeh Karimi [Department of Photonics, Faculty of Physics, University of Kashan, Kashan (Iran, Islamic Republic of)

    2015-12-15

    We develop an effective medium theory to obtain effective permittivity of a composite of two-dimensional (2D) aligned single-walled carbon nanotubes. Electronic excitations on each nanotube surface are modeled by an infinitesimally thin layer of a 2D electron gas represented by two interacting fluids, which takes into account different nature of the σ and π electrons. Calculations of both real and imaginary parts of the effective dielectric function of the system are presented, for different values of the filling factor and radius of carbon nanotubes.

  11. Noncovalent Attachment of PbS Quantum Dots to Single- and Multiwalled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Anirban Das

    2014-01-01

    Full Text Available Attachment of PbS quantum dots (QD to single-walled carbon nanotubes (SWNT and multiwalled carbon nanotubes (MWCNT is described; wherein commercially obtained PbS-QD of size 2.7 nm, stabilized by oleic acid, are added to a suspension of single- or multiwalled carbon nanotubes (CNT prefunctionalized noncovalently with 1,2-benzenedimethanethiol (1,2-BDMT in ethanol. The aromatic part of 1,2-BDMT attaches to the CNT by π-π stacking interactions, noncovalently functionalizing the CNT. The thiol part of the 1,2-BDMT on the functionalized CNT replaces oleic acid on the surface of the QD facilitating the noncovalent attachment of the QD to the CNT. The composites were characterized by TEM and FTIR spectroscopy. Quenching of NIR fluorescence of the PbS-QD on attachment to the carbon nanotubes (CNT was observed, indicating FRET from the QD to the CNT.

  12. Weighing a single atom using a coupled plasmon–carbon nanotube system

    Directory of Open Access Journals (Sweden)

    Jin-Jin Li and Ka-Di Zhu

    2012-01-01

    Full Text Available We propose an optical weighing technique with a sensitivity down to a single atom, using a surface plasmon and a doubly clamped carbon nanotube resonator. The mass of a single atom is determined via the vibrational frequency shift of the carbon nanotube while the atom attaches to the nanotube surface. Owing to the ultralight mass and high quality factor of the carbon nanotube, and the spectral enhancement by the use of surface plasmon, this method results in a narrow linewidth (kHz and high sensitivity (2.3×10−28 Hzcenterdot g−1, which is five orders of magnitude more sensitive than traditional electrical mass detection techniques.

  13. Rings and rackets from single-wall carbon nanotubes: manifestations of mesoscale mechanics.

    Science.gov (United States)

    Wang, Yuezhou; Semler, Matthew R; Ostanin, Igor; Hobbie, Erik K; Dumitrică, Traian

    2014-11-21

    We combine experiments and distinct element method simulations to understand the stability of rings and rackets formed by single-walled carbon nanotubes assembled into ropes. Bending remains a soft deformation mode in ropes because intra-rope sliding of the constituent nanotubes occurs with ease. Our simulations indicate that the formation of these aggregates can be attributed to the mesoscopic mechanics of entangled nanotubes and to the sliding at the contacts. Starting from the single-walled carbon nanotubes, the sizes of the rings and rackets' heads increase with the rope diameter, indicating that the stability of the experimental aggregates can be largely explained by the competition between bending and van der Waals adhesion energies. Our results and simulation method should be useful for understanding nanoscale fibers in general.

  14. Chirality-Controlled Growth of Single-Wall Carbon Nanotubes Using Vapor Phase Epitaxy: Mechanistic Understanding and Scalable Production

    Science.gov (United States)

    2016-09-15

    AFRL-AFOSR-VA-TR-2016-0319 Chirality-Controlled Growth of Single -Wall Carbon Nanotubes Using Vapor Phase Epitaxy: Mechanistic Understanding and...controlled growth of single -wall carbon nanotubes using vapor phase epitaxy: mechanistic understanding and scalable production FA9550-14-1-0115 Zhou...controlled synthesis of single -wall carbon nanotubes. Firstly, we have successfully demonstrated a vapor-phase-epitaxy-analogous general strategy for

  15. Conjugated polymer-wrapped carbon nanotubes : physical properties and device applications

    NARCIS (Netherlands)

    Gomulya, Widianta; Gao, Jia; Loi, Maria Antonietta

    2013-01-01

    The aim of this article is to present an overview about the preparation method and physical properties of a new hybrid system consisting of single-walled carbon nanotubes (SWNTs) wrapped by conjugated polymers. The technique firstly demonstrated in 2007 has attracted great interest because of the

  16. Single-use device reuse risks.

    Science.gov (United States)

    Lee, Robert C; Berzins, Sandy; Alfieri, Nancy

    2007-01-01

    Efforts to reduce both costs and medical waste have led many health systems to start reusing single-use medical devices (SUDs) after cleaning and sterilizing (i.e. reprocessing). There is a currently a wide range of SUD types being reused in many health systems. The objective of this paper is to provide a brief summary of risk issues associated with critical SUDs, based on a rapid review of the available literature. The specific focus is on risk issues, but includes discussion of economic and legal/ethical issues as well. The evidence in the literature regarding the safety of reuse of SUDs indicates that for certain devices (e.g. heart catheters) reuse can be safe (in terms of patient infection) and cost-effective as long as stringent reprocessing protocols are followed. However, potential risks associated with reusing SUDs are not just limited to infection of patients. There are staff and environmental risks, plus important legal, ethical, and financial issues to consider in a reuse policy. There are currently no Canadian guidelines on reuse or reprocessing SUDs, although a national Scientific Advisory Panel on Reprocessing of Medical Devices has made recommendations. Additionally, reuse of SUDs is interwoven with the issue of infection control and reprocessing procedures in general and as applied to multiple-use devices. With limited healthcare resources, there will always be a trade-off between the human resources and costs required to clean and sterilize reused devices with costs associated with purchasing and disposing of non-reused SUDs. Evaluation of complete operational pathways, especially for more expensive and commonly used SUDs, will be useful to properly determine the balance of benefits, risks, and costs under a reuse policy.

  17. Hydrogen storage in single-wall carbon nano-tubes by means of laser excitation

    International Nuclear Information System (INIS)

    Oksengorn, B.

    2010-01-01

    A new mode for hydrogen adsorption and storage in single-wall carbon nano-tubes is used, on the basis of laser excitation. Remember that this method has been useful to obtain, in the case of the fullerene C 60 , many complex C 60 -atoms or C 60 -molecules, where atoms or molecular particles are trapped inside the C 60 -molecules. We think this method might be important to store many hydrogen molecules inside carbon nano-tubes. (author)

  18. Functionalization of single-walled carbon nanotubes regulates their effect on hemostasis

    International Nuclear Information System (INIS)

    Sokolov, A V; Aseychev, A V; Kostevich, V A; Gusev, A A; Gusev, S A; Vlasova, I I

    2011-01-01

    Applications of single-walled carbon nanotubes (SWNTs) in medical field imply the use of drug-coupled carbon nanotubes as well as carbon nanotubes functionalized with different chemical groups that change nanotube surface properties and interactions between nanotubes and cells. Covalent attachment of polyethylene glycol (PEG) to carboxylated single-walled carbon nanotubes (c-SWNT) is known to prevent the nanotubes from interaction with macrophages. Here we characterized nanotube's ability to stimulate coagulation processes in platelet-poor plasma (PPP), and evaluated the effect of SWNTs on platelet aggregation in platelet-rich plasma (PRP). Our study showed that PEG-SWNT did not affect the rate of clotting in PPP, while c-SWNT shortened the clot formation time five times compared to the control PPP. Since c-SWNT failed to accelerate coagulation in plasma lacking coagulation factor XI, it may be suggested that c-SWNT affects the contact activation pathway. In PRP, platelets responded to both SWNT types with irreversible aggregation, as evidenced by changes in the aggregate mean radius. However, the rate of aggregation induced by c-SWNT was two times higher than it was with PEG-SWNT. Cytological analysis also showed that c-SWNT was two times more efficient when compared to PEG-SWNT in aggregating platelets in PRP. Taken together, our results show that functionalization of nanoparticles can diminish their negative influence on blood cells. As seen from our data, modification of c-SWNT with PEG, when only a one percent of carbon atoms is bound to polymer (70 wt %), decreased the nanotube-induced coagulation in PRP and repelled the accelerating effect on the coagulation in PPP. Thus, when functionalized SWNTs are used for administration into bloodstream of laboratory animals, their possible pro-coagulant and pro-aggregating properties must be taken into account.

  19. Functionalization of single-walled carbon nanotubes regulates their effect on hemostasis

    Energy Technology Data Exchange (ETDEWEB)

    Sokolov, A V; Aseychev, A V; Kostevich, V A; Gusev, A A; Gusev, S A; Vlasova, I I, E-mail: irina.vlasova@yahoo.com [Research Institute for Physico-Chemical Medicine, FMBA, M. Pirogovskaya Str. 1a, Moscow (Russian Federation)

    2011-04-01

    Applications of single-walled carbon nanotubes (SWNTs) in medical field imply the use of drug-coupled carbon nanotubes as well as carbon nanotubes functionalized with different chemical groups that change nanotube surface properties and interactions between nanotubes and cells. Covalent attachment of polyethylene glycol (PEG) to carboxylated single-walled carbon nanotubes (c-SWNT) is known to prevent the nanotubes from interaction with macrophages. Here we characterized nanotube's ability to stimulate coagulation processes in platelet-poor plasma (PPP), and evaluated the effect of SWNTs on platelet aggregation in platelet-rich plasma (PRP). Our study showed that PEG-SWNT did not affect the rate of clotting in PPP, while c-SWNT shortened the clot formation time five times compared to the control PPP. Since c-SWNT failed to accelerate coagulation in plasma lacking coagulation factor XI, it may be suggested that c-SWNT affects the contact activation pathway. In PRP, platelets responded to both SWNT types with irreversible aggregation, as evidenced by changes in the aggregate mean radius. However, the rate of aggregation induced by c-SWNT was two times higher than it was with PEG-SWNT. Cytological analysis also showed that c-SWNT was two times more efficient when compared to PEG-SWNT in aggregating platelets in PRP. Taken together, our results show that functionalization of nanoparticles can diminish their negative influence on blood cells. As seen from our data, modification of c-SWNT with PEG, when only a one percent of carbon atoms is bound to polymer (70 wt %), decreased the nanotube-induced coagulation in PRP and repelled the accelerating effect on the coagulation in PPP. Thus, when functionalized SWNTs are used for administration into bloodstream of laboratory animals, their possible pro-coagulant and pro-aggregating properties must be taken into account.

  20. Functionalization of single-walled carbon nanotubes regulates their effect on hemostasis

    Science.gov (United States)

    Sokolov, A. V.; Aseychev, A. V.; Kostevich, V. A.; Gusev, A. A.; Gusev, S. A.; Vlasova, I. I.

    2011-04-01

    Applications of single-walled carbon nanotubes (SWNTs) in medical field imply the use of drug-coupled carbon nanotubes as well as carbon nanotubes functionalized with different chemical groups that change nanotube surface properties and interactions between nanotubes and cells. Covalent attachment of polyethylene glycol (PEG) to carboxylated single-walled carbon nanotubes (c-SWNT) is known to prevent the nanotubes from interaction with macrophages. Here we characterized nanotube's ability to stimulate coagulation processes in platelet-poor plasma (PPP), and evaluated the effect of SWNTs on platelet aggregation in platelet-rich plasma (PRP). Our study showed that PEG-SWNT did not affect the rate of clotting in PPP, while c-SWNT shortened the clot formation time five times compared to the control PPP. Since c-SWNT failed to accelerate coagulation in plasma lacking coagulation factor XI, it may be suggested that c-SWNT affects the contact activation pathway. In PRP, platelets responded to both SWNT types with irreversible aggregation, as evidenced by changes in the aggregate mean radius. However, the rate of aggregation induced by c-SWNT was two times higher than it was with PEG-SWNT. Cytological analysis also showed that c-SWNT was two times more efficient when compared to PEG-SWNT in aggregating platelets in PRP. Taken together, our results show that functionalization of nanoparticles can diminish their negative influence on blood cells. As seen from our data, modification of c-SWNT with PEG, when only a one percent of carbon atoms is bound to polymer (70 wt %), decreased the nanotube-induced coagulation in PRP and repelled the accelerating effect on the coagulation in PPP. Thus, when functionalized SWNTs are used for administration into bloodstream of laboratory animals, their possible pro-coagulant and pro-aggregating properties must be taken into account.

  1. Noncovalent functionalization of single-walled carbon nanotubes with porphyrins

    Energy Technology Data Exchange (ETDEWEB)

    Bassiouk, María; Basiuk, Vladimir A. [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, 04510 México D.F. (Mexico); Basiuk, Elena V., E-mail: elenagd@unam.mx [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, 04510 México D.F. (Mexico); Álvarez-Zauco, Edgar [Facultad de Ciencias, Universidad Nacional Autónoma de México, Circuito Exterior C.U., 04510 México D.F. (Mexico); Martínez-Herrera, Melchor [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, 04510 México D.F. (Mexico); Rojas-Aguilar, Aaron [Centro de Investigación y de Estudios Avanzados, Instituto Politécnico Nacional, Av. Instituto Politécnico Nacional 2508, San Pedro Zacatenco, 07360 México D.F. (Mexico); Puente-Lee, Iván [Facultad de Química, Universidad Nacional Autónoma de México, Circuito Exterior C.U., 04510 México D.F. (Mexico)

    2013-06-15

    The covalent and noncovalent interactions of porphyrins and related tetraazamacrocyclic compounds with single-walled carbon nanotubes (SWNTs) is a subject of increasing research effort, directed toward the design of novel hybrid nanomaterials combining unique electronic and optical properties of both molecular species. In this report, we used different experimental techniques as well as molecular mechanics (MM) calculations to analyze the adsorption of meso-tetraphenylporphine (or 5,10,15,20-tetraphenyl-21H,23H-porphine, H{sub 2}TPP) and its complexes with Ni(II) and Co(II) (NiTPP and CoTPP, respectively), as well as hemin (a natural porphyrin), onto the surface of SWNTs. Altogether, the results suggested that all four porphyrin species noncovalently interact with SWNTs, forming hybrid nanomaterials. Nevertheless, of all four porphyrin species, the strongest interaction with SWNTs occurs in the case of CoTPP, which is able to intercalate and considerably disperse SWNT bundles, and therefore absorb onto the surface of individual SWNTs. In contrast, NiTPP, CoTPP and hemin, due to a weaker interaction, are unable to do so and therefore are only capable to adsorb onto the surface of SWNT bundles. According to the scanning tunneling microscopy (STM) imaging and MM results, the adsorption of CoTPP onto SWNT sidewalls results in the formation of porphyrin arrays in the shape of long-period interacting helixes with variable periodicity, possibly due to different diameters and chiralities of SWNTs present in the samples. Since the remaining porphyrin species were found to adsorb onto the surface of SWNT bundles, the precise geometry of the corresponding porphyrin/SWNT complexes is difficult to characterize.

  2. Noncovalent functionalization of single-walled carbon nanotubes with porphyrins

    International Nuclear Information System (INIS)

    Bassiouk, María; Basiuk, Vladimir A.; Basiuk, Elena V.; Álvarez-Zauco, Edgar; Martínez-Herrera, Melchor; Rojas-Aguilar, Aaron; Puente-Lee, Iván

    2013-01-01

    The covalent and noncovalent interactions of porphyrins and related tetraazamacrocyclic compounds with single-walled carbon nanotubes (SWNTs) is a subject of increasing research effort, directed toward the design of novel hybrid nanomaterials combining unique electronic and optical properties of both molecular species. In this report, we used different experimental techniques as well as molecular mechanics (MM) calculations to analyze the adsorption of meso-tetraphenylporphine (or 5,10,15,20-tetraphenyl-21H,23H-porphine, H 2 TPP) and its complexes with Ni(II) and Co(II) (NiTPP and CoTPP, respectively), as well as hemin (a natural porphyrin), onto the surface of SWNTs. Altogether, the results suggested that all four porphyrin species noncovalently interact with SWNTs, forming hybrid nanomaterials. Nevertheless, of all four porphyrin species, the strongest interaction with SWNTs occurs in the case of CoTPP, which is able to intercalate and considerably disperse SWNT bundles, and therefore absorb onto the surface of individual SWNTs. In contrast, NiTPP, CoTPP and hemin, due to a weaker interaction, are unable to do so and therefore are only capable to adsorb onto the surface of SWNT bundles. According to the scanning tunneling microscopy (STM) imaging and MM results, the adsorption of CoTPP onto SWNT sidewalls results in the formation of porphyrin arrays in the shape of long-period interacting helixes with variable periodicity, possibly due to different diameters and chiralities of SWNTs present in the samples. Since the remaining porphyrin species were found to adsorb onto the surface of SWNT bundles, the precise geometry of the corresponding porphyrin/SWNT complexes is difficult to characterize.

  3. Nanotube phonon waveguide

    Science.gov (United States)

    Chang, Chih-Wei; Zettl, Alexander K.

    2013-10-29

    Disclosed are methods and devices in which certain types of nanotubes (e.g., carbon nanotubes and boron nitride nanotubes conduct heat with high efficiency and are therefore useful in electronic-type devices.

  4. Terahertz Spectroscopy of Individual Single-Walled Carbon Nanotubes as a Probe of Luttinger Liquid Physics.

    Science.gov (United States)

    Chudow, Joel D; Santavicca, Daniel F; Prober, Daniel E

    2016-08-10

    Luttinger liquid theory predicts that collective electron excitations due to strong electron-electron interactions in a one-dimensional (1D) system will result in a modification of the collective charge-propagation velocity. By utilizing a circuit model for an individual metallic single-walled carbon nanotube as a nanotransmission line, it has been shown that the frequency-dependent terahertz impedance of a carbon nanotube can probe this expected 1D Luttinger liquid behavior. We excite terahertz standing-wave resonances on individual antenna-coupled metallic single-walled carbon nanotubes. The terahertz signal is rectified using the nanotube contact nonlinearity, allowing for a low-frequency readout of the coupled terahertz current. The charge velocity on the nanotube is determined from the terahertz spectral response. Our measurements show that a carbon nanotube can behave as a Luttinger liquid system with charge-propagation velocities that are faster than the Fermi velocity. Understanding what determines the charge velocity in low-dimensional conductors is important for the development of next generation nanodevices.

  5. Novel Materials Containing Single-Wall Carbon Nanotubes Wrapped in Polymer Molecules

    Science.gov (United States)

    Smalley, Richard E.; O'Connell, Michael J.; Smith, Kenneth; Colbert, Daniel T.

    2009-01-01

    In this design, single-wall carbon nanotubes (SWNTs) have been coated in polymer molecules to create a new type of material that has low electrical conductivity, but still contains individual nanotubes, and small ropes of individual nanotubes, which are themselves good electrical conductors and serve as small conducting rods immersed in an electrically insulating matrix. The polymer is attached through weak chemical forces that are primarily non-covalent in nature, caused primarily through polarization rather than the sharing of valence electrons. Therefore, the electronic structure of the SWNT involved is substantially the same as that of free, individual (and small ropes of) SWNT. Their high conductivity makes the individual nanotubes extremely electrically polarizable, and materials containing these individual, highly polarizable molecules exhibit novel electrical properties including a high dielectric constant.

  6. A triple quantum dot in a single-wall carbon nanotube

    DEFF Research Database (Denmark)

    Grove-Rasmussen, Kasper; Jørgensen, Henrik Ingerslev; Hayashi, T.

    2008-01-01

    A top-gated single-wall carbon nanotube is used to define three coupled quantum dots in series between two electrodes. The additional electron number on each quantum dot is controlled by top-gate voltages allowing for current measurements of single, double, and triple quantum dot stability diagrams...

  7. A Facile Route to Metal Oxides/Single-Walled Carbon Nanotube Macrofilm Nanocomposites for Energy Storage

    Directory of Open Access Journals (Sweden)

    Zeyuan eCao

    2015-05-01

    Full Text Available Nanocomposites consisting of transition-metal oxides and carbon nanomaterials with a desired size and structure are highly demanded for high performance energy storage devices. Here, a facile two-step and cost-efficient approach relying on directly thermal treatment of chemical-vapor-deposition products is developed as a general synthetic method to prepare a family of metal oxides (MxOy (M=Fe, Co, Ni/single-walled carbon nanotube (SWNT macrofilm nanocomposites. The MxOy nanoparticles obtained are of 3-17 nm in diameter and homogeneously anchor on the free-standing SWNT macrofilms. NiO/SWNT also exhibits a high specific capacitance of 400 F g-1 and fast charge-transfer Faradaic redox reactions to achieve asymmetric supercapacitors with a high power and energy density. All MxOy/SWNT nanocomposites could deliver a high capacity beyond 1000 mAh g-1 and show excellent cycling stability for lithium-ion batteries. The impressive results demonstrate the promise for energy storage devices and the general approach may pave the way to synthesize other functional nanocomposites.

  8. Radiation-Hard Complementary Integrated Circuits Based on Semiconducting Single-Walled Carbon Nanotubes.

    Science.gov (United States)

    McMorrow, Julian J; Cress, Cory D; Gaviria Rojas, William A; Geier, Michael L; Marks, Tobin J; Hersam, Mark C

    2017-03-28

    Increasingly complex demonstrations of integrated circuit elements based on semiconducting single-walled carbon nanotubes (SWCNTs) mark the maturation of this technology for use in next-generation electronics. In particular, organic materials have recently been leveraged as dopant and encapsulation layers to enable stable SWCNT-based rail-to-rail, low-power complementary metal-oxide-semiconductor (CMOS) logic circuits. To explore the limits of this technology in extreme environments, here we study total ionizing dose (TID) effects in enhancement-mode SWCNT-CMOS inverters that employ organic doping and encapsulation layers. Details of the evolution of the device transport properties are revealed by in situ and in operando measurements, identifying n-type transistors as the more TID-sensitive component of the CMOS system with over an order of magnitude larger degradation of the static power dissipation. To further improve device stability, radiation-hardening approaches are explored, resulting in the observation that SWNCT-CMOS circuits are TID-hard under dynamic bias operation. Overall, this work reveals conditions under which SWCNTs can be employed for radiation-hard integrated circuits, thus presenting significant potential for next-generation satellite and space applications.

  9. Solution-processed single-wall carbon nanotube transistor arrays for wearable display backplanes

    Directory of Open Access Journals (Sweden)

    Byeong-Cheol Kang

    2018-01-01

    Full Text Available In this paper, we demonstrate solution-processed single-wall carbon nanotube thin-film transistor (SWCNT-TFT arrays with polymeric gate dielectrics on the polymeric substrates for wearable display backplanes, which can be directly attached to the human body. The optimized SWCNT-TFTs without any buffer layer on flexible substrates exhibit a linear field-effect mobility of 1.5cm2/V-s and a threshold voltage of around 0V. The statistical plot of the key device metrics extracted from 35 SWCNT-TFTs which were fabricated in different batches at different times conclusively support that we successfully demonstrated high-performance solution-processed SWCNT-TFT arrays which demand excellent uniformity in the device performance. We also investigate the operational stability of wearable SWCNT-TFT arrays against an applied strain of up to 40%, which is the essential for a harsh degree of strain on human body. We believe that the demonstration of flexible SWCNT-TFT arrays which were fabricated by all solution-process except the deposition of metal electrodes at process temperature below 130oC can open up new routes for wearable display backplanes.

  10. Solution-processed zinc oxide nanoparticles/single-walled carbon nanotubes hybrid thin-film transistors

    Science.gov (United States)

    Liu, Fangmei; Sun, Jia; Qian, Chuan; Hu, Xiaotao; Wu, Han; Huang, Yulan; Yang, Junliang

    2016-09-01

    Solution-processed thin-film transistors (TFTs) are the essential building blocks for manufacturing the low-cost and large-area consumptive electronics. Herein, solution-processed TFTs based on the composites of zinc oxide (ZnO) nanoparticles and single-walled carbon nanotubes (SWCNTs) were fabricated by the methods of spin-coating and doctor-blading. Through controlling the weight of SWCNTs, the ZnO/SWCNTs TFTs fabricated by spin-coating demonstrated a field-effect mobility of 4.7 cm2/Vs and a low threshold voltage of 0.8 V, while the TFTs devices fabricated by doctor-blading technique showed reasonable electrical performance with a mobility of 0.22 cm2/Vs. Furthermore, the ion-gel was used as an efficient electrochemical gate dielectric because of its large electric double-layer capacitance. The operating voltage of all the TFTs devices is as low as 4.0 V. The research suggests that ZnO/SWCNTs TFTs have the potential applications in low-cost, large-area and flexible consumptive electronics, such as chemical-biological sensors and smart label.

  11. Solution-processed single-wall carbon nanotube transistor arrays for wearable display backplanes

    Science.gov (United States)

    Kang, Byeong-Cheol; Ha, Tae-Jun

    2018-01-01

    In this paper, we demonstrate solution-processed single-wall carbon nanotube thin-film transistor (SWCNT-TFT) arrays with polymeric gate dielectrics on the polymeric substrates for wearable display backplanes, which can be directly attached to the human body. The optimized SWCNT-TFTs without any buffer layer on flexible substrates exhibit a linear field-effect mobility of 1.5cm2/V-s and a threshold voltage of around 0V. The statistical plot of the key device metrics extracted from 35 SWCNT-TFTs which were fabricated in different batches at different times conclusively support that we successfully demonstrated high-performance solution-processed SWCNT-TFT arrays which demand excellent uniformity in the device performance. We also investigate the operational stability of wearable SWCNT-TFT arrays against an applied strain of up to 40%, which is the essential for a harsh degree of strain on human body. We believe that the demonstration of flexible SWCNT-TFT arrays which were fabricated by all solution-process except the deposition of metal electrodes at process temperature below 130oC can open up new routes for wearable display backplanes.

  12. Developing Xenopus Embryos Recover by Compacting and Expelling Single-Wall Carbon Nanotubes

    Science.gov (United States)

    Holt, Brian D.; Shawky, Joseph H.; Dahl, Kris Noel; Davidson, Lance A.; Islam, Mohammad F.

    2015-01-01

    Single-wall carbon nanotubes are high aspect ratio nanomaterials that are being developed for use in materials, technological and biological applications due to their high mechanical stiffness, optical properties, and chemical inertness. Because of their prevalence, it is inevitable that biological systems will be exposed to nanotubes, yet studies of the effects of nanotubes on developing embryos have been inconclusive and are lacking for single-wall carbon nanotubes exposed to the widely studied model organism Xenopus laevis (African clawed frog). Microinjection of experimental substances into the Xenopus embryo is a standard technique for toxicology studies and cellular lineage tracing. Here we report the surprising finding that superficial (12.5 ± 7.5 μm below the membrane) microinjection of nanotubes dispersed with Pluronic F127 into one-to-two cell Xenopus embryos resulted in the formation and expulsion of compacted, nanotube-filled, punctate masses, at the blastula to mid-gastrula developmental stages, which we call “boluses”. Such expulsion of microinjected materials by Xenopus embryos has not been reported before and is dramatically different from the typical distribution of the materials throughout the progeny of the microinjected cells. Previous studies of microinjections of nanomaterials such as nanodiamonds, quantum dots or spherical nanoparticles report that nanomaterials often induce toxicity and remain localized within the embryos. In contrast, our results demonstrate an active recovery pathway for embryos after exposure to Pluronic F127-coated nanotubes, which we speculate is due to a combined effect of the membrane activity of the dispersing agent, Pluronic F127, and the large aspect ratio of nanotubes. PMID:26153061

  13. The effect of fibronectin on structural and biological properties of single walled carbon nanotube

    Energy Technology Data Exchange (ETDEWEB)

    Mottaghitalab, Fatemeh [Department of Nanobiotechnology, Faculty of Biological Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Farokhi, Mehdi [National cell bank of Iran, Pasteur Institute, Tehran (Iran, Islamic Republic of); Atyabi, Fatemeh [Department of Pharmaceutical Nanoechnology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Omidvar, Ramin [Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran (Iran, Islamic Republic of); Shokrgozar, Mohammad Ali, E-mail: mashokrgozar@pasteur.ac.ir [National cell bank of Iran, Pasteur Institute, Tehran (Iran, Islamic Republic of); Sadeghizadeh, Majid, E-mail: sadeghma@modares.ac.ir [Department Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)

    2015-06-01

    Highlights: • Increasing the cytocompatibility of single walled carbon nanotube by loading fibronectin. • Enhancing the hydrophilicity and nanosurface roughness of single walled carbon nanotube after loading fibronectin. • Fibronectin makes the surface properties of single walled carbon nanotube more suitable for cell proliferation and growth. - Abstract: Despite the attractive properties of carbon nanotubes (CNTs), cytoxicity and hydrophobicity are two main considerable features which limit their application in biomedical fields. It was well established that treating CNTs with extracellular matrix components could reduce these unfavourable characteristics. In an attempt to address these issues, fibronectin (FN) with different concentrations was loaded on single walled carbon nanotubes (SWCNTs) substrate. Scanning electron microscope, atomic force microscopy (AFM), contact angles and X-ray photoelectron spectroscopy (XPS) were preformed in order to characterize FN loaded SWCNTs substrates. According to XPS and AFM results, FN could interact with SWCNTs and for this, the hydrophilicity of SWCNTs was improved. Additionally, SWCNT modified with FN showed less cytotoxicity compared with neat SWCNT. Finally, FN was shown to act as an interesting extracellular component for enhancing the biological properties of SWCNT.

  14. Single wall carbon nanotube supports for portable direct methanol fuel cells.

    Science.gov (United States)

    Girishkumar, G; Hall, Timothy D; Vinodgopal, K; Kamat, Prashant V

    2006-01-12

    Single-wall and multiwall carbon nanotubes are employed as carbon supports in direct methanol fuel cells (DMFC). The morphology and electrochemical activity of single-wall and multiwall carbon nanotubes obtained from different sources have been examined to probe the influence of carbon support on the overall performance of DMFC. The improved activity of the Pt-Ru catalyst dispersed on carbon nanotubes toward methanol oxidation is reflected as a shift in the onset potential and a lower charge transfer resistance at the electrode/electrolyte interface. The evaluation of carbon supports in a passive air breathing DMFC indicates that the observed power density depends on the nature and source of carbon nanostructures. The intrinsic property of the nanotubes, dispersion of the electrocatalyst and the electrochemically active surface area collectively influence the performance of the membrane electrode assembly (MEA). As compared to the commercial carbon black support, single wall carbon nanotubes when employed as the support for anchoring the electrocatalyst particles in the anode and cathode sides of MEA exhibited a approximately 30% enhancement in the power density of a single stack DMFC operating at 70 degrees C.

  15. The effect of fibronectin on structural and biological properties of single walled carbon nanotube

    International Nuclear Information System (INIS)

    Mottaghitalab, Fatemeh; Farokhi, Mehdi; Atyabi, Fatemeh; Omidvar, Ramin; Shokrgozar, Mohammad Ali; Sadeghizadeh, Majid

    2015-01-01

    Highlights: • Increasing the cytocompatibility of single walled carbon nanotube by loading fibronectin. • Enhancing the hydrophilicity and nanosurface roughness of single walled carbon nanotube after loading fibronectin. • Fibronectin makes the surface properties of single walled carbon nanotube more suitable for cell proliferation and growth. - Abstract: Despite the attractive properties of carbon nanotubes (CNTs), cytoxicity and hydrophobicity are two main considerable features which limit their application in biomedical fields. It was well established that treating CNTs with extracellular matrix components could reduce these unfavourable characteristics. In an attempt to address these issues, fibronectin (FN) with different concentrations was loaded on single walled carbon nanotubes (SWCNTs) substrate. Scanning electron microscope, atomic force microscopy (AFM), contact angles and X-ray photoelectron spectroscopy (XPS) were preformed in order to characterize FN loaded SWCNTs substrates. According to XPS and AFM results, FN could interact with SWCNTs and for this, the hydrophilicity of SWCNTs was improved. Additionally, SWCNT modified with FN showed less cytotoxicity compared with neat SWCNT. Finally, FN was shown to act as an interesting extracellular component for enhancing the biological properties of SWCNT

  16. Improved synthesis of carbon nanotubes with junctions and of single ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Pyrolysis of thiophene over nickel nanoparticles dispersed on silica is shown to yield Y- junction carbon nanotubes with smaller diameters than those obtained by the pyrolysis of organometallic- thiophene mixtures. In the presence of water vapour, the pyrolysis of organometallic-hydrocarbon mixtures.

  17. Analytical approach to phonons and electron-phonon interactions in single-walled zigzag carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Kandemir, B S; Keskin, M [Department of Physics, Faculty of Sciences, Ankara University, 06100 Tandogan, Ankara (Turkey)

    2008-08-13

    In this paper, exact analytical expressions for the entire phonon spectra in single-walled carbon nanotubes with zigzag geometry are presented by using a new approach, originally developed by Kandemir and Altanhan. This approach is based on the concept of construction of a classical lattice Hamiltonian of single-walled carbon nanotubes, wherein the nearest and next nearest neighbor and bond bending interactions are all included, then its quantization and finally diagonalization of the resulting second quantized Hamiltonian. Furthermore, within this context, explicit analytical expressions for the relevant electron-phonon interaction coefficients are also investigated for single-walled carbon nanotubes having this geometry, by the phonon modulation of the hopping interaction.

  18. Analytical approach to phonons and electron-phonon interactions in single-walled zigzag carbon nanotubes

    International Nuclear Information System (INIS)

    Kandemir, B S; Keskin, M

    2008-01-01

    In this paper, exact analytical expressions for the entire phonon spectra in single-walled carbon nanotubes with zigzag geometry are presented by using a new approach, originally developed by Kandemir and Altanhan. This approach is based on the concept of construction of a classical lattice Hamiltonian of single-walled carbon nanotubes, wherein the nearest and next nearest neighbor and bond bending interactions are all included, then its quantization and finally diagonalization of the resulting second quantized Hamiltonian. Furthermore, within this context, explicit analytical expressions for the relevant electron-phonon interaction coefficients are also investigated for single-walled carbon nanotubes having this geometry, by the phonon modulation of the hopping interaction

  19. Continuous growth of single-wall carbon nanotubes using chemical vapor deposition

    Science.gov (United States)

    Grigorian, Leonid [Raymond, OH; Hornyak, Louis [Evergreen, CO; Dillon, Anne C [Boulder, CO; Heben, Michael J [Denver, CO

    2008-10-07

    The invention relates to a chemical vapor deposition process for the continuous growth of a carbon single-wall nanotube where a carbon-containing gas composition is contacted with a porous membrane and decomposed in the presence of a catalyst to grow single-wall carbon nanotube material. A pressure differential exists across the porous membrane such that the pressure on one side of the membrane is less than that on the other side of the membrane. The single-wall carbon nanotube growth may occur predominately on the low-pressure side of the membrane or, in a different embodiment of the invention, may occur predominately in between the catalyst and the membrane. The invention also relates to an apparatus used with the carbon vapor deposition process.

  20. Single walled carbon nanotube-based junction biosensor for detection of Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Kara Yamada

    Full Text Available Foodborne pathogen detection using biomolecules and nanomaterials may lead to platforms for rapid and simple electronic biosensing. Integration of single walled carbon nanotubes (SWCNTs and immobilized antibodies into a disposable bio-nano combinatorial junction sensor was fabricated for detection of Escherichia coli K-12. Gold tungsten wires (50 µm diameter coated with polyethylenimine (PEI and SWCNTs were aligned to form a crossbar junction, which was functionalized with streptavidin and biotinylated antibodies to allow for enhanced specificity towards targeted microbes. In this study, changes in electrical current (ΔI after bioaffinity reactions between bacterial cells (E. coli K-12 and antibodies on the SWCNT surface were monitored to evaluate the sensor's performance. The averaged ΔI increased from 33.13 nA to 290.9 nA with the presence of SWCNTs in a 10(8 CFU/mL concentration of E. coli, thus showing an improvement in sensing magnitude. Electrical current measurements demonstrated a linear relationship (R2 = 0.973 between the changes in current and concentrations of bacterial suspension in range of 10(2-10(5 CFU/mL. Current decreased as cell concentrations increased, due to increased bacterial resistance on the bio-nano modified surface. The detection limit of the developed sensor was 10(2 CFU/mL with a detection time of less than 5 min with nanotubes. Therefore, the fabricated disposable junction biosensor with a functionalized SWCNT platform shows potential for high-performance biosensing and application as a detection device for foodborne pathogens.

  1. Single-walled carbon nanotubes as stabilizing agents in red phosphorus Li-ion battery anodes

    KAUST Repository

    Smajic, Jasmin

    2017-08-16

    Phosphorus boasts extremely high gravimetric and volumetric capacities but suffers from poor electrochemical stability with significant capacity loss immediately after the first cycle. We propose to circumvent this issue by mixing amorphous red phosphorus with single-walled carbon nanotubes. Employing a non-destructive sublimation–deposition method, we have synthesized composites where the synergetic effect between red phosphorus and single-walled carbon nanotubes allows for a considerable improvement in the electrochemical stability of battery anodes. In contrast to the average 40% loss of capacity after 50 cycles for other phosphorus–carbon composites in the literature, our material shows losses of just 22% under analogous cycling conditions.

  2. Efficient organometallic spin filter between single-wall carbon nanotube or graphene electrodes

    DEFF Research Database (Denmark)

    Koleini, Mohammad; Paulsson, Magnus; Brandbyge, Mads

    2007-01-01

    We present a theoretical study of spin transport in a class of molecular systems consisting of an organometallic benzene-vanadium cluster placed in between graphene or single-wall carbon-nanotube-model contacts. Ab initio modeling is performed by combining spin density functional theory and noneq......We present a theoretical study of spin transport in a class of molecular systems consisting of an organometallic benzene-vanadium cluster placed in between graphene or single-wall carbon-nanotube-model contacts. Ab initio modeling is performed by combining spin density functional theory...

  3. Improving Formate and Methanol Fuels: Catalytic Activity of Single Pd Coated Carbon Nanotubes.

    Science.gov (United States)

    Li, Xiuting; Hodson, Hannah; Batchelor-McAuley, Christopher; Shao, Lidong; Compton, Richard G

    2016-10-07

    The oxidations of formate and methanol on nitrogen-doped carbon nanotubes decorated with palladium nanoparticles were studied at both the single-nanotube and ensemble levels. Significant voltammetric differences were seen. Pd oxide formation as a competitive reaction with formate or methanol oxidation is significantly inhibited at high overpotentials under the high mass transport conditions associated with single-particle materials in comparison with that seen with ensembles, where slower diffusion prevails. Higher electro-oxidation efficiency for the organic fuels is achieved.

  4. Using single-walled carbon nanotubes nonwoven films as scaffolds to enhance long-term cell proliferation in vitro.

    Science.gov (United States)

    Meng, Jie; Song, Li; Meng, Jie; Kong, Hua; Zhu, Guangjin; Wang, Chaoying; Xu, Lianghua; Xie, Sishen; Xu, Haiyan

    2006-11-01

    Carbon nanotubes have attracted intensive interests in biomedical research in recent years. In this study, a novel type of carbon nanotubes material so called nonwoven single-walled carbon nanotubes (SWNTs) with nanotopographic structure and macroscopic volume was used as cell growing scaffold. The morphology and surface chemistry of nonwoven SWNTs were observed and characterized through scanning electron microscopy and X-ray photoelectron spectroscopy, respectively. The cells were cultivated in nonwoven SWNTs and in other types of substrate as control. The cells growth behaviors including adhesion, proliferation, and cytoskeletal development was investigated by using cell viability assay and confocal observation. The experimental results indicated that nonwoven SWNTs exhibited significant enhancement to the cells adhesion and proliferation in at least 3 weeks. Numerous and highly organized cytoskeletal structures were observed when the cells were cultured in nonwoven SWNTs. Furthermore, an obvious promotional influence of the cells cultivated in nonwoven SWNTs scaffold upon the proliferation of those growing in the other kind of substrate through cell-cell communication had been found. The results obtained in this work are of significance to in vitro cell amplification in large scale, tissue regeneration, or guided repair, as well as biomedical device application.

  5. Measuring single-walled carbon nanotube length distributions from diffusional trajectories.

    Science.gov (United States)

    Streit, Jason K; Bachilo, Sergei M; Naumov, Anton V; Khripin, Constantine; Zheng, Ming; Weisman, R Bruce

    2012-09-25

    A new method is demonstrated for measuring the length distributions of dispersed single-walled carbon nanotube (SWCNT) samples by analyzing diffusional motions of many individual nanotubes in parallel. In this method, termed "length analysis by nanotube diffusion" (LAND), video sequences of near-IR fluorescence microscope images showing many semiconducting SWCNTs are recorded and processed by custom image analysis software. This processing locates the individual nanotubes, tracks their translational trajectories, computes the corresponding diffusion coefficients, and converts those values to nanotube lengths. The deduced length values are then compiled into a histogram of lengths present in the sample. By using specific excitation wavelengths and emission filters, this analysis is performed on selected (n,m) structural species. The new LAND method has been found to give distributions in very good agreement with those obtained by conventional AFM analysis of the same samples. Because it is fluorescence-based, LAND monitors only semiconducting, relatively pristine SWCNTs. However, it is less sensitive to artifacts from impurities and bundled nanotubes than AFM or light scattering methods. In addition, samples can be analyzed with less time and operator attention than by AFM. LAND is a promising alternative method for characterizing length distributions of SWCNTs in liquid suspension.

  6. Taguchi analysis of parameters for small-diameter single wall carbon nanotube growth

    Directory of Open Access Journals (Sweden)

    DaeJin Kang

    2017-09-01

    Full Text Available Small diameter single wall carbon nanotubes are desirable for various physical and electrical properties of carbon nanotubes. Here, we report the sensitivities of parameters and the optimal conditions for small diameter carbon nanotube growth by chemical vapor deposition (CVD. These results were obtained using the Taguchi method, which is commonly used to find the optimal parameters of various processes. The possible parameter ranges given by the experimental equipment and laboratory conditions, we attempted several times to determine the proper ranges, using photoluminescence (PL imaging to determine the exact positions of suspended carbon nanotubes on the quartz substrates after synthesis. The diameters of the carbon nanotubes were then determined from the radial breathing modes (RBM using Raman spectroscopy with a 785nm wavelength laser. Among the 4 major parameters listed above, we concluded that the temperature was the most significant parameter in determining carbon nanotube diameter, hydrogen flow rate was the second most significant, the ethanol and argon gas flow rate was the third, and finally time was the least significant factor.

  7. Exposure to carbon nanotube material: aerosol release during the handling of unrefined single-walled carbon nanotube material.

    Science.gov (United States)

    Maynard, Andrew D; Baron, Paul A; Foley, Michael; Shvedova, Anna A; Kisin, Elena R; Castranova, Vincent

    2004-01-09

    Carbon nanotubes represent a relatively recently discovered allotrope of carbon that exhibits unique properties. While commercial interest in the material is leading to the development of mass production and handling facilities, little is known of the risk associated with exposure. In a two-part study, preliminary investigations have been carried out into the potential exposure routes and toxicity of single-walled carbon nanotube material (SWCNT)--a specific form of the allotrope. The material is characterized by bundles of fibrous carbon molecules that may be a few nanometers in diameter, but micrometers in length. The two production processes investigated use-transition metal catalysts, leading to the inclusion of nanometer-scale metallic particles within unrefined SWCNT material. A laboratory-based study was undertaken to evaluate the physical nature of the aerosol formed from SWCNT during mechanical agitation. This was complemented by a field study in which airborne and dermal exposure to SWCNT was investigated while handling unrefined material. Although laboratory studies indicated that with sufficient agitation, unrefined SWCNT material can release fine particles into the air, concentrations generated while handling material in the field were very low. Estimates of the airborne concentration of nanotube material generated during handling suggest that concentrations were lower than 53 microg/m(3) in all cases. Glove deposits of SWCNT during handling were estimated at between 0.2 mg and 6 mg per hand.

  8. Control of the Diameter and Chiral Angle Distributions during Production of Single-Wall Carbon Nanotubes

    Science.gov (United States)

    Nikolaev, Pavel

    2009-01-01

    Many applications of single wall carbon nanotubes (SWCNT), especially in microelectronics, will benefit from use of certain (n,m) nanotube types (metallic, small gap semiconductor, etc.) Especially fascinating is the possibility of quantum conductors that require metallic armchair nanotubes. However, as produced SWCNT samples are polydisperse, with many (n,m) types present and typical approx.1:2 metal/semiconductor ratio. Nanotube nucleation models predict that armchair nuclei are energetically preferential due to formation of partial triple bonds along the armchair edge. However, nuclei can not reach any meaningful thermal equilibrium in a rapidly expanding and cooling plume of carbon clusters, leading to polydispersity. In the present work, SWCNTs were produced by a pulsed laser vaporization (PLV) technique. The carbon vapor plume cooling rate was either increased by change in the oven temperature (expansion into colder gas), or decreased via "warm-up" with a laser pulse at the moment of nucleation. The effect of oven temperature and "warm-up" on nanotube type population was studied via photoluminescence, UV-Vis-NIR absorption and Raman spectroscopy. It was found that reduced temperatures leads to smaller average diameters, progressively narrower diameter distributions, and some preference toward armchair structures. "Warm-up" shifts nanotube population towards arm-chair structures as well, but the effect is small. Possible improvement of the "warm-up" approach to produce armchair SWCNTs will be discussed. These results demonstrate that PLV production technique can provide at least partial control over the nanotube (n,m) population. In addition, these results have implications for the understanding the nanotube nucleation mechanism in the laser oven.

  9. Response of asymmetric carbon nanotube network devices to sub-terahertz and terahertz radiation

    International Nuclear Information System (INIS)

    Gayduchenko, I.; Kardakova, A.; Voronov, B.; Finkel, M.; Fedorov, G.; Jiménez, D.; Morozov, S.; Presniakov, M.; Goltsman, G.

    2015-01-01

    Demand for efficient terahertz radiation detectors resulted in intensive study of the asymmetric carbon nanostructures as a possible solution for that problem. It was maintained that photothermoelectric effect under certain conditions results in strong response of such devices to terahertz radiation even at room temperature. In this work, we investigate different mechanisms underlying the response of asymmetric carbon nanotube (CNT) based devices to sub-terahertz and terahertz radiation. Our structures are formed with CNT networks instead of individual CNTs so that effects probed are more generic and not caused by peculiarities of an individual nanoscale object. We conclude that the DC voltage response observed in our structures is not only thermal in origin. So called diode-type response caused by asymmetry of the device IV characteristic turns out to be dominant at room temperature. Quantitative analysis provides further routes for the optimization of the device configuration, which may result in appearance of novel terahertz radiation detectors

  10. Selective Etching of Thin Single-Walled Carbon Nanotubes

    Czech Academy of Sciences Publication Activity Database

    Kalbáč, Martin; Kavan, Ladislav; Dunsch, L.

    2009-01-01

    Roč. 131, č. 12 (2009), s. 4529-4534 ISSN 0002-7863 R&D Projects: GA AV ČR IAA400400804; GA ČR GC203/07/J067; GA AV ČR IAA400400911 Institutional research plan: CEZ:AV0Z40400503 Keywords : carbon nanotubes * Raman spectroelectrochemistry * Raman spectroscopy Subject RIV: CG - Electrochemistry Impact factor: 8.580, year: 2009

  11. Single-Wall Carbon Nanotube-Coated Cotton Yarn for Electrocardiography Transmission

    Directory of Open Access Journals (Sweden)

    Yuliang Zhao

    2018-03-01

    Full Text Available We fabricated a type of conductive fabric, specifically single-wall carbon nanotube-coated cotton yarns (SWNT-CYs, for electrocardiography (ECG signal transmission utilizing a “dipping and drying” method. The conductive cotton yarns were prepared by dipping cotton yarns in SWNTs (single-wall carbon nanotubes solutions and then drying them at room temperature—a simple process that shows consistency in successfully coating cotton yarns with conductive carbon nanotubes (CNTs. The influence of fabrication conditions on the conductivity properties of SWNT-CYs was investigated. The results demonstrate that our conductive yarns can transmit weak bio-electrical (i.e., ECG signals without significant attenuation and distortion. Our conductive cotton yarns, which combine the flexibility of conventional fabrics and the good conductivity of SWNTs, are promising materials for wearable electronics and sensor applications in the future.

  12. Facile Preparation of Carbon-Nanotube-based 3-Dimensional Transparent Conducting Networks for Flexible Noncontact Sensing Device

    KAUST Repository

    Tai, Yanlong

    2016-04-12

    Here, we report the controllable fabrication of transparent conductive films (TCFs) for moisture-sensing applications based on heating-rate-triggered, 3-dimensional porous conducting networks of single-walled carbon nanotube (SWCNT)/poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT:PSS). How baking conditions influence the self-assembled microstructure of the TCFs is discussed. The sensor presents high-performance properties, including a reasonable sheet resistance (2.1 kohm/sq), a high visible-range transmittance (> 69 %, PET = 90 %), and good stability when subjected to cyclic loading (> 1000 cycles, better than indium tin oxide film) during processing. Moreover, the benefits of these kinds of TCFs were verified through a fully transparent, highly sensitive, rapid response, noncontact moisture-sensing device (5×5 sensing pixels).

  13. Enrichment of semiconducting single-walled carbon nanotubes by carbothermic reaction for use in all-nanotube field effect transistors.

    Science.gov (United States)

    Li, Shisheng; Liu, Chang; Hou, Peng-Xiang; Sun, Dong-Ming; Cheng, Hui-Ming

    2012-11-27

    Selective removal of metallic single-walled carbon nanotubes (SWCNTs) and consequent enrichment of semiconducting SWCNTs were achieved through an efficient carbothermic reaction with a NiO thin film at a relatively low temperature of 350 °C. All-SWCNT field effect transistors (FETs) were fabricated with the aid of a patterned NiO mask, in which the as-grown SWCNTs behaving as source/drain electrodes and the remaining semiconducting SWCNTs that survive in the carbothermic reaction as a channel material. The all-SWCNT FETs demonstrate improved current ON/OFF ratios of ∼10(3).

  14. Electrical conduction and photoresponses of gamma-ray-irradiated single-stranded DNA/single-walled carbon nanotube composite systems

    Energy Technology Data Exchange (ETDEWEB)

    Hong, W.; Lee, E.M.; Kim, D.W.; Lee, Cheol Eui, E-mail: rscel@korea.ac.kr

    2015-04-15

    Highlights: •Effects of gamma-ray irradiation on single-stranded DNA (ssDNA)/single-walled carbon nanotube (SWNT) composite films. •Barrier for thermally activated conduction in the composite systems modified by the gamma-ray irradiation. •Photoresponses reveal photoexcitation and oxygen photodesorption modified by gamma-ray irradiation. -- Abstract: Effects of gamma-ray irradiation on the electrical conductivity and photoresponse have been studied for single-stranded DNA (ssDNA)/single-walled carbon nanotube (SWNT) composite films. The temperature-dependent electrical conductivity of the ssDNA/SWNT composite films, well described by a fluctuation-induced tunneling model, indicated modification of the barrier for thermally activated conduction by the gamma-ray irradiation. Besides, the photoresponse measurements indicated modified photoexcited charge carrier generation and oxygen photodesorption in the composite systems due to the gamma-ray irradiation.

  15. Conducting polymer functionalized single-walled carbon nanotube based chemiresistive biosensor for the detection of human cardiac myoglobin

    Energy Technology Data Exchange (ETDEWEB)

    Puri, Nidhi [CSIR-National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi 110012 (India); Department of Physics, Faculty of Natural Sciences, Jamia Millia Islamia, New Delhi 110025 (India); Niazi, Asad [Department of Physics, Faculty of Natural Sciences, Jamia Millia Islamia, New Delhi 110025 (India); Biradar, Ashok M.; Rajesh, E-mail: rajesh-csir@yahoo.com, E-mail: adani@engr.ucr.edu [CSIR-National Physical Laboratory, Dr. K. S. Krishnan Road, New Delhi 110012 (India); Mulchandani, Ashok, E-mail: rajesh-csir@yahoo.com, E-mail: adani@engr.ucr.edu [Department of Chemical and Environmental Engineering, University of California, Riverside, California 92521 (United States)

    2014-10-13

    We report the fabrication of a single-walled carbon nanotube (SWNT) based ultrasensitive label-free chemiresistive biosensor for the detection of human cardiac biomarker, myoglobin (Ag-cMb). Poly(pyrrole-co-pyrrolepropylic acid) with pendant carboxyl groups was electrochemically deposited on electrophoretically aligned SWNT channel, as a conducting linker, for biomolecular immobilization of highly specific cardiac myoglobin antibody. The device was characterized by scanning electron microscopy, source-drain current-voltage (I-V), and charge-transfer characteristic studies. The device exhibited a linear response with a change in conductance in SWNT channel towards the target, Ag-cMb, over the concentration range of 1.0 to 1000 ng ml{sup −1} with a sensitivity of ∼118% per decade with high specificity.

  16. Conducting polymer functionalized single-walled carbon nanotube based chemiresistive biosensor for the detection of human cardiac myoglobin

    Science.gov (United States)

    Puri, Nidhi; Niazi, Asad; Biradar, Ashok M.; Mulchandani, Ashok; Rajesh

    2014-10-01

    We report the fabrication of a single-walled carbon nanotube (SWNT) based ultrasensitive label-free chemiresistive biosensor for the detection of human cardiac biomarker, myoglobin (Ag-cMb). Poly(pyrrole-co-pyrrolepropylic acid) with pendant carboxyl groups was electrochemically deposited on electrophoretically aligned SWNT channel, as a conducting linker, for biomolecular immobilization of highly specific cardiac myoglobin antibody. The device was characterized by scanning electron microscopy, source-drain current-voltage (I-V), and charge-transfer characteristic studies. The device exhibited a linear response with a change in conductance in SWNT channel towards the target, Ag-cMb, over the concentration range of 1.0 to 1000 ng ml-1 with a sensitivity of ˜118% per decade with high specificity.

  17. Computational and experimental studies of the interaction between single-walled carbon nanotubes and folic acid

    DEFF Research Database (Denmark)

    Castillo, John J.; Rozo, Ciro E.; Castillo-León, Jaime

    2013-01-01

    This work involved the preparation of a conjugate between single-walled carbon nanotubes and folic acid that was obtained without covalent chemical functionalization using a simple “one pot” synthesis method. Subsequently, the conjugate was investigated by a computational hybrid method: our own N...

  18. Imaging 0.4nm single-walled carbon nanotubes with atomic force microscopy

    NARCIS (Netherlands)

    Zhang, Xieqiu; Ye, Jianting; Yang, Hongwei; Zhang, Chun; Ho, Kin Ming; Su, Tao; Wang, Ning; Tang, Zikang; Xiao, Xudong

    The discovery of the single-walled carbon nanotubes (SWCNTs) with a diameter of 0.4 nm has attracted extensive attentions. In this paper we report our attempt with two methods to directly observe these SWCNTs by AFM. The first one is to deposit the SWCNTs extracted from the zeolite matrix to a. at

  19. Effect of medium dielectric constant on the physical properties of single-walled carbon nanotubes

    NARCIS (Netherlands)

    Gao, J.; Gomulya, W.; Loi, M. A.

    2013-01-01

    The photophysical properties of semiconducting single walled carbon nanotubes (SWNTs) in different environments are analyzed by steady-state and time-resolved photoluminescence (PL) spectroscopy. The PL emission of SWNTs shows a red shift with the increase of the dielectric constant of the

  20. Nitrite electrochemical sensor based on prussian blue/single-walled carbon nanotubes modified pyrolytic graphite electrode

    CSIR Research Space (South Africa)

    Adekunle, AS

    2011-09-01

    Full Text Available that single-walled carbon nanotubes-Prussian blue hybrid (SWCNT-PB) modified electrode demonstrated greater sensitivity and catalysis towards nitrite compared to PB or a SWCNT modified electrode. The current response of the electrode was reduced...

  1. Synthesis of dark brown single-walled carbon nanotubes and their ...

    Indian Academy of Sciences (India)

    Abstract. We report here a simple and effective approach to the covalent attachment of single-walled carbon nanotubes (SWCNTs) and azo compounds. The functionalized SWCNTs prepared (through a radical mecha- nism) have been used for a diazonium coupling reaction. The results showed that the chemical method ...

  2. Plasma excitations in a single-walled carbon nanotube with an ...

    Indian Academy of Sciences (India)

    The effect of different uniform transverse external magnetic fields in plasma frequency when propagated parallel to the surface of the single-walled metallic carbon nanotubes is studied. The classical electrodynamics as well as Maxwell's equations are used in the calculations. Equations are developed for both short- and ...

  3. Synthesis of dark brown single-walled carbon nanotubes and their ...

    Indian Academy of Sciences (India)

    We report here a simple and effective approach to the covalent attachment of single-walled carbon nanotubes (SWCNTs) and azo compounds. The functionalized SWCNTs prepared (through a radical mechanism) have been used for a diazonium coupling reaction. The results showed that the chemical method used has ...

  4. Synthesis of single-walled carbon nanotubes by the pyrolysis of a ...

    Indian Academy of Sciences (India)

    Synthesis of single-walled carbon nanotubes by the pyrolysis of a compression activated iron(II) phthalocyanine/phthalocyanine metal-free derivative/ferric acetate mixture. TAWANDA MUGADZAa,b,∗, EDITH ANTUNESb and TEBELLO NYOKONGb. aDepartment of Chemical Technology, Midlands State University, Bag ...

  5. Structural and optical characteristics of GaN/ZnO coaxial nanotube heterostructure arrays for light-emitting device applications

    International Nuclear Information System (INIS)

    Hong, Young Joon; Jeon, Jong-Myeong; Kim, Miyoung; Jeon, Seong-Ran; Ho Park, Kyung; Yi, Gyu-Chul

    2009-01-01

    We report on the structural and optical characteristics of position-controlled GaN/ZnO coaxial nanotube heterostructure and GaN/In x Ga 1-x N coaxial nanotube quantum structure arrays for light-emitting diode (LED) applications. The GaN/ZnO nanotube heterostructures were fabricated by growing a GaN layer on the entire surface of position-controlled ZnO nanotube arrays using low-pressure metal-organic vapour-phase epitaxy. As determined by transmission-electron microscopy (TEM), an abrupt and coherent interface between the core ZnO and the GaN overlayer was observed. The optical characteristics of heteroepitaxial GaN/ZnO nanotube heterostructures were also investigated using cathodoluminescence (CL) spectroscopy. This position-controlled growth of high-quality single crystalline GaN/ZnO coaxial nanotube heterostructures allowed the fabrication of artificial arrays of high-quality GaN-based coaxial quantum structures by the heteroepitaxial growth of GaN/In x Ga 1-x N multiple quantum wells along the circumference of the GaN/ZnO nanotubes. The optical and structural characteristics of the position-controlled GaN/In x Ga 1-x N coaxial nanotube quantum structures were investigated by using CL spectroscopy and TEM analysis, respectively. The green LED microarrays were successfully fabricated by the controlled heteroepitaxial coaxial coatings of GaN/In x Ga 1-x N coaxial nanotube quantum structures and the outermost Mg-doped p-type GaN layer onto the GaN/ZnO coaxial nanotube heterostructures, presumably implying that the position-controlled growth of high-quality GaN/ZnO coaxial nanotube heterostructure arrays provides a general and rational route of integrating vertical nanodevices for nanoscale electronics and optoelectronics.

  6. Adsorption of triclosan on single wall carbon nanotubes: A first principle approach

    Energy Technology Data Exchange (ETDEWEB)

    Castro, S.M. [Departamento de Física, Universidade Federal do Maranhão, 65080-805 SãoLuís, MA (Brazil); Araújo, A.B. [Instituto Federal do Maranhão, Campus São Luis-Centro Histórico, 65010-500 SãoLuís, MA (Brazil); Nogueira, R.F.P. [Departamento de Química Analítica, Instituto de Química de Araraquara, UNESP e Univ Estadual Paulista, Araraquara, SP 14801-970 (Brazil); Guerini, S., E-mail: silvete@gmail.com [Departamento de Física, Universidade Federal do Maranhão, 65080-805 SãoLuís, MA (Brazil)

    2017-05-01

    Highlights: • The interaction between the (8,0) SWCNT and triclosan molecule occurs via chemical process in parallel configuration. • The semiconductor SWCNT present predominantly binding energies larger than that of metallic SWCNT. • Triclosan behaves as an electron donor or acceptor depending on configuration. - Abstract: The interaction of triclosan on (8,0) and (5,5) single wall carbon nanotube (SWCNT) was investigated using density functional calculations. The results show that the adsorption of triclosan modifies the electronic properties of pristine (8,0) and (5,5) SWCNT and induced changes in the electronic properties are dependent on the triclosan adsorption site. It was observed through binding energy that triclosan molecule interacts mainly via chemical process in parallel configuration to (8,0) SWCNT, while interaction via physical process was observed with both (8,0) and (5,5) SWCNT. It is proposed that these SWCNTs are a potential filter device due to reasonable physical interaction with triclosan molecule. Furthermore, this type of filter could be reusable, therefore after the filtering, the SWCNTs could be separated from triclosan molecule.

  7. Copper hexacyanoferrate functionalized single-walled carbon nano-tubes for selective cesium extraction

    International Nuclear Information System (INIS)

    Draouil, H.; Alvarez, L.; Bantignies, J.L.; Causse, J.; Cambedouzou, J.; Flaud, V.; Zaibi, M.A.; Oueslati, M.

    2017-01-01

    Single-walled carbon nano-tubes (SWCNTs) are functionalized with copper hexacyanoferrate (CuHCF) nanoparticles to prepare solid substrates for sorption of cesium ions (Cs + ) from liquid outflows. The high mechanical resistance and large electrical conductivity of SWCNTs are associated with the ability of CuHCF nanoparticles to selectively complex Cs + ions in order to achieve membrane-like buckypapers presenting high loading capacity of cesium. The materials are thoroughly characterized using electron microscopy, Raman scattering, X-ray photoelectron spectroscopy and thermogravimetric analyses. Cs sorption isotherms are plotted after having measured the Cs + concentration by liquid phase ionic chromatography in the solution before and after exposure to the materials. It is found that the total sorption capacity of the material reaches 230 mg.g -1 , and that about one third of the sorbed Cs (80 mg.g -1 ) is selectively complexed in the CuHCF nanoparticles grafted on SWCNTs. The quantification of Cs + ions on different sorption sites is made for the first time, and the high sorption rates open interesting outlooks in the integration of such materials in devices for the controlled sorption and desorption of these ions. (authors)

  8. Adsorption of triclosan on single wall carbon nanotubes: A first principle approach

    International Nuclear Information System (INIS)

    Castro, S.M.; Araújo, A.B.; Nogueira, R.F.P.; Guerini, S.

    2017-01-01

    Highlights: • The interaction between the (8,0) SWCNT and triclosan molecule occurs via chemical process in parallel configuration. • The semiconductor SWCNT present predominantly binding energies larger than that of metallic SWCNT. • Triclosan behaves as an electron donor or acceptor depending on configuration. - Abstract: The interaction of triclosan on (8,0) and (5,5) single wall carbon nanotube (SWCNT) was investigated using density functional calculations. The results show that the adsorption of triclosan modifies the electronic properties of pristine (8,0) and (5,5) SWCNT and induced changes in the electronic properties are dependent on the triclosan adsorption site. It was observed through binding energy that triclosan molecule interacts mainly via chemical process in parallel configuration to (8,0) SWCNT, while interaction via physical process was observed with both (8,0) and (5,5) SWCNT. It is proposed that these SWCNTs are a potential filter device due to reasonable physical interaction with triclosan molecule. Furthermore, this type of filter could be reusable, therefore after the filtering, the SWCNTs could be separated from triclosan molecule.

  9. Vacancy and curvature effects on the phonon properties of single wall carbon nanotube

    Science.gov (United States)

    Hossain Howlader, Ashraful; Sherajul Islam, Md.; Tanaka, Satoru; Makino, Takayuki; Hashimoto, Akihiro

    2018-02-01

    Single wall carbon nanotube (SWCNT) is considered as an ideal candidate for next-generation nanoelectronics owing to its unusual properties. Here we have performed an in-depth theoretical analysis of the effect of vacancy defects and curvature on the phonon properties of (10,0) and (10,10) SWCNTs using the forced vibrational method. We report that Raman active E2g mode softens towards the low-frequency region with increasing vacancies and curvature in both types of CNTs. Vacancy induces some new peaks at low-frequency region of the phonon density of states. Phonon localization properties are also manifested. Our calculated mode pattern and localization length show that optical phonon at Raman D-band frequency is strongly localized in vacancy defected and large curved CNTs. Our findings will be helpful in explaining the thermal conductivity, specific heat capacity, and Raman spectra in vacancy type disordered CNTs, as well as electron transport properties of CNT-based nanoelectronic devices.

  10. Thermal conductivity of a film of single walled carbon nanotubes measured with infrared thermal imager

    Science.gov (United States)

    Feng, Ya; Inoue, Taiki; Xiang, Rong; Chiashi, Shohei; Maruyama, Shigeo

    Heat dissipation has restricted the modern miniaturization trend with the development of electronic devices. Theoretically proven to be with high axial thermal conductivity, single walled carbon nanotubes (SWNT) have long been expected to cool down the nanoscale world. Even though the tube-tube contact resistance limits the capability of heat transfer of the bulk film, the high intrinsic thermal conductivity of SWNT still glorify the application of films of SWNT network as a thermal interface material. In this work, we proposed a new method to straightly measure the thermal conductivity of SWNT film. We bridged two cantilevered Si thin plate with SWNT film, and kept a steady state heat flow in between. With the infrared camera to record the temperature distribution, the Si plates with known thermal conductivity can work as a reference to calculate the heat flux going through the SWNT film. Further, the thermal conductivity of the SWNT film can be obtained through Fourier's law after deducting the effect of thermal radiation. The sizes of the structure, the heating temperature, the vacuum degree and other crucial impact factors are carefully considered and analyzed. The author Y. F. was supported through the Advanced Integration Science Innovation Education and Research Consortium Program by the Ministry of Education, Culture, Sport, Science and Technology.

  11. Room Temperature Single Walled Carbon Nanotubes (SWCNT Chemiresistive Ammonia Gas Sensor

    Directory of Open Access Journals (Sweden)

    Bala Sekhar DASARI

    2015-07-01

    Full Text Available Single walled carbon nanotubes were functionalized with carboxyl (–COOH group using simple acid treatment process. Thin films of functionalized SWCNTs were fabricated using drop cast technique from the dispersion prepared in de-ionized water. These films were characterized using FE-SEM, FTIR, Raman spectroscopy techniques and current-voltage measurements were carried at room and elevated temperature. SWCNT chemiresistor gas sensor devices on silicon substrate were fabricated using conventional microfabrication technology with pristine and functionalized SWCNTs. Fabricated gas sensors were exposed to ammonia in an in-house developed gas sensor characterization system and response was measured at ammonia concentration up to 50 ppm at room temperature. Functionalized SWCNTs chemiresistor showed an impressive ammonia response of 20.2 % compared with 2.9 % of pristine counterpart. Response enhancement mechanisms are discussed in terms of defects and gas molecule adsorption on CNT surface. The achieved results are a step towards development of miniaturized, room temperature ammonia sensor for environment pollution monitoring and control.

  12. Carbohydrate conjugation through microwave-assisted functionalization of single-walled carbon nanotubes using perfluorophenyl azides.

    Science.gov (United States)

    Kong, Na; Shimpi, Manishkumar R; Ramström, Olof; Yan, Mingdi

    2015-03-20

    Carbohydrate-functionalized single-walled carbon nanotubes (SWNTs) were synthesized using microwave-assisted reaction of perfluorophenyl azide with the nanotubes. The results showed that microwave radiation provides a rapid and effective means to covalently attach carbohydrates to SWNTs, producing carbohydrate-SWNT conjugates for biorecognition. The carbohydrate-functionalized SWNTs were furthermore shown to interact specifically with cognate carbohydrate-specific proteins (lectins), resulting in predicted recognition patterns. The carbohydrate-presenting SWNTs constitute a new platform for sensitive protein- or cell recognition, which pave the way for glycoconjugated carbon nanomaterials in biorecognition applications. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Immobilization of Lipase on Single Walled Carbon Nanotubes in Ionic Liquid

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Han Ki; Lee, Jae Kwan; Kim, Mahn Joo [Pohang University of Science and Technology, Pohang (Korea, Republic of); Lee, Cheol Jin [Korea University, Seoul (Korea, Republic of)

    2010-03-15

    A lipase from Pseudomonas cepacia was immobilized onto single walled carbon nanotubes (SWNTs) in two different ways in each of two solvent systems (buffer and ionic liquid). The most efficient immobilization was achieved in ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate, BMIM-BF4). In this procedure, carbon nanotubes were first functionalized noncovalently with 1-pyrenebutyric acid N-hydroxysuccinimide ester and then subject to the coupling reaction with the lipase in ionic liquid. The resulting immobilized enzyme displayed the highest activity in the transesterification of 1-phenylethyl alcohol in the presence of vinyl acetate in toluene.

  14. Reactivity of cycloparaphenylenes: Studying the possible growth of single-walled carbon nanotubes with DFT methods

    Science.gov (United States)

    Reche-Tamayo, M.; Pérez-Guardiola, A.; Pérez-Jiménez, A. J.; Sancho-García, J. C.

    2018-04-01

    We perform a theoretical study on a set of carbon nanorings (CycloParaPhenylenes or CPP) envisioned as molecular templates for the selective synthesis of carbon nanotubes. The shape of these precursors, originating from bending n phenylene units in para position until forming the corresponding nanoring [n]CPP, may drive the growth of armchair single-walled nanotubes. This kinetic and thermodynamic study covers a set of molecules with different diameters, analyzing the exothermicity and the reaction path of a CPP-based radicaloid mechanism. The methodology employed is based on validated density functionals for mechanistic studies, shedding light on the viability of this synthetic pathway.

  15. Application of electron energy loss spectroscopy for single wall carbon nanotubes (review)

    International Nuclear Information System (INIS)

    Mittal, N.; Jain, S.; Mittal, J.

    2015-01-01

    Electron energy loss spectroscopy (EELS) is among the few techniques that are available for the characterization of modified single wall carbon nanotubes (SWCNTs) having nanometer dimensions (~1-3 nm). CNTs can be modified either by surface functionalization or coating, between bundles of nanotubes by doping, intercalation and fully or partially filling the central core. EELS is an exclusive technique for the identification, composition analysis, and crystallization studies of the chemicals and materials used for the modification of SWCNTs. The present paper serves as a compendium of research work on the application of EELS for the characterization of modified SWCNTs. (authors)

  16. Diameter-dependent bending dynamics of single-walled carbon nanotubes in liquids.

    Science.gov (United States)

    Fakhri, Nikta; Tsyboulski, Dmitri A; Cognet, Laurent; Weisman, R Bruce; Pasquali, Matteo

    2009-08-25

    By relating nanotechnology to soft condensed matter, understanding the mechanics and dynamics of single-walled carbon nanotubes (SWCNTs) in fluids is crucial for both fundamental and applied science. Here, we study the Brownian bending dynamics of individual chirality-assigned SWCNTs in water by fluorescence microscopy. The bending stiffness scales as the cube of the nanotube diameter and the shape relaxation times agree with the semiflexible chain model. This suggests that SWCNTs may be the archetypal semiflexible filaments, highly suited to act as nanoprobes in complex fluids or biological systems.

  17. Quantum ion-acoustic oscillations in single-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Khan, S.A. [Kyoto Univ., Katsura (Japan). Graduate School of Engineering; Quaid-i-Azam Univ., Islamabad (Pakistan). National Centre for Physics; Iqbal, Z. [University of Management and Technology, Sialkot (Pakistan); Wazir, Z. [Riphah International Univ., Islamabad (Pakistan). Dept. of Basic Sciences; Rehman, Aman ur [Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad (Pakistan)

    2016-08-01

    Quantum ion-acoustic oscillations in single-walled carbon nanotubes are studied by employing a quantum hydrodynamics model. The dispersion equation is obtained by Fourier transformation, which exhibits the existence of quantum ion-acoustic wave affected by change of density balance due to presence of positive or negative heavy species as stationary ion clusters and wave potential at equilibrium. The numerical results are presented, and the role of quantum degeneracy, nanotube geometry, electron exchange-correlation effects, and concentration and polarity of heavy species on wave dispersion is pointed out for typical systems of interest.

  18. Quantum Ion-Acoustic Oscillations in Single-Walled Carbon Nanotubes

    Science.gov (United States)

    Khan, S. A.; Iqbal, Z.; Wazir, Z.; Aman-ur-Rehman

    2016-05-01

    Quantum ion-acoustic oscillations in single-walled carbon nanotubes are studied by employing a quantum hydrodynamics model. The dispersion equation is obtained by Fourier transformation, which exhibits the existence of quantum ion-acoustic wave affected by change of density balance due to presence of positive or negative heavy species as stationary ion clusters and wave potential at equilibrium. The numerical results are presented, and the role of quantum degeneracy, nanotube geometry, electron exchange-correlation effects, and concentration and polarity of heavy species on wave dispersion is pointed out for typical systems of interest.

  19. Influence of the structural properties on the pseudocritical magnetic behavior of single-wall ferromagnetic nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Salazar-Enriquez, C.D. [PCM Computational Applications, Universidad Nacional de Colombia - Sede Manizales, A.A. 127 Manizales (Colombia); Restrepo-Parra, E., E-mail: erestrepopa@unal.edu.co [PCM Computational Applications, Universidad Nacional de Colombia - Sede Manizales, A.A. 127 Manizales (Colombia); Restrepo, J. [Grupo de Magnetismo y Simulacion Gplus, Instituto de Fisica, Universidad de Antioquia, A.A. 1226 Medellin (Colombia)

    2012-04-15

    In this work we address the influence of the crystalline structure, concretely when the system under study is formed by square or hexagonal unit cells, upon the magnetic properties and pseudocritical behavior of single-wall ferromagnetic nanotubes. We focus not only on the effect of the geometrical shape of the unit cell but also on their dimensions. The model employed is based on the Monte Carlo method, the Metropolis dynamics and a nearest neighbors classical Heisenberg Hamiltonian. Magnetization per magnetic site, magnetic susceptibility, specific heat and magnetic energy were computed. These properties were computed varying the system size, unit cell dimension and temperature. The dependence of the nearest neighbor exchange integral on the nanotubes geometrical characteristics is also discussed. Results revealed a strong influence of the system topology on the magnetic properties caused by the difference in the coordination number between square and hexagonal unit cell. Moreover, the nanotubes diameter influence on magnetic properties is only observed at very low values, when the distance between atoms is less than it, presented by the 2D sheet. On the other hand, it was concluded that the surface-related finite-size effects do not influence the magnetic nanotubes properties, contrary to the case of other nano-systems as thin films and nanoparticles among others. - Highlights: Black-Right-Pointing-Pointer Unit cell geometry has strong influence on the magnetic properties in ferromagnetic nanotubes. Black-Right-Pointing-Pointer The nanotube diameter increase produces a decrease of interaction between nearest neighbor. Black-Right-Pointing-Pointer Surface-related finite-size effects do not influence the magnetic nanotubes properties.

  20. Realizing one-dimensional quantum and high-frequency transport features in aligned single-walled carbon nanotube ropes

    International Nuclear Information System (INIS)

    Ncube, Siphephile; Chimowa, George; Chiguvare, Zivayi; Bhattacharyya, Somnath

    2014-01-01

    The superiority of the electronic transport properties of single-walled carbon nanotube (SWNT) ropes over SWNT mats is verified from low temperature and frequency-dependent transport. The overall change of resistance versus in nanotube mats shows that 3D variable range hopping is the dominant conduction mechanism within the 2–300 K range. The magneto-resistance (MR) is found to be predominantly negative with a parabolic nature, which can also be described by the hopping model. Although the positive upturn of the MR at low temperatures establishes the contribution from quantum interference, the inherent quantum transport in individual tubes is suppressed at elevated temperatures. Therefore, to minimize multi-channel effects from inter-tube interactions and other defects, two-terminal devices were fabricated from aligned SWNT (extracted from a mat) for low temperature transport as well as high-frequency measurements. In contrast to the mat, the aligned ropes exhibit step-like features in the differential conductance within the 80–300 K temperature range. The effects of plasmon propagation, unique to one dimension, were identified in electronic transport as a non-universal power-law dependence of the differential conductance on temperature and source-drain voltage. The complex impedance showed high power transmission capabilities up to 65 GHz as well as oscillations in the frequency range up to 30 GHz. The measurements suggest that aligned SWNT ropes have a realistic potential for high-speed device applications.

  1. Ultrahigh Carrier Mobility Achieved in Photoresponsive Hybrid Perovskite Films via Coupling with Single-Walled Carbon Nanotubes

    KAUST Repository

    Li, Feng

    2017-02-22

    Organolead trihalide perovskites have drawn substantial interest for photovoltaic and optoelectronic applications due to their remarkable physical properties and low processing cost. However, perovskite thin films suffer from low carrier mobility as a result of their structural imperfections such as grain boundaries and pinholes, limiting their device performance and application potential. Here we demonstrate a simple and straightforward synthetic strategy based on coupling perovskite films with embedded single-walled carbon nanotubes. We are able to significantly enhance the hole and electron mobilities of the perovskite film to record-high values of 595.3 and 108.7 cm(2) V(-1) s(-1) , respectively. Such a synergistic effect can be harnessed to construct ambipolar phototransistors with an ultrahigh detectivity of 3.7 × 10(14) Jones and a responsivity of 1 × 10(4) A W(-1) , on a par with the best devices available to date. The perovskite/carbon nanotube hybrids should provide a platform that is highly desirable for fields as diverse as optoelectronics, solar energy conversion, and molecular sensing.

  2. Recent Developments in Single-Walled Carbon Nanotube Thin Films Fabricated by Dry Floating Catalyst Chemical Vapor Deposition.

    Science.gov (United States)

    Zhang, Qiang; Wei, Nan; Laiho, Patrik; Kauppinen, Esko I

    2017-11-27

    Transparent conducting films (TCFs) are critical components of many optoelectronic devices that pervade modern technology. Due to their excellent optoelectronic properties and flexibility, single-walled carbon nanotube (SWNT) films are regarded as an important alternative to doped metal oxides or brittle and expensive ceramic materials. Compared with liquid-phase processing, the dry floating catalyst chemical vapor deposition (FCCVD) method without dispersion of carbon nanotubes (CNTs) in solution is more direct and simpler. By overcoming the tradeoff between CNT length and solubility during film fabrication, the dry FCCVD method enables production of films that contain longer CNTs and offer excellent optoelectronic properties. This review focuses on fabrication of SWNT films using the dry FCCVD method, covering SWNT synthesis, thin-film fabrication and performance regulation, the morphology of SWNTs and bundles, transparency and conductivity characteristics, random bundle films, patterned films, individual CNT networks, and various applications, especially as TCFs in touch displays. Films based on SWNTs produced by the dry FCCVD method are already commercially available for application in touch display devices. Further research on the dry FCCVD method could advance development of not only industrial applications of CNTs but also the fundamental science of related nanostructured materials and nanodevices.

  3. Theory of energy and power flow of plasmonic waves on single-walled carbon nanotubes

    Science.gov (United States)

    Moradi, Afshin

    2017-10-01

    The energy theorem of electrodynamics is extended so as to apply to the plasmonic waves on single-walled carbon nanotubes which propagate parallel to the axial direction of the system and are periodic waves in the azimuthal direction. Electronic excitations on the nanotube surface are modeled by an infinitesimally thin layer of free-electron gas which is described by means of the linearized hydrodynamic theory. General expressions of energy and power flow associated with surface waves are obtained by solving Maxwell and hydrodynamic equations with appropriate boundary conditions. Numerical results for the transverse magnetic mode show that energy, power flow, and energy transport velocity of the plasmonic waves strongly depend on the nanotube radius in the long-wavelength region.

  4. XPS Protocol for the Characterization of Pristine and Functionalized Single Wall Carbon Nanotubes

    Science.gov (United States)

    Sosa, E. D.; Allada, R.; Huffman, C. B.; Arepalli, S.

    2009-01-01

    Recent interest in developing new applications for carbon nanotubes (CNT) has fueled the need to use accurate macroscopic and nanoscopic techniques to characterize and understand their chemistry. X-ray photoelectron spectroscopy (XPS) has proved to be a useful analytical tool for nanoscale surface characterization of materials including carbon nanotubes. Recent nanotechnology research at NASA Johnson Space Center (NASA-JSC) helped to establish a characterization protocol for quality assessment for single wall carbon nanotubes (SWCNTs). Here, a review of some of the major factors of the XPS technique that can influence the quality of analytical data, suggestions for methods to maximize the quality of data obtained by XPS, and the development of a protocol for XPS characterization as a complementary technique for analyzing the purity and surface characteristics of SWCNTs is presented. The XPS protocol is then applied to a number of experiments including impurity analysis and the study of chemical modifications for SWCNTs.

  5. Solution-phase synthesis of chromium-functionalized single-walled carbon nanotubes

    KAUST Repository

    Kalinina, Irina V.

    2015-03-01

    The solution phase reactions of single-walled carbon nanotubes (SWNTs) with Cr(CO)6 and benzene-Cr(CO)3 can lead to the formation of small chromium clusters. The cluster size can be varied from less than 1 nm to about 4 nm by increasing the reaction time. TEM images suggest that the clusters are deposited predominantly on the exterior walls of the nanotubes. TGA analysis was used to obtain the Cr content and carbon to chromium ratio in the Cr-complexed SWNTs. It is suggested that the carbon nanotube benzenoid structure templates the condensation of chromium atoms and facilitates the loss of carbon monoxide leading to well defined metal clusters.

  6. Energy Band Gap Study of Semiconducting Single Walled Carbon Nanotube Bundle

    Science.gov (United States)

    Elkadi, Asmaa; Decrossas, Emmanuel; El-Ghazaly, Samir

    2013-01-01

    The electronic properties of multiple semiconducting single walled carbon nanotubes (s-SWCNTs) considering various distribution inside a bundle are studied. The model derived from the proposed analytical potential function of electron density for na individual s-SWCNT is general and can be easily applied to multiple nanotubes. This work demonstrates that regardless the number of carbon nanotubes, the strong coupling occurring between the closet neighbors reduces the energy band gap of the bundle by 10%. As expected, the coupling is strongly dependent on the distance separating the s-SWCNTs. In addition, based on the developed model, it is proposed to enhance this coupling effect by applying an electric field across the bundle to significantly reduce the energy band gap of the bundle by 20%.

  7. Acyclic cucurbit[n]uril molecular containers selectively solubilize single-walled carbon nanotubes in water.

    Science.gov (United States)

    Shen, Cai; Ma, Da; Meany, Brendan; Isaacs, Lyle; Wang, YuHuang

    2012-05-02

    Making single-walled carbon nanotubes (SWNTs) soluble in water is a challenging first step to use their remarkable electronic and optical properties in a variety of applications. We report that acyclic cucurbit[n]uril molecular containers 1 and 2 selectively solubilize small-diameter and low chiral angle SWNTs. The selectivity is tunable by increasing the concentration of the molecular containers or by adjusting the ionic strength of the solution. Even at a concentration 1000 times lower than typically required for surfactants, the molecular containers render SWNTs soluble in water. Molecular mechanics simulations suggest that these C-shaped acyclic molecules complex the SWNTs such that a large portion of nanotube sidewalls are exposed to the external environment. These "naked" nanotubes fluoresce upon patching the exposed surface with sodium dodecylbenzene sulfonate. © 2012 American Chemical Society

  8. Transverse electric field–induced deformation of armchair single-walled carbon nanotube

    Directory of Open Access Journals (Sweden)

    Yuan Ningyi

    2010-01-01

    Full Text Available Abstract The deformation of armchair single-walled carbon nanotube under transverse electric field has been investigated using density functional theory. The results show that the circular cross-sections of the nanotubes are deformed to elliptic ones, in which the tube diameter along the field direction is increased, whereas the diameter perpendicular to the field direction is reduced. The electronic structures of the deformed nanotubes were also studied. The ratio of the major diameter to the minor diameter of the elliptic cross-section was used to estimate the degree of the deformation. It is found that this ratio depends on the field strength and the tube diameter. However, the field direction has little role in the deformation. (See supplementary material 1 Electronic supplementary material The online version of this article (doi:10.1007/s11671-010-9617-y contains supplementary material, which is available to authorized users. Click here for file

  9. Interaction between fullerene halves C{sub n} (n ≤ 40) and single wall carbon nanotube

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Amrish, E-mail: amrish99@gmail.com; Kaur, Sandeep, E-mail: sipusukhn@gmail.com [Department of Physics, Punjabi University, Patiala (India); Mudahar, Isha, E-mail: isha@pbi.ac.in [Department of Basic and Applied Sciences, Punjabi University, Patiala (India)

    2016-05-06

    We have investigated the structural and electronic properties of carbon nanotube with small fullerene halves C{sub n} (n ≤ 40) which are covalently bonded to the side wall of an armchair single wall carbon nanotube (SWCNT) using first principle method based on density functional theory. The fullerene size results in weak bonding between fullerene halves and carbon nanotube (CNT). Further, it was found that the C-C bond distance that attaches the fullerene half and CNT is of the order of 1.60 Å. The calculated binding energies indicate the stability of the complexes formed. The HOMO-LUMO gaps and electron density of state plots points towards the metallicity of the complex formed. Our calculations on charge transfer reveal that very small amount of charge is transferred from CNT to fullerene halves.

  10. Purification of Single-Wall carbon nanotubes by heat treatment and supercritical extraction

    Directory of Open Access Journals (Sweden)

    Mariana Bertoncini

    2011-09-01

    Full Text Available Arc discharge is the most practical method for the synthesis of single wall carbon nanotubes (SWCNT. However, the production of SWCNT by this technique has low selectivity and yield, requiring further purification steps. This work is a study of purification of SWCNT by heat treatment in an inert atmosphere followed by supercritical fluid extraction. The raw arc discharge material was first heat-treated at 1250 °C under argon. The nanotubes were further submitted to an extraction process using supercritical CO2 as solvent. A surfactant (tributylphosphate, TBP and a chelating agent (hexafluoroacetylacetone, HFA were used together to eliminate metallic impurities from the remaining arc discharge catalysts. Analysis of Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES showed an efficient removal of iron and cobalt (>80%. The purified nanotubes were further analyzed by TGA and Raman spectroscopy.

  11. Electric field effect on (6,0) zigzag single-walled aluminum nitride nanotube.

    Science.gov (United States)

    Baei, Mohammad T; Peyghan, Ali Ahmadi; Moghimi, Masoumeh

    2012-09-01

    Structural, electronic, and electrical responses of the H-capped (6,0) zigzag single-walled aluminum nitride nanotube was studied under the parallel and transverse electric fields with strengths 0-140 × 10(-4) a.u. by using density functional calculations. Geometry optimizations were carried out at the B3LYP/6-31G* level of theory using a locally modified version of the GAMESS electronic structure program. The dipole moments, atomic charge variations, and total energy of the (6,0) zigzag AlNNT show increases with increase in the applied external electric field strengths. The length, tip diameters, electronic spatial extent, and molecular volume of the nanotube do not significantly change with increasing electric field strength. The energy gap of the nanotube decreases with increases of the electric field strength and its reactivity is increased. Increase of the ionization potential, electron affinity, chemical potential, electrophilicity, and HOMO and LUMO in the nanotube with increase of the applied parallel electric field strengths shows that the parallel field has a much stronger interaction with the nanotube with respect to the transverse electric field strengths. Analysis of the parameters indicates that the properties of AlNNTs can be controlled by the proper external electric field.

  12. Estimating Young’s Modulus of Single-Walled Zirconia Nanotubes Using Nonlinear Finite Element Modeling

    Directory of Open Access Journals (Sweden)

    Ibrahim Dauda Muhammad

    2015-01-01

    Full Text Available The single-walled zirconia nanotube is structurally modeled and its Young’s modulus is valued by using the finite element approach. The nanotube was assumed to be a frame-like structure with bonds between atoms regarded as beam elements. The properties of the beam required for input into the finite element analysis were computed by connecting energy equivalence between molecular and continuum mechanics. Simulation was conducted by applying axial tensile strain on one end of the nanotube while the other end was fixed and the corresponding reaction force recorded to compute Young’s modulus. It was found out that Young’s modulus of zirconia nanotubes is significantly affected by some geometrical parameters such as chirality, diameter, thickness, and length. The obtained values of Young’s modulus for a certain range of diameters are in agreement with what was obtained in the few experiments that have been conducted so far. This study was conducted on the cubic phase of zirconia having armchair and zigzag configuration. The optimal diameter and thickness were obtained, which will assist in designing and fabricating bulk nanostructured components containing zirconia nanotubes for various applications.

  13. Free vibration analysis of single-walled boron nitride nanotubes based on a computational mechanics framework

    Science.gov (United States)

    Yan, J. W.; Tong, L. H.; Xiang, Ping

    2017-12-01

    Free vibration behaviors of single-walled boron nitride nanotubes are investigated using a computational mechanics approach. Tersoff-Brenner potential is used to reflect atomic interaction between boron and nitrogen atoms. The higher-order Cauchy-Born rule is employed to establish the constitutive relationship for single-walled boron nitride nanotubes on the basis of higher-order gradient continuum theory. It bridges the gaps between the nanoscale lattice structures with a continuum body. A mesh-free modeling framework is constructed, using the moving Kriging interpolation which automatically satisfies the higher-order continuity, to implement numerical simulation in order to match the higher-order constitutive model. In comparison with conventional atomistic simulation methods, the established atomistic-continuum multi-scale approach possesses advantages in tackling atomic structures with high-accuracy and high-efficiency. Free vibration characteristics of single-walled boron nitride nanotubes with different boundary conditions, tube chiralities, lengths and radii are examined in case studies. In this research, it is pointed out that a critical radius exists for the evaluation of fundamental vibration frequencies of boron nitride nanotubes; opposite trends can be observed prior to and beyond the critical radius. Simulation results are presented and discussed.

  14. Dielectrophoresis Aligned Single-Walled Carbon Nanotubes as pH Sensors.

    Science.gov (United States)

    Li, Pengfei; Martin, Caleb M; Yeung, Kan Kan; Xue, Wei

    2011-01-31

    Here we report the fabrication and characterization of pH sensors using aligned single-walled carbon nanotubes (SWNTs). The SWNTs are dispersed in deionized (DI) water after chemical functionalization and filtration. They are deposited and organized on silicon substrates with the dielectrophoresis process. Electrodes with "teeth"-like patterns-fabricated with photolithography and wet etching-are used to generate concentrated electric fields and strong dielectrophoretic forces for the SWNTs to deposit and align in desired locations. The device fabrication is inexpensive, solution-based, and conducted at room temperature. The devices are used as pH sensors with the electrodes as the testing pads and the dielectrophoretically captured SWNTs as the sensing elements. When exposed to aqueous solutions with various pH values, the SWNTs change their resistance accordingly. The SWNT-based sensors demonstrate a linear relationship between the sensor resistance and the pH values in the range of 5-9. The characterization of multiple sensors proves that their pH sensitivity is highly repeatable. The real-time data acquisition shows that the sensor response time depends on the pH value, ranging from 2.26 s for the pH-5 solution to 23.82 s for the pH-9 solution. The long-term stability tests illustrate that the sensors can maintain their original sensitivity for a long period of time. The simple fabrication process, high sensitivity, and fast response of the SWNT-based sensors facilitate their applications in a wide range of areas.

  15. Dielectrophoresis Aligned Single-Walled Carbon Nanotubes as pH Sensors

    Directory of Open Access Journals (Sweden)

    Wei Xue

    2011-01-01

    Full Text Available Here we report the fabrication and characterization of pH sensors using aligned single-walled carbon nanotubes (SWNTs. The SWNTs are dispersed in deionized (DI water after chemical functionalization and filtration. They are deposited and organized on silicon substrates with the dielectrophoresis process. Electrodes with “teeth”-like patterns—fabricated with photolithography and wet etching—are used to generate concentrated electric fields and strong dielectrophoretic forces for the SWNTs to deposit and align in desired locations. The device fabrication is inexpensive, solution-based, and conducted at room temperature. The devices are used as pH sensors with the electrodes as the testing pads and the dielectrophoretically captured SWNTs as the sensing elements. When exposed to aqueous solutions with various pH values, the SWNTs change their resistance accordingly. The SWNT-based sensors demonstrate a linear relationship between the sensor resistance and the pH values in the range of 5–9. The characterization of multiple sensors proves that their pH sensitivity is highly repeatable. The real-time data acquisition shows that the sensor response time depends on the pH value, ranging from 2.26 s for the pH-5 solution to 23.82 s for the pH-9 solution. The long-term stability tests illustrate that the sensors can maintain their original sensitivity for a long period of time. The simple fabrication process, high sensitivity, and fast response of the SWNT-based sensors facilitate their applications in a wide range of areas.

  16. ZnO nanotube-based dye-sensitized solar cell and its application in self-powered devices

    KAUST Repository

    Han, Jingbin

    2010-09-10

    Abstract High-density vertically aligned ZnO nanotube arrays were fabricated on FTO substrates by a simple and facile chemical etching process from electrodeposited ZnO nanorods. The nanotube formation was rationalized in terms of selective dissolution of the (001) polar face. The morphology of the nanotubes can be readily controlled by electrodeposition parameters for the nanorod precursor. By employing the 5.1 μm-length nanotubes as the photoanode for a dye-sensitized solar cell (DSSC), a full-sun conversion efficiency of 1.18% was achieved. Furthermore, we show that the DSSC unit can serve as a robust power source to drive a humidity sensor, with a potential for self-powered devices. © 2010 IOP Publishing Ltd.

  17. Ab initio studies of vacancies in (8,0) and (8,8) single-walled carbon and boron nitride nanotubes

    CSIR Research Space (South Africa)

    Mashapa, MG

    2012-09-01

    Full Text Available A systematic study of vacancies in single-walled carbon nanotubes and boron nitride nanotubes was carried out. First principles calculations within the framework of density functional theory using the CASTEP code are used to optimize fully...

  18. PEGylated single-walled carbon nanotubes activate neutrophils to increase production of hypochlorous acid, the oxidant capable of degrading nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Vlasova, Irina I., E-mail: irina.vlasova@yahoo.com [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation); Vakhrusheva, Tatyana V. [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation); Sokolov, Alexey V.; Kostevich, Valeria A. [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation); Research Institute for Experimental Medicine, Russian Academy of Medical Science, Saint Petersburg (Russian Federation); Gusev, Alexandr A.; Gusev, Sergey A. [Research Institute for Physico-Chemical Medicine, Federal Medico-Biological Agency, Moscow (Russian Federation); Melnikova, Viktoriya I. [Institute of Developmental Biology, Russian Academy of Science, Moscow (Russian Federation); Lobach, Anatolii S. [Institute of Problems of Chemical Physics, Russian Academy of Science, Chernogolovka (Russian Federation)

    2012-10-01

    Perspectives for the use of carbon nanotubes in biomedical applications depend largely on their ability to degrade in the body into products that can be easily cleared out. Carboxylated single-walled carbon nanotubes (c-SWCNTs) were shown to be degraded by oxidants generated by peroxidases in the presence of hydrogen peroxide. In the present study we demonstrated that conjugation of poly(ethylene glycol) (PEG) to c-SWCNTs does not interfere with their degradation by peroxidase/H{sub 2}O{sub 2} system or by hypochlorite. Comparison of different heme-containing proteins for their ability to degrade PEG-SWCNTs has led us to conclude that the myeloperoxidase (MPO) product hypochlorous acid (HOCl) is the major oxidant that may be responsible for biodegradation of PEG-SWCNTs in vivo. MPO is secreted mainly by neutrophils upon activation. We hypothesize that SWCNTs may enhance neutrophil activation and therefore stimulate their own biodegradation due to MPO-generated HOCl. PEG-SWCNTs at concentrations similar to those commonly used in in vivo studies were found to activate isolated human neutrophils to produce HOCl. Both PEG-SWCNTs and c-SWCNTs enhanced HOCl generation from isolated neutrophils upon serum-opsonized zymosan stimulation. Both types of nanotubes were also found to activate neutrophils in whole blood samples. Intraperitoneal injection of a low dose of PEG-SWCNTs into mice induced an increase in percentage of circulating neutrophils and activation of neutrophils and macrophages in the peritoneal cavity, suggesting the evolution of an inflammatory response. Activated neutrophils can produce high local concentrations of HOCl, thereby creating the conditions favorable for degradation of the nanotubes. -- Highlights: ► Myeloperoxidase (MPO) product hypochlorous acid is able to degrade CNTs. ► PEGylated SWCNTs stimulate isolated neutrophils to produce hypochlorous acid. ► SWCNTs are capable of activating neutrophils in blood samples. ► Activation of

  19. Modelling of single walled carbon nanotube cylindrical structures with finite element method simulations

    Energy Technology Data Exchange (ETDEWEB)

    Günay, E. [Gazi University, Mechanical Engineering Department, 06570, Ankara (Turkey)

    2016-04-21

    In this study, the modulus of elasticity and shear modulus values of single-walled carbon nanotubes SWCNTs were modelled by using both finite element method and the Matlab code. Initially, cylindrical armchair and zigzag single walled 3D space frames were demonstrated as carbon nanostructures. Thereafter, macro programs were written by the Matlab code producing the space truss for zigzag and armchair models. 3D space frames were introduced to the ANSYS software and then tension, compression and additionally torsion tests were performed on zigzag and armchair carbon nanotubes with BEAM4 element in obtaining the exact values of elastic and shear modulus values. In this study, two different boundary conditions were tested and especially used in torsion loading. The equivalent shear modulus data was found by averaging the corresponding values obtained from ten different nodal points on the nanotube path. Finally, in this study it was determined that the elastic constant values showed proportional changes by increasing the carbon nanotube diameters up to a certain level but beyond this level these values remained stable.

  20. Modelling of single walled carbon nanotube cylindrical structures with finite element method simulations

    Science.gov (United States)

    Günay, E.

    2016-04-01

    In this study, the modulus of elasticity and shear modulus values of single-walled carbon nanotubes SWCNTs were modelled by using both finite element method and the Matlab code. Initially, cylindrical armchair and zigzag single walled 3D space frames were demonstrated as carbon nanostructures. Thereafter, macro programs were written by the Matlab code producing the space truss for zigzag and armchair models. 3D space frames were introduced to the ANSYS software and then tension, compression and additionally torsion tests were performed on zigzag and armchair carbon nanotubes with BEAM4 element in obtaining the exact values of elastic and shear modulus values. In this study, two different boundary conditions were tested and especially used in torsion loading. The equivalent shear modulus data was found by averaging the corresponding values obtained from ten different nodal points on the nanotube path. Finally, in this study it was determined that the elastic constant values showed proportional changes by increasing the carbon nanotube diameters up to a certain level but beyond this level these values remained stable.

  1. Modelling of single walled carbon nanotube cylindrical structures with finite element method simulations

    International Nuclear Information System (INIS)

    Günay, E.

    2016-01-01

    In this study, the modulus of elasticity and shear modulus values of single-walled carbon nanotubes SWCNTs were modelled by using both finite element method and the Matlab code. Initially, cylindrical armchair and zigzag single walled 3D space frames were demonstrated as carbon nanostructures. Thereafter, macro programs were written by the Matlab code producing the space truss for zigzag and armchair models. 3D space frames were introduced to the ANSYS software and then tension, compression and additionally torsion tests were performed on zigzag and armchair carbon nanotubes with BEAM4 element in obtaining the exact values of elastic and shear modulus values. In this study, two different boundary conditions were tested and especially used in torsion loading. The equivalent shear modulus data was found by averaging the corresponding values obtained from ten different nodal points on the nanotube path. Finally, in this study it was determined that the elastic constant values showed proportional changes by increasing the carbon nanotube diameters up to a certain level but beyond this level these values remained stable.

  2. A novel drug delivery of 5-fluorouracil device based on TiO2/ZnS nanotubes.

    Science.gov (United States)

    Faria, Henrique Antonio Mendonça; de Queiroz, Alvaro Antonio Alencar

    2015-11-01

    The structural and electronic properties of titanium oxide nanotubes (TiO2) have attracted considerable attention for the development of therapeutic devices and imaging probes for nanomedicine. However, the fluorescence response of TiO2 has typically been within ultraviolet spectrum. In this study, the surface modification of TiO2 nanotubes with ZnS quantum dots was found to produce a red shift in the ultra violet emission band. The TiO2 nanotubes used in this work were obtained by sol-gel template synthesis. The ZnS quantum dots were deposited onto TiO2 nanotube surface by a micelle-template inducing reaction. The structure and morphology of the resulting hybrid TiO2/ZnS nanotubes were investigated by scanning electron microscopy, transmission electron microscopy and X-ray diffraction techniques. According to the results of fluorescence spectroscopy, pure TiO2 nanotubes exhibited a high emission at 380nm (3.26eV), whereas TiO2/ZnS exhibited an emission at 410nm (3.02eV). The TiO2/ZnS nanotubes demonstrated good bio-imaging ability on sycamore cultured plant cells. The biocompatibility against mammalian cells (Chinese Hamster Ovarian Cells-CHO) suggesting that TiO2/ZnS may also have suitable optical properties for use as biological markers in diagnostic medicine. The drug release characteristic of TiO2/ZnS nanotubes was explored using 5-fluorouracil (5-FU), an anticancer drug used in photodynamic therapy. The results show that the TiO2/ZnS nanotubes are a promising candidate for anticancer drug delivery systems. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Thermal dissipation media for high power electronic devices using a carbon nanotube-based composite

    International Nuclear Information System (INIS)

    Bui, Hung Thang; Nguyen, Van Chuc; Pham, Van Trinh; Ngo, Thi Thanh Tam; Phan, Ngoc Minh

    2011-01-01

    Challenges in the thermal dissipation of an electronic package arise from the continuous increase in power density of higher-power devices. Carbon nanotubes (CNTs) are known as the highest thermal conductivity material (2000 W mK −1 ). This excellent thermal property suggests an approach in applying the CNTs in thermal dispersion materials to solve the aforementioned problems. In this work, we present an effect of thermal dissipation of the CNTs in the high-brightness light emitting diode (HB-LED) and micro-processor. For the thermal dissipation of the HB-LED, a vertically aligned carbon nanotube (VA-CNT) film on a Cu substrate was applied. Meanwhile, for the thermal dissipation of a micro-processor, the composite of commercial thermal paste/CNTs was used instead of the VA-CNTs. The experimental and simulation results have confirmed the advantages of the VA-CNT film and thermal paste/CNT composite as excellent thermal dissipation media for HB-LEDs, μ-processors and other high power electronic devices

  4. Legal implications of single-use medical device reprocessing.

    Science.gov (United States)

    Larose, Emily

    2013-01-01

    Over 10 years ago, the Public Health Agency of Canada released the results of a nation-wide survey of hospitals that demonstrated that the reuse of single-use medical devices was widespread in Canadian healthcare institutions. In this article, the author discusses the reuse and reprocessing of these devices, as well as the risks this practice presents. She then goes on to outline the legal implications of reusing single-use devices. Copyright © 2013 Longwoods Publishing.

  5. Formation of single-walled aluminosilicate nanotubes from molecular precursors and curved nanoscale intermediates.

    Science.gov (United States)

    Yucelen, G Ipek; Choudhury, Rudra Prosad; Vyalikh, Anastasia; Scheler, Ulrich; Beckham, Haskell W; Nair, Sankar

    2011-04-13

    We report the identification and elucidation of the mechanistic role of molecular precursors and nanoscale (1-3 nm) intermediates with intrinsic curvature in the formation of single-walled aluminosilicate nanotubes. We characterize the structural and compositional evolution of molecular and nanoscale species over a length scale of 0.1-100 nm by electrospray ionization mass spectrometry, nuclear magnetic resonance spectroscopy ((27)Al liquid-state, (27)Al and (29)Si solid-state MAS), and dynamic light scattering. Together with structural optimization of key experimentally identified species by solvated density functional theory calculations, this study reveals the existence of intermediates with bonding environments, as well as intrinsic curvature, similar to the structure of the final nanotube product. We show that "proto-nanotube-like" intermediates with inherent curvature form in aqueous synthesis solutions immediately after initial hydrolysis of reactants, disappear from the solution upon heating to 95 °C due to condensation accompanied by an abrupt pH decrease, and finally form ordered single-walled aluminosilicate nanotubes. Detailed quantitative analysis of NMR and ESI-MS spectra from the relevant aluminosilicate, aluminate, and silicate solutions reveals the presence of a variety of monomeric and polymeric aluminate and aluminosilicate species (Al(1)Si(x)-Al(13)Si(x)), such as Keggin ions [AlO(4)Al(12)(OH)(24)(H(2)O)(12)](7+) and polynuclear species with a six-membered Al oxide ring unit. Our study also directly reveals the complexation of aluminate and aluminosilicate species with perchlorate species that most likely inhibit the formation of larger condensates or nontubular structures. Integration of all of our results leads to the construction of the first molecular-level mechanism of single-walled metal oxide nanotube formation, incorporating the role of monomeric and polymeric aluminosilicate species as well as larger nanoparticles. © 2011 American

  6. Stretchable carbon nanotube charge-trap floating-gate memory and logic devices for wearable electronics.

    Science.gov (United States)

    Son, Donghee; Koo, Ja Hoon; Song, Jun-Kyul; Kim, Jaemin; Lee, Mincheol; Shim, Hyung Joon; Park, Minjoon; Lee, Minbaek; Kim, Ji Hoon; Kim, Dae-Hyeong

    2015-05-26

    Electronics for wearable applications require soft, flexible, and stretchable materials and designs to overcome the mechanical mismatch between the human body and devices. A key requirement for such wearable electronics is reliable operation with high performance and robustness during various deformations induced by motions. Here, we present materials and device design strategies for the core elements of wearable electronics, such as transistors, charge-trap floating-gate memory units, and various logic gates, with stretchable form factors. The use of semiconducting carbon nanotube networks designed for integration with charge traps and ultrathin dielectric layers meets the performance requirements as well as reliability, proven by detailed material and electrical characterizations using statistics. Serpentine interconnections and neutral mechanical plane layouts further enhance the deformability required for skin-based systems. Repetitive stretching tests and studies in mechanics corroborate the validity of the current approaches.

  7. Adsorption of sodium dodecylsulfate on single-walled carbon nanotubes characterised using small-angle neutron scattering.

    Science.gov (United States)

    Kastrisianaki-Guyton, E S; Chen, L; Rogers, S E; Cosgrove, T; van Duijneveldt, J S

    2016-06-15

    Aqueous dispersions of single-walled carbon nanotubes are often made using sodium dodecylsulfate (SDS), which adsorbs to the nanotube surface to stabilise them. Despite SDS being commonly used with single-walled carbon nanotubes, there is no consensus on the structure of the adsorbed layer. Small-angle neutron and X-ray scattering results reported here show that the data can be fitted to a relatively simple core-shell cylinder model, consistent with a polydisperse nanotube core of radius 10Å, surrounded by an adsorbed surfactant layer of thickness 18Å and volume fraction of 0.5. This is consistent with small nanotube bundles surrounded by an adsorbed layer of extended SDS molecules. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  8. Poly(vinylidene fluoride)-functionalized single-walled carbon nanotubes for the preparation of composites with improved conductivity

    NARCIS (Netherlands)

    Vukićević, R.; Vukovic, I.; Stoyanov, H.; Korwitz, A.; Pospiech, D.; Kofod, G.; Loos, K.; Brinke, G. ten; Beuermann, S.

    2012-01-01

    The surface of single-walled carbon nanotubes (SWCNTs) was functionalized with azide-terminated poly(vinylidene fluoride) (PVDF). Functionalization was confirmed by dispersibility, Raman spectroscopy, and thermogravimetric analyses. Raman spectra show disordering of the SWCNTs, thus, strongly

  9. Electrocatalytic oxidation of diethylaminoethanethiol and hydrazine at single-walled carbon nanotubes modified with prussian blue nanoparticles

    CSIR Research Space (South Africa)

    Adekunle, AS

    2010-11-01

    Full Text Available In this work, edged plane pyrolytic graphite electrode EPPGE was modified with functionalised single-walled carbon nanotubes and Prussian blue nanoparticles (PB). The modified electrode was characterised by techniques such as TEM, FTIR, XPS, EDX...

  10. Effects of functionalization on thermal properties of single-wall and multi-wall carbon nanotube-polymer nanocomposites.

    Science.gov (United States)

    Gulotty, Richard; Castellino, Micaela; Jagdale, Pravin; Tagliaferro, Alberto; Balandin, Alexander A

    2013-06-25

    Carboxylic functionalization (-COOH groups) of carbon nanotubes is known to improve their dispersion properties and increase the electrical conductivity of carbon-nanotube-polymer nanocomposites. We have studied experimentally the effects of this type of functionalization on the thermal conductivity of the nanocomposites. It was found that while even small quantities of carbon nanotubes (~1 wt %) can increase the electrical conductivity, a larger loading fraction (~3 wt %) is required to enhance the thermal conductivity of nanocomposites. Functionalized multi-wall carbon nanotubes performed the best as filler material leading to a simultaneous improvement of the electrical and thermal properties of the composites. Functionalization of the single-wall carbon nanotubes reduced the thermal conductivity enhancement. The observed trends were explained by the fact that while surface functionalization increases the coupling between carbon nanotube and polymer matrix, it also leads to formation of defects, which impede the acoustic phonon transport in the single-wall carbon nanotubes. The obtained results are important for applications of carbon nanotubes and graphene flakes as fillers for improving thermal, electrical and mechanical properties of composites.

  11. Raman-active modes in homogeneous and inhomogeneous bundles of single-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Sbai, K; Rahmani, A; Chadli, H [Laboratoire de Physique des materiaux et Modelisation des Systemes, Universite Moulay Ismail, Faculte des Sciences, BP 11201, Zitoune, 50000 Meknes (Morocco); Sauvajol, J-L [Laboratoire des Colloides, Verres et Nanomateriaux (UMR CNRS 5587), Universite Montpellier II, F-34095 Montpellier Cedex 5 (France)], E-mail: rahmani@fs-umi.ac.ma

    2009-01-28

    In the present work, the non-resonant Raman-active modes are calculated for several diameters, chiralities and sizes for homogeneous and inhomogeneous bundles of single-walled carbon nanotubes (BWCNTs), using the spectral moment's method (SMM). Additional intense Raman-active modes are present in the breathing-like modes (BLM) spectra of these systems in comparison with a single fully symmetric A{sub 1g} mode characteristic of isolated nanotubes (SWCNTs). The dependence of the wavenumber of these modes in terms of diameters, lengths and number of tubes was investigated. We found that, for a finite (in)homogeneous bundle, additional breathing-like modes appear as a specific signature.

  12. Electrochemical impedance-based DNA sensor using a modified single walled carbon nanotube electrode

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Jessica E. [Department of Mechanical Engineering, University of South Florida, Tampa, FL (United States); Nanomaterials and Nanomanufacturing Research Center, University of South Florida, Tampa, FL (United States); Pillai, Shreekumar [Center for NanoBiotechnology Research, Alabama State University, Montgomery, AL (United States); Ram, Manoj Kumar, E-mail: mkram@usf.edu [Department of Mechanical Engineering, University of South Florida, Tampa, FL (United States); Nanomaterials and Nanomanufacturing Research Center, University of South Florida, Tampa, FL (United States); Kumar, Ashok [Department of Mechanical Engineering, University of South Florida, Tampa, FL (United States); Nanomaterials and Nanomanufacturing Research Center, University of South Florida, Tampa, FL (United States); Singh, Shree R. [Center for NanoBiotechnology Research, Alabama State University, Montgomery, AL (United States)

    2011-07-20

    Carbon nanotubes have become promising functional materials for the development of advanced electrochemical biosensors with novel features which could promote electron-transfer with various redox active biomolecules. This paper presents the detection of Salmonella enterica serovar Typhimurium using chemically modified single walled carbon nanotubes (SWNTs) with single stranded DNA (ssDNA) on a polished glassy carbon electrode. Hybridization with the corresponding complementary ssDNA has shown a shift in the impedance studies due to a higher charge transfer in ssDNA. The developed biosensor has revealed an excellent specificity for the appropriate targeted DNA strand. The methodologies to prepare and functionalize the electrode could be adopted in the development of DNA hybridization biosensor.

  13. Non-radiative Exciton Decay in Single-walled Carbon Nanotubes

    Science.gov (United States)

    Harrah, Mark; Swan, Anna

    2010-03-01

    Experiments have shown step-wise changes in the fluorescence intensity from single-walled carbon nanotubes [1,2]. It has been proposed that the underlying mechanism for the step-wise changes is diffusion-limited quenching of excitons at defects [1]. This property has been used to demonstrate single-molecule detection for biological applications [3]. We perform a Monte-Carlo simulation of nanotube fluorescence with a diffusion-limited quenching model. The fluorescence intensity is seen to depend on the mean-square distance between defects, implying a nonlinear dependence on the number of defects. The intensity for consecutive defect counts can overlap depending on the positions of the defects. [4pt] [1] Cognet, L. et al. Science 316, 1465-1468 (2007).[0pt] [2] Jin, H. et al. Nano Lett. 8, 4299-4304 (2008).[0pt] [3] Heller, D. A. et al. Nature Nanotech. 4, 114-120 (2009).

  14. Stable double helical iodine chains inside single-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Zhen [College of Science, Liaoning University of Technology, Jinzhou, Liaoning, 121001 (China); Liu, Chun-Jian [College of Mathematics and Physics, Bohai University, Jinzhou, Liaoning, 121000 (China); Lv, Hang [Institute of New Energy, Bohai University, Jinzhou, Liaoning, 121000 (China); Liu, Bing-Bing, E-mail: liubb@jlu.edu.cn [State Key Laboratory of Superhard Materials, Jilin University, Changchun, 130012 (China)

    2016-08-12

    The helicity of stable double helical iodine chains inside single-walled carbon nanotubes (SWCNTs) is studied by calculating the systematic interaction energy. Our results present clear images of stable double helical structures inside SWCNTs. The optimum helical radius and helical angle increase and decrease with increasing diameter, respectively. The tube's diameter plays a leading role in the helicity of encapsulated structures, while the tube's chirality may induce different metastable structures. This study indicates that the observed double helical iodine chains in experiments are not necessarily the optimum structures, but may also be metastable structures. - Highlights: • The stable double helical iodine chain inside single-walled carbon nanotubes is proposed. • The influence of tube's diameter and chirality on the stability of encapsulated iodine chains is studied. • The metastable double helical structures may be co-existence with the stable structure but not in the same tubes.

  15. Spin-curvature interaction from curved Dirac equation: Application to single-wall carbon nanotubes

    Science.gov (United States)

    Zhang, Kai; Zhang, Erhu; Chen, Huawei; Zhang, Shengli

    2017-06-01

    The spin-curvature interaction (SCI) and its effects are investigated based on curved Dirac equation. Through the low-energy approximation of curved Dirac equation, the Hamiltonian of SCI is obtained and depends on the geometry and spinor structure of manifold. We find that the curvature can be considered as field strength and couples with spin through Zeeman-like term. Then, we use dimension reduction to derive the local Hamiltonian of SCI for cylinder surface, which implies that the effective Hamiltonian of single-wall carbon nanotubes results from the geometry and spinor structure of lattice and includes two types of interactions: one does not break any symmetries of the lattice and only shifts the Dirac points for all nanotubes, while the other one does and opens the gaps except for armchair nanotubes. At last, analytical expressions of the band gaps and the shifts of their positions induced by curvature are given for metallic nanotubes. These results agree well with experiments and can be verified experimentally.

  16. Defects in individual semiconducting single wall carbon nanotubes: Raman spectroscopic and in situ Raman spectroelectrochemical study.

    Science.gov (United States)

    Kalbac, Martin; Hsieh, Ya-Ping; Farhat, Hootan; Kavan, Ladislav; Hofmann, Mario; Kong, Jing; Dresselhaus, Mildred S

    2010-11-10

    Raman spectroscopy and in situ Raman spectroelectrochemistry have been used to study the influence of defects on the Raman spectra of semiconducting individual single-walled carbon nanotubes (SWCNTs). The defects were created intentionally on part of an originally defect-free individual semiconducting nanotube, which allowed us to analyze how defects influence this particular nanotube. The formation of defects was followed by Raman spectroscopy that showed D band intensity coming from the defective part and no D band intensity coming from the original part of the same nanotube. It is shown that the presence of defects also reduces the intensity of the symmetry-allowed Raman features. Furthermore, the changes to the Raman resonance window upon the introduction of defects are analyzed. It is demonstrated that defects lead to both a broadening of the Raman resonance profile and a decrease in the maximum intensity of the resonance profile. The in situ Raman spectroelectrochemical data show a doping dependence of the Raman features taken from the defective part of the tested SWCNT.

  17. Poly(ethylene oxide) Crystallization in Single Walled Carbon Nanotube Based Nanocomposites: Kinetics and Structural Consequences

    Energy Technology Data Exchange (ETDEWEB)

    T Chatterjee; A Lorenzo; R Krishnamoorti

    2011-12-31

    The overall isothermal crystallization behavior of poly(ethylene oxide) (PEO) in single walled carbon nanotube (SWNT) based nanocomposites is studied with a focus on growth kinetics and morphological evolution of PEO using differential scanning calorimetry and in-situ small angle x-ray scattering measurements respectively. The characteristic time for crystallization of PEO increases due to the presence of lithium dodecyl sulfate (LDS) stabilized carbon nanotubes. Further, analysis of crystallization data using the Lauritzen-Hoffman regime theory of crystal growth shows the PEO chains stiffen in presence of LDS with an increased energy barrier associated with the nucleation and crystal growth, and the nanotubes further act as a barrier to chain transport or enhance the efficacy of the LDS action. The energy penalty and diffusional barrier to chain transport in the nanocomposites disrupt the crystalline PEO helical conformation. This destabilization leads to preferential growth of local nuclei resulting in formation of thinner crystal lamellae and suggests that the crystallization kinetics is strongly affected by the nucleation and crystal growth events. This study is particularly interesting considering the suppression of the PEO crystallinity in presence of small fraction of Lithium ion based surfactant and carbon nanotubes.

  18. Viscosity and Morphology Modification of Length Sorted Single-Walled Carbon Nanotubes in PIB Matrices

    Directory of Open Access Journals (Sweden)

    Hanxiao Huang

    2017-01-01

    Full Text Available This work evaluates the effectiveness of nanoscale particulates in producing non-Einstein-like responses in polymer matrices, to reduce their negative effects in low shear rate processing. This is of value to material processing applications which encompass extrusion, flow into cold mold, and generalized processing of nanocomposites. Through control and understanding of the structure processing relationships entailed through nanoscale additive materials, we begin to manage dispersion characteristics for more reliable and defect-free product development. In pursuit of identifying system characteristics that produce non-Einstein-like responses we isolate and characterize homogenous fractions of single-walled carbon nanotubes (SWNTs with singular lengths. This enables the definition of a well-defined nanoscale particulate phase, within the polymer matrices. The effect of nanotube length and weight fraction on the polyisobutylene (PIB matrices was evaluated with thermal and rheological testing. Our findings show that the viscosity of the produced nanocomposite systems has a length dependence and does not demonstrate the expected monotonous increases in the viscosity with an increase in weight fraction of nanotube additive within the matrix, demonstrating a non-Einstein-like viscosity response. Furthermore, we demonstrate length dependent crystallization in the studied systems, as an intermediate length nanotube initiates crystallization of polyisobutylene (PIB affecting viscosity and mechanical properties.

  19. Antimicrobial Activity of Single-Walled Carbon Nanotubes Suspended in Different Surfactants

    Directory of Open Access Journals (Sweden)

    Lifeng Dong

    2012-01-01

    Full Text Available We investigated the antibacterial activity of single-walled carbon nanotubes (SWCNTs dispersed in surfactant solutions of sodium cholate, sodium dodecylbenzene sulfonate, and sodium dodecyl sulfate. Among the three surfactants, sodium cholate demonstrated the weakest antibacterial activity against Salmonella enterica, Escherichia coli, and Enterococcus faecium and thereby was used to disperse bundled SWCNTs in order to study nanotube antibiotic activity. SWCNTs exhibited antibacterial characteristics for both S. enterica and E. coli. With the increase of nanotube concentrations from 0.3 mg/mL to 1.5 mg/mL, the growth curves had plateaus at lower absorbance values whereas the absorbance value was not obviously affected by the incubation ranging from 5 min to 2 h. Our findings indicate that carbon nanotubes could become an effective alternative to antibiotics in dealing with drug-resistant and multidrug-resistant bacterial strains because of the physical mode of bactericidal action that SWCNTs display.

  20. Isotherm, thermodynamic, kinetics, and adsorption mechanism studies of Ethidium bromide by single-walled carbon nanotube and carboxylate group functionalized single-walled carbon nanotube.

    Science.gov (United States)

    Moradi, Omid; Fakhri, Ali; Adami, Saeideh; Adami, Sepideh

    2013-04-01

    The studies of kinetics and thermodynamics of adsorption of Ethidium bromide in aqueous solutions on single-walled carbon nanotube (SWCNT) and carboxylate group functionalized single-walled carbon nanotube (SWCNT-COOH) surfaces were by UV-Vis spectroscopy. The adsorption kinetics for SWCNT-COOH and SWCNTs were well described by a intra-particle diffusion model, while Langmuir, Freundlich, Harkins-Jura, and Halsey isotherms described the adsorption isotherms, and the adsorption thermodynamic parameters of equilibrium constant (K0), standard free energy (ΔG0), standard enthalpy (ΔH0), and standard entropy changes (ΔS0) were measured. The maximum surface coverage for SWCNTs is 36.10% and for SWCNT-COOH is 38.42%. The values of ΔH0 and ΔG0 suggested that the adsorption of EtBr on SWCNT-COOH and SWCNTs was endothermic and spontaneous. The adsorption of EtBr on SWCNT-COOH is more than SWCNTs surfaces. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. A Forest of Sub-1.5-nm-wide Single-Walled Carbon Nanotubes over an Engineered Alumina Support

    Science.gov (United States)

    Yang, Ning; Li, Meng; Patscheider, Jörg; Youn, Seul Ki; Park, Hyung Gyu

    2017-04-01

    A precise control of the dimension of carbon nanotubes (CNTs) in their vertical array could enable many promising applications in various fields. Here, we demonstrate the growth of vertically aligned, single-walled CNTs (VA-SWCNTs) with diameters in the sub-1.5-nm range (0.98 ± 0.24 nm), by engineering a catalyst support layer of alumina via thermal annealing followed by ion beam treatment. We find out that the ion beam bombardment on the alumina allows the growth of ultra-narrow nanotubes, whereas the thermal annealing promotes the vertical alignment at the expense of enlarged diameters; in an optimal combination, these two effects can cooperate to produce the ultra-narrow VA-SWCNTs. According to micro- and spectroscopic characterizations, ion beam bombardment amorphizes the alumina surface to increase the porosity, defects, and oxygen-laden functional groups on it to inhibit Ostwald ripening of catalytic Fe nanoparticles effectively, while thermal annealing can densify bulk alumina to prevent subsurface diffusion of the catalyst particles. Our findings contribute to the current efforts of precise diameter control of VA-SWCNTs, essential for applications such as membranes and energy storage devices.

  2. Investigation of Chirality Selection Mechanism of Single-Walled Carbon Nanotube

    Science.gov (United States)

    2015-07-17

    strong fibers [6, 7], membranes [8], and super - capacitor electrodes [9] have been proposed and demonstrated in a laboratory environment. However, the...Hatori, M. Yumura, and S. Iijima, “Shape-engineerable and highly densely packed single-walled carbon nanotubes and their application as super ... capacitor electrodes,” Nature Mater. 5, 987 (2006). [10] Y. Li, D. Mann, M. Rolandi, W. Kim, A. Ural, S. Hung, A. Javey, J. Cao, D. Dunwei, E. Yenilmez

  3. Investigation of Chirality Selection Mechanism of Single Walled Carbon Nanotube-3

    Science.gov (United States)

    2017-12-14

    paper as a result of the grant titled: Synthesis of CNT forest with narrow diameter distribution from the Fe ion implanted wafer, Carbon , vol. 123, pp...Jin Park, Seung Min Kim*, and Kun-Hong Lee*, “Synthesis of CNT forest with narrow diameter distribution from the Fe ion implanted wafer”, Carbon ...AFRL-AFOSR-JP-TR-2017-0078 Investigation of Chirality Selection Mechanism of Single-Walled Carbon Nanotube-3 Seun Min Kim KOREA INSTITUTE OF SCIENCE

  4. Single- and Multiwalled Carbon Nanotubes with Phosphorus Based Flame Retardants for Textiles

    OpenAIRE

    D. Wesolek; W. Gieparda

    2014-01-01

    Due to growing popularity of composites, modification methods to obtain the best properties are searched for. The aim of the study is to reduce the flammability of textile materials using nanocomposite polymer back-coating. Different types of carbon nanotubes (single- and multiwalled) and different phosphorus flame retardants (ammonium polyphosphates and melamine polyphosphate) were introduced into the resin and then the fabrics were covered by the obtained composites. Homogeneous dispersion ...

  5. Dynamic Raman Spectroelectrochemistry of Single Walled Carbon Nanotubes modified electrodes using a Langmuir-Schaefer method

    OpenAIRE

    Ibáñez, David; Romero, Edna Cecilia; Colina, Álvaro; Heras, Aránzazu

    2014-01-01

    Raman spectroelectrochemistry is a fundamental technique to characterize single walled carbon nanotube (SWCNT) films. In this work, we have performed the study of SWCNT films transferred to a glassy carbon electrode using a Langmuir-Schaefer method. Langmuir balance has allowed us to control the characteristics of the film that can be easily transferred to the electrode support. Time-resolved Raman spectroelectrochemistry experiments at scan rates between 20 and 400 mV s−1 were done in two di...

  6. The Effects of Single-Wall Carbon Nanotubes on the Shear Piezoelectricity of Biopolymers

    Science.gov (United States)

    Lovell, Conrad; Fitz-Gerald, James M.; Harrison, Joycelyn S.; Park, Cheol

    2008-01-01

    Shear piezoelectricity was investigated in a series of composites consisting of increased loadings of single-wall carbon nanotubes (SWCNTs) in poly (gamma-benzyl-L-glutamate), or PBLG. The effects of the SWCNTs on this material property in PBLG will be discussed. Their influence on the morphology of the polymer (degree of orientation and crystallinity), and electrical and dielectric properties of the composite will be reported

  7. Alignment characterization of single-wall carbon nanotubes by Raman scattering

    International Nuclear Information System (INIS)

    Liu Pijun; Liu Liyue; Zhang Yafei

    2003-01-01

    A novel method for identifying the Raman modes of single-wall carbon nanotubes (SWNT) based on the symmetry of the vibration modes has been studied. The Raman intensity of each vibration mode varies with polarization direction, and the relationship can be expressed as analytical functions. This method avoids troublesome numerical calculation and easily gives clear relations between Raman intensity and polarization direction. In this way, one can distinguish each Raman-active mode of SWNT through the polarized Raman spectrum

  8. Structure and Characterization of Vertically Aligned Single-Walled Carbon Nanotube Bundles

    International Nuclear Information System (INIS)

    Marquez, F.; Morant, C.; Elizalde, E.; Roque-Malherbe, R.; Lopez, V.; Zamora, F.; Domingo, C.

    2010-01-01

    Arrays of vertically aligned single-walled carbon nanotube bundles, SWCNTs, have been synthesized by simple alcohol catalytic chemical vapor deposition process, carried out at 800 degree C. The formed SWCNTs are organized in small groups perpendicularly aligned and attached to the substrate. These small bundles show a constant diameter of ca. 30 nm and are formed by the adhesion of no more than twenty individual SWCNTs perfectly aligned along their length.

  9. Photodoping and enhanced visible light absorption in single-walled carbon nanotubes functionalized with a wide band gap oligomer.

    Science.gov (United States)

    Bunes, Benjamin R; Xu, Miao; Zhang, Yaqiong; Gross, Dustin E; Saha, Avishek; Jacobs, Daniel L; Yang, Xiaomei; Moore, Jeffrey S; Zang, Ling

    2015-01-07

    Carbon nanotubes feature excellent electronic properties but narrow absorption bands limit their utility in certain optoelectronic devices, including photovoltaic cells. Here, the addition of a wide-bandgap gap oligomer enhances light absorption in the visible spectrum. Furthermore, the oligomer interacts with the carbon nanotube through a peculiar charge transfer, which provides insight into Type II heterojunctions. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Device physics of single layer organic light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Crone, B.K.; Campbell, I.H.; Davids, P.S.; Smith, D.L. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Neef, C.J.; Ferraris, J.P. [The University of Texas at Dallas, Richardson, Texas 75080 (United States)

    1999-11-01

    We present experimental and device model results for electron only, hole only, and bipolar organic light-emitting diodes fabricated using a soluble poly ({ital p}-phenylene vinylene) based polymer. Current{endash}voltage (I{endash}V) characteristics were measured for a series of electron only devices in which the polymer thickness was varied. The I{endash}V curves were described using a device model from which the electron mobility parameters were extracted. Similarly, the hole mobility parameters were extracted using a device model description of I{endash}V characteristics for a series of hole only devices where the barrier to hole injection was varied by appropriate choices of hole injecting electrode. The electron and hole mobilities extracted from the single carrier devices are then used, without additional adjustable parameters, to describe the measured current{endash}voltage characteristics of a series of bipolar devices where both the device thickness and contacts were varied. The model successfully describes the I{endash}V characteristics of single carrier and bipolar devices as a function of polymer thickness and for structures that are contact limited, space charge limited, and for cases in between. We find qualitative agreement between the device model and measured external luminance for a thickness series of devices. We investigate the sensitivity of the device model calculations to the magnitude of the bimolecular recombination rate prefactor. {copyright} {ital 1999 American Institute of Physics.}

  11. Single and competitive adsorption of OMPs by carbon nanotubes - mechanism and fitting models

    Science.gov (United States)

    Kamińska, Gabriela; Dudziak, Mariusz; Bohdziewicz, Jolanta; Kudlek, Edyta

    2017-11-01

    The adsorption of three organic micropollutants (diclofenac - DFN, pentachlorophenol - PCP and octylphenol - OP) on two kinds of carbon nanotubes (single walled carbon nanotubes - SWCNT and single walled carbon nanotubes with amine group - SWCNT-NH2) was investigated, in single and bicomponent solution at pH 5. SWCNT-NH2 had three times lower specific surface area than SWCNT. Significant differences were observed in sorption capacity of SWCNT and SWCNT-NH2 for given chemicals. The sorption uptake changes in the following order: OP > PCP > DFN for SWCNT and DFN > PCP > OP for SWCNT-NH2. A few times higher adsorption of OP on SWCNT came from low OP solubility in water in comparison to PCP and DFN. While, higher adsorption of DFN and PCP on SWCNT-NH2 was a result of electrostatic attraction between dissociated form of these chemicals and positively charged SWCNT-NH2 at pH 5. In adsorption from bicomponent solution, significant competition was observed between PCP and DFN due to similar adsorption mechanism on SWCNT-NH2. Opposite tendency was observed for SWCNT, DFN did not greatly affect adsorption of PCP and OP since they were very easily absorbable by sigma-sigma interaction.

  12. Single and competitive adsorption of OMPs by carbon nanotubes – mechanism and fitting models

    Directory of Open Access Journals (Sweden)

    Kamińska Gabriela

    2017-01-01

    Full Text Available The adsorption of three organic micropollutants (diclofenac – DFN, pentachlorophenol – PCP and octylphenol – OP on two kinds of carbon nanotubes (single walled carbon nanotubes – SWCNT and single walled carbon nanotubes with amine group – SWCNT-NH2 was investigated, in single and bicomponent solution at pH 5. SWCNT-NH2 had three times lower specific surface area than SWCNT. Significant differences were observed in sorption capacity of SWCNT and SWCNT-NH2 for given chemicals. The sorption uptake changes in the following order: OP > PCP > DFN for SWCNT and DFN > PCP > OP for SWCNT-NH2. A few times higher adsorption of OP on SWCNT came from low OP solubility in water in comparison to PCP and DFN. While, higher adsorption of DFN and PCP on SWCNT-NH2 was a result of electrostatic attraction between dissociated form of these chemicals and positively charged SWCNT-NH2 at pH 5. In adsorption from bicomponent solution, significant competition was observed between PCP and DFN due to similar adsorption mechanism on SWCNT-NH2. Opposite tendency was observed for SWCNT, DFN did not greatly affect adsorption of PCP and OP since they were very easily absorbable by sigma-sigma interaction.

  13. A Hydrogel/Carbon-Nanotube Needle-Free Device for Electrostimulated Skin Drug Delivery.

    Science.gov (United States)

    Guillet, Jean-François; Flahaut, Emmanuel; Golzio, Muriel

    2017-10-06

    The permeability of skin allows passive diffusion across the epidermis to reach blood vessels but this is possible only for small molecules such as nicotine. In order to achieve transdermal delivery of large molecules such as insulin or plasmid DNA, permeability of the skin and mainly the permeability of the stratum corneum skin layer has to be increased. Moreover, alternative routes that avoid the use of needles will improve the quality of life of patients. A method known as electropermeabilisation has been shown to increase skin permeability. Herein, we report the fabrication of an innovative hydrogel made of a nanocomposite material. This nanocomposite device aims to permeabilise the skin and deliver drug molecules at the same time. It includes a biocompatible polymer matrix (hydrogel) and double-walled carbon nanotubes (DWCNTs) in order to bring electrical conductivity and improve mechanical properties. Carbon nanotubes and especially DWCNTs are ideal candidates, combining high electrical conductivity with a very high specific surface area together with a good biocompatibility when included into a material. The preparation and characterization of the nanocomposite hydrogel as well as first results of electrostimulated transdermal delivery using an ex vivo mouse skin model are presented. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Doped Halloysite Nanotubes for Use in the 3D Printing of Medical Devices

    Directory of Open Access Journals (Sweden)

    Jeffery A. Weisman

    2017-12-01

    Full Text Available Previous studies have established halloysite nanotubes (HNTs as viable nanocontainers capable of sustained release of a variety of antibiotics, corrosion agents, chemotherapeutics and growth factors either from their lumen or in outer surface coatings. Accordingly, halloysite nanotubes (HNTs hold great promise as drug delivery carriers in the fields of pharmaceutical science and regenerative medicine. This study explored the potential of 3D printing drug doped HNT constructs. We used a model drug, gentamicin (GS and polylactic acid (PLA to fabricate GS releasing disks, beads, and pellets. Gentamicin was released from 3D printed constructs in a sustained manner and had a superior anti-bacterial growth inhibition effect that was dependent on GS doping concentration. While this study focused on a model drug, gentamicin, combination therapy is possible through the fabrication of medical devices containing HNTs doped with a suite of antibiotics or antifungals. Furthermore, tailored dosage levels, suites of antimicrobials, delivered locally would reduce the toxicity of individual agents, prevent the emergence of resistant strains, and enable the treatment of mixed infections.

  15. Reduced graphene oxide and vertically aligned carbon nanotubes superhydrophilic films for supercapacitors devices

    Energy Technology Data Exchange (ETDEWEB)

    Zanin, H., E-mail: hudsonzanin@gmail.com [Associated Laboratory of Sensors and Materials of the National Institute for Space Research, Av. dos Astronautas 1758, Sao Jose dos Campos CEP 12227-010, SP (Brazil); Departamento de Semicondutores, Instrumentos e Fotônica, Faculdade de Engenharia Elétrica e Computação, Universidade Estadual de Campinas, UNICAMP, Campinas 13083-970 (Brazil); Saito, E., E-mail: esaito135@gmail.com [Associated Laboratory of Sensors and Materials of the National Institute for Space Research, Av. dos Astronautas 1758, Sao Jose dos Campos CEP 12227-010, SP (Brazil); Ceragioli, H.J., E-mail: helderjc@gmail.com [Departamento de Semicondutores, Instrumentos e Fotônica, Faculdade de Engenharia Elétrica e Computação, Universidade Estadual de Campinas, UNICAMP, Campinas 13083-970 (Brazil); Baranauskas, V., E-mail: vitor@dsif.fee.unicamp.br [Departamento de Semicondutores, Instrumentos e Fotônica, Faculdade de Engenharia Elétrica e Computação, Universidade Estadual de Campinas, UNICAMP, Campinas 13083-970 (Brazil); Corat, E.J., E-mail: corat@las.inpe.br [Associated Laboratory of Sensors and Materials of the National Institute for Space Research, Av. dos Astronautas 1758, Sao Jose dos Campos CEP 12227-010, SP (Brazil)

    2014-01-01

    Graphical abstract: - Highlights: • Graphene nanosheets were produced onto wire rods. • RGO and VACNT-O were evaluated and compared as supercapacitor electrode. • RGO and VACNT-O have structural and electrochemical properties quite similars. • The materials present good specific capacitance, energy storage and power delivery. - Abstract: Reduced graphene oxide (RGO) and vertically aligned carbon nanotubes (VACNT) superhydrophilic films were prepared by chemical vapor deposition techniques for electrical energy storage investigations. These electrodes were characterized in terms of their material and electrochemical properties by scanning electron microscopy (SEM), surface wettability, Fourier transform infrared spectroscopy (FTIR), energy dispersive and Raman spectroscopies, cyclic voltammetry (CV) and galvanostatic charge–discharge. We observed several physical structural and electrochemical similarities between these carbon-based materials with particular attention to very good specific capacitance, ultra-high energy storage and fast power delivery. Our results showed that the main difference between specific capacitance values is attributed to pseudocapacitive contribution and high density of multiwall nanotubes tips. In this work we have tested a supercapacitor device using the VACNT electrodes.

  16. A novel drug delivery of 5-fluorouracil device based on TiO{sub 2}/ZnS nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Mendonça Faria, Henrique Antonio, E-mail: henrique.fisica@ifsc.usp.br [Institute of Physics and Chemistry, Federal University of Itajubá (UNIFEI), Av. BPS, 1303, Pinheirinho, Itajubá, MG, PO Box 50, CEP: 37500-903 (Brazil); Nanomedicine and Nanotoxicology Laboratory, São Carlos Institute of Physics, University of São Paulo. Av. Trabalhador São-carlense, 400, Arnold Schimidt, São Carlos, SP CEP: 13566-590 (Brazil); Alencar de Queiroz, Alvaro Antonio, E-mail: alencar@unifei.edu.br [Institute of Physics and Chemistry, Federal University of Itajubá (UNIFEI), Av. BPS, 1303, Pinheirinho, Itajubá, MG, PO Box 50, CEP: 37500-903 (Brazil)

    2015-11-01

    The structural and electronic properties of titanium oxide nanotubes (TiO{sub 2}) have attracted considerable attention for the development of therapeutic devices and imaging probes for nanomedicine. However, the fluorescence response of TiO{sub 2} has typically been within ultraviolet spectrum. In this study, the surface modification of TiO{sub 2} nanotubes with ZnS quantum dots was found to produce a red shift in the ultra violet emission band. The TiO{sub 2} nanotubes used in this work were obtained by sol–gel template synthesis. The ZnS quantum dots were deposited onto TiO{sub 2} nanotube surface by a micelle-template inducing reaction. The structure and morphology of the resulting hybrid TiO{sub 2}/ZnS nanotubes were investigated by scanning electron microscopy, transmission electron microscopy and X-ray diffraction techniques. According to the results of fluorescence spectroscopy, pure TiO{sub 2} nanotubes exhibited a high emission at 380 nm (3.26 eV), whereas TiO{sub 2}/ZnS exhibited an emission at 410 nm (3.02 eV). The TiO{sub 2}/ZnS nanotubes demonstrated good bio-imaging ability on sycamore cultured plant cells. The biocompatibility against mammalian cells (Chinese Hamster Ovarian Cells—CHO) suggesting that TiO{sub 2}/ZnS may also have suitable optical properties for use as biological markers in diagnostic medicine. The drug release characteristic of TiO{sub 2}/ZnS nanotubes was explored using 5-fluorouracil (5-FU), an anticancer drug used in photodynamic therapy. The results show that the TiO{sub 2}/ZnS nanotubes are a promising candidate for anticancer drug delivery systems. - Highlights: • TiO{sub 2}/ZnS nanotubes showed a redshift in fluorescence spectrum. • Cytotoxicity against mammalian cells revealed biocompatibility of the nanotubes. • TiO{sub 2}/ZnS proved an efficient delivery system for anti-tumor 5-fluorouracil.

  17. Long-term stability of superhydrophilic oxygen plasma-modified single-walled carbon nanotube network surfaces and the influence on ammonia gas detection

    Energy Technology Data Exchange (ETDEWEB)

    Min, Sungjoon [Department of Biomicrosystem Technology, Korea University, Seoul 136-713 (Korea, Republic of); Kim, Joonhyub [Department of Control and Instrumentation Engineering, Korea University, 2511 Sejong-ro, Sejong City 339-770 (Korea, Republic of); Park, Chanwon [Department of Electrical and Electronic Engineering, Kangwon National University, Chuncheon 200-701 (Korea, Republic of); Jin, Joon-Hyung, E-mail: jj1023@chol.com [Department of Chemical Engineering, Kyonggi University, 154-42 Gwanggyosan-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 16227 (Korea, Republic of); Min, Nam Ki, E-mail: nkmin@korea.ac.kr [Department of Biomicrosystem Technology, Korea University, Seoul 136-713 (Korea, Republic of)

    2017-07-15

    Graphical abstract: Superhydrophilic single-walled carbon nanotube obtained by O{sub 2} plasma treatment voluntarily and non-reversibly reverts to a metastable state. This aerobic aging is an essential process to develop a stable carbon nanotube-based sensor. - Highlights: • Superhydrophilic single-walled carbon nanotube network can be obtained by O{sub 2} plasma-based surface modification. • The modified carbon nanotube surface invariably reverts to a metastable state in a non-reversible manner. • Aerobic aging is essential to stabilize the modified carbon nanotube and the carbon nanotube-based sensing device due to minimized sensor-to-sensor variation. - Abstract: Single-walled carbon nanotube (SWCNT) networks are subjected to a low-powered oxygen plasma for the surface modification. Changes in the surface chemical composition and the stability of the plasma-treated SWCNT (p-SWCNT) with aging in air for up to five weeks are studied using X-ray photoelectron spectroscopy (XPS) and contact angle analysis. The contact angle decreases from 120° of the untreated hydrophobic SWCNT to 0° for the superhydrophilic p-SWCNT. Similarly, the ratio of oxygen to carbon (O:C) based on the XPS spectra increases from 0.25 to 1.19, indicating an increase in surface energy of the p-SWCNT. The enhanced surface energy is gradually dissipated and the p-SWCNT network loses the superhydrophilic surface property. However, it never revert to the original hydrophobic surface state but to a metastable hydrophilic state. The aging effect on sensitivity of the p-SWCNT network-based ammonia sensor is investigated to show the importance of the aging process for the stabilization of the p-SWCNT. The best sensitivity for monitoring NH{sub 3} gas is observed with the as-prepared p-SWCNT, and the sensitivity decreases as similar as the p-SWCNT loses its hydrophilicity with time goes by. After a large performance degradation during the aging time for about two weeks, the response

  18. Single-Event Effects in Silicon Carbide Power Devices

    Science.gov (United States)

    Lauenstein, Jean-Marie; Casey, Megan C.; LaBel, Kenneth A.; Ikpe, Stanley; Topper, Alyson D.; Wilcox, Edward P.; Kim, Hak; Phan, Anthony M.

    2015-01-01

    This report summarizes the NASA Electronic Parts and Packaging Program Silicon Carbide Power Device Subtask efforts in FY15. Benefits of SiC are described and example NASA Programs and Projects desiring this technology are given. The current status of the radiation tolerance of silicon carbide power devices is given and paths forward in the effort to develop heavy-ion single-event effect hardened devices indicated.

  19. Designable and dynamic single-walled stiff nanotubes assembled from sequence-defined peptoids

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Haibao; Ding, Yanhuai; Wang, Mingming; Song, Yang; Liao, Zhihao; Newcomb, Christina J.; Wu, Xuepeng; Tang, Xian-Qiong; Li, Zheng; Lin, Yuehe; Yan, Feng; Jian, Teng-Yue; Mu, Peng; Chen, Chunlong

    2018-01-18

    Despite recent advances in assembly of organic nanotubes, conferral of sequence-defined engineering and dynamic response characteristics to the tubules remains a challenge. Here we report a new family of highly-designable and dynamic single-walled nanotubes assembled from sequence-defined peptoids through a unique “rolling-up and closure of nanosheet” mechanism. During the assembly process, amorphous spherical particles of amphiphilic peptoid oligomers (APOs) crystallized to form well-defined nanosheets which were then folded to form single-walled peptoid nanotubes (SW-PNTs). These SW-PNTs undergo a pH-triggered, reversible contraction-expansion motion. By varying the number of hydrophobic residues of APOs, we demonstrate the tuning of PNT wall thickness and diameter, and mechanical properties. AFM-based mechanical measurements indicate that PNTs are highly stiff (Young’s Modulus ~13-17 GPa), comparable to the stiffest known biological materials. We further demonstrate that the precise incorporation of functional groups within PNTs and the application of functional PNTs in water decontamination. We believe these SW-PNTs can provide a robust platform for development of biomimetic materials tailored to specific applications.

  20. Immunosensors Based on Single-Walled Carbon Nanotubes (SWCNT for the Detection of Deep Venous Thrombosis

    Directory of Open Access Journals (Sweden)

    Sondes BOURIGUA

    2014-05-01

    Full Text Available Thanks to their properties, Single-Walled carbon nanotubes (SWNT open a new way to the fabrication of Immunosensors with the particularity to amplify the response signal from antibody–antigen interaction and to improve the Immunosensors characteristics. In this context, two new impedimetric immunosensors were developed by immobilizing antibody on Single-Walled carbon, the later was immobilized following two ways the first consist of immobilizing the carbon nanotubes on a polypyrrole layer by adsorption and the second consist of functionalized gold with amino thiol and then immobilizing the carbon nanotubes with covalent binding. The electrical properties and the morphology of the immunosensors have been characterized respectively by Electrochemical Impedance Spectroscopy, cyclic voltammetry and Atomic Force Spectroscopy. A low detection limit for both immunosensors was determined as 1 pg/ml and linear ranges up to 10 ng/ml with polypyrrole and up to 100 ng/ml with amino thiol were obtained. Moreover, the studied Immunosensors exhibited high sensitivity, stability and reproducibility.

  1. Retracted-Enhanced X-Ray Absorption Property of Gold-Doped Single Wall Carbon Nanotube

    Directory of Open Access Journals (Sweden)

    Alimin Alimin

    2015-11-01

    Full Text Available Enhanced X-ray absorption property of single wall carbon nanotube (SWCNT through gold (Au doping (Au@SWCNT has been studied. Mass attenuation coefficient of SWCNT increased 5.2-fold after Au doping treatment. The use of ethanol in the liquid phase adsorption could produce Au nanoparticles as confirmed by the X-ray Diffraction (XRD patterns. The possibility of gold nanoparticles encapsulated in the internal tube space of SWCNT was observed by transmission electron microscope technique. A significant decrease of nitrogen uptakes and upshifts of Radial Breathing Mode (RBM of Au@SWCNT specimen suggest that the nanoparticles might be encapsulated in the internal tube spaces of the nanotube. In addition, a decrease intensity of XRD pattern of Au@SWCNT at around 2θ ≈ 2.6° supports the suggestion that Au nanoparticles are really encapsulated into SWCNT.

  2. Investigation on optical absorption properties of ion irradiated single walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Vishalli,, E-mail: vishalli-2008@yahoo.com; Dharamvir, Keya, E-mail: keya@pu.ac.in [Department of Physics, Panjab University, Chandigarh (India); Kaur, Ramneek; Raina, K. K. [Materials Research Laboratory, School of Physics and Materials Science, Thapar University, Patiala (India); Avasthi, D. K. [Materials Science Group, Inter University Accelerator Centre, ArunaAsaf Ali Marg, NewDelhi (India); Jeet, Kiran [Electron Microscopy and Nanoscience laboratory, Punjab Agriculture University, Ludhiana (India)

    2015-08-28

    In the present study change in the optical absorption properties of single walled carbon nanotubes (SWCNTs) under nickel ion (60 MeV) irradiation at various fluences has been investigated. Langmuir Blodgett technique is used to deposit SWCNT thin film of uniform thickness. AFM analysis shows a network of interconnected bundles of nanotubes. UV-Vis-NIR absorption spectra indicate that the sample mainly contain SWCNTs of semiconducting nature. It has been found in absorption spectra that there is decrease in the intensity of the characteristic SWCNT peaks with increase in fluence. At fluence value 1×10{sup 14} ions/cm{sup 2} there is almost complete suppression of the characteristic SWCNTs peaks.The decrease in the optical absorption with increase in fluence is due to the increase in the disorder in the system which leads to the decrease in optically active states.

  3. 2H nuclear magnetic resonance spectroscopy of deuterium adsorption on single-walled carbon nanotubes

    Science.gov (United States)

    Shen, Kai; Pietraß, Tanja

    2004-03-01

    2H nuclear magnetic resonance (NMR) spectroscopy was employed to study the interaction between deuterated hydrogen gas and single walled carbon nanotubes before and after purification. Transmission electron micrographs revealed strong bundling of the tubes. After purification, very little amorphous carbon and no graphitic particles were present, implying that the interactions observed are truly due to the nanotubes. In the parent material, the NMR signal is dominated by interaction of hydrogen with residual metal catalyst particles. For purified material, hydrogen in the gas phase is discernible from adsorbed hydrogen. The two phases do not exchange with each other on a ms time scale. The hydrogen molecules move among different adsorption sites, presumably outer tube surfaces and interstitial channels. This process is diffusion limited in the pressure range investigated.

  4. STUDY OF SINGLE WALLED CARBON NANOTUBE REINFORCED POLYMER COMPOSITES BY HANSEN SOLUBILITY PARAMETERS

    DEFF Research Database (Denmark)

    Ma, Jing

    reinforcement of the polymer by the addition of SWNTs. Existence of agglomerates, voids, and the lower glass transition temperature of epoxy resin, may give the negative effect on the mechanical properties of nanocomposite materials. In the design aspect of the composite material, HSP could help match SWNTs......Single Walled carbon nanotubes (SWNTs) possess superior mechanical, thermal and electrical properties. The use of SWNTs as a reinforcement in polymer matrix is a hot research topic. However, the poor dispersion of SWNTs in polymers and the weak interface between the nanotubes and polymers are two...... major challenges which limit the use of SWNTs for reinforced polymer composites. The main objectives of this PhD work are to design, fabricate SWNTs/polymer composites and characterize the mechanical properties of the composite materials. This study uses the Hansen solubility parameters (HSP) to predict...

  5. Extinction properties of single-walled carbon nanotubes: Two-fluid model

    Energy Technology Data Exchange (ETDEWEB)

    Moradi, Afshin, E-mail: a.moradi@kut.ac.ir [Department of Basic Sciences, Kermanshah University of Technology, Kermanshah, Iran and Department of Nano Science, Institute for Studies in Theoretical Physics and Mathematics (IPM), Tehran (Iran, Islamic Republic of)

    2014-03-15

    The extinction spectra of a single-walled carbon nanotube are investigated, within the framework of the vector wave function method in conjunction with the hydrodynamic model. Both polarizations of the incident plane wave (TE and TM with respect to the x-z plane) are treated. Electronic excitations on the nanotube surface are modeled by an infinitesimally thin layer of a two-dimensional electron gas represented by two interacting fluids, which takes into account the different nature of the σ and π electrons. Numerical results show that strong interaction between the fluids gives rise to the splitting of the extinction spectra into two peaks in quantitative agreement with the π and σ + π plasmon energies.

  6. Wrinkling instabilities in compressed networks of polymer supported single-wall carbon nanotubes

    Science.gov (United States)

    Harris, John; Iyer, Swathi; Huh, Ji Yeon; Fagan, Jeffrey A.; Chun, Jun Young; Hudson, Steven D.; Obrzut, Jan; Stafford, Christopher M.; Hobbie, Erik K.

    2011-03-01

    Strain-induced structural and electronic changes in polymer supported membranes of purified single-wall carbon nanotubes (SWCNTs) are evaluated through the wrinkling instabilities that develop under both uniaxial and isotropic compression. Nanotubes that have been purified by length or electronic type using density-gradient ultracentrifugation are assembled as surfactant-free thin membranes on prestrained polydimethylsiloxane (PDMS) substrates, and the strain response is measured using a broad range of techniques. The small-strain behavior is inferred from kinetic changes in the wrinkling topography of the SWCNT membranes during the slow drying of pre-swelled polymer supports. The measurements suggest a remarkable degree of strain softening that strongly couples to the anisotropic sheet resistance of the films, which we in turn relate to the microscale anisotropy that develops through excluded volume interactions. Supported by the NSF through CMMI-0969155 and the DOE through DE-FG36-08GO88160.

  7. Thermal characteristics of a transparent film heater using single-walled carbon nanotubes.

    Science.gov (United States)

    Kwak, Ho Sang; Kim, Kyoungjin; Shon, Byoung Chul; Lee, Hyunchang; Han, Chang-Soo

    2010-05-01

    This article presents thermal characteristics of a transparent thin-film heater made of single-walled carbon nanotubes on a glass substrate. A simplified analysis model is developed for predicting the thermal behaviors of the heater and its validity is verified by numerical and experimental results. The analytic solution discloses that the key factors controlling steady thermal performance and transient thermal adjustment. For a thin heater of which the Biot number is very small, the temperature of the heater is determined by the applied gradient of electric potential, the sheet resistance of the nanotube film, and the surface heat transfer coefficient. The time scale required for transient heat-up is a function of the thermal mass of glass substrate and the surface heat transfer coefficient.

  8. Dispersion and characterization of arc discharge single-walled carbon nanotubes--towards conducting transparent films.

    Science.gov (United States)

    Rösner, B; Guldi, D M; Chen, J; Minett, A I; Fink, R H

    2014-04-07

    This study addresses a combination of a well-developed and mild dispersion method and high-quality arc discharge single-walled carbon nanotubes (SWCNTs) as starting materials. Thus, we advance in fabrication of transparent, conducting films with extraordinary low material loss during SWCNT processing. The starting material was characterized by means of thermogravimetric analysis, high-resolution transmission electron microscopy and Raman spectroscopy. The quality of the starting material and produced dispersions was evaluated by ultraviolet and visible light absorption spectroscopy and Raman spectroscopy. A transparent conductive film was fabricated by drop-casting, whereas films were obtained with electrical to optical conductivity ratios (σDC/σOp) as high as 2.2, combined with a loss of nanotube material during processing well below 20 wt%. High pressure carbon monoxide conversion (HiPCO) SWCNTs, which are very well described in the literature, were used for comparison.

  9. Influence of Polymer Electronics on Selective Dispersion of Single-Walled Carbon Nanotubes.

    Science.gov (United States)

    Fong, Darryl; Bodnaryk, William J; Rice, Nicole A; Saem, Sokunthearath; Moran-Mirabal, Jose M; Adronov, Alex

    2016-10-04

    The separation and isolation of semiconducting and metallic single-walled carbon nanotubes (SWNTs) on a large scale remains a barrier to many commercial applications. Selective extraction of semiconducting SWNTs by wrapping and dispersion with conjugated polymers has been demonstrated to be effective, but the structural parameters of conjugated polymers that dictate selectivity are poorly understood. Here, we report nanotube dispersions with a poly(fluorene-co-pyridine) copolymer and its cationic methylated derivative, and show that electron-deficient conjugated π-systems bias the dispersion selectivity toward metallic SWNTs. Differentiation of semiconducting and metallic SWNT populations was carried out by a combination of UV/Vis-NIR absorption spectroscopy, Raman spectroscopy, fluorescence spectroscopy, and electrical conductivity measurements. These results provide new insight into the rational design of conjugated polymers for the selective dispersion of metallic SWNTs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Coating individual single-walled carbon nanotubes with nylon 6,10 through emulsion polymerization.

    Science.gov (United States)

    Chen, Wei-Chiang; Wang, Randy K; Ziegler, Kirk J

    2009-08-01

    Solvent microenvironments are formed around individual single-walled carbon nanotubes (SWNTs) by mixing SWNT suspensions with water-immiscible organic solvents. These microenvironments are used to encapsulate the SWNTs with the monomer sebacoyl chloride. Hexamethylene diamine is then injected into the aqueous phase so the formation of nylon 6,10 is restricted to the interface between the microenvironment and water. This emulsion polymerization process results in uniform coatings of nylon 6,10 around individual SWNTs. The nylon-coated SWNTs remain dispersed in the aqueous phase and are highly luminescent at pH values ranging from 3 to 12. This emulsion polymerization method provides a general approach to coat nanotubes with various polymers.

  11. Enzymatic formation of carbohydrate rings catalyzed by single-walled carbon nanotubes.

    Science.gov (United States)

    Hyun, Moon Seop; Park, Jong Pil; Seo, Dongkyun; Chang, Sung-Jin; Lee, Seok Jae; Lee, Sang Yup; Kwak, Kyungwon; Park, Tae Jung

    2016-05-01

    Macrocyclic carbohydrate rings were formed via enzymatic reactions around single-walled carbon nanotubes (SWNTs) as a catalyst. Cyclodextrin glucanotransferase, starch substrate and SWNTs were reacted in buffer solution to yield cyclodextrin (CD) rings wrapped around individual SWNTs. Atomic force microscopy showed the resulting complexes to be rings of 12-50 nm in diameter, which were highly soluble and dispersed in aqueous solution. They were further characterized by Raman and Fourier transform infrared spectroscopy and molecular simulation using density functional theory calculation. In the absence of SWNT, hydrogen bonding between glucose units determines the structure of maltose (the precursor of CD) and produces the curvature along the glucose chain. Wrapping SWNT along the short axis was preferred with curvature in the presence of SWNTs and with the hydrophobic interactions between the SWNTs and CD molecules. This synthetic approach may be useful for the functionalization of carbon nanotubes for development of nanostructures.

  12. Optical properties of graphene nanoribbons encapsulated in single-walled carbon nanotubes.

    Science.gov (United States)

    Chernov, Alexander I; Fedotov, Pavel V; Talyzin, Alexandr V; Suarez Lopez, Inma; Anoshkin, Ilya V; Nasibulin, Albert G; Kauppinen, Esko I; Obraztsova, Elena D

    2013-07-23

    We report the photoluminescence (PL) from graphene nanoribbons (GNRs) encapsulated in single-walled carbon nanotubes (SWCNTs). New PL spectral features originating from GNRs have been detected in the visible spectral range. PL peaks from GNRs have resonant character, and their positions depend on the ribbon geometrical structure in accordance with the theoretical predictions. GNRs were synthesized using confined polymerization and fusion of coronene molecules. GNR@SWCNTs material demonstrates a bright photoluminescence both in infrared (IR) and visible regions. The photoluminescence excitation mapping in the near-IR spectral range has revealed the geometry-dependent shifts of the SWCNT peaks (up to 11 meV in excitation and emission) after the process of polymerization of coronene molecules inside the nanotubes. This behavior has been attributed to the strain of SWCNTs induced by insertion of the coronene molecules.

  13. DNA Linked To Single Wall Carbon Nanotubes: Covalent Versus Non-Covalent Approach

    Science.gov (United States)

    Chung, C.-L.; Nguyen, K.; Lyonnais, S.; Streiff, S.; Campidelli, S.; Goux-Capes, L.; Bourgoin, J.-P.; Filoramo, A.

    2008-10-01

    Nanometer-scale structures represent a novel and intriguing field, where scientists and engineers manipulate materials at the atomic and molecular scale levels to produce innovative materials. Carbon nanotubes constitute a relatively new class of materials exhibiting exceptional mechanical and electronic properties and were found to be promising candidates for molecular electronics, sensing or biomedical applications. Considering the bottom-up strategy in nanotechnology, the combination of the recognition properties of DNA with the electronic properties of single walled carbon nanotubes (SWNTs) seems to be a promising approach for the future of electronics. With the aim to assemble DNA with SWNTs, two complementary strategies have been envisioned: the covalent linkage of DNA on carboxylic groups of SWNTs under classical coupling condition and the non-covalent approach based on biotin-streptavidin molecular recognition properties. Here, we present and compare the results that we obtained with these two different methods; we want to objectively show the advantages and disadvantages of each approach.

  14. Dependence of single-walled carbon nanotube adsorption kinetics on temperature and binding energy.

    Science.gov (United States)

    Rawat, D S; Krungleviciute, V; Heroux, L; Bulut, M; Calbi, M M; Migone, A D

    2008-12-02

    We present results for the isothermal adsorption kinetics of methane, hydrogen, and tetrafluoromethane on closed-ended single-walled carbon nanotubes. In these experiments, we monitor the pressure decrease as a function of time as equilibrium is approached, after a dose of gas is added to the cell containing the nanotubes. The measurements were performed at different fractional coverages limited to the first layer. The results indicate that, for a given coverage and temperature, the equilibration time is an increasing function of E/(k(B)T), where E is the binding energy of the adsorbate and k(B)T is the thermal energy. These findings are consistent with recent theoretical predictions and computer simulations results that we use to interpret the experimental measurements.

  15. Atomic scale mass delivery driven by bend kink in single walled carbon nanotube

    International Nuclear Information System (INIS)

    Kan Biao; Ding Jianning; Ling Zhiyong; Yuan Ningyi; Cheng Guanggui

    2010-01-01

    The possibility of atomic scale mass delivery by bend kink in single walled carbon nanotube was investigated with the aid of molecular dynamics simulation. By keeping the bending angle while moving the tube end, the encapsulated atomic scale mass such as atom, molecule and atom group were successfully delivered through the nanotube. The van der Waals interaction between the encapsulated mass and the tube wall provided the driving force for the delivery. There were no dramatic changes in the van der Waals interaction, and a smooth and steady delivery was achieved when constant loading rate was applied. The influence of temperature on the atom group delivery was also analyzed. It is found raising temperature is harmful to the smooth movement of the atom group. However, the delivery rate can be promoted under higher temperature when the atom group is situated before the kink during the delivery.

  16. Photoluminescence quenching, structures, and photovoltaic properties of ZnO nanostructures decorated plasma grown single walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Aïssa, Brahim, E-mail: brahim.aissa@mpbc.ca [University of Quebec, Centre Énergie, Matériaux et Télécommunications, INRS-EMT (Canada); Nedil, Mourad [Telebec Wireless Underground Communication Laboratory, UQAT (Canada); Belaidi, Abdelhak; Isaifan, Rima J. [Hamad Bin Khalifa University, Qatar Foundation, Qatar Environment and Energy Research Institute (Qatar); Bentouaf, Ali [University Hassiba Ben Bouali, Physics Department, Faculty of Science (Algeria); Fauteux, Christian; Therriault, Daniel [École Polytechnique de Montréal, Laboratory for Multiscale Mechanics (LM2), Mechanical Engineering Department (Canada)

    2017-05-15

    Zinc oxide (ZnO) nanostructures were successfully grown directly on single walled carbon nanotubes (SWCNT) template through the CO{sub 2} laser-induced chemical liquid deposition (LCLD) process. Photoluminescence (PL) of the deposited ZnO/SWCNT hybrid composites exhibits, at room temperature, a narrow near UV band located at 390 nm with no emission bands in the visible region, indicating a high degree of crystalline quality of the ZnO nanostructures. Moreover, when the relative SWCNT loads are varied within the composites, the PL intensity and the diffused optical reflectance diminish in comparison with those of ZnO alone, owing to the transfer of photo-excited electrons from ZnO to the SWCNT, and the enhancement of the optical absorbance, respectively. Finally, these ZnO/SWCNT hybrid composites are integrated into a heterojunction photovoltaic-based device, using PEDOT:PSS on ITO/glass substrate. The devices show an evident p–n junction behavior in the dark, and a clear I–V curve shift downward when illuminated with an open-circuit voltage of 1.1 V, a short circuit current density of 14.05 μA cm{sup −2}, and a fill factor of ∼35%. These results indicate that these composites fabricated via LCLD process could be promising for optoelectronic and energy-harvesting devices.

  17. Photoluminescence quenching, structures, and photovoltaic properties of ZnO nanostructures decorated plasma grown single walled carbon nanotubes

    Science.gov (United States)

    Aïssa, Brahim; Nedil, Mourad; Belaidi, Abdelhak; Isaifan, Rima J.; Bentouaf, Ali; Fauteux, Christian; Therriault, Daniel

    2017-05-01

    Zinc oxide (ZnO) nanostructures were successfully grown directly on single walled carbon nanotubes (SWCNT) template through the CO2 laser-induced chemical liquid deposition (LCLD) process. Photoluminescence (PL) of the deposited ZnO/SWCNT hybrid composites exhibits, at room temperature, a narrow near UV band located at 390 nm with no emission bands in the visible region, indicating a high degree of crystalline quality of the ZnO nanostructures. Moreover, when the relative SWCNT loads are varied within the composites, the PL intensity and the diffused optical reflectance diminish in comparison with those of ZnO alone, owing to the transfer of photo-excited electrons from ZnO to the SWCNT, and the enhancement of the optical absorbance, respectively. Finally, these ZnO/SWCNT hybrid composites are integrated into a heterojunction photovoltaic-based device, using PEDOT:PSS on ITO/glass substrate. The devices show an evident p-n junction behavior in the dark, and a clear I- V curve shift downward when illuminated with an open-circuit voltage of 1.1 V, a short circuit current density of 14.05 μA cm-2, and a fill factor of ˜35%. These results indicate that these composites fabricated via LCLD process could be promising for optoelectronic and energy-harvesting devices.

  18. High-performance thin-film-transistors based on semiconducting-enriched single-walled carbon nanotubes processed by electrical-breakdown strategy

    Energy Technology Data Exchange (ETDEWEB)

    Aïssa, B., E-mail: aissab@emt.inrs.ca [Centre Énergie, Matériaux et Télécommunications, INRS, 1650, boulevard Lionel-Boulet, Varennes, Quebec J3X 1S2 (Canada); Qatar Environment and Energy Research Institute (QEERI), Qatar Foundation, P.O. Box 5825, Doha (Qatar); Nedil, M. [Telebec Wireless Underground Communication Laboratory, UQAT, 675, 1" è" r" e Avenue, Val d’Or, Québec J9P 1Y3 (Canada); Habib, M.A. [Computer Sciences and Engineering Department, Yanbu University College, P.O. Box 30031 (Saudi Arabia); Abdul-Hafidh, E.H. [High Energy Physics Department, Yanbu University College, P.O. Box 30031 (Saudi Arabia); Rosei, F. [Centre Énergie, Matériaux et Télécommunications, INRS, 1650, boulevard Lionel-Boulet, Varennes, Quebec J3X 1S2 (Canada)

    2015-02-15

    Highlights: • We selectively burn metallic single wall carbon nanotubes (SWCNT) by electrical breakdown. • We successfully achieve a semiconducting enriched-SWCNT in TFT configuration. • High performance, like On/Off of 10{sup 5} and a subthreshold swing of 165 mV/decades were obtained. • After PMMA coating, the SWCNT–TFTs were found stables for more than 4 months. - Abstract: Over the past two decades, among remarkable variety of nanomaterials, single-walled carbon nanotubes (SWCNTs) remain the most intriguing and uniquely well suited materials for applications in high-performance electronics. The most advanced technologies require the ability to form purely semiconducting SWCNTs. Here, we report on our strategy based on the well known progressive electrical breakdown process that offer this capability and serves as highly efficient means for selectively removing metallic carbon nanotubes from electronically heterogeneous random networks, deposited on silicon substrates in a thin film transistor (TFT) configuration. We demonstrate the successful achievement of semiconducting enriched-SWCNT networks in TFT scheme that reach On/Off switching ratios of ∼100,000, on-conductance of 20 μS, and a subthreshold swing of less than 165 mV/decades. The obtained TFT devices were then protected with thin film poly(methyl methacrylate) (PMMA) to keep the percolation level of the SWCNTs network spatially and temporally stable, while protecting it from atmosphere exchanges. TFT devices were found to be air-stable and maintained their excellent characteristics in ambient atmosphere for more than 4 months. This approach could work as a platform for future nanotube-based nanoelectronics.

  19. Controlling Structural Characteristics of Single-Walled Carbon Nanotubes (SWNT) by Tailoring Catalyst Composition and Synthesis Conditions

    International Nuclear Information System (INIS)

    Resasco, Daniel E.

    2010-01-01

    This report shows the extensive research on the mechanism responsible for the formation of single walled carbon nanotubes in order to get control over their structural parameters (diameter and chirality). Catalyst formulations, pre-treatment conditions, and reaction conditions are described in detail as well as mechanisms to produce nanotubes structures of specific arrays (vertical forest, nanotube pillars). Applications of SWNT in different fields are also described in this report. In relation to this project five students have graduated (3 PhD and 2 MS) and 35 papers have been published.

  20. Mechanical and Electrical Properties of a Polyimide Film Significantly Enhanced by the Addition of Single-Wall Carbon Nanotubes

    Science.gov (United States)

    Meador, Michael A.

    2005-01-01

    Single-wall carbon nanotubes have been shown to possess a combination of outstanding mechanical, electrical, and thermal properties. The use of carbon nanotubes as an additive to improve the mechanical properties of polymers and/or enhance their thermal and electrical conductivity has been a topic of intense interest. Nanotube-modified polymeric materials could find a variety of applications in NASA missions including large-area antennas, solar arrays, and solar sails; radiation shielding materials for vehicles, habitats, and extravehicular activity suits; and multifunctional materials for vehicle structures and habitats. Use of these revolutionary materials could reduce vehicle weight significantly and improve vehicle performance and capabilities.

  1. Very long single- and few-walled boron nitride nanotubes via the pressurized vapor/condenser method

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Michael W. [NASA Langley Research Center, Hampton, VA (United States); Jordan, Kevin C. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Park, Cheol [NASA Langley Research Center, Hampton, VA (United States); Kim, Jae-Woo [NASA Langley Research Center, Hampton, VA (United States); Lillehei, Peter T. [NASA Langley Research Center, Hampton, VA (United States); Crooks, Roy [NASA Langley Research Center, Hampton, VA (United States); Harrison, Joycelyn S. [NASA Langley Research Center, Hampton, VA (United States)

    2009-11-01

    Boron nitride nanotubes (BNNTs) are desired for their exceptional mechanical, electronic, thermal, structural, textural, optical, and quantum properties. A new method for producing long, small-diameter, single- and few-walled, boron nitride nanotubes (BNNTs) in macroscopic quantities is reported. The pressurized vapor/condenser (PVC) method produces, without catalysts, highly crystalline, very long, small-diameter, BNNTs. Palm-sized, cotton-like masses of BNNT raw material were grown by this technique and spun directly into centimeters-long yarn. Nanotube lengths were observed to be 100 times that of those grown by the most closely related method. Self-assembly and growth models for these long BNNTs are discussed.

  2. Surface Adsorption and Replacement of Acid-Oxidized Single-Walled Carbon Nanotubes and Poly(vinyl pyrrolidone Chains

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2007-01-01

    Full Text Available Quartz crystal microbalance (QCM was used to investigate the adsorption of acid-oxidized single-walled carbon nanotubes (Ox-SWNTs and poly(vinyl pyrrolidone, PVP. It was found for the first time that Ox-SWNTs adsorbed onto the QCM electrode can be effectively replaced by PVP chains in an aqueous solution. This replacement process was also investigated by atomic force miscroscopic (AFM imaging, which shows good agreement with the QCM measurements. This study provides powerful tools for fundamental investigation of polymer-nanotube interactions and for controlled design/fabrication of functional polymer-nanotube surfaces for potential applications.

  3. The effect of amine protonation on the electrical properties of spin-assembled single-walled carbon nanotube networks

    International Nuclear Information System (INIS)

    Opatkiewicz, Justin P; LeMieux, Melburne C; Bao Zhenan; Patil, Nishant P; Wei Hai; Mitra, Subhasish

    2011-01-01

    Amine-terminated self-assembled monolayers (SAMs) have been shown to selectively adsorb semiconducting single-walled carbon nanotubes (sc-SWNTs). Previous studies have shown that when deposited by spin coating, the resulting nanotube networks (SWNTnts) can be strongly influenced by the charge state of the amine (primary, secondary, and tertiary). When the amine surfaces were exposed to varying pH solutions, the conductivity and overall quality of the resulting fabricated networks were altered. Atomic force microscopy (AFM) topography had shown that the density of the SWNTnts was reduced as the amine protonation decreased, indicating that the electrostatic attraction between the SWNTs in solution and the surface influenced the adsorption. Simultaneously, μ-Raman analysis had suggested that when exposed to more basic conditions, the resulting networks were enhanced with sc-SWNTs. To directly confirm this enhancement, Ti/Pd contacts were deposited and devices were tested in air. Key device characteristics were found to match the enhancement trends previously observed by spectroscopy. For the primary and secondary amines, on/off current ratios were commensurate with the Raman trends in metallic contribution, while no trends were observed on the tertiary amine (due to weaker interactions). Finally, differing SWNT solution volumes were used to compensate for adsorption differences and yielded identical SWNTnt densities on the various pH-treated samples to eliminate the influence of network density. These results further the understanding of the amine-SWNT interaction during the spin coating process. Overall, we provide a convenient route to provide SWNT-based TFTs with highly tunable electronic charge transport through better understanding of the influence of these specific interactions.

  4. Empirical Equation Based Chirality (n, m Assignment of Semiconducting Single Wall Carbon Nanotubes from Resonant Raman Scattering Data

    Directory of Open Access Journals (Sweden)

    Md Shamsul Arefin

    2012-12-01

    Full Text Available This work presents a technique for the chirality (n, m assignment of semiconducting single wall carbon nanotubes by solving a set of empirical equations of the tight binding model parameters. The empirical equations of the nearest neighbor hopping parameters, relating the term (2n, m with the first and second optical transition energies of the semiconducting single wall carbon nanotubes, are also proposed. They provide almost the same level of accuracy for lower and higher diameter nanotubes. An algorithm is presented to determine the chiral index (n, m of any unknown semiconducting tube by solving these empirical equations using values of radial breathing mode frequency and the first or second optical transition energy from resonant Raman spectroscopy. In this paper, the chirality of 55 semiconducting nanotubes is assigned using the first and second optical transition energies. Unlike the existing methods of chirality assignment, this technique does not require graphical comparison or pattern recognition between existing experimental and theoretical Kataura plot.

  5. Fabrication of single-crystal silicon nanotubes with sub-10 nm walls using cryogenic inductively coupled plasma reactive ion etching

    Science.gov (United States)

    Li, Zhiqin; Chen, Yiqin; Zhu, Xupeng; Zheng, Mengjie; Dong, Fengliang; Chen, Peipei; Xu, Lihua; Chu, Weiguo; Duan, Huigao

    2016-09-01

    Single-crystal silicon nanostructures have attracted much attention in recent years due in part to their unique optical properties. In this work, we demonstrate direct fabrication of single-crystal silicon nanotubes with sub-10 nm walls which show low reflectivity. The fabrication was based on a cryogenic inductively coupled plasma reactive ion etching process using high-resolution hydrogen silsesquioxane nanostructures as the hard mask. Two main etching parameters including substrate low-frequency power and SF6/O2 flow rate ratio were investigated to determine the etching mechanism in the process. With optimized etching parameters, high-aspect-ratio silicon nanotubes with smooth and vertical sub-10 nm walls were fabricated. Compared to commonly-used antireflection silicon nanopillars with the same feature size, the densely packed silicon nanotubes possessed a lower reflectivity, implying possible potential applications of silicon nanotubes in photovoltaics.

  6. Elemental Characterization of Single-Wall Carbon Nanotube Certified Reference Material by Neutron and Prompt gamma Activation Analysis

    Czech Academy of Sciences Publication Activity Database

    Kučera, Jan; Bennett, J. W.; Oflaz, R.; Paul, R. L.; De Nadai Fernandes, E. A.; Kubešová, Marie; Bacchi, M. A.; Stopic, A. J.; Sturgeon, R. E.; Grinberg, P.

    2015-01-01

    Roč. 87, č. 7 (2015), s. 3699-3705 ISSN 0003-2700 R&D Projects: GA ČR(CZ) GBP108/12/G108; GA MŠk LM2011019 Institutional support: RVO:61389005 Keywords : Neutron Activation Analyses * nanotechnology * Carbon nanotubes * Chemical activation * Single-walled carbon nanotubes (SWCN) Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 5.886, year: 2015

  7. Design, Fabrication, and Characterization of Carbon Nanotube Field Emission Devices for Advanced Applications

    Science.gov (United States)

    Radauscher, Erich Justin

    Carbon nanotubes (CNTs) have recently emerged as promising candidates for electron field emission (FE) cathodes in integrated FE devices. These nanostructured carbon materials possess exceptional properties and their synthesis can be thoroughly controlled. Their integration into advanced electronic devices, including not only FE cathodes, but sensors, energy storage devices, and circuit components, has seen rapid growth in recent years. The results of the studies presented here demonstrate that the CNT field emitter is an excellent candidate for next generation vacuum microelectronics and related electron emission devices in several advanced applications. The work presented in this study addresses determining factors that currently confine the performance and application of CNT-FE devices. Characterization studies and improvements to the FE properties of CNTs, along with Micro-Electro-Mechanical Systems (MEMS) design and fabrication, were utilized in achieving these goals. Important performance limiting parameters, including emitter lifetime and failure from poor substrate adhesion, are examined. The compatibility and integration of CNT emitters with the governing MEMS substrate (i.e., polycrystalline silicon), and its impact on these performance limiting parameters, are reported. CNT growth mechanisms and kinetics were investigated and compared to silicon (100) to improve the design of CNT emitter integrated MEMS based electronic devices, specifically in vacuum microelectronic device (VMD) applications. Improved growth allowed for design and development of novel cold-cathode FE devices utilizing CNT field emitters. A chemical ionization (CI) source based on a CNT-FE electron source was developed and evaluated in a commercial desktop mass spectrometer for explosives trace detection. This work demonstrated the first reported use of a CNT-based ion source capable of collecting CI mass spectra. The CNT-FE source demonstrated low power requirements, pulsing

  8. Towards sustainable design for single-use medical devices.

    Science.gov (United States)

    Hanson, Jacob J; Hitchcock, Robert W

    2009-01-01

    Despite their sophistication and value, single-use medical devices have become commodity items in the developed world. Cheap raw materials along with large scale manufacturing and distribution processes have combined to make many medical devices more expensive to resterilize, package and restock than to simply discard. This practice is not sustainable or scalable on a global basis. As the petrochemicals that provide raw materials become more expensive and the global reach of these devices continues into rapidly developing economies, there is a need for device designs that take into account the total life-cycle of these products, minimize the amount of non-renewable materials consumed and consider alternative hybrid reusable / disposable approaches. In this paper, we describe a methodology to perform life cycle and functional analyses to create additional design requirements for medical devices. These types of sustainable approaches can move the medical device industry even closer to the "triple bottom line"--people, planet, profit.

  9. High-temperature operating non-volatile memory of printable single-wall carbon nanotubes self-assembled with a conjugate block copolymer.

    Science.gov (United States)

    Hwang, Sun Kak; Choi, Jae Ryung; Bae, Insung; Hwang, Ihn; Cho, Suk Man; Huh, June; Park, Cheolmin

    2013-03-25

    Printable non-volatile polymer memories are fabricated with solution-processed nanocomposite films of poly(styrene-block-paraphenylene) (PS-b-PPP) and single-wall carbon nanotubes (SWNTs). The devices show stable data retention at high temperatures of up to 100 °C without significant performance degradation due to the strong, non-destructive, and isomorphic π-π interactions between the SWNTs and PPP block. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Pressure-sensing properties of single-walled carbon nanotubes covered with a corona-poled piezoelectric polymer

    Energy Technology Data Exchange (ETDEWEB)

    Ikawa, Takeshi; Tabata, Hiroshi, E-mail: tabata@eei.eng.osaka-u.ac.jp; Yoshizawa, Takeshi; Utaka, Ken; Kubo, Osamu; Katayama, Mitsuhiro [Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2016-07-18

    Single-walled carbon nanotubes (SWNTs) have been studied extensively as sensing elements for chemical and biochemical sensors because of their excellent electrical properties, their ultrahigh ratio of surface area to volume, and the consequent extremely high sensitivity of their surface to the surrounding environment. The extremely high sensitivity indicates that SWNTs can operate as excellent transducers when combined with piezoelectric materials. In this paper, we present a touch sensor based on SWNT thin-film transistors (SWNT-TFTs) covered with a thin film of the piezoelectric polymer poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)). Devices were fabricated by spin-coating a P(VDF-TrFE) layer on an SWNT-TFT, which was followed by in situ corona poling to polarize the P(VDF-TrFE) layer. We studied the effect of the corona polarity on the device characteristics and revealed that poling with a negative corona discharge induced a large amount of hole doping in the SWNTs and improved the touch-sensing performance of the devices, while a positive discharge had a negligible effect. The poled devices exhibited regular, stable, and positive drain current modulation in response to intermittent pressing, and the response was proportional to the magnitude of the applied pressure, suggesting that it was caused by the piezoelectric effect of the polarized P(VDF-TrFE) layer. Furthermore, we also fabricated a device using horizontally aligned SWNTs with a lower SWNT density as an alternative transducer to an SWNT thin film, which demonstrated sensitivity as high as 70%/MPa.

  11. Heating-Rate-Triggered Carbon-Nanotube-based 3-Dimensional Conducting Networks for a Highly Sensitive Noncontact Sensing Device

    KAUST Repository

    Tai, Yanlong

    2016-01-28

    Recently, flexible and transparent conductive films (TCFs) are drawing more attention for their central role in future applications of flexible electronics. Here, we report the controllable fabrication of TCFs for moisture-sensing applications based on heating-rate-triggered, 3-dimensional porous conducting networks through drop casting lithography of single-walled carbon nanotube (SWCNT)/poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT:PSS) ink. How ink formula and baking conditions influence the self-assembled microstructure of the TCFs is discussed. The sensor presents high-performance properties, including a reasonable sheet resistance (2.1 kohm/sq), a high visible-range transmittance (>69%, PET = 90%), and good stability when subjected to cyclic loading (>1000 cycles, better than indium tin oxide film) during processing, when formulation parameters are well optimized (weight ratio of SWCNT to PEDOT:PSS: 1:0.5, SWCNT concentration: 0.3 mg/ml, and heating rate: 36 °C/minute). Moreover, the benefits of these kinds of TCFs were verified through a fully transparent, highly sensitive, rapid response, noncontact moisture-sensing device (5 × 5 sensing pixels).

  12. Nanocatalyst shape and composition during nucleation of single-walled carbon nanotubes.

    Science.gov (United States)

    Gomez-Ballesteros, Jose L; Burgos, Juan C; Lin, Pin Ann; Sharma, Renu; Balbuena, Perla B

    The dynamic evolution of nanocatalyst particle shape and carbon composition during the initial stages of single-walled carbon nanotube growth by chemical vapor deposition synthesis is investigated. Classical reactive and ab initio molecular dynamics simulations are used, along with environmental transmission electron microscope video imaging analyses. A clear migration of carbon is detected from the nanocatalyst/substrate interface, leading to a carbon gradient showing enrichment of the nanocatalyst layers in the immediate vicinity of the contact layer. However, as the metal nanocatalyst particle becomes saturated with carbon, a dynamic equilibrium is established, with carbon precipitating on the surface and nucleating a carbon cap that is the precursor of nanotube growth. A carbon composition profile decreasing towards the nanoparticle top is clearly revealed by the computational and experimental results that show a negligible amount of carbon in the nanoparticle region in contact with the nucleating cap. The carbon composition profile inside the nanoparticle is accompanied by a well-defined shape evolution of the nanocatalyst driven by the various opposing forces acting upon it both from the substrate and from the nascent carbon nanostructure. This new understanding suggests that tuning the nanoparticle/substrate interaction would provide unique ways of controlling the nanotube synthesis.

  13. Effect of swift heavy ion irradiation on single- and multiwalled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Olejniczak, Andrzej, E-mail: aolejnic@chem.uni.torun.pl [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Faculty of Chemistry, Nicolaus Copernicus University, ul. Gagarina 7, 87-100 Toruń (Poland); Skuratov, Vladimir A. [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation)

    2014-05-01

    The effect of irradiation with swift heavy ions on the structure and properties of carbon nanotubes was investigated by Raman spectroscopy. It was found that disordering of the system occurred mainly at the surface. No ordering phenomena have been observed over a whole range of both fluences and electronic stopping powers studied. The disorder parameter (i.e., the ratio of the D and G band intensities (I{sub D}/I{sub G})) increases non-linearly with the irradiation dose, showing a tendency to saturate at high fluences. The increase in the disorder parameter upon irradiation was proportional to the square root of the ion fluence. The radiation stability of the few-walled nanotubes was ca. 1.6 higher than that of the single-walled ones. The irradiation with both the Xe and Kr ions leads to essentially the same increase in the I{sub D}/I{sub G} ratio with respect to the deposited electronic energy density. In the case of the Ar ion irradiation, the observed increase in the I{sub D}/I{sub G} ratio is much lower, suggesting that the electronic stopping power threshold for defects creation in carbon nanotubes is lower than that for graphite.

  14. Assembly and melting of DNA nanotubes from single-sequence tiles

    International Nuclear Information System (INIS)

    Sobey, T L; Renner, S; Simmel, F C

    2009-01-01

    DNA melting and renaturation studies are an extremely valuable tool to study the kinetics and thermodynamics of duplex dissociation and reassociation reactions. These are important not only in a biological or biotechnological context, but also for DNA nanotechnology which aims at the construction of molecular materials by DNA self-assembly. We here study experimentally the formation and melting of a DNA nanotube structure, which is composed of many copies of an oligonucleotide containing several palindromic sequences. This is done using temperature-controlled UV absorption measurements correlated with atomic force microscopy, fluorescence microscopy and transmission electron microscopy techniques. In the melting studies, important factors such as DNA strand concentration, hierarchy of assembly and annealing protocol are investigated. Assembly and melting of the nanotubes are shown to proceed via different pathways. Whereas assembly occurs in several hierarchical steps related to the formation of tiles, lattices and tubes, melting of DNA nanotubes appears to occur in a single step. This is proposed to relate to fundamental differences between closed, three-dimensional tube-like structures and open, two-dimensional lattices. DNA melting studies can lead to a better understanding of the many factors that affect the assembly process which will be essential for the assembly of increasingly complex DNA nanostructures.

  15. Theoretical studies on lattice-oriented growth of single-walled carbon nanotubes on sapphire

    Science.gov (United States)

    Li, Zhengwei; Meng, Xianhong; Xiao, Jianliang

    2017-09-01

    Due to their excellent mechanical and electrical properties, single-walled carbon nanotubes (SWNTs) can find broad applications in many areas, such as field-effect transistors, logic circuits, sensors and flexible electronics. High-density, horizontally aligned arrays of SWNTs are essential for high performance electronics. Many experimental studies have demonstrated that chemical vapor deposition growth of nanotubes on crystalline substrates such as sapphire offers a promising route to achieve such dense, perfectly aligned arrays. In this work, a theoretical study is performed to quantitatively understand the van der Waals interactions between SWNTs and sapphire substrates. The energetically preferred alignment directions of SWNTs on A-, R- and M-planes and the random alignment on the C-plane predicted by this study are all in good agreement with experiments. It is also shown that smaller SWNTs have better alignment than larger SWNTs due to their stronger interaction with sapphire substrate. The strong vdW interactions along preferred alignment directions can be intuitively explained by the nanoscale ‘grooves’ formed by atomic lattice structures on the surface of sapphire. This study provides important insights to the controlled growth of nanotubes and potentially other nanomaterials.

  16. Single- and Multiwalled Carbon Nanotubes with Phosphorus Based Flame Retardants for Textiles

    Directory of Open Access Journals (Sweden)

    D. Wesolek

    2014-01-01

    Full Text Available Due to growing popularity of composites, modification methods to obtain the best properties are searched for. The aim of the study is to reduce the flammability of textile materials using nanocomposite polymer back-coating. Different types of carbon nanotubes (single- and multiwalled and different phosphorus flame retardants (ammonium polyphosphates and melamine polyphosphate were introduced into the resin and then the fabrics were covered by the obtained composites. Homogeneous dispersion of multiwalled carbon nanotubes in the polyurethane resin was obtained by sonification, which was confirmed by scanning electron microscopy. Flammability tests of fabrics coated by modified polyurethane resin were carried out using pyrolysis combustion flow calorimeter (PCFC and thermal stability of textiles was evaluated. Also, organoleptic estimation of coatings was conducted (flexibility and fragility. The use of polymer nanocomposites with phophorus flame retardants as a back-coating for textiles effectively reduces flammability and improves thermal stability of the fabric. Furthermore, the synergistic effect beetwen carbon nanotubes and phosphorous compound occurs. The resulting coatings are flexible and do not crack or change the feel of fabrics.

  17. Properties of Cs-intercalated single wall carbon nanotubes investigated by 133Cs Nuclear Magnetic resonance

    KAUST Repository

    Schmid, Marc R.

    2012-11-01

    In the present study, we investigated Cs-intercalated single wall carbon nanotubes (SWCNTs) using 133Cs Nuclear Magnetic resonance. We show that there are two types of Cs cations depending on the insertion level. Indeed, at low concentrations, Static spectra analysis shows that the Cs (α)+ species are fully ionized, i.e. α equal ca.1, while at higher concentrations a second paramagnetically shifted line appears, indicating the formation of Cs (β)+ ions with β < α ∼ +1. At low concentrations and low temperatures the Cs (α)+ ions exhibit a weak hyperfine coupling to the SWCNT conduction electrons, whereas, at higher temperatures, a thermally activated slow-motion diffusion process of the Cs (α)+ ions occurs along the interstitial channels present within the carbon nanotube bundles. At high concentrations, the Cs (β)+ ions seem to occupy well defined positions relative to the carbon lattice. As a matter of fact, the Korringa relaxation behavior suggests a strong hyperfine coupling between Cs nuclei and conduction electrons in the carbon nanotubes and a partial charge transfer, which suggest a plausible Cs(6s)-C(2p) hybridization. © 2012 Elsevier Ltd. All rights reserved.

  18. Periodic density functional theory study of structural and electronic properties of single-walled zinc oxide and carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Marana, Naiara L. [Modeling and Molecular Simulations Group, São Paulo State University, UNESP, 17033-360 Bauru, SP (Brazil); Albuquerque, Anderson R. [Federal Institute of Education, Science and Technology of Sertão Pernambucano, 56400-000 Floresta, PE (Brazil); La Porta, Felipe A. [Chemistry Department, Federal Technological University of Paraná, 86036-370 Londrina, PR (Brazil); Longo, Elson [São Paulo State University, Chemistry Institute, UNESP, 14801-907 Araraquara, SP (Brazil); Sambrano, Julio R. [Modeling and Molecular Simulations Group, São Paulo State University, UNESP, 17033-360 Bauru, SP (Brazil)

    2016-05-15

    Periodic density functional theory calculations with the B3LYP hybrid functional and all-electron Gaussian basis set were performed to simulate the structural and electronic properties as well as the strain and formation energies of single-walled ZnO nanotubes (SWZnONTs) and Carbon nanotubes (SWCNTs) with different chiralities as functions of their diameters. For all SWZnONTs, the band gap, strain energy, and formation energy converge to ~4.5 eV, 0.0 eV/atom, and 0.40 eV/atom, respectively. This result suggests that the nanotubes are formed more easily from the surface than from the bulk. For SWCNTs, the strain energy is always positive, while the formation energy is negative for armchair and zigzag nanotubes, therefore suggesting that these types of nanotubes can be preferentially formed from the bulk. The electronic properties of SWCNTs depend on the chirality; all armchair nanotubes are metallic, while zigzag and chiral nanotubes can be metallic or semiconducting, depending on the n and m vectors. - Graphical abstract: DFT/B3LYP were performed to simulate the structural and electronic properties as well as the strain and formation energies of SWZnONTs and SWCNTs with different chiralities as functions of their diameters. - Highlights: • The energies of SWZnONTs converge for chirality with diameters up 20 Å. • SWCNTs electronic properties depend on the chirality. • The properties of SWZnONTs are very similar to those of monolayer surface.

  19. Phosphatidylserine targeted single-walled carbon nanotubes for photothermal ablation of bladder cancer

    Science.gov (United States)

    Virani, Needa A.; Davis, Carole; McKernan, Patrick; Hauser, Paul; Hurst, Robert E.; Slaton, Joel; Silvy, Ricardo P.; Resasco, Daniel E.; Harrison, Roger G.

    2018-01-01

    Bladder cancer has a 60%-70% recurrence rate most likely due to any residual tumour left behind after a transurethral resection (TUR). Failure to completely resect the cancer can lead to recurrence and progression into higher grade tumours with metastatic potential. We present here a novel therapy to treat superficial tumours with the potential to decrease recurrence. The therapy is a heat-based approach in which bladder tumour specific single-walled carbon nanotubes (SWCNTs) are delivered intravesically at a very low dose (0.1 mg SWCNT per kg body weight) followed 24 h later by a short 30 s treatment with a 360° near-infrared light that heats only the bound nanotubes. The energy density of the treatment was 50 J cm-2, and the power density that this treatment corresponds to is 1.7 W cm-2, which is relatively low. Nanotubes are specifically targeted to the tumour via the interaction of annexin V (AV) and phosphatidylserine, which is normally internalised on healthy tissue but externalised on tumours and the tumour vasculature. SWCNTs are conjugated to AV, which binds specifically to bladder cancer cells as confirmed in vitro and in vivo. Due to this specific localisation, NIR light can be used to heat the tumour while conserving the healthy bladder wall. In a short-term efficacy study in mice with orthotopic MB49 murine bladder tumours treated with the SWCNT-AV conjugate and NIR light, no tumours were visible on the bladder wall 24 h after NIR light treatment, and there was no damage to the bladder. In a separate survival study in mice with the same type of orthotopic tumours, there was a 50% cure rate at 116 days when the study was ended. At 116 days, no treatment toxicity was observed, and no nanotubes were detected in the clearance organs or bladder.

  20. Powerful greenhouse gas nitrous oxide adsorption onto intrinsic and Pd doped Single walled carbon nanotube

    International Nuclear Information System (INIS)

    Yoosefian, Mehdi

    2017-01-01

    Highlights: • Investigation of the adsorption of Nitrous oxide on SWCNT and Pd/SWCNT. • Nitrous oxide adsorbed on Pd/SWCNT system demonstrates a strong adsorption. • The Pd/SWCNT is potential sensor for the Nitrous oxide gaseous molecule detection. - Abstract: Density functional studies on the adsorption behavior of nitrous oxide (N 2 O) onto intrinsic carbon nanotube (CNT) and Pd-doped (5,5) single-walled carbon nanotube (Pd-CNT) have been reported. Introduction of Pd dopant facilitates in adsorption of N 2 O on the otherwise inert nanotube as observed from the adsorption energies and global reactivity descriptor values. Among three adsorption features of N 2 O onto CNT, the horizontal adsorption with E ads = −0.16 eV exhibits higher adsorption energy. On the other hand the Pd-CNT exhibit strong affinity toward gas molecule and would cause a huge increase in N 2 O adsorption energies. Chemical and electronic properties of CNT and Pd-CNT in the absence and presence of N 2 O were investigated. Adsorption of N 2 O gas molecule would affect the electronic conductance of Pd-CNT that can serve as a signal of gas sensors and the increased energy gaps demonstrate the formation of more stable systems. The atoms in molecules (AIM) theory and the natural bond orbital (NBO) calculations were performed to get more details about the nature and charge transfers in intermolecular interactions within adsorption process. As a final point, the density of states (DOSs) calculations was achieved to confirm previous results. According to our results, intrinsic CNT cannot act as a suitable adsorbent while Pd-CNT can be introduced as novel detectable complex for designing high sensitive, fast response and high efficient carbon nanotube based gas sensor to detect N 2 O gas as an air pollutant. Our results could provide helpful information for the design and fabrication of the N 2 O sensors.

  1. Powerful greenhouse gas nitrous oxide adsorption onto intrinsic and Pd doped Single walled carbon nanotube

    Science.gov (United States)

    Yoosefian, Mehdi

    2017-01-01

    Density functional studies on the adsorption behavior of nitrous oxide (N2O) onto intrinsic carbon nanotube (CNT) and Pd-doped (5,5) single-walled carbon nanotube (Pd-CNT) have been reported. Introduction of Pd dopant facilitates in adsorption of N2O on the otherwise inert nanotube as observed from the adsorption energies and global reactivity descriptor values. Among three adsorption features of N2O onto CNT, the horizontal adsorption with Eads = -0.16 eV exhibits higher adsorption energy. On the other hand the Pd-CNT exhibit strong affinity toward gas molecule and would cause a huge increase in N2O adsorption energies. Chemical and electronic properties of CNT and Pd-CNT in the absence and presence of N2O were investigated. Adsorption of N2O gas molecule would affect the electronic conductance of Pd-CNT that can serve as a signal of gas sensors and the increased energy gaps demonstrate the formation of more stable systems. The atoms in molecules (AIM) theory and the natural bond orbital (NBO) calculations were performed to get more details about the nature and charge transfers in intermolecular interactions within adsorption process. As a final point, the density of states (DOSs) calculations was achieved to confirm previous results. According to our results, intrinsic CNT cannot act as a suitable adsorbent while Pd-CNT can be introduced as novel detectable complex for designing high sensitive, fast response and high efficient carbon nanotube based gas sensor to detect N2O gas as an air pollutant. Our results could provide helpful information for the design and fabrication of the N2O sensors.

  2. Electrochemically-gated single-molecule electrical devices

    International Nuclear Information System (INIS)

    Guo, Shaoyin; Artés, Juan Manuel; Díez-Pérez, Ismael

    2013-01-01

    In the last decade, single-molecule electrical contacts have emerged as a new experimental platform that allows exploring charge transport phenomena in individual molecular blocks. This novel tool has evolved into an essential element within the Molecular Electronics field to understand charge transport processes in hybrid (bio)molecule/electrode interfaces at the nanoscale, and prospect the implementation of active molecular components into functional nanoscale optoelectronic devices. Within this area, three-terminal single-molecule devices have been sought, provided that they are highly desired to achieve full functionality in logic electronic circuits. Despite the latest experimental developments offer consistent methods to bridge a molecule between two electrodes (source and drain in a transistor notation), placing a third electrode (gate) close to the single-molecule electrical contact is still technically challenging. In this vein, electrochemically-gated single-molecule devices have emerged as an experimentally affordable alternative to overcome these technical limitations. In this review, the operating principle of an electrochemically-gated single-molecule device is presented together with the latest experimental methodologies to built them and characterize their charge transport characteristics. Then, an up-to-date comprehensive overview of the most prominent examples will be given, emphasizing on the relationship between the molecular structure and the final device electrical behaviour

  3. Theoretical prediction of high carrier mobility in single-walled black phosphorus nanotubes

    Science.gov (United States)

    Li, Q. F.; Wang, H. F.; Yang, C. H.; Li, Q. Q.; Rao, W. F.

    2018-05-01

    One-dimensional semiconductors are promising materials for high-performance nanoscale devices. Using the first-principles calculations combined with deformation potential approximation, we study the electronic structures and carrier transport properties of black phosphorus nanotubes (BPNTs). It is found that both armchair and zigzag BPNTs with diameter 13.5-18.5 Å are direct bandgap semiconductors. At a similar diameter, the carrier mobility of zigzag BPNT is one order of magnitude larger than that of armchair BPNT. For armchair BPNTs, the electron mobility is about 90.70-155.33 cm2 V-1 s-1 at room temperature, which is about three times of its hole counterpart. For zigzag BPNTs, the maximum mobility can reach 2.87 ×103 cm2 V-1 s-1. Furthermore, the electronic properties can be effectively tuned by the strain. For zigzag (0,13) nanotube, there is a direct-to-indirect band gap transition at a tensile strain of about 6%. Moreover, the electron mobility is boosted sharply by one order of magnitude by applying the compressive or tensile strain. The electron mobility increases to 14.05 ×103 cm2 V-1 s-1 at a tensile strain of 9%. Our calculations highlight the tunable electronic properties and superior carrier mobility of BPNTs that are promising for interesting applications in future nano-electronic devices.

  4. Studies of single walled carbon nanotubes for biomedical, mechanical and electrical applications using atomic force microscopy

    Science.gov (United States)

    Lahiji, Roya Roientan

    The promise of carbon nanotubes to provide high-strength composites implies that carbon nanotubes might find widespread use throughout the world, implying that humans everywhere will be exposed to carbon nanotube-containing materials. In order to study what effects if any carbon nanotubes might have on the function of living cells, we have studied the association of single stranded DNA (ssDNA) with single wall carbon nanotubes (SWCNTs) as a first step toward understanding the interaction of SWCNTs with living matter. Studies have been performed on both as-received and chemically oxidized SWCNTs to better understand the preferential association of ssDNA with SWCNTs. Samples of T30 ssDNA:SWCNT were examined under ambient conditions using non-contact Atomic Force Microscopy (AFM)) techniques. AFM images of well-dispersed, as-received SWCNTs revealed isolated features on the SWCNT that are 1.4 to 2.8 nm higher than the bare SWCNT itself. X-ray Photoemission Spectroscopy (XPS) confirmed these features to be T30 ssDNA in nature. Chemically oxidizing SWCNTs before dispersion by sonication is found to be an effective way to increase the number of T30 ssDNA features. A series of experiments showed that free radical scavengers such as ascorbic acid and trolox can effectively prevent the conjugation of ssDNA to SWCNTs, suggesting a significant role of free radicals in this association. Also hybridization of the complimentary ssDNA sequences showed the covalent nature of this association. These results are important to understanding the precise mechanism of ssDNA:SWCNT association and provide valuable information for future use in electronics, biosensors and as a possible drug carrier into individual cells. If SWCNTs are used in biosensor or circuit design applications then it is important to note how much energy can be stored in a SWCNT based on its shape and configuration before a permanent damage is introduced to it. Therefore a study has been done on bending SWCNTs into

  5. Single Gold Nanorod Charge Modulation in an Ion Gel Device.

    Science.gov (United States)

    Collins, Sean S E; Wei, Xingzhan; McKenzie, Thomas G; Funston, Alison M; Mulvaney, Paul

    2016-11-09

    A reliable and reproducible method to rapidly charge single gold nanocrystals in a solid-state device is reported. Gold nanorods (Au NRs) were integrated into an ion gel capacitor, enabling them to be charged in a transparent and highly capacitive device, ideal for optical transmission. Changes in the electron concentration of a single Au NR were observed with dark-field imaging spectroscopy via localized surface plasmon resonance (LSPR) shifts in the scattering spectrum. A time-resolved, laser-illuminated, dark-field system was developed to enable direct measurement of single particle charging rates with time resolution below one millisecond. The added sensitivity of this new approach has enabled the optical detection of fewer than 110 electrons on a single Au NR. Single wavelength resonance shifts provide a much faster, more sensitive method for all surface plasmon-based sensing applications.

  6. Femtosecond laser fabrication of optofluidic devices for single cell manipulation

    Directory of Open Access Journals (Sweden)

    Bragheri Francesca

    2015-01-01

    Full Text Available In this work we fabricate and validate two optofludic devices for the manipulation and analysis of single cells. The chips are fabricated by femtosecond laser micromachining exploiting the 3D capabilities of the technique and the inherent perfect alignment between microfluidic channels and optical networks. Both devices have been validated by probing the mechanical properties of different cancer cell lines, which are expected to show different elasticity because of their different metastatic potential.

  7. Defects in Individual Semiconducting Single Wall Carbon Nanotubes: Raman Spectroscopic and in Situ Raman Spectroelectrochemical Study

    Czech Academy of Sciences Publication Activity Database

    Kalbáč, Martin; Hsieh, Y. P.; Farhat, H.; Kavan, Ladislav; Hofmann, M.; Kong, J.; Dresselhaus, M. S.

    2010-01-01

    Roč. 10, č. 11 (2010), s. 4619-4626 ISSN 1530-6984 R&D Projects: GA ČR GC203/07/J067; GA AV ČR IAA400400804; GA AV ČR IAA400400911; GA AV ČR KAN200100801; GA MŠk ME09060 Institutional research plan: CEZ:AV0Z40400503 Keywords : single wall carbon nanotubes * Raman spectroscopy * defects Subject RIV: CG - Electrochemistry Impact factor: 12.186, year: 2010

  8. Structural profiling and biological performance of phospholipid-hyaluronan functionalized single-walled carbon nanotubes

    DEFF Research Database (Denmark)

    Dvash, Ram; Khatchatouriants, Artium; Solmesky, Leonardo J

    2013-01-01

    In spite of significant insolubility and toxicity, carbon nanotubes (CNTs) erupt into the biomedical research, and create an increasing interest in the field of nanomedicine. Single-walled CNTs (SWCNTs) are highly hydrophobic and have been shown to be toxic while systemically administrated. Thus...... an inflammatory response in macrophages as evidenced by the cytokine profiling and the use of image-based high-content analysis approach in contrast to non-modified CNTs. In addition, systemic administration of CNT-PL-HA into healthy C57BL/6 mice did not alter the total number of leukocytes nor increased liver...

  9. Purification and alignment of arc-synthesis single-walled carbon nanotube bundles

    Science.gov (United States)

    Huang, Houjin; Kajiura, Hisashi; Yamada, Atsuo; Ata, Masafumi

    2002-04-01

    We report here a scalable method for purification and alignment of single-walled carbon nanotubes (SWNT) in an aqueous solution. Arc-synthesis soot containing SWNTs is first treated with a concentrated nitric acid. After removal of most of the impurities and water, macroscopic and well-aligned SWNT bundles up to several centimeters long are formed in a rotary evaporator. Alignment of the SWNT bundles is ascribed to the liquid flow induced by rotary evaporation and van der Waals interactions among the bundles. The aligned SWNT bundles are further purified by ultrasonic Soxhlet extraction and annealing.

  10. Structure of single-wall carbon nanotubes purified and cut using polymer

    Science.gov (United States)

    Zhang, M.; Yudasaka, M.; Koshio, A.; Jabs, C.; Ichihashi, T.; Iijima, S.

    2002-01-01

    Following on from our previous report that a monochlorobenzene solution of polymethylmethacrylate is useful for purifying and cutting single-wall carbon nanotubes (SWNTs) and thinning SWNT bundles, we show in this report that polymer and residual amorphous carbon can be removed by burning in oxygen gas. The SWNTs thus obtained had many holes (giving them a worm-eaten look) and were thermally unstable. Such severe damage caused by oxidation is unusual for SWNTs; we think that they were chemically damaged during ultrasonication in the monochlorobenzene solution of polymethylmethacrylate.

  11. Molecular adsorption study of nicotine and caffeine on single-walled carbon nanotubes from first principles

    Science.gov (United States)

    Lee, Hyung-June; Kim, Gunn; Kwon, Young-Kyun

    2013-08-01

    Using first-principles calculations, we investigate the electronic structures and binding properties of nicotine and caffeine adsorbed on single-walled carbon nanotubes to determine whether CNTs are appropriate for filtering or sensing nicotine and caffeine molecules. We find that caffeine adsorbs more strongly than nicotine. The different binding characteristics are discussed by analyzing the modification of the electronic structure of the molecule-adsorbed CNTs. We also calculate the quantum conductance of the CNTs in the presence of nicotine or caffeine adsorbates and demonstrate that the influence of caffeine is stronger than nicotine on the conductance of the host CNT.

  12. Heating-Enhanced Dielectrophoresis for Aligned Single-Walled Carbon Nanotube Film of Ultrahigh Density.

    Science.gov (United States)

    Gu, Qingyuan; Guezo, Maud; Folliot, Hervé; Batte, Thomas; Loualiche, Slimane; Stervinou, Julie

    2017-12-01

    In this paper, we demonstrate that the alignment density of individualized single-walled carbon nanotubes (SWCNTs) can be greatly improved by heating-enhanced dielectrophoresis (HE-DEP) process. The observations by scanning electron microscope (SEM) suggest ultrahigh alignment density and good alignment quality of SWCNTs. The intuitive alignment density of individualized SWCNTs is much higher than the currently reported best results. The reason of this HE-DEP process is explained by simulation work and ascribed to the heating-enhanced convection process, and the "convection force" induced by the heating effect is assessed in a novel way.

  13. Fabrication and electrochemical behavior of single-walled carbon nanotube/graphite-based electrode

    International Nuclear Information System (INIS)

    Moghaddam, Abdolmajid Bayandori; Ganjali, Mohammad Reza; Dinarvand, Rassoul; Razavi, Taherehsadat; Riahi, Siavash; Rezaei-Zarchi, Saeed; Norouzi, Parviz

    2009-01-01

    An electrochemical method for determining the dihydroxybenzene derivatives on glassy carbon (GC) has been developed. In this method, the performance of a single-walled carbon nanotube (SWCNT)/graphite-based electrode, prepared by mixing SWCNTs and graphite powder, was described. The resulting electrode shows an excellent behavior for redox of 3,4-dihydroxybenzoic acid (DBA). SWCNT/graphite-based electrode presents a significant decrease in the overvoltage for DBA oxidation as well as a dramatic improvement in the reversibility of DBA redox behavior in comparison with graphite-based and glassy carbon (GC) electrodes. In addition, scanning electron microscopy (SEM) and atomic force microscopy (AFM) procedures performed for used SWCNTs

  14. Effect of Surface Modification on the Hansen Solubility Parameters of Single-Walled Carbon Nanotubes

    DEFF Research Database (Denmark)

    Ma, Jing; Larsen, Mikael

    2013-01-01

    In this work, seven types of surface-modified single-walled carbon nanotubes (SWNTs) were studied by X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy to investigate the functional groups and extent of functionalization. Hansen solubility parameters were determined based on observations...... of the sedimentation and swollen states of the SWNTs in solvents after ultrasonication, and the results were compared with the hydrodynamic sizes of the SWNTs evaluated by the dynamic light scattering method. We found that the solubility of SWNTs is related to their functional groups and degree of functionalization...

  15. BUCKLING BEHAVIOUR OF SINGLE-WALLED CARBON NANOTUBES UNDER AXIAL LOADING

    Directory of Open Access Journals (Sweden)

    Grzegorz Litak

    2017-03-01

    Full Text Available We investigate a single walled Carbon Nanotube under an axially directed compressive line loading applied at both of its edges. The expected buckling behavior we study by application of a molecular computation approach. We formulate a global potential and search for its minimum to obtain the equilibrium configuration. Using besides the main parameter, which is the value of the loading, as second parameter the diameter of the tube, we are able to define the critical value of the diameter, for which we obtain the coincident case of local shell buckling.

  16. Fine Structure of the Low-Frequency Raman Phonon Bands of Single-Wall Carbon Nanotubes

    Science.gov (United States)

    Iliev, M. N.; Litvinchuk, A. P.; Arepalli, S.; Nikolaev, P.; Scott, C. D.

    1999-01-01

    The Raman spectra of singled-wall carbon nanotubes (SWNT) produced by laser and are process were studied between 5 and 500 kappa. The line width vs. temperature dependence of the low-frequency Raman bands between 150 and 200/ cm deviates from that expected for phonon decay through phonon-phonon scattering mechanism. The experimental results and their analysis provided convincing evidence that each of the low-frequency Raman lines is a superposition of several narrower Raman lines corresponding to tubes of nearly the same diameter. The application of Raman spectroscopy to probe the distribution of SWNT by both diameter and chirality is discussed.

  17. Surprising synthesis of nanodiamond from single-walled carbon nanotubes by the spark plasma sintering process

    Science.gov (United States)

    Mirzaei, Ali; Ham, Heon; Na, Han Gil; Kwon, Yong Jung; Kang, Sung Yong; Choi, Myung Sik; Bang, Jae Hoon; Park, No-Hyung; Kang, Inpil; Kim, Hyoun Woo

    2016-10-01

    Nanodiamond (ND) was successfully synthesized using single-walled carbon nanotubes (SWCNTs) as a pure solid carbon source by means of a spark plasma sintering process. Raman spectra and X-ray diffraction patterns revealed the generation of the cubic diamond phase by means of the SPS process. Lattice-resolved TEM images confirmed that diamond nanoparticles with a diameter of about ˜10 nm existed in the products. The NDs were generated mainly through the gas-phase nucleation of carbon atoms evaporated from the SWCNTs. [Figure not available: see fulltext.

  18. Observation and Characterization of Fragile Organometallic Molecules Encapsulated in Single-Wall Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Daisuke Ogawa

    2014-01-01

    Full Text Available Thermally fragile tris(η5-cyclopentadienylerbium (ErCp3 molecules are encapsulated in single-wall carbon nanotubes (SWCNTs with high yield. We realized the encapsulation of ErCp3 with high filling ratio by using high quality SWCNTs at an optimized temperature under higher vacuum. Structure determination based on high-resolution transmission electron microscope observations together with the image simulations reveals the presence of almost free rotation of each ErCp3 molecule in SWCNTs. The encapsulation is also confirmed by X-ray diffraction. Trivalent character of Er ions (i.e., Er3+ is confirmed by X-ray absorption spectrum.

  19. The reaction of lithium metal vapor with single walled carbon nanotubes of large diameters

    Czech Academy of Sciences Publication Activity Database

    Kalbáč, Martin; Kavan, Ladislav; Dunsch, L.

    2009-01-01

    Roč. 246, 11-12 (2009), s. 2428-2431 ISSN 0370-1972 R&D Projects: GA AV ČR IAA400400911; GA AV ČR KAN200100801; GA AV ČR IAA400400804; GA ČR GC203/07/J067; GA MŠk LC510 Institutional research plan: CEZ:AV0Z40400503 Keywords : lithium * single walled carbon nanotubes * Raman spectroscopy Subject RIV: CG - Electrochemistry Impact factor: 1.150, year: 2009

  20. Purification of carbon nanotubes via selective heating

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, John A.; Wilson, William L.; Jin, Sung Hun; Dunham, Simon N.; Xie, Xu; Islam, Ahmad; Du, Frank; Huang, Yonggang; Song, Jizhou

    2017-11-21

    The present invention provides methods for purifying a layer of carbon nanotubes comprising providing a precursor layer of substantially aligned carbon nanotubes supported by a substrate, wherein the precursor layer comprises a mixture of first carbon nanotubes and second carbon nanotubes; selectively heating the first carbon nanotubes; and separating the first carbon nanotubes from the second carbon nanotubes, thereby generating a purified layer of carbon nanotubes. Devices benefiting from enhanced electrical properties enabled by the purified layer of carbon nanotubes are also described.

  1. Insertion of Short Amino-Functionalized Single-Walled Carbon Nanotubes into Phospholipid Bilayer Occurs by Passive Diffusion

    Science.gov (United States)

    Kraszewski, Sebastian; Bianco, Alberto; Tarek, Mounir; Ramseyer, Christophe

    2012-01-01

    Carbon nanotubes have been proposed to be efficient nanovectors able to deliver genetic or therapeutic cargo into living cells. However, a direct evidence of the molecular mechanism of their translocation across cell membranes is still needed. Here, we report on an extensive computational study of short (5 nm length) pristine and functionalized single-walled carbon nanotubes uptake by phospholipid bilayer models using all-atom molecular dynamics simulations. Our data support the hypothesis of a direct translocation of the nanotubes through the phospholipid membrane. We find that insertion of neat nanotubes within the bilayer is a “nanoneedle” like process, which can often be divided in three consecutive steps: landing and floating, penetration of the lipid headgroup area and finally sliding into the membrane core. The presence of functional groups at moderate concentrations does not modify the overall scheme of diffusion mechanism, provided that their deprotonated state favors translocation through the lipid bilayer. PMID:22815794

  2. Investigating interfacial contact configuration and behavior of single-walled carbon nanotube-based nanodevice with atomistic simulations

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Jianlei, E-mail: cjlxjtu@mail.xjtu.edu.cn; Zhang, Jianwei [Xi’an Jiaotong University, State Key Laboratory for Manufacturing Systems Engineering (China); He, Xiaoqiao, E-mail: bcxqhe@cityu.edu.hk [City University of Hong Kong, Department of Architecture and Civil Engineering (Hong Kong); Mei, Xuesong; Wang, Wenjun [Xi’an Jiaotong University, State Key Laboratory for Manufacturing Systems Engineering (China); Yang, Xinju [Fudan University, State Key Laboratory of Surface Physics and Department of Physics (China); Xie, Hui; Yang, Lijun; Wang, Yang [Harbin Institute of Technology, State Key Laboratory of Robotics and Systems (China)

    2017-03-15

    Carbon nanotubes (CNTs), including single-walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs), are considered to be the promising candidates for next-generation interconnects with excellent physical and chemical properties ranging from ultrahigh mechanical strength, to electrical properties, to thermal conductivity, to optical properties, etc. To further study the interfacial contact configurations of SWNT-based nanodevice with a 13.56-Å diameter, the corresponding simulations are carried out with the molecular dynamic method. The nanotube collapses dramatically into the surface with the complete collapse on the Au/Ag/graphite electrode surface and slight distortion on the Si/SiO{sub 2} substrate surface, respectively. The related dominant mechanism is studied and explained. Meanwhile, the interfacial contact configuration and behavior, depended on other factors, are also analyzed in this article.

  3. Probing nuclear dynamics and architecture using single-walled carbon nanotubes

    Science.gov (United States)

    Jung, Yoon; Li, Junang; Fakhri, Nikta

    Chromatin is a multiscale dynamic architecture that acts as a template for many biochemical processes such as transcription and DNA replication. Recent developments such as Hi-C technology enable an identification of chromatin interactions across an entire genome. However, a single cell dynamic view of chromatin organization is far from understood. We discuss a new live cell imaging technique to probe the dynamics of the nucleus at a single cell level using single-walled carbon nanotubes (SWNTs). SWNTs are non-perturbing rigid rods (diameter of 1 nm and length of roughly 100 nm) that fluoresce in the near infrared region. Due to their high aspect ratio, they can diffuse in tight spaces and report on the architecture and dynamics of the nucleoplasm. We develop 3D imaging and tracking of SWNTs in the volume of the nucleus using double helix point spread function microscopy (DH-PSF) and discuss the capabilities of the DH-PSF for inferring the 3D orientation of nanotubes based on vectorial diffraction theory.

  4. Semiconducting single-walled carbon nanotubes sorting with a removable solubilizer based on dynamic supramolecular coordination chemistry.

    Science.gov (United States)

    Toshimitsu, Fumiyuki; Nakashima, Naotoshi

    2014-10-03

    Highly pure semiconducting single-walled carbon nanotubes (SWNTs) are essential for the next generation of electronic devices, such as field-effect transistors and photovoltaic applications; however, contamination by metallic SWNTs reduces the efficiency of their associated devices. Here we report a simple and efficient method for the separation of semiconducting- and metallic SWNTs based on supramolecular complex chemistry. We here describe the synthesis of metal-coordination polymers (CP-Ms) composed of a fluorene-bridged bis-phenanthroline ligand and metal ions. On the basis of a difference in the 'solubility product' of CP-M-solubilized semiconducting SWNTs and metallic SWNTs, we readily separated semiconducting SWNTs. Furthermore, the CP-M polymers on the SWNTs were simply removed by adding a protic acid and inducing depolymerization to the monomer components. We also describe molecular mechanics calculations to reveal the difference of binding and wrapping mode between CP-M/semiconducting SWNTs and CP-M/metallic SWNTs. This study opens a new stage for the use of such highly pure semiconducting SWNTs in many possible applications.

  5. Optical properties of 0.4-nm single-wall carbon nanotubes aligned in channels of AlPO4-5 single crystals

    NARCIS (Netherlands)

    Li, ZM; Liu, HJ; Ye, JT; Chan, CT; Tang, ZK

    Single-walled carbon nanotubes (SWNTs) of 0.4 nm in diameter are produced inside channels of microporous zeolite single crystals. Three possible structures: (5,0), (4,2), and (3,3) contribute to three bands at 1.37, 2.1, and 3.1 eV in optical absorption spectra. The direct correspondence between

  6. Self Assembled Carbon Nanotube Enhanced Ultracapacitors, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this NASA STTR program is to develop single wall carbon nanotube (SWCNT) based ultracapacitors for energy storage devices (ESD) application, using...

  7. Optical and Electrical Detection of Single Molecule Translocation through Carbon Nanotubes

    Science.gov (United States)

    Song, Weisi; Pang, Pei; He, Jin; Lindsay, Stuart

    2013-01-01

    Ion current through a single-walled carbon nanotube (SWCNT) was monitored at the same time as fluorescence was recorded from charged dye molecules translocating through the SWCNT. Fluorescence bursts generally follow ion-current peaks with a delay time consistent with diffusion from the end of the SWCNT to the fluorescence collection point. The fluorescence amplitude distribution of the bursts is consistent with single molecule signals. Thus each peak in the ion current flowing through the SWCNT is associated with the translocation of a single molecule. Ion current peaks (as opposed to blockades) were produced by both positively (Rhodamine 6G) and negatively (Alexa 546) charged molecules, showing that the charge filtering responsible for the current bursts is caused by the molecules themselves. PMID:23248975

  8. Interactions of phospholipid monolayer with single-walled carbon nanotube wrapped by lysophospholipid

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Siwool; Kim, Hyungsu, E-mail: hkim@dku.edu

    2012-10-01

    In this study, we prepared single-walled carbon nanotubes (SWNTs) wrapped by 1-stearoyl-2-hydroxy-sn-glycero-3-phospho-(1 Prime -rac-glycerol) (LPG), leading to a complex of SWNT-LPG. In an attempt to investigate the interactions of SWNT-LPG with a mimicked cell surface, SWNT-LPG solution was injected into the sub-phase of Langmuir trough to form a mixed monolayer with dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylglycerol (DPPG), respectively. In addition to the measurement of typical surface pressure-area isotherms under compression mode, area changes occurring during insertion of SWNT-LPG into the monolayer were recorded at various surface pressures. Changes in surface potential were also measured for evident tracing of the degree of interactions between sub-phase and monolayer. A systematic comparison of relaxation patterns and insertion behavior along with surface potential data provided a rational basis to distinguish the degree of interactions between SWNT-LPG and the designated monolayer. The observed tendencies were found to be in accordance with the surface topography as revealed by the tapping mode atomic force microscopy. It was consistently observed that SWNT-LPG interacted with DPPC to a greater extent than with DPPG, when the sufficient coverage of nanotube surface by LPG molecules was assured. - Highlights: Black-Right-Pointing-Pointer Complex of single-walled carbon nanotubes and lysophospholipid (SWNT-LPG) is formed. Black-Right-Pointing-Pointer Composite monolayer is formed by inserting SWNT-LPG into the phospholipid monolayer. Black-Right-Pointing-Pointer We measure area-pressure responses and dipole potentials during the insertion process. Black-Right-Pointing-Pointer Properties of composite monolayer depend on the kind of phospholipid and LPG content.

  9. Synergistic Effects in the Gas Sensitivity of Polypyrrole/Single Wall Carbon Nanotube Composites

    Directory of Open Access Journals (Sweden)

    Nguyen Duc Thien

    2012-06-01

    Full Text Available Polypyrrole/single wall carbon nanotube composites were synthesized by in-situ chemical polymerization using pyrrole (PPy as precursor and single wall carbon nanotubes (SWNTs as additive component. Electron microscope images reveal that SWNTs component acts as nucleation sites for PPy growth in the form of spherical and cylindrical core-shell structures. The SWNTs/PPy core-shell results in thin n-p junctions which modify the PPy bandgap and reduce the work function of electrons. As a result of the strong coupling, Raman and IR spectra show that the PPy undergoes a transition from polaron to bipolaron state, i.e., indicating an increase in the conductivity. In the UV-Vis spectra, the 340 nm adsorption band (π*-π transition exhibits a red shift, while the 460 nm adsorption band (bipolaron transition experiences a blue shift indicating a change in electronic structure and a relocation of polaron levels in the band gap of PPy. The modification in PPy electronic structure brings in a synergistic effect in sensing feature. Upon exposure to oxygen (an oxidizing agent and NH3 gas (a reducing agent, the PPy/SWNTs nanocomposite shows an enhancement in sensitivity exceeding ten folds in comparison with those of PPy or SWNTs.

  10. A Failure Criterion for Single-Walled Carbon Nanotubes Based on Molecular Mechanics

    Science.gov (United States)

    Avila, Antonio; Lacerda, Guilherme

    2008-03-01

    Single-walled carbon nanotubes (SWNT) are the natural choice for high performance materials. The problem, however, rises when the experimental data are compared against each other. The large variability of experimental data lead to development of a new set of numerical simulations called molecular mechanics, which is a ``symbiotic'' association of molecular dynamics and solid mechanics. This papers deals with a molecular mechanics simulations of single-walled carbon nanotubes. Three SWNT configurations and its combinations were simulated, i.e. armchair, zigzag and chiral. The failure criterion introduced is based on modified Morse's potential with dissociation energy of 124 Kcal/mol and an inflection point considered is around 13% of strain. The numerical data are in good agreement with data from Belytschko et al. (2002) where the failure occurred at 10.6% strain at 65.2 GPa of stress. To be able to identify the highest stress concentration region, one end of the SWNT all degrees-of-freedom were fixed and a prescribed axial displacement was applied at the opposite end. The Sadoc (chiral-chiral) configuration had the highest stress at the smallest chiral SWNT. For the Dunlap configuration (chiral-zigzag) the highest stress occurred at chiral part close to the pentagon location.

  11. Decolorisation of Reactive Red 120 Dye by Using Single-Walled Carbon Nanotubes in Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Edris Bazrafshan

    2013-01-01

    Full Text Available Dyes are one of the most hazardous chemical compound classes found in industrial effluents and need to be treated since their presence in water bodies reduces light penetration, precluding the photosynthesis of aqueous flora. In the present study, single-walled carbon nanotubes (SWCNTs was used as an adsorbent for the successful removal of Reactive Red 120 (RR-120 textile dye from aqueous solutions. The effect of various operating parameters such as initial concentration of dye, contact time, adsorbent dosage and initial pH was investigated in order to find the optimum adsorption conditions. Equilibrium isotherms were used to identify the possible mechanism of the adsorption process. The optimum pH for removing of RR-120 dye from aqueous solutions was found to be 5 and for this condition maximum predicted adsorption capacity for RR-120 dye was obtained as 426.49 mg/g. Also, the equilibrium data were also fitted to the Langmuir, Freundlich and BET equilibrium isotherm models. It was found that the data fitted to BET (R2=0.9897 better than Langmuir (R2=0.9190 and Freundlich (R2=0.8819 model. Finally it was concluded that the single-walled carbon nanotubes can be used for dye removal from aqueous solutions.

  12. Giant Magnetoresistance in Carbon Nanotubes with Single-Molecule Magnets TbPc2.

    Science.gov (United States)

    Krainov, Igor V; Klier, Janina; Dmitriev, Alexander P; Klyatskaya, Svetlana; Ruben, Mario; Wernsdorfer, Wolfgang; Gornyi, Igor V

    2017-07-25

    We present experimental results and a theoretical model for the gate-controlled spin-valve effect in carbon nanotubes with side-attached single-molecule magnets TbPc 2 (Terbium(III) bis-phthalocyanine). These structures show a giant magnetoresistance up to 1000% in experiments on single-wall nanotubes that are tunnel-coupled to the leads. The proposed theoretical model combines the spin-dependent Fano effect with Coulomb blockade and predicts a spin-spin interaction between the TbPc 2 molecules, mediated by conducting electrons via the charging effect. This gate-tuned interaction is responsible for the stable magnetic ordering of the inner spins of the molecules in the absence of magnetic field. In the case of antiferromagnetic arrangement, electrons with either spin experience the scattering by the molecules, which results in blocking the linear transport. In strong magnetic fields, the Zeeman energy exceeds the effective antiferromagnetic coupling and one species of electrons is not scattered by molecules, which leads to a much lower total resistance at the resonant values of gate voltage, and hence to a supramolecular spin-valve effect.

  13. Single Event Effects in FPGA Devices 2015-2016

    Science.gov (United States)

    Berg, Melanie; LaBel, Kenneth; Pellish, Jonathan

    2016-01-01

    This presentation provides an overview of single event effects in FPGA devices 2015-2016 including commercial Xilinx V5 heavy ion accelerated testing, Xilinx Kintex-7 heavy ion accelerated testing, mitigation study, and investigation of various types of triple modular redundancy (TMR) for commercial SRAM based FPGAs.

  14. Tunable color parallel tandem organic light emitting devices with carbon nanotube and metallic sheet interlayers

    International Nuclear Information System (INIS)

    Oliva, Jorge; Desirena, Haggeo; De la Rosa, Elder; Papadimitratos, Alexios; Zakhidov, Anvar A.

    2015-01-01

    Parallel tandem organic light emitting devices (OLEDs) were fabricated with transparent multiwall carbon nanotube sheets (MWCNT) and thin metal films (Al, Ag) as interlayers. In parallel monolithic tandem architecture, the MWCNT (or metallic films) interlayers are an active electrode which injects similar charges into subunits. In the case of parallel tandems with common anode (C.A.) of this study, holes are injected into top and bottom subunits from the common interlayer electrode; whereas in the configuration of common cathode (C.C.), electrons are injected into the top and bottom subunits. Both subunits of the tandem can thus be monolithically connected functionally in an active structure in which each subunit can be electrically addressed separately. Our tandem OLEDs have a polymer as emitter in the bottom subunit and a small molecule emitter in the top subunit. We also compared the performance of the parallel tandem with that of in series and the additional advantages of the parallel architecture over the in-series were: tunable chromaticity, lower voltage operation, and higher brightness. Finally, we demonstrate that processing of the MWCNT sheets as a common anode in parallel tandems is an easy and low cost process, since their integration as electrodes in OLEDs is achieved by simple dry lamination process

  15. On-chip mitochondrial assay microfluidic devices and protein nanopore/nanotube hybrid transistor

    Science.gov (United States)

    Lim, Taesun

    Tremendous efforts to understand the cause, mechanism of development and the way to treat various diseases as well as an early diagnosis have been made so far and people are still working hardly on these researches. Even now, countless people are suffering from diseases such as Alzhemer's disease, Parkinson's disease, diabetes and cancer without knowing clues to cure their diseases completely. Generally speaking, we still have a long way to go through to comprehensively figure out these our long-lasting homeworks. One of possible solutions is to merge current advanced technology and science together to find a powerful synergetic effect for a specific purpose that can be tailored depending on user's need. Here this research tried to put nanotechnology and biological science together to find a way to resolve current challenges by developing a new generation of the analytical sensing device. Mitochondrial functions and biological roles in regulating life and death control will be discussed indicating mitochondrion is a crucial organism to monitor to obtain important information regarding degenerative diseases and aging process. On-chip mitochondrial functional assay microsensor that could facilitate the mitochondrial evaluation will be extensively demonstrated and discussed in both technical and biological perspectives. The novel fusion technological approach will be demonstrated by combining artificial cell membrane with carbon nanotube electronics to interrogate interactions between biomolecules and electronic circuitries. In addition, molecular dynamics at the cell membrane could be investigated closely which can help understand the cell-cell communication and the regulation of ion transport.

  16. Dispersion of single-wall carbon nanotubes with supramolecular Congo red - properties of the complexes and mechanism of the interaction.

    Science.gov (United States)

    Jagusiak, Anna; Piekarska, Barbara; Pańczyk, Tomasz; Jemioła-Rzemińska, Małgorzata; Bielańska, Elżbieta; Stopa, Barbara; Zemanek, Grzegorz; Rybarska, Janina; Roterman, Irena; Konieczny, Leszek

    2017-01-01

    A method of dispersion of single-wall carbon nanotubes (SWNTs) in aqueous media using Congo red (CR) is proposed. Nanotubes covered with CR constitute the high capacity system that provides the possibility of binding and targeted delivery of different drugs, which can intercalate into the supramolecular, ribbon-like CR structure. The study revealed the presence of strong interactions between CR and the surface of SWNTs. The aim of the study was to explain the mechanism of this interaction. The interaction of CR and carbon nanotubes was studied using spectral analysis of the SWNT-CR complex, dynamic light scattering (DLS), differential scanning calorimetry (DSC) and microscopic methods: atomic force microscopy (AFM), transmission (TEM), scanning (SEM) and optical microscopy. The results indicate that the binding of supramolecular CR structures to the surface of the nanotubes is based on the "face to face stacking". CR molecules attached directly to the surface of the nanotubes can bind further, parallel-oriented molecules and form supramolecular and protruding structures. This explains the high CR binding capacity of carbon nanotubes. The presented system - containing SWNTs covered with CR - offers a wide range of biomedical applications.

  17. Single cell array impedance analysis in a microfluidic device

    Science.gov (United States)

    Altinagac, Emre; Taskin, Selen; Kizil, Huseyin

    2016-10-01

    Impedance analysis of single cells is presented in this paper. Following the separation of a target cell type by dielectrophoresis in our previous work, this paper focuses on capturing the cells as a single array and performing impedance analysis to point out the signature difference between each cell type. Lab-on-a-chip devices having a titanium interdigitated electrode layer on a glass substrate and a PDMS microchannel are fabricated to capture each cell in a single form and perform impedance analysis. HCT116 (homosapiens colon colorectal carcin) and HEK293 (human embryonic kidney) cells are used in our experiments.

  18. Controlled growth and electrical characterization of bent single-walled carbon nanotubes

    Science.gov (United States)

    Huang, Jun; Choi, Won Bong

    2008-12-01

    The frequency of appearance and curvature of zigzag shaped single-walled carbon nanotubes (SWNTs) are tailored by adjusting the gas flow rate, and changing the gas flow direction with respect to the step-edges on a single-crystal quartz substrate. The electrical resistance of SWNTs is found to increase with the number of bends. The resistance in SWNT segments with sharp curvature is observed to be 10-880 kΩ µm-1 higher than that in segments with smooth curvature. The increment in resistance may be attributed to the introduction of topological defects and heterojunctions at the curved part. Our results suggest the possibility of growing SWNTs with multiple-bend geometry in a simple one-step process and modulating the conductance of SWNTs by controlling the number of bends and the curvature of bends.

  19. Predicting excitonic gaps of semiconducting single-walled carbon nanotubes from a field theoretic analysis

    Science.gov (United States)

    Konik, Robert M.; Sfeir, Matthew Y.; Misewich, James A.

    2015-02-01

    We demonstrate that a nonperturbative framework for the treatment of the excitations of single-walled carbon nanotubes based upon a field theoretic reduction is able to accurately describe experiment observations of the absolute values of excitonic energies. This theoretical framework yields a simple scaling function from which the excitonic energies can be read off. This scaling function is primarily determined by a single parameter, the charge Luttinger parameter of the tube, which is in turn a function of the tube chirality, dielectric environment, and the tube's dimensions, thus expressing disparate influences on the excitonic energies in a unified fashion. We test this theory explicitly on the data reported by Dukovic et al. [Nano Lett. 5, 2314 (2005), 10.1021/nl0518122] and Sfeir et al. [Phys. Rev. B 82, 195424 (2010), 10.1103/PhysRevB.82.195424] and so demonstrate the method works over a wide range of reported excitonic spectra.

  20. Magnetoexcitons and Faraday rotation in single-walled carbon nanotubes and graphene nanoribbons

    Science.gov (United States)

    Have, Jonas; Pedersen, Thomas G.

    2018-03-01

    The magneto-optical response of single-walled carbon nanotubes (CNTs) and graphene nanoribbons (GNRs) is studied theoretically, including excitonic effects. Both diagonal and nondiagonal response functions are obtained and employed to compute Faraday rotation spectra. For single-walled CNTs in a parallel field, the results show field-dependent splitting of the exciton absorption peaks caused by brightening a dark exciton state. Similarly, for GNRs in a perpendicular magnetic field, we observe a field-dependent shift of the exciton peaks and the emergence of an absorption peak above the energy gap. Results show that excitonic effects play a significant role in the optical response of both materials, particularly for the off-diagonal tensor elements.

  1. High-Purity Semiconducting Single-Walled Carbon Nanotubes: A Key Enabling Material in Emerging Electronics.

    Science.gov (United States)

    Lefebvre, Jacques; Ding, Jianfu; Li, Zhao; Finnie, Paul; Lopinski, Gregory; Malenfant, Patrick R L

    2017-10-17

    Semiconducting single-walled carbon nanotubes (sc-SWCNTs) are emerging as a promising material for high-performance, high-density devices as well as low-cost, large-area macroelectronics produced via additive manufacturing methods such as roll-to-roll printing. Proof-of-concept demonstrations have indicated the potential of sc-SWCNTs for digital electronics, radiofrequency circuits, radiation hard memory, improved sensors, and flexible, stretchable, conformable electronics. Advances toward commercial applications bring numerous opportunities in SWCNT materials development and characterization as well as fabrication processes and printing technologies. Commercialization in electronics will require large quantities of sc-SWCNTs, and the challenge for materials science is the development of scalable synthesis, purification, and enrichment methods. While a few synthesis routes have shown promising results in making near-monochiral SWCNTs, gram quantities are available only for small-diameter sc-SWCNTs, which underperform in transistors. Most synthesis routes yield mixtures of SWCNTs, typically 30% metallic and 70% semiconducting, necessitating the extraction of sc-SWCNTs from their metallic counterparts in high purity using scalable postsynthetic methods. Numerous routes to obtain high-purity sc-SWCNTs from raw soot have been developed, including density-gradient ultracentrifugation, chromatography, aqueous two-phase extraction, and selective DNA or polymer wrapping. By these methods (termed sorting or enrichment), >99% sc-SWCNT content can be achieved. Currently, all of these approaches have drawbacks and limitations with respect to electronics applications, such as excessive dilution, expensive consumables, and high ionic impurity content. Excess amount of dispersant is a common challenge that hinders direct inclusion of sc-SWCNTs into electronic devices. At present, conjugated polymer extraction may represent the most practical route to sc-SWCNTs. By the use of

  2. Improving the Sound Pressure Level of Two-Dimensional Audio Actuators by Coating Single-Walled Carbon Nanotubes on Piezoelectric Films.

    Science.gov (United States)

    Um, Keehong

    2015-10-01

    As devices for amplifying or transforming electronic signals into audible signals through electromechanical operations, acoustic actuators in the form of loudspeakers are usually solid structures in three dimensional space. Recently there has been increasing demand for mobile electronic devices, such as mobile phones, to become smaller, thinner, and lighter. In contrast to a three dimensional audio system with magnets, we have invented a new type of flexible two dimensional device by utilizing the reverse piezoelectric effect in certain piezoelectric materials. Crystalline piezoelectric materials show electromechanical interaction between the mechanical state and the electrically-charged state. The piezoelectric effect is a reversible process in that materials exhibiting the direct piezoelectric effect (the internal generation of electrical charge resulting from an applied mechanical force) also exhibit the reverse piezoelectric effect (the internal generation of a mechanical strain resulting from an applied electrical field). We have adopted the plasma surface treatment in order to put coating materials on the surface of piezoelectric film. We compared two kinds of coating material, indium tin oxide and single-walled carbon nanotube, and found that single-walled carbon nanotube shows better performance. The results showed improvement of output power in a wider range of operating frequency; for the surface resistance of 0.5 kΩ/square, the single-walled CNT shows the range of operating frequency to be 0.75-17.5 kHz, but ITO shows 2.5-13.4 kHz. For the surface resistance of 1 kΩ/square, single-walled CNT shows the range of operating frequency to be 0.81-17 kHz, but ITO shows it cannot generate audible sound.

  3. Plasma-synthesized single-walled carbon nanotubes and their applications

    International Nuclear Information System (INIS)

    Hatakeyama, R; Kaneko, T; Kato, T; Li, Y F

    2011-01-01

    Plasma-based nanotechnology is a rapidly developing area of research ranging from physics of gaseous and liquid plasmas to material science, surface science and nanofabrication. In our case, nanoscopic plasma processing is performed to grow single-walled carbon nanotubes (SWNTs) with controlled chirality distribution and to further develop SWNT-based materials with new functions corresponding to electronic and biomedical applications. Since SWNTs are furnished with hollow inner spaces, it is very interesting to inject various kinds of atoms and molecules into their nanospaces based on plasma nanotechnology. The encapsulation of alkali-metal atoms, halogen atoms, fullerene or azafullerene molecules inside the carbon nanotubes is realized using ionic plasmas of positive and negative ions such as alkali-fullerene, alkali-halogen, and pair or quasipair ion plasmas. Furthermore, an electrolyte solution plasma with DNA negative ions is prepared in order to encapsulate DNA molecules into the nanotubes. It is found that the electronic and optical properties of various encapsulated SWNTs are significantly changed compared with those of pristine ones. As a result, a number of interesting transport phenomena such as air-stable n- and p-type behaviour, p-n junction characteristic, and photoinduced electron transfer are observed. Finally, the creation of an emerging SWNTs-based nanobioelectronics system is challenged. Specifically, the bottom-up electric-field-assisted reactive ion etching is proposed to control the chirality of SWNTs, unexplored SWNT properties of magnetism and superconductivity are aimed at being pioneered, and innovative biomedical-nanoengineering with encapsulated SWNTs of higher-order structure are expected to be developed by applying advanced gas-liquid interfacial plasmas.

  4. Transport properties of boron-doped single-walled silicon carbide nanotubes

    International Nuclear Information System (INIS)

    Yang, Y.T.; Ding, R.X.; Song, J.X.

    2011-01-01

    The doped boron (B) atom in silicon carbide nanotube (SiCNT) can substitute carbon or silicon atom, forming two different structures. The transport properties of both B-doped SiCNT structures are investigated by the method combined non-equilibrium Green's function with density functional theory (DFT). As the bias ranging from 0.8 to 1.0 V, the negative differential resistance (NDR) effect occurs, which is derived from the great difficulty for electrons tunneling from one electrode to another with the increasing of localization of molecular orbital. The high similar transport properties of both B-doped SiCNT indicate that boron is a suitable impurity for fabricating nano-scale SiCNT electronic devices.

  5. Pulmonary toxicity of single-wall carbon nanotubes in mice 7 and 90 days after intratracheal instillation

    Science.gov (United States)

    Lam, Chiu-Wing; James, John T.; McCluskey, Richard; Hunter, Robert L.

    2004-01-01

    Nanomaterials are part of an industrial revolution to develop lightweight but strong materials for a variety of purposes. Single-wall carbon nanotubes are an important member of this class of materials. They structurally resemble rolled-up graphite sheets, usually with one end capped; individually they are about 1 nm in diameter and several microns long, but they often pack tightly together to form rods or ropes of microscopic sizes. Carbon nanotubes possess unique electrical, mechanical, and thermal properties and have many potential applications in the electronics, computer, and aerospace industries. Unprocessed nanotubes are very light and could become airborne and potentially reach the lungs. Because the toxicity of nanotubes in the lung is not known, their pulmonary toxicity was investigated. The three products studied were made by different methods and contained different types and amounts of residual catalytic metals. Mice were intratracheally instilled with 0, 0.1, or 0.5 mg of carbon nanotubes, a carbon black negative control, or a quartz positive control and euthanized 7 d or 90 d after the single treatment for histopathological study of the lungs. All nanotube products induced dose-dependent epithelioid granulomas and, in some cases, interstitial inflammation in the animals of the 7-d groups. These lesions persisted and were more pronounced in the 90-d groups; the lungs of some animals also revealed peribronchial inflammation and necrosis that had extended into the alveolar septa. The lungs of mice treated with carbon black were normal, whereas those treated with high-dose quartz revealed mild to moderate inflammation. These results show that, for the test conditions described here and on an equal-weight basis, if carbon nanotubes reach the lungs, they are much more toxic than carbon black and can be more toxic than quartz, which is considered a serious occupational health hazard in chronic inhalation exposures.

  6. Process for derivatizing carbon nanotubes with diazonium species and compositions thereof

    Science.gov (United States)

    Tour, James M. (Inventor); Bahr, Jeffrey L. (Inventor); Yang, Jiping (Inventor)

    2011-01-01

    Methods for the chemical modification of carbon nanotubes involve the derivatization of multi- and single-wall carbon nanotubes, including small diameter (ca. 0.7 nm) single-wall carbon nanotubes, with diazonium species. The method allows the chemical attachment of a variety of organic compounds to the side and ends of carbon nanotubes. These chemically modified nanotubes have applications in polymer composite materials, molecular electronic applications, and sensor devices. The methods of derivatization include electrochemical induced reactions, thermally induced reactions, and photochemically induced reactions. Moreover, when modified with suitable chemical groups, the derivatized nanotubes are chemically compatible with a polymer matrix, allowing transfer of the properties of the nanotubes (such as, mechanical strength or electrical conductivity) to the properties of the composite material as a whole. Furthermore, when modified with suitable chemical groups, the groups can be polymerized to form a polymer that includes carbon nanotubes.

  7. ACID FUNCTIONALIZED SINGLE-WALLED CARBON NANOTUBES ENHANCE CARDIAC ISCHEMIC/REPERFUSIOIN INJURY

    Science.gov (United States)

    Engineered carbon nanotubes are being intensively developed for wide applications. Because of their unique light properties, nanotubes can impose some potentially toxic effects, particularly if they have been modified to express functionally reactive chemical groups on their sur...

  8. ACID-FUNCTIONALIZED SINGLE-WALLED CARBON NANOTUBES ENHANCE CARDIAC ISCHEMIC/REPERFUSION INJURY

    Science.gov (United States)

    Engineered nanotubes are being intensively developed for biomedical applications such as gene and drug delivery. Because of their unique properties, nanotubes can impose some potentially toxic effects, particularly if they have been modified to express functionally reactive chem...

  9. Use of Functionalized Carbon Nanotubes for Covalent Attachment of Nanotubes to Silicon

    Science.gov (United States)

    Tour, James M.; Dyke, Christopher A.; Maya, Francisco; Stewart, Michael P.; Chen, Bo; Flatt, Austen K.

    2012-01-01

    The purpose of the invention is to covalently attach functionalized carbon nanotubes to silicon. This step allows for the introduction of carbon nanotubes onto all manner of silicon surfaces, and thereby introduction of carbon nano - tubes covalently into silicon-based devices, onto silicon particles, and onto silicon surfaces. Single-walled carbon nanotubes (SWNTs) dispersed as individuals in surfactant were functionalized. The nano - tube was first treated with 4-t-butylbenzenediazonium tetrafluoroborate to give increased solubility to the carbon nanotube; the second group attached to the sidewall of the nanotube has a silyl-protected terminal alkyne that is de-protected in situ. This gives a soluble carbon nanotube that has functional groups appended to the sidewall that can be attached covalently to silicon. This reaction was monitored by UV/vis/NJR to assure direct covalent functionalization.

  10. Multi-method analysis of functionalized single-walled carbon nanotubes for cesium liquid–solid extraction

    Energy Technology Data Exchange (ETDEWEB)

    Kaper, Helena [Institut de Chimie Séparative de Marcoule, UMR 5257 CEA/CNRS/ENSCM/Université Montpellier 2, BP 17171, F-30207 Bagnols-sur-Cèze (France); Laboratoire de Synthèse et Fonctionnalisation des Céramiques, UMR 3080 Saint Gobain/CNRS, F-84306 Cavaillon (France); Nicolle, Jimmy [Institut de Chimie Séparative de Marcoule, UMR 5257 CEA/CNRS/ENSCM/Université Montpellier 2, BP 17171, F-30207 Bagnols-sur-Cèze (France); Cambedouzou, Julien, E-mail: julien.cambedouzou@enscm.fr [Institut de Chimie Séparative de Marcoule, UMR 5257 CEA/CNRS/ENSCM/Université Montpellier 2, BP 17171, F-30207 Bagnols-sur-Cèze (France); Grandjean, Agnès [Institut de Chimie Séparative de Marcoule, UMR 5257 CEA/CNRS/ENSCM/Université Montpellier 2, BP 17171, F-30207 Bagnols-sur-Cèze (France)

    2014-09-15

    We report a detailed analysis of single-walled carbon nanotubes (SWCNTs) functionalized with Dimethyl Acetylenedicarboxylate (DMAD) using a large range of techniques, involving different spectroscopic analysis, transmission electron microscopy, thermogravimetric analysis, and X-ray diffraction. SWCNT functionalization is based on a simple protocol associating ultrasonication and moderate heating under endogenous pressure of the molecules to be grafted. The complete and careful characterization of the resulting grafted SWCNTs revealed that a grafting rate of more than 1 molecule per nanometer of tube length is achieved. Furthermore an original quantification of the grafting homogeneity is developed using the micro-Raman mapping technique. Sorption experiments of Cs{sup +} ions onto grafted SWCNTs resulted in a high loading capacity, i.e. about 250 mg of Cs{sup +} per gram of grafted carbon nanotubes, opening exciting opportunities towards the design of carbon nanotube based materials for liquid treatment applications. - Highlights: • We functionalized single-walled carbon nanotubes by dimethyl acetylenedicarboxylate. • We performed a complete characterization using a wide range of analytical techniques. • We quantified grafting homogeneity using a micro-Raman mapping based procedure. • A Cesium sorption rate of 250 mg per gram of grafted nanotubes was measured.

  11. Studies of irradiation sterilization for single infusion device

    International Nuclear Information System (INIS)

    Chen Ruyan; Wang Keqin; Lu Zongmeng; Xiao Fenyuan; Xie Meizhi

    1988-05-01

    In practice of irradiation sterilization for single infusion device, object bacteria were selected and then their radiosensitivity were tested on the basis of practical production and irradiation environment. In view of the cylinder source and the static irradiation form, the dose rate of irradiation field and the dose distribution and uniformity in product box were measured in order to control sterilization quality. Through the measurements of material properties for irradiated infusion device and the test of causing rabbit fever as well as the survey of clinical practice, it was verified that the irradiation apparatus, the irradiation process and the product material etc. can satisfy the demands of sterilixzation and praction

  12. Powerful greenhouse gas nitrous oxide adsorption onto intrinsic and Pd doped Single walled carbon nanotube

    Energy Technology Data Exchange (ETDEWEB)

    Yoosefian, Mehdi, E-mail: m.yoosefian@kgut.ac.ir

    2017-01-15

    Highlights: • Investigation of the adsorption of Nitrous oxide on SWCNT and Pd/SWCNT. • Nitrous oxide adsorbed on Pd/SWCNT system demonstrates a strong adsorption. • The Pd/SWCNT is potential sensor for the Nitrous oxide gaseous molecule detection. - Abstract: Density functional studies on the adsorption behavior of nitrous oxide (N{sub 2}O) onto intrinsic carbon nanotube (CNT) and Pd-doped (5,5) single-walled carbon nanotube (Pd-CNT) have been reported. Introduction of Pd dopant facilitates in adsorption of N{sub 2}O on the otherwise inert nanotube as observed from the adsorption energies and global reactivity descriptor values. Among three adsorption features of N{sub 2}O onto CNT, the horizontal adsorption with E{sub ads} = −0.16 eV exhibits higher adsorption energy. On the other hand the Pd-CNT exhibit strong affinity toward gas molecule and would cause a huge increase in N{sub 2}O adsorption energies. Chemical and electronic properties of CNT and Pd-CNT in the absence and presence of N{sub 2}O were investigated. Adsorption of N{sub 2}O gas molecule would affect the electronic conductance of Pd-CNT that can serve as a signal of gas sensors and the increased energy gaps demonstrate the formation of more stable systems. The atoms in molecules (AIM) theory and the natural bond orbital (NBO) calculations were performed to get more details about the nature and charge transfers in intermolecular interactions within adsorption process. As a final point, the density of states (DOSs) calculations was achieved to confirm previous results. According to our results, intrinsic CNT cannot act as a suitable adsorbent while Pd-CNT can be introduced as novel detectable complex for designing high sensitive, fast response and high efficient carbon nanotube based gas sensor to detect N{sub 2}O gas as an air pollutant. Our results could provide helpful information for the design and fabrication of the N{sub 2}O sensors.

  13. Resonant anti-Stokes Raman scattering in single-walled carbon nanotubes

    Science.gov (United States)

    Gordeev, Georgy; Jorio, Ado; Kusch, Patryk; Vieira, Bruno G. M.; Flavel, Benjamin; Krupke, Ralph; Barros, Eduardo B.; Reich, Stephanie

    2017-12-01

    The dependence of the anti-Stokes Raman intensity on the excitation laser energy in carbon nanotubes is studied by resonant Raman spectroscopy. The complete resonant anti-Stokes and Stokes Raman profiles of the high-energy longitudinal phonon (G+) are obtained for (8,3), (7,5), (6,4), and (6,5) single chirality enriched samples. A high asymmetry between the intensity of the incoming and outgoing resonance is observed in the resonant Raman profiles. In contrast to Stokes scattering, anti-Stokes scattering is more intense at the outgoing resonance then at the incoming resonance. The resonance profiles are explained by a Raman process that includes the phonon-mediated interactions with the dark excitonic state. The chirality dependence of the Raman profiles is due to the variation in the exciton-phonon matrix elements, in agreement with tight-binding calculations. Based on the asymmetric Raman profiles we present the resonance factors for the Stokes/anti-Stokes ratios in carbon nanotubes.

  14. Electronic properties of Cs-intercalated single-walled carbon nanotubes derived from nuclear magnetic resonance

    KAUST Repository

    Abou-Hamad, E

    2011-05-24

    We report on the electronic properties of Cs-intercalated single-walled carbon nanotubes (SWNTs). A detailed analysis of the 13C and 133Cs nuclear magnetic resonance (NMR) spectra reveals an increased metallization of the pristine SWNTs under Cs intercalation. The \\'metallization\\' of CsxC materials where x=0–0.144 is evidenced from the increased local electronic density of states (DOS) n(EF) at the Fermi level of the SWNTs as determined from spin–lattice relaxation measurements. In particular, there are two distinct electronic phases called α and β and the transition between these occurs around x=0.05. The electronic DOS at the Fermi level increases monotonically at low intercalation levels x<0.05 (α-phase), whereas it reaches a plateau in the range 0.05≤x≤0.143 at high intercalation levels (β-phase). The new β-phase is accompanied by a hybridization of Cs(6s) orbitals with C(sp2) orbitals of the SWNTs. In both phases, two types of metallic nanotubes are found with a low and a high local n(EF), corresponding to different local electronic band structures of the SWNTs.

  15. Rod hydrodynamics and length distributions of single-wall carbon nanotubes using analytical ultracentrifugation.

    Science.gov (United States)

    Batista, Carlos A Silvera; Zheng, Ming; Khripin, Constantine Y; Tu, Xiaomin; Fagan, Jeffrey A

    2014-05-06

    Because of their repetitive chemical structure, extreme rigidity, and the separability of populations with varying aspect ratio, SWCNTs are excellent candidates for use as model rodlike colloids. In this contribution, the sedimentation velocities of length and density sorted single-wall carbon nanotubes (SWCNTs) are compared to predictions from rod hydrodynamic theories of increasing complexity over a range of aspect ratios from 400. Independently measuring all contributions to the sedimentation velocity besides the shape factor, excellent agreement is found between the experimental findings and theoretical predictions for numerically calculated hydrodynamic radius values and for multiterm analytical expansion approximations; values for the hydrodynamic radii in these cases are additionally found to be consistent with the apparent hydrated particle radius determined independently by buoyancy measurements. Lastly, we utilize this equivalency to calculate the apparent distribution of nanotube lengths in each population from their sedimentation coefficient distribution without adjustable parameters, achieving excellent agreement with distributions from atomic force microscopy. The method developed herein provides an alternative for the ensemble measurement of SWCNT length distributions and others rodlike particles.

  16. Feeding Single-Walled Carbon Nanotubes or Graphene to Silkworms for Reinforced Silk Fibers.

    Science.gov (United States)

    Wang, Qi; Wang, Chunya; Zhang, Mingchao; Jian, Muqiang; Zhang, Yingying

    2016-10-12

    Silkworm silk is gaining significant attention from both the textile industry and research society because of its outstanding mechanical properties and lustrous appearance. The possibility of creating tougher silks attracts particular research interest. Carbon nanotubes and graphene are widely studied for their use as reinforcement. In this work, we report mechanically enhanced silk directly collected by feeding Bombyx mori larval silkworms with single-walled carbon nanotubes (SWNTs) and graphene. We found that parts of the fed carbon nanomaterials were incorporated into the as-spun silk fibers, whereas the others went into the excrement of silkworms. Spectroscopy study indicated that nanocarbon additions hindered the conformation transition of silk fibroin from random coil and α-helix to β-sheet, which may contribute to increased elongation at break and toughness modules. We further investigated the pyrolysis of modified silk, and a highly developed graphitic structure with obviously enhanced electrical conductivity was obtained through the introduction of SWNTs and graphene. The successful generation of these SWNT- or graphene-embedded silks by in vivo feeding is expected to open up possibilities for the large-scale production of high-strength silk fibers.

  17. NASA-JSC Protocol for the Characterization of Single Wall Carbon Nanotube Material Quality

    Science.gov (United States)

    Arepalli, Sivaram; Nikolaev, Pasha; Gorelik, Olga; Hadjiev, Victor; Holmes, William; Devivar, Rodrigo; Files, Bradley; Yowell, Leonard

    2010-01-01

    It is well known that the raw as well as purified single wall carbon nanotube (SWCNT) material always contain certain amount of impurities of varying composition (mostly metal catalyst and non-tubular carbon). Particular purification method also creates defects and/or functional groups in the SWCNT material and therefore affects the its dispersability in solvents (important to subsequent application development). A number of analytical characterization tools have been used successfully in the past years to assess various properties of nanotube materials, but lack of standards makes it difficult to compare these measurements across the board. In this work we report the protocol developed at NASA-JSC which standardizes measurements using TEM, SEM, TGA, Raman and UV-Vis-NIR absorption techniques. Numerical measures are established for parameters such as metal content, homogeneity, thermal stability and dispersability, to allow easy comparison of SWCNT materials. We will also report on the recent progress in quantitative measurement of non-tubular carbon impurities and a possible purity standard for SWCNT materials.

  18. Low-frequency excitations of C60 chains inserted inside single-walled carbon nanotubes

    International Nuclear Information System (INIS)

    Cambedouzou, J.; Rols, S.; Almairac, R.; Sauvajol, J.-L.; Kataura, H.; Schober, H.

    2005-01-01

    The low-frequency excitations of C 60 chains inserted inside single-walled carbon nanotubes (SWNTs) have been studied by inelastic neutron scattering on a high-quality sample of peapods. The comparison of the neutron-derived generalized phonon density of states (GDOS) of the peapods sample with that of raw SWNTs allows the vibrational properties of the C 60 chains encapsulated in the hollow core of the SWNTs to be probed. Lattice dynamical models are used to calculate the GDOS of chains of monomers, dimers, and polymers inserted into SWNTs, which are compared to the experimental data. The presence of strong interactions between C 60 cages inside the nanotube is clearly demonstrated by an excess of mode density in the frequency range around 10 meV. However, the presence of a quasielastic signal indicates that some of the C 60 's undergo rotational motion. This suggests that peapods are made from a mixture of C 60 monomers and C 60 n-mer (dimer, trimer, ..., polymer) structures

  19. Assessment of continuum mechanics models in predicting buckling strains of single-walled carbon nanotubes.

    Science.gov (United States)

    Zhang, Y Y; Wang, C M; Duan, W H; Xiang, Y; Zong, Z

    2009-09-30

    This paper presents an assessment of continuum mechanics (beam and cylindrical shell) models in the prediction of critical buckling strains of axially loaded single-walled carbon nanotubes (SWCNTs). Molecular dynamics (MD) simulation results for SWCNTs with various aspect (length-to-diameter) ratios and diameters will be used as the reference solutions for this assessment exercise. From MD simulations, two distinct buckling modes are observed, i.e. the shell-type buckling mode, when the aspect ratios are small, and the beam-type mode, when the aspect ratios are large. For moderate aspect ratios, the SWCNTs buckle in a mixed beam-shell mode. Therefore one chooses either the beam or the shell model depending on the aspect ratio of the carbon nanotubes (CNTs). It will be shown herein that for SWCNTs with long aspect ratios, the local Euler beam results are comparable to MD simulation results carried out at room temperature. However, when the SWCNTs have moderate aspect ratios, it is necessary to use the more refined nonlocal beam theory or the Timoshenko beam model for a better prediction of the critical strain. For short SWCNTs with large diameters, the nonlocal shell model with the appropriate small length scale parameter can provide critical strains that are in good agreement with MD results. However, for short SWCNTs with small diameters, more work has to be done to refine the nonlocal cylindrical shell model for better prediction of critical strains.

  20. Rational concept to recognize/extract single-walled carbon nanotubes with a specific chirality.

    Science.gov (United States)

    Ozawa, Hiroaki; Fujigaya, Tsuyohiko; Niidome, Yasuro; Hotta, Naosuke; Fujiki, Michiya; Nakashima, Naotoshi

    2011-03-02

    Single-walled carbon nanotubes (SWNTs) have remarkable and unique electronic, mechanical, and thermal properties, which are closely related to their chiralities; thus, the chirality-selective recognition/extraction of the SWNTs is one of the central issues in nanotube science. However, any rational materials design enabling one to efficiently extract/solubilize pure SWNT with a desired chirality has yet not been demonstrated. Herein we report that certain chiral polyfluorene copolymers can well-recognize SWNTs with a certain chirality preferentially, leading to solubilization of specific chiral SWNTs. The chiral copolymers were prepared by the Ni(0)-catalyzed Yamamoto coupling reaction of 2,7-dibromo-9,9-di-n-decylfluorene and 2,7-dibromo-9,9-bis[(S)-(+)-2-methylbutyl]fluorene comonomers. The selectivity of the SWNT chirality was mainly determined by the relative fraction of the achiral and chiral side groups. By a molecular mechanics simulation, the cooperative interaction between the fluorene moiety, alkyl side chain, and graphene wall were responsible for the recognition/dissolution ability of SWNT chirality. This is a first example describing the rational design and synthesis of novel fluorene-based copolymers toward the recognition/extraction of targeted (n, m) chirality of the SWNTs.

  1. Electronic properties of prismatic modifications of single-wall carbon nanotubes

    Science.gov (United States)

    Tomilin, O. B.; Muryumin, E. E.; Rodionova, E. V.; Ryskina, N. P.

    2018-01-01

    The article shows the possibility of target modifying the prismatic single-walled carbon nanotubes (SWCNTs) by regular chemisorption of fluorine atoms in the graphene surface. It is shown that the electronic properties of prismatic SWCNT modifications are determined by the interaction of π- and ρ(in-plane)-electron conjugation in the carbon-conjugated subsystems (tracks) formed in the faces. The contributions of π- and ρ(in-plane)-electron conjugation depend on the structural characteristics of the tracks. It was found that the minimum of degree deviation of the track from the plane of the prism face and the maximum of the track width ensure the maximum contribution of the π-electron conjugation, and the band gap of the prismatic modifications of the SWCNT tends to the band gap of the hydrocarbon analog of the carbon track. It is established that the maximum of degree deviation of the track from the plane of the prism face and the maximum of track width ensure the maximum contribution of the ρ(in-plane) electron interface, and the band gap of the prismatic modifications of the SWCNT tends to the band gap of the unmodified carbon nanotube. The calculation of the model systems has been carried out using an ab initio Hartree-Fock method in the 3-21G basis.

  2. Investigating the Potential of Single-Walled Aluminosilicate Nanotubes in Water Desalination.

    Science.gov (United States)

    Liou, Kai-Hsin; Kang, Dun-Yen; Lin, Li-Chiang

    2017-01-18

    Water shortage has become a critical issue. To facilitate the large-scale deployment of reverse-osmosis water desalination to produce fresh water, discovering novel membranes is essential. Here, we computationally demonstrate the great potential of single-walled aluminosilicate nanotubes (AlSiNTs), materials that can be synthesized through scalable methods, in desalination. State-of-the-art molecular dynamics simulations were employed to investigate the desalination performance and structure-performance relationship of AlSiNTs. Free energy profiles, passage time distribution, and water density map were also analyzed to further understand the dependence of transport properties on diameter and water dynamics in the nanotubes. AlSiNTs with an inner diameter of 0.86 nm were found to fully reject NaCl ions while allowing orders of magnitude higher water fluxes compared to currently available reverse osmosis membranes, providing opportunities in water desalination. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Electron-electron interaction effects on the optical excitations of single-walled carbon nanotubes

    Science.gov (United States)

    Mazumdar, Sumit

    2005-03-01

    We report correlated-electron calculations of optically excited states in ten semiconducting single-walled carbon nanotubes (SWCNTs) with a wide range of diameters.ootnotetextHongbo Zhao and Sumit Mazumdar, Phys. Rev. Lett. 93, 157402 (2004) First, we show that optical excitation in SWCNTs occurs to excitons whose binding energies decrease with the increasing nanotube diameter, and are smaller than the binding energy of an isolated strand of poly-(paraphenylenevinylene), (PPV). Second, electron-electron interactions split the degeneracies characteristic of cylindrical geometries, and in all cases there occur forbidden excitons below the optical exciton. We ascribe the experimentally observed low quantum efficiency of the photoluminescence of SWCNTs to the presence of these forbidden states. Third, while within one-electron theory the transverse photo-excitations occur exactly halfway between the two lowest longitudinally polarized absorptions, they are shifted to considerably above the central region for nonzero electron-electron interactions. Finally, the ratio of the threshold energy of the second longitudinally polarized optical absorption to that of the lowest such transition in the widest SWCNTs is less than 2 within correlated-electron theory, in agreement with experiments.

  4. Electrical Transport and Magnetoresistance in Single-Wall Carbon Nanotubes Films

    Directory of Open Access Journals (Sweden)

    Vitaly KSENEVICH

    2014-06-01

    Full Text Available Electrical transport properties and magnetoresistance of single-wall carbon nanotubes (SWCNT films were investigated within temperature range (2 – 300 K and in magnetic fields up to 8 T. A crossover between metallic (dR/dT > 0 and non-metallic (dR/dT < 0 temperature dependence of the resistance as well as low-temperature saturation of the resistance in high bias regime indicated on the diminishing of role of the contact barriers between individual nanotubes essential for the charge transport in SWCNT arrays. The magnetoresistance (MR data demonstrated influence of weak localization and electron-electron interactions on charge transport properties in SWCNT films. The low-field negative MR with positive upturn was observed at low temperatures. At T > 10 K only negative MR was observed in the whole range of available magnetic fields. The negative MR can be approximated using 1D weak localization (WL model. The low temperature positive MR is induced by contribution from electron-electron interactions. DOI: http://dx.doi.org/10.5755/j01.ms.20.2.6311

  5. Assembly of three-dimensional hetero-epitaxial ZnO/ZnS core/shell nanorod and single crystalline hollow ZnS nanotube arrays.

    Science.gov (United States)

    Huang, Xing; Wang, Meng; Willinger, Marc-Georg; Shao, Lidong; Su, Dang Sheng; Meng, Xiang-Min

    2012-08-28

    Hetero-epitaxial growth along three-dimensional (3D) interfaces from materials with an intrinsic large lattice mismatch is a key challenge today. In this work we report, for the first time, the controlled synthesis of vertically aligned ZnO/ZnS core/shell nanorod arrays composed of single crystalline wurtzite (WZ) ZnS conformally grown on ZnO rods along 3D interfaces through a simple two-step thermal evaporation method. Structural characterization reveals a "(01-10)(ZnO)//(01-10)(ZnS) and [0001](ZnO)//[0001](ZnS)" epitaxial relationship between the ZnO core and the ZnS shell. It is exciting that arrays of single crystalline hollow ZnS nanotubes are also innovatively obtained by simply etching away the inner ZnO cores. On the basis of systematic structural analysis, a rational growth mechanism for the formation of hetero-epitaxial core/shell nanorods is proposed. Optical properties are also investigated via cathodoluminescence and photoluminescence measurements. Remarkably, the synthesized ZnO/ZnS core/shell heterostructures exhibit a greatly reduced ultraviolet emission and dramatically enhanced green emission compared to the pure ZnO nanorods. The present single-crystalline heterostructure and hollow nanotube arrays are envisaged to be highly promising for applications in novel nanoscale optoelectronic devices, such as UV-A photodetectors, lasers, solar cells, and nanogenerators.

  6. In situ Raman spectroelectrochemistry as a tool for the differentiation of inner tubes of double-wall carbon nanotubes and thin single-wall carbon nanotubes.

    Science.gov (United States)

    Kalbác, Martin; Kavan, Ladislav; Dunsch, Lothar

    2007-12-01

    In situ Raman spectroelectrochemistry has been used to distinguish between thin single-wall carbon nanotubes (SWCNT) and the inner tubes of double-wall carbon nanotubes (DWCNT). The spectroelectrochemical method is based on the different change of the electronic structure of the inner tube in DWCNT and that of SWCNT during electrochemical charging, which is reflected in the Raman spectra. During electrochemical charging the inner tubes of DWCNT exhibit a delayed attenuation of the intensities of their Raman modes as referred to the behavior of SWCNT of similar diameter. The changes are pronounced for the radial breathing mode (RBM), and thus, these modes are diagnostic for the distinction of inner tubes of DWCNT from the thin SWCNT. The different sensitivities of inner and outer tubes to the applied electrochemical charging is a simple analytical tool for differentiation of SWCNT and DWCNT in a mixture. The significance of the proposed method is demonstrated on a commercial DWCNT sample.

  7. Selective and Scalable Chemical Removal of Thin Single-Walled Carbon Nanotubes from their Mixtures with Double-Walled Carbon Nanotubes.

    Science.gov (United States)

    Komínková, Zuzana; Valeš, Václav; Kalbáč, Martin

    2015-11-02

    Double-walled carbon nanotubes (DWCNTs) are materials in high demand due to their superior properties. However, it is very challenging to prepare DWCNTs samples of high purity. In particular, the removal of single-walled carbon nanotubes (SWCNTs) contaminants is a major problem. Here, a procedure for a selective removal of thin-diameter SWCNTs from their mixtures with DWCNTs by lithium vapor treatment is investigated. The results are evaluated by Raman spectroscopy and in situ Raman spectroelectrochemistry. It is shown that the amount of SWCNTs was reduced by about 35 % after lithium vapor treatment of the studied SWCNTs-DWCNTs mixture. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Tailoring crystallinity and configuration of silica nanotubes by electron irradiation

    International Nuclear Information System (INIS)

    Taguchi, Tomitsugu; Yamaguchi, Kenji

    2015-01-01

    Highlights: •Single-crystal SiO 2 nanotubes were successfully synthesized for the first time. •The single-crystal SiO 2 was α-crystobalite. •Desired area of single-crystal nanotube can be changed to amorphous by electron irradiation. •The configuration of nanotube can be controlled using the focused electron irradiation technique. -- Abstract: SiO 2 nanotubes show potential in applications such as nanoscale electronic and optical devices, bioseparation, biocatalysis, and nanomedicine. As-grown SiO 2 nanotubes in the previous studies always have an amorphous wall, and here we demonstrate the successful synthesis of single-crystal nanotubes for the first time by the heat treatment of SiC nanotubes at 1300 °C for 10 h under low-vacuum conditions. According to TEM observations, the single-crystal SiO 2 was α-cristobalite. We also demonstrate that single-crystal SiO 2 nanotubes can be transformed into amorphous SiO 2 nanotubes by electron beam irradiation. Moreover, we synthesized a crystalline/amorphous SiO 2 composite nanotube, in which crystalline and amorphous SiO 2 coexisted in different localized regions. In addition, for biomedical applications such as drug delivery systems, controlling the configuration of the open end, the diameter, and capsulation of SiO 2 nanotubes is crucial. We can also obturate, capsulate, and cut a SiO 2 nanotube, as well as modify the inner diameter of the nanotube at a specific, nanometer-sized region using the focused electron beam irradiation technique

  9. Tailoring crystallinity and configuration of silica nanotubes by electron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Taguchi, Tomitsugu, E-mail: taguchi.tomitsugu@jaea.go.jp; Yamaguchi, Kenji

    2015-05-01

    Highlights: •Single-crystal SiO{sub 2} nanotubes were successfully synthesized for the first time. •The single-crystal SiO{sub 2} was α-crystobalite. •Desired area of single-crystal nanotube can be changed to amorphous by electron irradiation. •The configuration of nanotube can be controlled using the focused electron irradiation technique. -- Abstract: SiO{sub 2} nanotubes show potential in applications such as nanoscale electronic and optical devices, bioseparation, biocatalysis, and nanomedicine. As-grown SiO{sub 2} nanotubes in the previous studies always have an amorphous wall, and here we demonstrate the successful synthesis of single-crystal nanotubes for the first time by the heat treatment of SiC nanotubes at 1300 °C for 10 h under low-vacuum conditions. According to TEM observations, the single-crystal SiO{sub 2} was α-cristobalite. We also demonstrate that single-crystal SiO{sub 2} nanotubes can be transformed into amorphous SiO{sub 2} nanotubes by electron beam irradiation. Moreover, we synthesized a crystalline/amorphous SiO{sub 2} composite nanotube, in which crystalline and amorphous SiO{sub 2} coexisted in different localized regions. In addition, for biomedical applications such as drug delivery systems, controlling the configuration of the open end, the diameter, and capsulation of SiO{sub 2} nanotubes is crucial. We can also obturate, capsulate, and cut a SiO{sub 2} nanotube, as well as modify the inner diameter of the nanotube at a specific, nanometer-sized region using the focused electron beam irradiation technique.

  10. Electrode property of single-walled carbon nanotubes in all-solid-state lithium ion battery using polymer electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, Y.; Ishii, Y.; Kawasaki, S., E-mail: kawasaki.shinji@nitech.ac.jp [Nagoya Institute of Technology, Gokiso, Showa, Nagoya, Aichi (Japan)

    2016-07-06

    Electrode properties of single-walled carbon nanotubes (SWCNTs) in an all-solid-state lithium ion battery were investigated using poly-ethylene oxide (PEO) solid electrolyte. Charge-discharge curves of SWCNTs in the solid electrolyte cell were successfully observed. It was found that PEO electrolyte decomposes on the surface of SWCNTs.

  11. Single walled carbon nanotube-based electrical biosensor for the label-free detection of pathogenic bacteria

    DEFF Research Database (Denmark)

    Yoo, S. M.; Baek, Y. K.; Shin, S.

    2016-01-01

    We herein describe the development of a single-walled carbon nanotube (SWNT)-based electrical biosensor consisting of a two-terminal resistor, and report its use for the specific, label-free detection of pathogenic bacteria via changes in conductance. The ability of this biosensor to recognize...

  12. Non-covalent conjugates of single-walled carbon nanotubes and folic acid for interaction with cells overexpressing folate receptors

    DEFF Research Database (Denmark)

    Castillo, John J.; Rindzevicius, Tomas; Novoa, Leidy V.

    2013-01-01

    We here present amethod to form a noncovalent conjugate of single-walled carbon nanotubes and folic acid aimed to interact with cells over-expressing folate receptors. The bonding was obtained without covalent chemical functionalization using a simple, rapid “one pot” synthesis method. The zeta p...

  13. Fermi energy dependence of the G-band resonance Raman spectra of single-wall carbon nanotubes

    Czech Academy of Sciences Publication Activity Database

    Park, J. S.; Sasaki, K.; Saito, R.; Izumida, W.; Kalbáč, Martin; Farhat, H.; Dresselhaus, G.; Dresselhaus, M. S.

    2009-01-01

    Roč. 80, č. 8 (2009), 081402-1-081402-4 ISSN 1098-0121 R&D Projects: GA MŠk LC510; GA MŠk ME09060 Institutional research plan: CEZ:AV0Z40400503 Keywords : Fermi energy dependence * Raman spectroscopy * single waled carbon nanotubes Subject RIV: CG - Electrochemistry Impact factor: 3.475, year: 2009

  14. In vivo biocompatibility of ultra-short single-walled carbon nanotube/biodegradable polymer nanocomposites for bone tissue engineering.

    NARCIS (Netherlands)

    Sitharaman, B.; Shi, X.; Walboomers, X.F.; Liao, H.; Cuijpers, V.; Wilson, L.J.; Mikos, A.G.; Jansen, J.A.

    2008-01-01

    Scaffolds play a pivotal role in the tissue engineering paradigm by providing temporary structural support, guiding cells to grow, assisting the transport of essential nutrients and waste products, and facilitating the formation of functional tissues and organs. Single-walled carbon nanotubes

  15. Bioaccumulation and Toxicity of Single-Walled Carbon Nanotubes to Benthic Organisms at the Base of the Marine Food Chain

    Science.gov (United States)

    As the use of single-walled carbon nanotubes (SWNTs) increases over time, so does the potential for environmental release. This research aimed to determine the toxicity, bioavailability, and bioaccumulation of SWNTs in marine benthic organisms at the base of the food chain. The t...

  16. A First-Principle Theoretical Study of Mechanical and Electronic Properties in Graphene Single-Walled Carbon Nanotube Junctions

    Directory of Open Access Journals (Sweden)

    Ning Yang

    2017-11-01

    Full Text Available The new three-dimensional structure that the graphene connected with SWCNTs (G-CNTs, Graphene Single-Walled Carbon Nanotubes can solve graphene and CNTs′ problems. A comprehensive study of the mechanical and electrical performance of the junctions was performed by first-principles theory. There were eight types of junctions that were constituted by armchair and zigzag graphene and (3,3, (4,0, (4,4, and (6,0 CNTs. First, the junction strength was investigated. Generally, the binding energy of armchair G-CNTs was stronger than that of zigzag G-CNTs, and it was the biggest in the armchair G-CNTs (6,0. Likewise, the electrical performance of armchair G-CNTs was better than that of zigzag G-CNTs. Charge density distribution of G-CNTs (6,0 was the most homogeneous. Next, the impact factors of the electronic properties of armchair G-CNTs were investigated. We suggest that the band gap is increased with the length of CNTs, and its value should be dependent on the combined effect of both the graphene’s width and the CNTs’ length. Last, the relationship between voltage and current (U/I were studied. The U/I curve of armchair G-CNTs (6,0 possessed a good linearity and symmetry. These discoveries will contribute to the design and production of G-CNT-based devices.

  17. Increasing the luminous efficiency of an MEH-PPV based PLED using salmon DNA and single walled carbon nanotube

    Energy Technology Data Exchange (ETDEWEB)

    Madhwal, Devinder, E-mail: devindermadhwal@gmail.co [Department of Electronic Science, University of Delhi South campus, Benito Juarez Road, New Delhi 110021 (India); Singh, Inderpreet; Kumar, Jitender [Department of Electronic Science, University of Delhi South campus, Benito Juarez Road, New Delhi 110021 (India); Bhatia, C.S. [Department of Electrical and Computer Engineering, National University of Singapore (Singapore); Bhatnagar, P.K.; Mathur, P.C. [Department of Electronic Science, University of Delhi South campus, Benito Juarez Road, New Delhi 110021 (India)

    2011-07-15

    The combined effect of a salmon deoxyribonucleic acid (DNA)-based electron blocking layer and a single walled carbon nanotube (SWCNT) composite-based electron transport layer on the performance of a poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene](MEH-PPV) polymer light emitting diode (PLED) has been examined. The SWCNT network in the composite layer improves electron injection from cathode and the DNA blocks these high mobility electrons at the electron blocking layer-polymer interface, leading to high luminance from the device. The luminous efficiency of the PLED is increased {approx}20 times compared to that of a PLED using only MEH-PPV. - Highlights: {yields} We report fabrication of a high luminous efficiency MEH-PPV based polymer LED. {yields} Salmon DNA-CTMA layer is used to block injected electrons in the polymer layer. {yields} MEH-PPV-SWCNT composite is used to transport electrons in the polymer layer. {yields} The luminous efficiency of the polymer LED thereby improves about 20 times.

  18. One-Step Synthesis of Single-Wall Carbon Nanotube-ZnS Core-Shell Nanocables

    Directory of Open Access Journals (Sweden)

    Yanli Zhang

    2016-08-01

    Full Text Available Nanocables with a single-wall carbon nanotube (SWCNT core and a ZnS shell were directly synthesized in one step through a thermal reaction method by using carbon, Zn, and FeS powder as starting materials. The as-fabricated nanocables were studied using scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The nanocables have diameters of ~50 nm, lengths of several micrometers, and shell thickness of ~20 nm. TEM analysis revealed that the shell is polycrystalline wurtzite-type ZnS with good crystallinity, and the core of the nanocables is one to several SWCNTs. Raman results showed that the diameters of SWCNTs core are mainly distributed at 1.28 and 1.16 nm, with high quality and metallic character. A growth mechanism is proposed to explain the formation of the nanocables. This simple method may be applied to other SWCNTs-metal sulfide nanocables, which may have potential applications in photocatalysts, photocurrent, and other optical-electrical devices.

  19. One-Step Synthesis of Single-Wall Carbon Nanotube-ZnS Core-Shell Nanocables.

    Science.gov (United States)

    Zhang, Yanli; He, Xiangming; Wang, Li; Gao, Jian; Li, Jianjun

    2016-08-24

    Nanocables with a single-wall carbon nanotube (SWCNT) core and a ZnS shell were directly synthesized in one step through a thermal reaction method by using carbon, Zn, and FeS powder as starting materials. The as-fabricated nanocables were studied using scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The nanocables have diameters of ~50 nm, lengths of several micrometers, and shell thickness of ~20 nm. TEM analysis revealed that the shell is polycrystalline wurtzite-type ZnS with good crystallinity, and the core of the nanocables is one to several SWCNTs. Raman results showed that the diameters of SWCNTs core are mainly distributed at 1.28 and 1.16 nm, with high quality and metallic character. A growth mechanism is proposed to explain the formation of the nanocables. This simple method may be applied to other SWCNTs-metal sulfide nanocables, which may have potential applications in photocatalysts, photocurrent, and other optical-electrical devices.

  20. Electro-oxidized epitaxial graphene channel field-effect transistors with single-walled carbon nanotube thin film gate electrode.

    Science.gov (United States)

    Ramesh, Palanisamy; Itkis, Mikhail E; Bekyarova, Elena; Wang, Feihu; Niyogi, Sandip; Chi, Xiaoliu; Berger, Claire; de Heer, Walt; Haddon, Robert C

    2010-10-20

    We report the effect of electrochemical oxidation in nitric acid on the electronic properties of epitaxial graphene (EG) grown on silicon carbide substrates; we demonstrate the availability of an additional reaction channel in EG, which is not present in graphite but which facilitates the introduction of the reaction medium into the graphene galleries during electro-oxidation. The device performance of the chemically processed graphene was studied by patterning the EG wafers with two geometrically identical macroscopic channels; the electro-oxidized channel showed a logarithmic increase of resistance with decreasing temperature, which is ascribed to the scattering of charge carriers in a two-dimensional electronic gas, rather than the presence of an energy gap at the Fermi level. Field-effect transistors were fabricated on the electro-oxidized and pristine graphene channels using single-walled carbon nanotube thin film top gate electrodes, thereby allowing the study of the effect of oxidative chemistry on the transistor performance of EG. The electro-oxidized channel showed higher values for the on-off ratio and the mobility of the graphene field-effect transistor, which we ascribe to the availability of high-quality internal graphene layers after electro-oxidation of the more defective top layers. Thus, the present oxidative process provides a clear contrast with previously demonstrated covalent chemistry in which sp(3) hybridized carbon atoms are introduced into the graphitic transport layer of the lattice by carbon-carbon bond formation, thereby opening an energy gap.

  1. Pinched flow fractionation devices for detection of single nucleotide polymorphisms

    DEFF Research Database (Denmark)

    Larsen, A.V.; Poulsen, L.; Birgens, H.

    2008-01-01

    We demonstrate a new and flexible micro fluidic based method for genotyping single nucleotide polymorphisms ( SNPs). The method relies on size separation of selectively hybridized polystyrene microspheres in a micro fluidic pinched flow fractionation (PFF) device. The micro fluidic PFF devices...... and 5.6 mu m were functionalized with biotin-labeled oligonucleotides for the detection of a mutant (Mt) or wild-type (Wt) DNA sequence in the HBB gene, respectively. Hybridization to functionalized beads was performed with fluorescent targets comprising synthetic DNA oligonucleotides or amplified RNA......, synthesized using human DNA samples from individuals with point mutations in the HBB gene. Following a stringent wash, the beads were separated in a PFF device and the fluorescent signal from the beads was analyzed. Patients being wildtypes, heterozygotes or mutated respectively for the investigated mutation...

  2. Single Event Rates for Devices Sensitive to Particle Energy

    Science.gov (United States)

    Edmonds, L. D.; Scheick, L. Z.; Banker, M. W.

    2012-01-01

    Single event rates (SER) can include contributions from low-energy particles such that the linear energy transfer (LET) is not constant. Previous work found that the environmental description that is most relevant to the low-energy contribution to the rate is a "stopping rate per unit volume" even when the physical mechanisms for a single-event effect do not require an ion to stop in some device region. Stopping rate tables are presented for four heavy-ion environments that are commonly used to assess device suitability for space applications. A conservative rate estimate utilizing limited test data is derived, and the example of SEGR rate in a power MOSFET is presented.

  3. CMOS-compatible photonic devices for single-photon generation

    Directory of Open Access Journals (Sweden)

    Xiong Chunle

    2016-09-01

    Full Text Available Sources of single photons are one of the key building blocks for quantum photonic technologies such as quantum secure communication and powerful quantum computing. To bring the proof-of-principle demonstration of these technologies from the laboratory to the real world, complementary metal–oxide–semiconductor (CMOS-compatible photonic chips are highly desirable for photon generation, manipulation, processing and even detection because of their compactness, scalability, robustness, and the potential for integration with electronics. In this paper, we review the development of photonic devices made from materials (e.g., silicon and processes that are compatible with CMOS fabrication facilities for the generation of single photons.

  4. Single-molecule detection of protein efflux from microorganisms using fluorescent single-walled carbon nanotube sensor arrays

    Science.gov (United States)

    Landry, Markita Patricia; Ando, Hiroki; Chen, Allen Y.; Cao, Jicong; Kottadiel, Vishal Isaac; Chio, Linda; Yang, Darwin; Dong, Juyao; Lu, Timothy K.; Strano, Michael S.

    2017-05-01

    A distinct advantage of nanosensor arrays is their ability to achieve ultralow detection limits in solution by proximity placement to an analyte. Here, we demonstrate label-free detection of individual proteins from Escherichia coli (bacteria) and Pichia pastoris (yeast) immobilized in a microfluidic chamber, measuring protein efflux from single organisms in real time. The array is fabricated using non-covalent conjugation of an aptamer-anchor polynucleotide sequence to near-infrared emissive single-walled carbon nanotubes, using a variable chemical spacer shown to optimize sensor response. Unlabelled RAP1 GTPase and HIV integrase proteins were selectively detected from various cell lines, via large near-infrared fluorescent turn-on responses. We show that the process of E. coli induction, protein synthesis and protein export is highly stochastic, yielding variability in protein secretion, with E. coli cells undergoing division under starved conditions producing 66% fewer secreted protein products than their non-dividing counterparts. We further demonstrate the detection of a unique protein product resulting from T7 bacteriophage infection of E. coli, illustrating that nanosensor arrays can enable real-time, single-cell analysis of a broad range of protein products from various cell types.

  5. Coatings of Different Carbon Nanotubes on Platinum Electrodes for Neuronal Devices: Preparation, Cytocompatibility and Interaction with Spiral Ganglion Cells.

    Science.gov (United States)

    Burblies, Niklas; Schulze, Jennifer; Schwarz, Hans-Christoph; Kranz, Katharina; Motz, Damian; Vogt, Carla; Lenarz, Thomas; Warnecke, Athanasia; Behrens, Peter

    2016-01-01

    Cochlear and deep brain implants are prominent examples for neuronal prostheses with clinical relevance. Current research focuses on the improvement of the long-term functionality and the size reduction of neural interface electrodes. A promising approach is the application of carbon nanotubes (CNTs), either as pure electrodes but especially as coating material for electrodes. The interaction of CNTs with neuronal cells has shown promising results in various studies, but these appear to depend on the specific type of neurons as well as on the kind of nanotubes. To evaluate a potential application of carbon nanotube coatings for cochlear electrodes, it is necessary to investigate the cytocompatibility of carbon nanotube coatings on platinum for the specific type of neuron in the inner ear, namely spiral ganglion neurons. In this study we have combined the chemical processing of as-delivered CNTs, the fabrication of coatings on platinum, and the characterization of the electrical properties of the coatings as well as a general cytocompatibility testing and the first cell culture investigations of CNTs with spiral ganglion neurons. By applying a modification process to three different as-received CNTs via a reflux treatment with nitric acid, long-term stable aqueous CNT dispersions free of dispersing agents were obtained. These were used to coat platinum substrates by an automated spray-coating process. These coatings enhance the electrical properties of platinum electrodes, decreasing the impedance values and raising the capacitances. Cell culture investigations of the different CNT coatings on platinum with NIH3T3 fibroblasts attest an overall good cytocompatibility of these coatings. For spiral ganglion neurons, this can also be observed but a desired positive effect of the CNTs on the neurons is absent. Furthermore, we found that the well-established DAPI staining assay does not function on the coatings prepared from single-wall nanotubes.

  6. Characteristic Features of Stone-Wales Defects in Single-Walled Carbon Nanotube; Adsorption, Dispersion, and Field Emission

    Directory of Open Access Journals (Sweden)

    Seungkwang Roh

    2010-01-01

    Full Text Available Adsorption behaviors of dodecanethiol (C12H25SH molecules are investigated on the surface of single-walled carbon nanotubes (SWCNTs with vibrational and X-ray photoelectron spectrometers. The active adsorption sites are proved as Stone-Wales (SW defects (5–7 ring defects. The SW defect-removed SWCNTs formed by reacting nanotubes with allyl acrylate molecules are compared with pristine SWCNTs in dispersion and field emission. The former shows higher dispersion and field emission than the latter.

  7. Very Long Single and Few-Walled Boron Nitride Nanotubes via the Pressurized Vapor/Condenser Method

    Science.gov (United States)

    Smith, Michael W.; Jordan, Kevin C.; Park, Cheol; Kim, Jae-Woo; Lillehei, Peter T.; Crooks, Roy; Harrison, Joycelyn S.

    2009-01-01

    A new method for producing long, small diameter, single and few-walled, boron nitride nanotubes (BNNTs) in macroscopic quantities is reported. The pressurized vapor/condenser (PVC) method produces, without catalysts, highly crystalline, very long, small diameter, BNNTs. Palm-sized, cotton-like masses of BNNT raw material were grown by this technique and spun directly into centimeters-long yarn. Nanotube lengths were observed to be 100 times that of those grown by the most closely related method. Self-assembly and growth models for these long BNNTs are discussed.

  8. Electrochemical lithium-ion storage properties of quinone molecules encapsulated in single-walled carbon nanotubes.

    Science.gov (United States)

    Ishii, Yosuke; Tashiro, Kosuke; Hosoe, Kento; Al-Zubaidi, Ayar; Kawasaki, Shinji

    2016-04-21

    We investigated the electrochemical lithium-ion storage properties of 9,10-anthraquinone (AQ) and 9,10-phenanthrenequinone (PhQ) molecules encapsulated in the inner hollow core of single-walled carbon nanotubes (SWCNTs). The structural properties of the obtained encapsulated systems were characterized by electron microscopy, synchrotron powder X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy. We found that almost all quinone molecules encapsulated in the SWCNTs can store Li-ions reversibly. Interestingly, the undesired capacity fading, which comes from the dissolution of quinone molecules into the electrolyte, was suppressed by the encapsulation. It was also found that the overpotential of AQ was decreased by the encapsulation, probably due to the high-electric conductivity of SWCNTs.

  9. DFT Calculations of Hydrogen Adsorption inside Single-Walled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Igor K. Petrushenko

    2018-01-01

    Full Text Available DFT calculations have been performed to study noncovalent interactions of a hydrogen molecule and single-walled carbon nanotubes (SWCNTs of various diameters. Understanding these interactions is crucial for the development of systems for hydrogen storage and delivery. The barrier and barrier-free introduction of a hydrogen molecule into SWCNTs is observed. It has been found that hydrogen molecules bind differently onto SWCNTs, depending on their diameters and the orientation of an H2 molecule inside the SWCNT. The binding inside SWCNTs with small diameters ((3,3; (4,4 is very unfavorable; the opposite situation is in the case of larger ((5,5; (6,6 SWCNTs. Finally, in the case of ((7,7; (8,8 SWCNTs, the hydrogen binding energies decrease, and their values approach to those of graphene.

  10. Purity and Defect Characterization of Single-Wall Carbon Nanotubes Using Raman Spectroscopy

    Directory of Open Access Journals (Sweden)

    Yasumitsu Miyata

    2011-01-01

    Full Text Available We investigated the purity and defects of single-wall carbon nanotubes (SWCNTs produced by various synthetic methods including chemical vapor deposition, arc discharge, and laser ablation. The SWCNT samples were characterized using scanning electron microscopy (SEM, thermogravimetric analysis (TGA, and Raman spectroscopy. Quantitative analysis of SEM images suggested that the G-band Raman intensity serves as an index for the purity. By contrast, the intensity ratio of G-band to D-band (G/D ratio reflects both the purity and the defect density of SWCNTs. The combination of G-band intensity and G/D ratio is useful for a quick, nondestructive evaluation of the purity and defect density of a SWCNT sample.

  11. Swift heavy ion induced modifications of single walled carbon nanotube thin films

    Energy Technology Data Exchange (ETDEWEB)

    Vishalli, E-mail: vishalli_2008@yahoo.com [Department of Physics, Panjab University, Chandigarh 160014 (India); Raina, K.K. [Materials Research Laboratory, School of Physics and Materials Science, Thapar University, P.O. Box 32, Patiala 147004, Punjab (India); Avasthi, D.K. [Materials Science Group, Inter University Accelerator Centre, Aruna Asaf Ali Marg, P.O. Box 10502, New Delhi 110067 (India); Srivastava, Alok [Department of Chemistry, Panjab University, Chandigarh 160014 (India); Dharamvir, Keya [Department of Physics, Panjab University, Chandigarh 160014 (India)

    2016-04-15

    Thin films of single walled carbon nanotubes (SWCNTs) were prepared by Langmuir–Blodgett method and irradiated with swift heavy ions, carbon and nickel each of energy 60 MeV. The ion beams have different electronic energy loss (S{sub e}) values and the samples were exposed to various irradiation doses. The irradiated films were characterized using Raman and optical absorption spectroscopy. Raman spectroscopy results indicate the competing processes of defect creation and healing (annealing) of SWCNTs at lower fluences, while at higher fluences defect creation or damage dominates. In UV–Vis–NIR spectroscopy we find that there is decrease in the intensity of characteristic peaks with every increasing fluence, indicating decrease in the optically active states with irradiation.

  12. On the low temperature microwave absorption anomaly in single-wall carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Karsa, Anita; Quintavalle, Dario; Simon, Ferenc [Budapest University of Technology and Economics, Budapest (Hungary). Inst. of Physics; Hungarian Academy of Sciences, Budapest (Hungary). Condensed Matter Research Group; Forro, Laszlo [Institute of Physics of Complex Matter, FBS Swiss Federal Institute of Technology (EPFL), Lausanne (Switzerland)

    2012-12-15

    The low temperature microwave absorption anomaly reported by Corzilius et al. [Phys. Rev. B 75, 235416 (2007)] in single-wall carbon nanotubes (SWCNTs) is revisited. It was originally reported that the microwave absorption of CVD grown SWCNTs shows an unexpected increase below {proportional_to}20 K (using flow cryostats) which depends on the microwave power. The original observation was made using the microwave cavity perturbation method while sweeping the microwave frequency. We reproduced this effect on arc-discharge based SWCNTs, using static cryogenic conditions with cooled microwave cavities, and employing a stable frequency source locked to the cavity resonance. Our observation shows that the microwave absorption anomaly is robust against the tube type and the experimental conditions. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Surface tailored single walled carbon nanotubes as catalyst support for direct methanol fuel cell

    Science.gov (United States)

    Kireeti, Kota V. M. K.; Jha, Neetu

    2017-10-01

    A strategy for tuning the surface property of Single Walled Carbon Nanotubes (SWNTs) for enhanced methanol oxidation reaction (MOR) and oxygen reduction reaction (ORR) along with methanol tolerance is presented. The surface functionality is tailored using controlled acid and base treatment. Acid treatment leads to the attachment of carboxylic carbon (CC) fragments to SWNT making it hydrophilic (P3-SWNT). Base treatment of P3-SWNT with 0.05 M NaOH reduces the CCs and makes it hydrophobic (P33-SWNT). Pt catalyst supported on the P3-SWNT possesses enhanced MOR whereas that supported on P33-SWNT not only enhances ORR kinetics but also possess good tolerance towards methanol oxidation as verified by the electrochemical technique.

  14. Ion mass dependence for low energy channeling in single-wall nanotubes

    International Nuclear Information System (INIS)

    An Monte Carlo (MC) simulation program has been used to study ion mass dependence for the low energy channeling of natural- and pseudo-Ar ions in single-wall nanotubes. The MC simulations show that the channeling critical angle Ψ C obeys the (E) -1/2 and the (M 1 ) -1/2 rules, where E is the incident energy and M 1 is the ion mass. The reason for this may be that the motion of the channeled (or de-channeled) ions should be correlated with both the incident energy E and the incident momentum (2M 1 E) 1/2 , in order to obey the conservation of energy and momentum

  15. Acute toxicity of a mixture of copper and single-walled carbon nanotubes to Daphnia magna.

    Science.gov (United States)

    Kim, Ki T; Klaine, Stephen J; Lin, Sijie; Ke, Pu C; Kim, Sang D

    2010-01-01

    Nanomaterials released into the environment will interact with many materials including other contaminants. This may influence bioavailability and fate of both the nanoparticles and the other contaminants. The present study examined the effect of a combination of soluble copper and surface-modified single-walled carbon nanotubes (SWNTs) on Daphnia magna. Lysophosphatidylcholine (LPC) was used to modify the surface of SWNTs, reducing the surface hydrophobicity of the tubes and thereby producing a stable aqueous nanoparticle suspension. The toxicity of the nanoparticle-copper (Cu) mixture was determined to be additive. The addition of nontoxic concentration of LPC-SWNTs enhanced the uptake and toxicity of copper. Greater amounts of Cu were shown to accumulate in D. magna upon addition of 0.5 and 1.0 mg/L LPC-SWNTs.

  16. Fabrication and electrochemical properties of free-standing single-walled carbon nanotube film electrodes

    International Nuclear Information System (INIS)

    Niu Zhi-Qiang; Ma Wen-Jun; Dong Hai-Bo; Li Jin-Zhu; Zhou Wei-Ya

    2011-01-01

    An easily manipulative approach was presented to fabricate electrodes using free-standing single-walled carbon nanotube (SWCNT) films grown directly by chemical vapor deposition. Electrochemical properties of the electrodes were investigated. In comparison with the post-deposited SWCNT papers, the directly grown SWCNT film electrodes manifested enhanced electrochemical properties and sensitivity of sensors as well as excellent electrocatalytic activities. A transition from macroelectrode to nanoelectrode behaviours was observed with the increase of scan rate. The heat treatment of the SWCNT film electrodes increased the current signals of electrochemical analyser and background current, because the heat-treatment of the SWCNTs in air could create more oxide defects on the walls of the SWCNTs and make the surfaces of SWCNTs more hydrophilic. The excellent electrochemical properties of the directly grown and heat-treated free-standing SWCNT film electrodes show the potentials in biological and electrocatalytic applications. (cross-disciplinary physics and related areas of science and technology)

  17. Aggregated single-walled carbon nanotubes attenuate the behavioural and neurochemical effects of methamphetamine in mice

    Science.gov (United States)

    Xue, Xue; Yang, Jing-Yu; He, Yi; Wang, Li-Rong; Liu, Ping; Yu, Li-Sha; Bi, Guo-Hua; Zhu, Ming-Ming; Liu, Yue-Yang; Xiang, Rong-Wu; Yang, Xiao-Ting; Fan, Xin-Yu; Wang, Xiao-Min; Qi, Jia; Zhang, Hong-Jie; Wei, Tuo; Cui, Wei; Ge, Guang-Lu; Xi, Zheng-Xiong; Wu, Chun-Fu; Liang, Xing-Jie

    2016-07-01

    Methamphetamine (METH) abuse is a serious social and health problem worldwide. At present, there are no effective medications to treat METH addiction. Here, we report that aggregated single-walled carbon nanotubes (aSWNTs) significantly inhibited METH self-administration, METH-induced conditioned place preference and METH- or cue-induced relapse to drug-seeking behaviour in mice. The use of aSWNTs alone did not significantly alter the mesolimbic dopamine system, whereas pretreatment with aSWNTs attenuated METH-induced increases in extracellular dopamine in the ventral striatum. Electrochemical assays suggest that aSWNTs facilitated dopamine oxidation. In addition, aSWNTs attenuated METH-induced increases in tyrosine hydroxylase or synaptic protein expression. These findings suggest that aSWNTs may have therapeutic effects for treatment of METH addiction by oxidation of METH-enhanced extracellular dopamine in the striatum.

  18. Gas sensors based on deposited single-walled carbon nanotube networks for DMMP detection

    International Nuclear Information System (INIS)

    Wang Yanyan; Zhou Zhihua; Yang Zhi; Chen Xiaohang; Xu Dong; Zhang Yafei

    2009-01-01

    Sensors based on single-walled carbon nanotube (SWNT) networks were fabricated and their sensitive properties for the nerve agent stimulant dimethyl methylphosphonate (DMMP) vapor were investigated at room temperature. The SWNT networks were deposited on oxidized silicon surface functionalized with 3-aminopropyltrimethysilane (APS). Combining with a traditional silicon process, SWNT-based gas sensors were made at a wafer scale. The effects of the density of deposited SWNTs on the sensor response were studied. The excellent response is obtained under a density of 30-40 tubes μm -2 . The sensors exhibit high resistance response, fast response time, rapid recovery and good reproducibility for DMMP vapor. The deposited SWNT sensors will be potentially extended to large-scale fabrication.

  19. Non-covalent functionalization of single wall carbon nanotubes and graphene by a conjugated polymer

    KAUST Repository

    Jiwuer, Jilili

    2014-07-07

    We report first-principles calculations on the binding of poly[(9,9-bis-(6-bromohexylfluorene-2,7-diyl)-co-(benzene-1,4-diyl)] to a (8,0) single wall carbon nanotube (SWCNT) and to graphene. Considering different relative orientations of the subsystems, we find for the generalized gradient approximation a non-binding state, whereas the local density approximation predicts reasonable binding energies. The results coincide after inclusion of van der Waals corrections, which demonstrates a weak interaction between the polymer and SWCNT/graphene, mostly of van der Waals type. Accordingly, the density of states shows essentially no hybridization. The physisorption mechanism explains recent experimental observations and suggests that the conjugated polymer can be used for non-covalent functionalization.

  20. Reorientation of single-wall carbon nanotubes in negative anisotropy liquid crystals by an electric field.

    Science.gov (United States)

    García-García, Amanda; Vergaz, Ricardo; Algorri, José F; Zito, Gianluigi; Cacace, Teresa; Marino, Antigone; Otón, José M; Geday, Morten A

    2016-01-01

    Single-wall carbon nanotubes (SWCNT) are anisotropic nanoparticles that can cause modifications in the electrical and electro-optical properties of liquid crystals. The control of the SWCNT concentration, distribution and reorientation in such self-organized fluids allows for the possibility of tuning the liquid crystal properties. The alignment and reorientation of CNTs are studied in a system where the liquid crystal orientation effect has been isolated. Complementary studies including Raman spectroscopy, microscopic inspection and impedance studies were carried out. The results reveal an ordered reorientation of the CNTs induced by an electric field, which does not alter the orientation of the liquid crystal molecules. Moreover, impedance spectroscopy suggests a nonnegligible anchoring force between the CNTs and the liquid crystal molecules.

  1. Single walled carbon nanotubes: a model system for excitons in one dimension

    Science.gov (United States)

    Lefebvre, J.; Finnie, P.

    2011-03-01

    The semiconducting single walled carbon nanotube (s-SWNTs) with its direct bandgap and its strong 1D character absorbs and emits light efficiently. In contrast with other nanomaterials, the structure of an SWNT is uniquely defined and is set by a discrete number of carbon rings along its tubular section. Experimentally, optical spectroscopy has recently revealed this remarkable quantization. In our group, we focus primarily on the luminescence properties of individual s-SWNTs. Using imaging techniques, we reveal unambiguously that each s-SWNT with its quantized structure is characterized by a specific manifold of excitonic states. With the large diameter tunability achieved in SWNTs, we show that the material represents a model system for 1D photophysics. This proceeding is meant to be a review of past work and includes complementary data that have been presented at conferences but otherwise have never been published. Some emphasis is given on experimental details for luminescence imaging and spectroscopy.

  2. Bias-induced modulation of ultrafast carrier dynamics in metallic single-walled carbon nanotubes

    Science.gov (United States)

    Maekawa, Keisuke; Yanagi, Kazuhiro; Minami, Yasuo; Kitajima, Masahiro; Katayama, Ikufumi; Takeda, Jun

    2018-02-01

    The gate bias dependence of excited-state relaxation dynamics in metallic single-walled carbon nanotubes (MCNTs) was investigated using pump-probe transient absorption spectroscopy coupled with electrochemical doping through an ionic liquid. The transient transmittance decayed exponentially with the pump-probe delay time, whose value could be tuned via the Fermi-level modulation of Dirac electrons under a bias voltage. The obtained relaxation time was the shortest when the Fermi level was at the Dirac point of the MCNTs, and exhibited a U-shaped dependence on the bias voltage. Because optical dipole transitions between the Dirac bands are forbidden in MCNTs, the observed dynamics were attributed to carrier relaxation from the E11 band to the Dirac band. Using a model that considers the suppression of electron-electron scattering (impact ionization) due to Pauli blocking, we could qualitatively explain the obtained bias dependence of the relaxation time.

  3. Diameter Tuning of Single-Walled Carbon Nanotubes by Diffusion Plasma CVD

    Directory of Open Access Journals (Sweden)

    Toshiaki Kato

    2011-01-01

    Full Text Available We have realized a diameter tuning of single-walled carbon nanotubes (SWNTs by adjusting process gas pressures with plasma chemical vapor deposition (CVD. Detailed photoluminescence measurements reveal that the diameter distribution of SWNTs clearly shifts to a large-diameter region with an increase in the pressure during plasma CVD, which is also confirmed by Raman scattering spectroscopy. Based on the systematical investigation, it is found that the main diameter of SWNTs is determined by the pressure during the heating in an atmosphere of hydrogen and the diameter distribution is narrowed by adjusting the pressure during the plasma generation. Our results could contribute to an application of SWNTs to high-performance thin-film transistors, which requires the diameter-controlled semiconductor-rich SWNTs.

  4. Molecular scale buckling mechanics in individual aligned single-wall carbon nanotubes on elastomeric substrates.

    Science.gov (United States)

    Khang, Dahl-Young; Xiao, Jianliang; Kocabas, Coskun; MacLaren, Scott; Banks, Tony; Jiang, Hanqing; Huang, Yonggang Y; Rogers, John A

    2008-01-01

    We have studied the scaling of controlled nonlinear buckling processes in materials with dimensions in the molecular range (i.e., approximately 1 nm) through experimental and theoretical studies of buckling in individual single-wall carbon nanotubes on substrates of poly(dimethylsiloxane). The results show not only the ability to create and manipulate patterns of buckling at these molecular scales, but also, that analytical continuum mechanics theory can explain, quantitatively, all measurable aspects of this system. Inverse calculation applied to measurements of diameter-dependent buckling wavelengths yields accurate values of the Young's moduli of individual SWNTs. As an example of the value of this system beyond its use in this type of molecular scale metrology, we implement parallel arrays of buckled SWNTs as a class of mechanically stretchable conductor.

  5. Large Deflections Mechanical Analysis of a Suspended Single-Wall Carbon Nanotube under Thermoelectrical Loading

    Directory of Open Access Journals (Sweden)

    Assaf Ya'akobovitz

    2011-01-01

    Full Text Available Following the recent progress in integrating single-wall carbon nanotubes (SWCNTs into silicon-based micro-electromechanical systems (MEMS, new modeling tools are needed to predict their behavior under different loads, including thermal, electrical and mechanical. In the present study, the mechanical behavior of SWCNTs under thermoelectrical loading is analyzed using a large deflection geometrically nonlinear string model. The effect of the resistive heating was found to have a substantial influence on the SWCNTs behavior, including significant enhancement of the strain (up to the millistrains range and buckling due to the thermal expansion. The effect of local buckling sites was also studied and was found to enhance the local strain. The theoretical and numerical results obtained in the present study demonstrate the importance of resistive heating in the analysis of SWCNTs and provide an additional insight into the unique mechanics of suspended SWCNTs.

  6. Vibration analysis of viscoelastic single-walled carbon nanotubes resting on a viscoelastic foundation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Da Peng; Lei, Yong Jun; Shen, Zhi Bin [College of Aerospace Science and Engineering, National University of Defense Technology, Changsha (China); Wang, Cheng Yuan [Zienkiewicz Centre for Computational Engineering, College of Engineering, Swansea University, Swansea Wales (United Kingdom)

    2017-01-15

    Vibration responses were investigated for a viscoelastic Single-walled carbon nanotube (visco-SWCNT) resting on a viscoelastic foundation. Based on the nonlocal Euler-Bernoulli beam model, velocity-dependent external damping and Kelvin viscoelastic foundation model, the governing equations were derived. The Transfer function method (TFM) was then used to compute the natural frequencies for general boundary conditions and foundations. In particular, the exact analytical expressions of both complex natural frequencies and critical viscoelastic parameters were obtained for the Kelvin-Voigt visco-SWCNTs with full foundations and certain boundary conditions, and several physically intuitive special cases were discussed. Substantial nonlocal effects, the influence of geometric and physical parameters of the SWCNT and the viscoelastic foundation were observed for the natural frequencies of the supported SWCNTs. The study demonstrates the efficiency and robustness of the developed model for the vibration of the visco-SWCNT-viscoelastic foundation coupling system.

  7. Preparation and Properties of Nanocomposites Prepared From Shortened, Functionalized Single-Walled Carbon Nanotubes

    Science.gov (United States)

    Smith, J. G., Jr.; Delozier, D. M.; Watson, K. A.; Connell, J. W.; Yu, Aiping; Haddon, R. C.; Bekyarova, E.

    2006-01-01

    As part of a continuing materials development activity, low color space environmentally stable polymeric materials that possess sufficient electrical conductivity for electrostatic charge dissipation (ESD) have been investigated. One method of incorporating sufficient electrical conductivity for ESD without detrimental effects on other polymer properties of interest (i.e., optical and thermo-optical) is through the incorporation of single-walled carbon nanotubes (SWNTs). However, SWNTs are difficult to fully disperse in the polymer matrix. One means of improving dispersion is by shortening and functionalizing SWNTs. While this improves dispersion, other properties (i.e., electrical) of the SWNTs can be affected which can in turn alter the final nanocomposite properties. Additionally, functionalization of the polymer matrix can also influence nanocomposite properties obtained from shortened, functionalized SWNTs. The preparation and characterization of nanocomposites fabricated from a polyimide, both functionalized and unfunctionalized, and shortened, functionalized SWNTs will be presented.

  8. Vibration analysis of viscoelastic single-walled carbon nanotubes resting on a viscoelastic foundation

    International Nuclear Information System (INIS)

    Zhang, Da Peng; Lei, Yong Jun; Shen, Zhi Bin; Wang, Cheng Yuan

    2017-01-01

    Vibration responses were investigated for a viscoelastic Single-walled carbon nanotube (visco-SWCNT) resting on a viscoelastic foundation. Based on the nonlocal Euler-Bernoulli beam model, velocity-dependent external damping and Kelvin viscoelastic foundation model, the governing equations were derived. The Transfer function method (TFM) was then used to compute the natural frequencies for general boundary conditions and foundations. In particular, the exact analytical expressions of both complex natural frequencies and critical viscoelastic parameters were obtained for the Kelvin-Voigt visco-SWCNTs with full foundations and certain boundary conditions, and several physically intuitive special cases were discussed. Substantial nonlocal effects, the influence of geometric and physical parameters of the SWCNT and the viscoelastic foundation were observed for the natural frequencies of the supported SWCNTs. The study demonstrates the efficiency and robustness of the developed model for the vibration of the visco-SWCNT-viscoelastic foundation coupling system

  9. Interaction of molecular oxygen with single wall nanotubes: Role of surfactant contamination

    International Nuclear Information System (INIS)

    Larciprete, R.; Goldoni, A.; Lizzit, S.

    2003-01-01

    The interaction of molecular oxygen with single wall nanotubes in the form of a commercial bucky paper was investigated by high resolution photoemission spectroscopy. Sodium contamination was found in the sample, which was completely removed only after prolonged heating at 1250 K. The C 1s core level spectrum measured on the sample annealed to 1020 K dramatically changed upon exposure to molecular oxygen. On the contrary, when exposing the Na-free SWNTs to several KL of O 2 , the sample remained oxygen free and no modification in the C 1s core level was observed. Therefore the observed sensitivity of the sample to O 2 was due to a Na mediated oxidation, determining a charge transfer from the C tubes to the Na-O complex

  10. Light radiation through a transparent cathode plate with single-walled carbon nanotube field emitters

    International Nuclear Information System (INIS)

    Jang, E.S.; Goak, J.C.; Lee, H.S.; Lee, S.H.; Han, J.H.; Lee, C.S.; Sok, J.H.; Seo, Y.H.; Park, K.S.; Lee, N.S.

    2010-01-01

    In the conventional carbon nanotube backlight units (CNT-BLUs), light passes through the phosphor-coated anode glass plate, which thus faces closely the thin film transistor (TFT) backplate of a liquid crystal display panel. This configuration makes heat dissipation structurally difficult because light emission and heat generation occur simultaneously at the anode. We propose a novel configuration of a CNT-BLU where the cathode rather than the anode faces the TFT backplate by turning it upside down. In this design, light passes through the transparent cathode glass plate while heating occurs at the anode. We demonstrated a novel design of CNT-BLU by fabricating transparent single-walled CNT field emitters on the cathode and by coating a reflecting metal layer on the anode. This study hopefully provides a clue to solve the anode-heating problem which would be inevitably confronted for high-luminance and large-area CNT-BLUs.

  11. Vertical single- and double-walled carbon nanotubes grown from modified porous anodic alumina templates

    International Nuclear Information System (INIS)

    Maschmann, Matthew R; Franklin, Aaron D; Amama, Placidus B; Zakharov, Dmitri N; Stach, Eric A; Sands, Timothy D; Fisher, Timothy S

    2006-01-01

    Vertical single-walled and double-walled carbon nanotube (SWNT and DWNT) arrays have been grown using a catalyst embedded within the pore walls of a porous anodic alumina (PAA) template. The initial film structure consisted of a SiO x adhesion layer, a Ti layer, a bottom Al layer, a Fe layer, and a top Al layer deposited on a Si wafer. The Al and Fe layers were subsequently anodized to create a vertically oriented pore structure through the film stack. CNTs were synthesized from the catalyst layer by plasma-enhanced chemical vapour deposition (PECVD). The resulting structure is expected to form the basis for development of vertically oriented CNT-based electronics and sensors

  12. Reorientation of single-wall carbon nanotubes in negative anisotropy liquid crystals by an electric field

    Directory of Open Access Journals (Sweden)

    Amanda García-García

    2016-06-01

    Full Text Available Single-wall carbon nanotubes (SWCNT are anisotropic nanoparticles that can cause modifications in the electrical and electro-optical properties of liquid crystals. The control of the SWCNT concentration, distribution and reorientation in such self-organized fluids allows for the possibility of tuning the liquid crystal properties. The alignment and reorientation of CNTs are studied in a system where the liquid crystal orientation effect has been isolated. Complementary studies including Raman spectroscopy, microscopic inspection and impedance studies were carried out. The results reveal an ordered reorientation of the CNTs induced by an electric field, which does not alter the orientation of the liquid crystal molecules. Moreover, impedance spectroscopy suggests a nonnegligible anchoring force between the CNTs and the liquid crystal molecules.

  13. Charge calculation studies done on a single walled carbon nanotube using MOPAC

    Science.gov (United States)

    Negi, S.; Bhartiya, Vivek Kumar; Chaturvedi, S.

    2018-04-01

    Dipole symmetry of induced charges on DWNTs are required for their application as a nanomotor. Earlier a molecular dynamics analysis was performed for a double-walled carbon-nanotube based motor driven by an externally applied sinusoidally varying electric field. One of the ways to get such a system is chemical or end functionalization, which promises to accomplish this specific and rare configuration of the induced charges on the surface of the carbon nanotube (CNT). CNTs are also a promising system for attaching biomolecules for bio-related applications. In an earlier work, ab initio calculations were done to study the electronic and structural properties of the groups -COOH, -OH, -NH2 and -CONH2 functionalized to an (8, 0) SWNT. The systems were shown to have a very stable interaction with the CNTs. The exterior surface of the SWNT is found to be reactive to NH2 (amidogen). In this work, charge calculations are done on a CNT using MOPAC, which is a semi empirical quantum chemistry software package. As a first step, we calculate the effect of NH2 functionalization to a (5,0) SWNT of infinite length. The symmetric charge distribution of the bare SWNT is observed to be disturbed on addition of a single NH2 in the close proximity of the SWNT. A net positive and opposite charge is observed to be induced on the opposite sides of the nanotube circumference, which is, in turn, imperative for the nanomotor applications. The minimum and maximum value of the charge on any atom is observed to increase from - 0.3 to 0.6 and from - 0.3 to - 1.8 electronic charge as compared to the bare SWNT. This fluctuation of the surface charge to larger values than bare CNT, can be attributed to the coulomb repulsion between NH2 and the rest of the charge on the surface which results into minimizing the total energy of the system. No such opposite polarity of charges are observed on adding NH2 to each ring of the SWNT implying addition of a single amidogen to be the most appropriate

  14. Mechanical properties of nickel-coated single-walled carbon nanotubes and their embedded gold matrix composites

    International Nuclear Information System (INIS)

    Song Haiyang; Zha Xinwei

    2010-01-01

    The effects of nickel coating on the mechanical behaviors of armchair single-walled carbon nanotubes (SWCNTs) and their embedded gold matrix composites under axial tension are investigated using molecular dynamics (MD) simulation method. The results show that the Young's moduli and tensile strength of SWCNTs obviously decrease after nickel coating. For armchair SWCNTs, the decreased ratio of the Young's moduli of SWCNTs with smaller radius is larger than that of SWCNTs with larger radius. A comparison is made between the response to Young's modulus of a composite with parallel embedded nanotube and the response of a composite with vertically embedded nanotube. The results show that the uncoated SWCNT can enhance the Young's modulus of composite under the condition of parallel embedment, but such improvement disappears under the condition of vertical embedment because the interaction between SWCNT and gold matrix is too weak for effective load transfer. However, the nickel-coated SWCNT can indeed significantly improve the composite behavior.

  15. Altering F-Actin Structure of C17.2 Cells using Single-Walled Carbon Nanotubes

    Science.gov (United States)

    Magers, Jay; Gillette, Nathan L. D.; Rotkin, Slava V.; Jedlicka, Sabrina; Pirbhai, Massooma; Lehigh Univesity Collaboration; Susquehanna University Collaboration

    Advancements in nanotechnology have become fundamental to the delivery of drugs to treat various diseases. One such advancement is that of carbon nanotubes and their possible implications on drug delivery. Single-walled carbon nanotubes (SWCNTs) have great potential in the biomedical field as a means to deliver materials such as drugs and genes into the human body due to their size and chemistry. However, the effects of the nanotubes on cells they interact with are still unknown. Previous studies have shown that a low dosage of SWCNTs can affect differentiation of C17.2 neural stem cells. In this experiment, we investigate how the tubes affect the structure of the cells. Specifically, we determined the impact on the cell by examining the actin filament length, protrusions along the edge of the cells, and actin distribution. Presenter/Author 1.

  16. Soft cutting of single-wall carbon nanotubes by low temperature ultrasonication in a mixture of sulfuric and nitric acids.

    Science.gov (United States)

    Shuba, M V; Paddubskaya, A G; Kuzhir, P P; Maksimenko, S A; Ksenevich, V K; Niaura, G; Seliuta, D; Kasalynas, I; Valusis, G

    2012-12-14

    To decrease single-wall carbon nanotube (SWCNT) lengths to a value of 100-200 nm, aggressive cutting methods, accompanied by a high loss of starting material, are frequently used. We propose a cutting approach based on low temperature intensive ultrasonication in a mixture of sulfuric and nitric acids. The method is nondestructive with a yield close to 100%. It was applied to cut nanotubes produced in three different ways: gas-phase catalysis, chemical vapor deposition, and electric-arc-discharge methods. Raman and Fourier transform infrared spectroscopy were used to demonstrate that the cut carbon nanotubes have a low extent of sidewall degradation and their electronic properties are close to those of the untreated tubes. It was proposed to use the spectral position of the far-infrared absorption peak as a simple criterion for the estimation of SWCNT length distribution in the samples.

  17. Fabrication of nanopores with ultrashort single-walled carbon nanotubes inserted in a lipid bilayer.

    Science.gov (United States)

    Liu, Lei; Xie, Jiani; Li, Ting; Wu, Hai-Chen

    2015-11-01

    We describe a protocol for the insertion of ultrashort single-walled carbon nanotubes (SWCNTs) to form nanopores in a Montal-Mueller lipid bilayer. The SWCNTs are designed to bind to a specific analyte of interest; binding will result in the reduction of current in single-channel recording experiments. The first stage of the PROCEDURE is to cut and separate the SWCNTs. We cut long, purified SWCNTs with sonication in concentrated sulfuric acid/nitric acid (3/1). Isolation of ultrashort SWCNTs is carried out by size-exclusion HPLC separation. The second stage is to insert these short SWCNTs into the lipid bilayer. This step requires a microinjection probe made from a glass capillary. The setup for protein nanopore research can be adopted for the single-channel recording experiments without any special treatment. The obtained current traces are of very high quality, showing stable baselines and little background noise. Example procedures are shown for investigating ion transport and DNA translocation through these SWCNT nanopores. This nanopore has potential applications in molecular sensing, nanopore DNA sequencing and early disease diagnosis. For example, we have selectively detected modified 5-hydroxymethylcytosine in single-stranded DNA (ssDNA), which may have implications in screening specific genomic DNA sequences. The protocol takes ∼15 d, including SWCNT purification, cutting and separation, as well as the formation of SWCNT nanopores for DNA analyses.

  18. Impact of single-walled carbon nanotubes on the embryo: a brief review

    Directory of Open Access Journals (Sweden)

    Al Moustafa AE

    2016-01-01

    Full Text Available Ala-Eddin Al Moustafa,1–4 Etienne Mfoumou,5 Dacian E Roman,3 Vahe Nerguizian,6 Anas Alazzam,7 Ion Stiharu,3 Amber Yasmeen8 1College of Medicine & Biomedical Research Centre, Qatar University, Doha, Qatar; 2Oncology Department, McGill University, 3Mechanical and Industrial Engineering Department, Concordia University, Montreal, QC, Canada; 4Syrian Research Cancer Centre of the Syrian Society against Cancer, Aleppo, Syria; 5Nova Scotia Community College, Dartmouth, NS, 6École de Technologie Supérieure, Montreal, QC, Canada; 7Department of Mechanical Engineering, Khalifa University, Abu Dhabi, UAE; 8Segal Cancer Centre, Lady Davis Institute for Medical Research of the Sir Mortimer B. Davis-Jewish General Hospital, Montreal, QC, Canada Abstract: Carbon nanotubes (CNTs are considered one of the most interesting materials in the 21st century due to their unique physiochemical characteristics and applicability to various industrial products and medical applications. However, in the last few years, questions have been raised regarding the potential toxicity of CNTs to humans and the environment; it is believed that the physiochemical characteristics of these materials are key determinants of CNT interaction with living cells and hence determine their toxicity in humans and other organisms as well as their embryos. Thus, several recent studies, including ours, pointed out that CNTs have cytotoxic effects on human and animal cells, which occur via the alteration of key regulator genes of cell proliferation, apoptosis, survival, cell–cell adhesion, and angiogenesis. Meanwhile, few investigations revealed that CNTs could also be harmful to the normal development of the embryo. In this review, we will discuss the toxic role of single-walled CNTs in the embryo, which was recently explored by several groups including ours. Keywords: single-walled carbon nanotubes, embryo, toxicity

  19. Interaction of amidated single-walled carbon nanotubes with protein by multiple spectroscopic methods

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lili [China Pharmaceutical University, Nanjing 210009 (China); The Nursing College of Pingdingshan University, Pingdingshan 467000 (China); Lin, Rui [Yancheng Health Vocational and Technical College, Yancheng 224005 (China); He, Hua, E-mail: dochehua@163.com [China Pharmaceutical University, Nanjing 210009 (China); Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, China Pharmaceutical University, Nanjing 210009 (China); Sun, Meiling, E-mail: sml-nir@sohu.com [China Pharmaceutical University, Nanjing 210009 (China); Jiang, Li; Gao, Mengmeng [China Pharmaceutical University, Nanjing 210009 (China)

    2014-01-15

    The aim of this work was to investigate the detailed interaction between BSA and amidated single walled carbon nanotubes (e-SWNTs) in vitro. Ethylenediamine (EDA) was successfully linked on the surface of single-walled carbon nanotubes (SWNTs) via acylation to improve their dispersion and to introduce active groups. Bovine serum albumin (BSA) was selected as the template protein to inspect the interaction of e-SWNTs with protein. Decreases in fluorescence intensity of BSA induced by e-SWNTs demonstrated the occurrence of interaction between BSA and e-SWNTs. Quenching parameters and different absorption spectra for e-SWNTs–BSA show that the quenching effect of e-SWNTs was static quenching. Hydrophobic force had a leading contribution to the binding roles of BSA on e-SWNTs, which was confirmed by positive enthalpy change and entropy change. The interference of Na{sup +} with the quenching effect of e-SWNTs authenticated that electrostatic force existed in the interactive process simultaneously. The hydrophobicity of amino acid residues markedly increased with the addition of e-SWNTs viewed from UV spectra of BSA. The content of α-helix structure in BSA decreased by 6.8% due to the addition of e-SWNTs, indicating that e-SWNTs have an effect on the secondary conformation of BSA. -- Highlights: • The interaction between e-SWNTs and BSA was investigated by multiple spectroscopic methods. • Quenching mechanism was static quenching. • Changes in structure of BSA were inspected by synchronous fluorescence, UV–vis and CD spectrum.

  20. Tight binding simulation study on zigzag single-walled carbon nanotubes

    Science.gov (United States)

    Sharma, Deepa; Jaggi, Neena; Gupta, Vishu

    2018-01-01

    Tight binding simulation studies using the density functional tight binding (DFTB) model have been performed on various zigzag single-walled carbon-nanotubes (SWCNTs) to investigate their electronic properties using DFTB module of the Material Studio Software version 7.0. Various combinations of different eigen-solvers and charge mixing schemes available in the DFTB Module have been tried to chalk out the electronic structure. The analytically deduced values of the bandgap of (9, 0) SWCNT were compared with the experimentally determined value reported in the literature. On comparison, it was found that the tight binding approximations tend to drastically underestimate the bandgap values. However, the combination of Anderson charge mixing method with standard eigensolver when implemented using the smart algorithm was found to produce fairly close results. These optimized model parameters were then used to determine the band structures of various zigzag SWCNTs. (9, 0) Single-walled Nanotube which is extensively being used for sensing NH3, CH4 and NO2 has been picked up as a reference material since its experimental bandgap value has been reported in the literature. It has been found to exhibit a finite energy bandgap in contrast to its expected metallic nature. The study is of utmost significance as it not only probes and validates the simulation route for predicting suitable properties of nanomaterials but also throws light on the comparative efficacy of the different approximation and rationalization quantum mechanical techniques used in simulation studies. Such simulation studies if used intelligently prove to be immensely useful to the material scientists as they not only save time and effort but also pave the way to new experiments by making valuable predictions.