A5043243874- Carbon Nanotubes in Composites
- Graphene research and applications
- Hydrogen Storage and Materials
- Advanced Thermoelectric Materials and Devices
- Conducting polymers and applications
- Thermal properties of materials
- Diamond and Carbon-based Materials Research
- Fullerene Chemistry and Applications
- Synthesis and characterization of novel inorganic/organometallic compounds
- Mechanical and Optical Resonators
- Fuel Cells and Related Materials
- Organometallic Complex Synthesis and Catalysis
- Nanotechnology research and applications
- Nanopore and Nanochannel Transport Studies
- Silicone and Siloxane Chemistry
- Advancements in Battery Materials
- Force Microscopy Techniques and Applications
- Liquid Crystal Research Advancements
- Boron and Carbon Nanomaterials Research
- Silicon Nanostructures and Photoluminescence
- Thermal Radiation and Cooling Technologies
- Semiconductor materials and devices
- Metal complexes synthesis and properties
- Advanced Battery Materials and Technologies
- Advanced Battery Technologies Research
Technion – Israel Institute of Technology
2019
Fraunhofer Institute for Manufacturing Technology and Advanced Materials
2019
Korea University
2009-2015
Max Planck Institute for Solid State Research
2001-2011
Max Planck Society
1995-2010
Sineurop Nanotech (Germany)
2009-2010
Technische Universität Berlin
2008-2009
Georgi Nadjakov Institute of Solid State Physics
2008-2009
Bulgarian Academy of Sciences
2008-2009
Roth and Rau (Germany)
2009
Chemical modification by SOCl2 of an entangled network purified single-wall carbon nanotubes, also known as 'bucky paper', is reported to profoundly change the electrical and mechanical properties this system. Four-probe measurements indicate a conductivity increase up factor 5 at room temperature even more pronounced lower temperatures. This chemical improves SWNT networks. Whereas pristine sample shows overall semiconducting character, modified material behaves metal. The effect studied in...
We investigate the magnitude and temperature dependence of electrical conductivity, optical infrared absorption, Raman spectra single-walled carbon nanotube (SWNT) bucky-paper after chemical treatment determine correlations between changes in these properties. Ionic-acceptor doping SWNT (with SOCl(2), iodine, H(2)SO(3), etc.) causes an increase conductivity that correlates with absorbance far-IR region frequency spectral lines. Conversely, other molecules (e.g., aniline, PyPhF(5), PhCH(2)Br,...
A new method for the successful alignment of carbon nanotubes is presented. An aqueous lyotropic nematic liquid-crystal phase acts as a self-organizing template to align and disperse nonfunctionalized simultaneously, success confirmed through Raman spectroscopy analysis (see figure). This work could be extended allow tailoring specific purposes properties, using different liquid crystals.
Intermolecular carbon nanotube junctions were formed by coupling chemically functionalized nanotubes with molecular linkers. An end-to-side or end-to-end heterojunction can be reacting chloride terminated aliphatic diamine. The modified mats characterized Raman spectroscopy. peak shift in the tangential vibration mode reveals that attached chemical functional groups behave as either an electron donor acceptor, and facilitate charge transfer host. is also verified transport measurements on...
A periodically modulated graphene (PMG) generated by nanopatterned surfaces is reported to profoundly modify the intrinsic electronic properties of graphene. The temperature dependence sheet resistivity and gate response measurements clearly show a semiconductor-like behavior. Raman spectroscopy reveals significant shifts G 2D modes induced interaction with underlying grid-like nanostructure. influence periodic, alternating contact substrate surface was studied in terms strain caused bending...
Abstract Carbon nanotube networks showing superior electric properties, high chemical stability, strong mechanical and flexibility are also known to exhibit thermoelectric effects. However, the experimental figure of merit, ZT , pristine carbon nanotubes is typically in range 10 −3 –10 −2 which still not attractive for thermal energy conversion applications. In this work, we show possible ways improve properties single walled (SWCNTs) by means treatments. study, primarily investigated effect...
The thermoelectric power (TEP) of single walled carbon nanotube (SWCNT) thin films in pure metallic SWCNT (m-SWCNT) and semiconducting (s-SWCNT) networks as well m- s-SWCNT mixtures is investigated. TEP measured on the film (≈88 μV/K) was found to be almost 7 times higher than that m-SWCNTs (≈13 μV/K). Moreover, a quasilinear increase mixed observed fraction s-SWCNTs increased. experimentally determined relationship between mixture allows fast simple quantitative analysis s:m ratio any...
The two-dimensional silicon backbone structure of planar polysilane and W\"ohler siloxene is responsible for their exciting luminescing properties. We have prepared single crystals by a topotactic reaction from crystalline CaSi${}_{2}$. chemical composition was determined as [Si${}_{6}$H${}_{3}$(OH)${}_{3}$]${}_{n}.$ x-ray crystal analysis identifies the so-called 2D-poly[1,3,5-trihydroxocyclohexasilane]. Polysilane exhibits same structural properties but with [Si${}_{6}$H${}_{6}$]${}_{n}.$...
We grow high-density, aligned single wall carbon nanotube mats for use as interconnects in integrated circuits by remote plasma chemical vapor deposition from a Fe–Al2O3 thin film catalyst. carry out extensive Raman characterization of the resulting mats, and find that this catalyst system gives rise to broad range diameters, with no preferential selectivity semiconducting tubes, but at least 1∕3 metallic tubes.
This report demonstrates application of expanded graphite (ExG) for thermoelectric energy conversion, where it serves as a filler both p- and n-type organic materials. Thin ExG composite films showing improved properties were prepared. In particular, composites with intrinsically conducting polymer poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) yielding high electrical conductivity (up to 104 S m−1) enhanced thermopower (Seebeck coefficient) provided promising p-type...
Abstract Flexible, transparent and conducting poly(methyl methacrylate) (PMMA) composites films were prepared using SOCl 2 functionalized SWNTs. Optical absorption spectra measured on composite confirm that the preparation procedure preserves electronic properties (position of Fermi level) p‐doped nanotubes in polymer matrix. Due to doping effect electrical conductivity is improved by a factor 5. The light transmission depends film thickness nanotube concentration. optical transmittance...
We investigated a series of nanocomposites, built the hydrogen-bonded liquid crystal (LC) p-n-heptyloxybenzoic acid (7OBA) and single-walled carbon nanotubes (SWCNTs) by optical microtexture analysis other complementary methods. The surface orientation strength LC cell bulk interaction dimeric molecules with SWCNTs turn out to mainly govern type (symmetry), thermal stability, chirality states induced in these nanocomposites. As result, cascade phase transitions phases not typical for...
Raman spectra of HiPco SWNT and SWNT-pyrene films were measured in the 160–1800 cm−1 range. Due to non-covalent interaction between pyrene most intensive component G mode (1590 cm−1) is downshifted by 2 becomes narrower. Also intensity low-frequency (1550 decreases about 30%. Structures energies complexes zigzag (n, 0) SWNTs [6 ≤ n 20] determined at MP2 level theory. The BSSE-free geometry optimization pyrene-zigzag (12,0) complex converged a structure with 1/2staggered conformation an...
We studied the transition from electrochemical double-layer charging regime to intercalative doping of bundled single-walled carbon nanotubes (SWNT) in KCl and HCl aqueous solution. For this purpose we used high levels by applying constant potentials above 1000 mV approaching slightly exceeding oxidation potential for Cl(-) ions. At each situ Raman measurements radial breathing mode (RBM), high-energy tangential (HEM), disorder-induced (D) were performed. Furthermore, conductivity...