Suchergebnisse

The discovery of carbon nanotubes (CNTs) revealed that this new form of carbon can challenge traditional materials on many fronts. Remarkable electrical, thermal, mechanical and optical properties of individual CNTs have attracted significant attention, and so scientists have begun to consider their implementation in the everyday life. Unfortunately, CNT aggregates are composed of a wide range of CNT types, which has a strongly negative influence on the observed performance of macroscale devices made from them. Recently, however, it has become evident that different CNT types can be sorted according to length, diameter, electrical character, chiral angle and even handedness, which reignited interest in them. This review aims to demonstrate the state-of-the-art of all the mainstream methods of sorting CNTs (preferential synthesis, selective destruction, (di)electrophoresis, ultracentrifugation, chromatography, (co)polymer isolation and aqueous two-phase extraction). It is concluded with an overview of already tested applications using sorted CNTs and gives overlook of the field for the future. ; The Silesian University of Technology (Grant Agreement - 04/020/RGH17/0050). National Science Center, Poland (Grant Agreement - UMO-2015/19/P/ST5/03799). The European Union's Horizon 2020 research and innovation programme (Grant Agreement - 665778).

We have demonstrated fire-retardancy properties of a polymer matrix-free CNT film for the first time. As compared with classical fire-retardant materials such as Kevlar, Twaron or Nomex, the CNT film showed a spectrum of advantages. The material is lightweight, flexible and well-adherent to even the most complicated shapes. The results have showed that by using CNTs for fire-retardancy we can extend the operational time almost two-fold, what makes CNTs a much better protection than the solutions employed nowadays. We believe that among other great properties of CNT, their macroscopic assemblies such as CNT films show significant potential for becoming a fire protective coating, which exhibits high performance in not sustaining fire. ; The European Research Council (Grant Agreement - 259061). National Science Center, Poland (Grant Agreement - UMO-2015/19/P/ST5/03799). The European Union's Horizon 2020 research and innovation programme (Grant Agreement - 665778).

arXiv:1309.6918 ; We review our recent modelling work of carbon nanotubes as potential candidates for heat dissipation in microelectronics cooling. In the first part, we analyze the impact of nanotube defects on their thermal transport properties. In the second part, we investigate the loss of thermal properties of nanotubes in presence of an interface with various substances, including air and water. Comparison with previous works is established whenever is possible. ; This work was financially supported by the European Union through the FP7 project "Thermal management with carbon nanotube architectures" (THEMA-CNT) under the contract number: 228539. We also thank the support from Spanish Grants FIS2011-65702-C02-01 & PIB2010US-00652, Proyecto Diputación Foral de Guipuzkoa (Exp. 29/12), and Grupo Consolidado UPV/EHU from Gobierno Vasco (IT- 319-07 & IT-578-13). We acknowledge financial support from the European Research Council Advanced Grant DYNamo (ERC-2010-AdG -Proposal Number 267374) and European Commission projects CRONOS (Grant No. 280879-2 CRONOS CP-FP7). JMGL has been supported by the Subprograma Ramón y Cajal, Dirección General de Investigación y Gestión del Plan Nacional de I+D, reference RYC-2011-07782, Spain. TM acknowledges support from the Danish Council for Independent Research, FTP Grants Nos. 11-104592 and 11-120938. ; Peer Reviewed

We have demonstrated that nanocarbon materials such as carbon nanotubes (CNTs) or graphene have an intrinsically hydrophilic nature. Addition of liquid hydrocarbons or polycyclic aromatic compounds, which are the common side-products of nanocarbon syntheses, turned the otherwise hydrophilic CNT films hydrophobic. The very small amount needed to cause this effect was not discernable by SEM or Raman spectroscopy and also it could be easily overlooked by other methods of analysis. Upon simple and rapid thermal desorption of these species we were able to fully recover the water affinity in these CNT networks. Without using any oxidizing agents the material remains hydrophilic for weeks having water contact angle of about 35°. The results pave the way towards implementation of low-dimensional nanostructures in the real life without disrupting their inherent properties. ; The Silesian University of Technology (Grant Agreement - 04/020/ RGJ18/0057). National Science Center, Poland (Grant Agreement - UMO-2015/19/P/ST5/03799, UMO-2015/19/N/ST8/02184). The European Union's Horizon 2020 research and innovation programme (Grant Agreement - 665778).

3 pages, 1 figure.-- PACS nrs.: 73.21.La, 73.22.-f, 73.20.At, 71.15.Ap.-- Presented as poster communication to TNT 2008: Trends in NanoTechnology (Oviedo, Spain, Sep 1-5, 2008). ; The interface states of all-metallic carbon nanotube quantum dots are studied based on a tight-binding approach and a Green's function matching technique. We have found that depending on the type of metallic tube, the energy of interface states may show an oscillatory behavior. We identify these as steamming from Friedel oscillations. We comment on the possible implications of this finding on other physical properties, such as stability during the growth of nanotube junctions and magnetic interaction through carbon nanotubes. ; We acknowledge financial support by the ETORTEK (NANOMAT) program of the Basque government, the Intramural Special Project (Ref. No. 2006601242), the Spanish Ministerio de Ciencia y Tecnología (Grants No. Fis 2007-66711-C02-C01 and MAT2006-06242) and the European Network of Excellence NANOQUANTA (NM4-CT-2004-500198). ; Peer reviewed

A fast and convenient method to create n-doped or p-doped carbon nanotube (CNT) films of improved electrical conductivity is presented herein. Free-standing thin flexible films made from unsorted CNTs and composed of predominantly (6,5) or (7,6) chiral angle were exposed to hydrazine (N2H4) or boron trifluoride (BF3) solutions, which decreased the sheet resistance by almost up to an order of magnitude. Analysis of the CNT films surface chemistry indicates that despite benign influence of the dopants on their composition, they strongly, but favorably affected electronic structure. Depending on the type of employed dopant, the Fermi level was strongly shifted upwards or downwards to enhance conduction of electrons or holes for employed n-doping and p-doping agents, respectively. This work provides an effective approach for the formation of CNT or graphene-based macroscopic assemblies such as films or fibers of high electrical conductivity with predetermined type of predominant charge carriers without excessive processing. ; The Silesian University of Technology (Grant Agreement - 04/020/RGH17/0050). National Science Center, Poland (Grant Agreement - UMO-2015/19/P/ST5/03799). The European Union's Horizon 2020 research and innovation programme (Grant Agreement - 665778).