The functionalization of single wall carbon nanotubes (SWCNTs) is a very actively discussed topic in contemporary nanotube literature because the planned modification of SWCNT properties is believed to open the road towards real nanotechnology applications. In this contribution, some recent results are reported on the subject. Covalent attachment of functional groups, their influence on tube-tu...

Density-functional theory is used to investigate hydrogen physisorption on a graphene layer and on single wall carbon nanotubes. Both external and internal adsorption sites of 9, 0 and 10, 0 carbon nanotubes have been studied with the hydrogen molecular axis oriented parallel or perpendicular to the nanotube wall. A range of hydrogen molecule binding sites has been examined and it is found that...

We discuss existence of mixed state ρAB of two (or multy-) component system HAB = HA ⊗ HB with reduced density matrices ρA, ρB and given spectra λAB , λA, λB . We give a complete solution of the problem in terms of linear inequalities on the spectra, accompanied with extensive tables of marginal inequalities, including arrays up to 4 qubits. In the second part of the paper we pursue another app...

We investigate the nitrogen substitutional impurity in semiconducting zigzag and metallic armchair single-wall carbon nanotubes using ab initio density functional theory. At low concentrations (less than 1 at. %), the defect state in a semiconducting tube becomes spatially localized and develops a flat energy level in the band gap. Such a localized state makes the impurity site chemically and e...

We use inelastic light scattering (Raman) to probe individual and isolated single wall carbon nanotubes, suspended in air over trenches to explore the influence of the environment on the electronic transition energies. We find narrow and predominantly symmetric resonance profiles which are significantly downshifted as compared to isolated tubes in aqueous surfactant suspensions. A lower limit o...

We present photoluminescence studies of individual semiconducting single-wall carbon nanotubes at room and cryogenic temperatures. From the analysis of spatial and spectral features of nanotube photoluminescence, we identify characteristic signatures of unintentional exciton localization. Moreover, we quantify the energy scale of exciton localization potentials as ranging from a few to a few te...

We present preliminary results of Raman scattering measurements of multiwall carbon nanotubes (MWCNT). The nanotubes have been carefully dissolved, separated and then characterized by AFM. The micro-Raman spectra of the objects are taken with 514,5nm wavelength excitations and in the temperature range 4K 400K. Basically the spectra are quite similar to the well known single wall carbon nanotube...

Pool boiling heat transfer is measured with two individual working fluids on copper surfaces enhanced with sintered copper powder and carbon nanotubes. The working fluids are a segregated hydrofluoroether, HFE-7300, and deionized water. The surfaces considered in the experiments include smooth copper, copper with sintered copper particles, smooth copper with copper-coated carbon nanotubes (CNT)...

The electronic structure of single-wall nanotubes in intact, undissolved ‘‘buckypaper’’ has been studied using scanning tunneling microscopy ~STM! and scanning tunneling spectroscopy ~STS! at 23 K. STM topography shows, that single-wall carbon nanotubes ~SWNT’s! form microbundles that in turn aggregate in ropes. STS allows us to distinguish between room temperature metallic and wide-gap SWNT’s....