This communication describes scanning tunnelling microscopy investigations of the electronic properties of singlewalled carbon nanotubes (SWNTs). First, the unique relationship between the atomic structure and electronic properties of SWNTs is presented. Second, structural defects in nanotubes are addressed, and quantum size effects in SWNTs are discussed. Lastly, the effects of magnetic impuri...

Ab initio electronic structure calculations based on density functional theory are performed for SinFe clusters to determine stable structures. Our results show that these clusters can form the building block for Feencapsulated Si-nanotubes. The Si10Fe and Si12Fe clusters are found to be very stable, exhibiting large charge transfer, and can lead to Si-based nanotubes of the types Si5nFen21 and...

Moderate acid treatment of double-walled carbon nanotubes (DWCNTs) has given rise to two new experimentally observed second-order double resonant Raman scattering frequencies centered at 1901 cm(-1) and 1942 cm(-1), in the highly dispersive LOLA region. These LOLA overtones and combination modes have been predicted by double resonance theory for two phonons associated with the K- and Gamma-poin...

Dynamic surface rearrangement and thermal stability of N-functional groups on carbon nanotubes (CNTs), obtained by functionalization of pristine CNTs with NH(3), were studied by temperature-programmed XPS and MS: a link between the stability of the functional group and decomposition temperature have been established and a conversion into graphitic nitrogen was observed.

Using ab initio calculations we study the stability of Si-based cages and nanotubes stabilized by encapsulated transition metal atoms ~TMAs!. It is demonstrated that the stabilization of these cages and nanotubes as well as their magnetic properties are strongly guided by a delicate interplay between the attainable symmetry of the system and the d-band filling of the encapsulated TMA. As a resu...

quick identification of vibrio cholerae in epidemics is   important, on the other hand; conventional methods are time-consuming and   costly. the aim of this study was to develop a rapid, inexpensive and high   sensitivity method for quick identification of vibrio cholerae . for   this purpose we designed a pcr detection based on magnetic nanoparticles for   identification of bacterial dna by p...

We have utilized lysozyme to non-covalently functionalize and disperse double-walled carbon nanotubes (DWNTs) in aqueous solution. Lysozyme preferentially binds and disperses DWNTs with larger diameters. This is a facile and effective method to fractionalize and enrich DWNTs with certain diameters.

In this Account, we summarize some of our recent studies on the materials properties of the carbon nanotubes (CNTs). The focus is on single-wall carbon nanotubes (SWNTs). We describe experiments on synthesis of SWNTs with controlled molecular structures and assembly of functional macroscopic structures. In addition, we present results on the electron field emission properties of macroscopic CNT...