Search results for " single walled carbon nanotubes"

ORGANIC-INORGANIC HYBRID CATALYSTS BASED ON IMIDAZOLIUM AND THIAZOLIUM SALTS

In the last years, great attention was focused on immobilized ionic liquids for their application in the field of catalysis. The main challenge is represented by the possibility of combining the benefits of the ionic liquids to that of the supports. In order to achieve this ambitious objective both the choice of the support and the functionalization strategy are of fundamental importance. In this context, one of the aims of this doctoral project was to develop novel catalysts based on covalently mono- or multilayer imidazolium or thiazolium networks onto a high ordered mesoporous silica or carbon nanotubes materials. The second goal of this PhD thesis was to design novel imidazolium based c…

Local photo-oxidation of individual single walled carbon nanotubes probed by femtosecond four wave mixing imaging

2014

Photo-oxidation of individual, air-suspended single walled carbon nanotubes (SWCNTs) is studied by femtosecond laser spectroscopy and imaging. Individual SWCNTs are imaged by four wave mixing (FWM) microscopy under an inert gas (Ar or N2) atmosphere. When imaging is performed in an ambient air atmosphere, the decay of the FWM signal takes place. Electron microscopy shows that SWCNTs are not destroyed and the process is attributed to photoinduced oxidation reactions which proceed via a non-linear excitation mechanism, when irradiation is performed with ∼30 fs pulses in the visible spectral region (500-600 nm). Photo-oxidation can be localized in specific regions of SWCNTs within optical reso…

LIQUIDI IONICI E FULLERENI: PIATTAFORME PER NUOVI MATERIALI

The synthesis of innovative catalysts based on different carbon nanoforms (CNFs), namely fullerene C60 and carbon nanotubes (CNTs), and their application in Suzuki and Heck C-C coupling reactions, constitutes the common thread of the first part (Chapter 1 and 2) of this thesis. C60 and CNTs were functionalized with ionic liquids (ILs) and poly-amidoamine (PAMAM) dendrimers, respectively, and used as supports for palladium nanoparticles (PdNPs). Moreover, additional supported catalytic systems based on one of the synthesized C60-IL hybrids were prepared and successfully employed in the title coupling reactions. The final part (Chapter 3) of the thesis deals on the microwave-mediated synthesi…