Abstract:
This thesis consists of seven Chapters. Chapter 1 gives a brief overview of
nanomaterials. Chapter 2 consists of two parts of which Part 1 describes efforts
towards phase transfer of nanocrystals of gold and CdSe from aqueous or organic
medium to a fluorous medium and solubilization of ZnO nanorods and carbon
nanotubes in a fluorous medium. Part 2 deals with the one-step synthesis of fluorouscapped
nanoparticles of metal chalcogenides such as CdSe, CdS, PbSe, ZnSe and of
metal oxides such as γ-Fe2O3 and ZnO and of bimetallic FePt.
Chapter 3 describes the use of the Huisgen cycloaddition reaction to generate
assemblies of metal (gold) and semiconductor (CdSe) nanoparticles as well as to
covalently attached SWNT-gold and -CdSe nanoparticle composites. Connecting
carbon nanotubes by click chemistry is also reported.
Investigations on the dependence of magnetic and optical properties of
nanoparticles with interparticle distance are discussed in Chapter 4. Magnetic
properties are examined with FePt nanoparticles while spectroscopic properties are
examined in the case of CdSe nanoparticles.
Chapter 5 consists of two parts with Part 1 dealing with a spectroscopic study of
charge-transfer interactions of electron-withdrawing (nitrobenzene, TCNQ and TCNE)
and electron-donating (TTF and aniline) molecules with single-walled carbon
nanotubes (SWNTs). In Part 2, the effect nanoparticles of metals such as gold and
platinum on the electronic structure of SWNTs has been studied by Raman
spectroscopy.
Chapter 6 consists of three parts. Part 1 describes the separation of metallic and
semiconducting SWNTs based on molecular charge-transfer while Part 2 deals with a
novel method for the synthesis of metallic SWNTs by an arc-discharge method. An
arc-discharge method has also been employed to prepare Y-junction SWNTs (Part 3).
In Chapter 7, sensitivity of the electronic structure of graphene towards various
electron-donor and –acceptor molecules has been studied by Raman and optical
absorption spectroscopy as well as electrical resistivity measurements.
