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Green synthesis, characterization and applications of cdse based core-shell quantum dots and silver nanocomposites
Author(s)
Bhagyaraj, Sneha
Date Issued
2015
Type
Thesis
Publisher
Cape Peninsula University of Technology
Abstract
Researchers around the world are now focusing on inculcating green chemistry principles in all level
of research especially in nanotechnology to make these processes environmental friendly.
Nanoparticles synthesized using green chemistry principles has several advantages such as simplicity,
cost effectiveness, compatibility for biomedical and pharmaceutical applications and large scale
production for commercial purpose. Based on this background, this thesis present the design,
synthesis, characterization and applications of various CdSe based core-shell and core-multi shell
quantum dots (QDs), quantum dots-polymer nanocomposites, silver nanoparticles (Ag-NPs) and silver
nanocomposites via completely green methods. Various QDs like CdSe/CdS/ZnS and CdSe/ZnS, and
there polymer nanocomposites were successfully synthesized and characterized. The high quality of
the as-synthesized nanoparticles was confirmed using absorption and photoluminescence (PL)
spectroscopy, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, transmission
electron microscopy (TEM) and high resolution TEM (HRTEM). Detailed optical and morphological
characterization showed that the CdSe/CdS/ZnS core-multi shell QDs were small, monodispersed with
high fluorescent intensity and narrow emission width. The CdSe/CdS/ZnS core multi-shell QDs were
dispersed in epoxy polymer matrix to obtain fluorescent epoxy nanocomposite. The brillouin
spectroscopy analysis revealed that the presence of QDs inside polymer composite reduces the
acoustic frequency of the polymer. Highly fluorescent CdSe/ZnS core-shell QDs was also synthesized
and dispersed in PMMA polymer matrix to prepare bright yellow emitting nanocomposite film. The
as-synthesized QDs also undergone surface exchange to convert the organically soluble nanomaterial
to water soluble. After the ligand exchange, the morphology and above all the fluorescence property of
the quantum dots remained intact. In another approach, HDA-capped CdSe nanoparticles were
synthesized in the absence of an inert gas followed by dispersion in polymer polycaprolactone to
produce orange light emitting electrospun polymer nanocomposite nanofibre.
of research especially in nanotechnology to make these processes environmental friendly.
Nanoparticles synthesized using green chemistry principles has several advantages such as simplicity,
cost effectiveness, compatibility for biomedical and pharmaceutical applications and large scale
production for commercial purpose. Based on this background, this thesis present the design,
synthesis, characterization and applications of various CdSe based core-shell and core-multi shell
quantum dots (QDs), quantum dots-polymer nanocomposites, silver nanoparticles (Ag-NPs) and silver
nanocomposites via completely green methods. Various QDs like CdSe/CdS/ZnS and CdSe/ZnS, and
there polymer nanocomposites were successfully synthesized and characterized. The high quality of
the as-synthesized nanoparticles was confirmed using absorption and photoluminescence (PL)
spectroscopy, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, transmission
electron microscopy (TEM) and high resolution TEM (HRTEM). Detailed optical and morphological
characterization showed that the CdSe/CdS/ZnS core-multi shell QDs were small, monodispersed with
high fluorescent intensity and narrow emission width. The CdSe/CdS/ZnS core multi-shell QDs were
dispersed in epoxy polymer matrix to obtain fluorescent epoxy nanocomposite. The brillouin
spectroscopy analysis revealed that the presence of QDs inside polymer composite reduces the
acoustic frequency of the polymer. Highly fluorescent CdSe/ZnS core-shell QDs was also synthesized
and dispersed in PMMA polymer matrix to prepare bright yellow emitting nanocomposite film. The
as-synthesized QDs also undergone surface exchange to convert the organically soluble nanomaterial
to water soluble. After the ligand exchange, the morphology and above all the fluorescence property of
the quantum dots remained intact. In another approach, HDA-capped CdSe nanoparticles were
synthesized in the absence of an inert gas followed by dispersion in polymer polycaprolactone to
produce orange light emitting electrospun polymer nanocomposite nanofibre.
Additional information
Thesis (DTech (Chemistry))--Cape Peninsula University of Technology, 2015.
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