Synthesis and optical spectroscopy of a hybrid cadmium sulfide-dendrimer nanocomposite

Synthesis and Analytical Applications of Quantum Dots Coated with Different Generations of DAB Dendrimers

“…Also, there is a blueshift of the absorption band as the generation of the dendrimer is increased. This result is similar to that described in the literature when methanol was used as solvent (Gayen et al, 2007). The absorption shift that is observed for the different generations of DAB confirms that the amine groups are participating with MPA in the capping of the QDs.…”

“…The synthesized nanocomposites show similar emission maximum to literature reports of mercaptoacetic acid-capped-CdS (541 nm) (Wisher et al, 2006) and thioglycerol-capped-ZnS (411 nm) (Unni et al, 2009;Jie et al, 2007). Also, the synthesized CdS nanocomposites have similar emission spectral characteristics to those reported in the literature, namely broad spectra with maximum intensity wavelength in methanol solution at about 470 nm (Gayen et al, 2007). The fluorescence properties of the synthesised nanocomposites can be slighly modified if the reaction conditions are changed.…”

“…The same trends of the maximum emission wavelengths with the QDs type and DAB generation are observed. This last generation trend has already been described in the literature for diferent generations of DAB-CdS nanocomposites in methanol solution (Gayen et al, 2007). The aqueous solutions of nanocomposites emit in the range 431 mn (DAB-G 5 -ZnS) up to 607 nm (DAB-G 3 -CdS) with FWHM usually higher than the solid nanocomposites -a FWHM of 227 nm is observed for DAB-G 3 -CdS.…”

“…This result is a consequence of the quantum confinement effects in the nanoparticles confirming the existence of QDs. Also, the absorption wavelengths suggest that the sizes of the QDs are in the nanometers range (Gayen et al, 2007;Unni et al, 2009). The absorptions of the hybrid DAB-CdS:ZnS QDs occur at intermediate wavelengths of the absorptions of the single QDs.…”

“…CdSQDs and/or ZnS-QDs have been synthesized using dendrimer structure, where polyamide dendrimer (PAMAM) is employed as host confinement (Juan et al, 2008;Sooklal et al, 1998;Wisher et al, 2006;Ling & Cong, 2008). Hybrid CdS DAB dendrimer nanocomposite have been synthesised and characterized in methanol (Lemon & Crooks, 2000;Gayen et al, 2007). These nanocomposites are formed by the arrested precipitation of nanometer-scale CdS clusters in the presence of polyamide dendrimers.…”