Synthesis and characterization of quantum dot–polymer composites

Abstract

In this study, we demonstrate a facile and simple synthesis of quantum dot (QD)-polymer composites. Highly fluorescent semiconducting CdSe/ZnS quantum dots were embedded in different commercially available polymers using one easy step. QD-polymer composite nanoparticles were also synthesized using template-assisted synthesis. In particular, we self-assembled lamellar micelles inside nanoporous alumina membranes which were used for the synthesis of mesoporous silica hollow nanotubes and solid nanorods. We observed that the addition of excess free octadecylamine (ODA) in the QD-silica solution resulted in gelation. The gelation time was found to be dependent on free ODA concentration. Similarly, the emission of QD-polymer composites was also found to be dependent on free ODA concentration. Highly purified QDs provided polymer composites that have a much lower emission compared to unpurified nanocomposites. This was attributed to passivation of the QD surfaces by amine, which reduced the surface defects and non-radiative pathways for excited QDs. Finally, highly fluorescent QD-polymer patterns were demonstrated on glass substrates which retained their emission in both polar and non-polar solvents.

Rapid detection of vegetable cooking oils adulterated with inedible used oil using fluorescence quenching method with aqueous CTAB-coated quantum dots

“…The interdigitated bilayer structure of CTAB-TOPO-coated CdSe/ZnS QD, whose first layer was original surface ligands TOPO and the second layer was CTAB, made it a more sensitive and selective fluorescence probe than CdSe/ZnS QD to the quenchers [46]. Similar organic coated bilayer structures of water-soluble CdSe/ZnS QDs were also investigated by others as fluorescence quenching probes for selective detection and quantification of analytes like chloride anion [47], hypochlorite [48], heavy metal ions [27][28][29][30]49], nitroaromatic [50] and even chiral mixtures of enantiomers [51,52].…”

One-year changes in glucose and heart disease risk factors among participants in the WISEWOMAN programme

“…Several authors have published excellent well‐detailed protocols with descriptors for the preparation routes for QDs 32–34. In general, coatings on the CdSe QDs with higher bandgap materials is necessary, such as ZnS shells, in order to increase the photostability and luminescence properties of the resulting core–shell QDs 35. QDs made of CdSe/ZnS core–shell have been the preferred choice for bioapplications 22.…”

Polymer-Nanocrystal Hybrid Materials for Light Conversion Applications

“…Weaver et al for example studied the fluorescence quenching behavior during the incorporation of CdSe@ZnS NCs into cyanoacrylate, epoxy and silicone [46]. They found that excess of amines in the NCs solution passivated the NCs surface and preserved the PL QY of the NCs-polymer composites.…”