PubMed · 15164461
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
John deMello, Andrew deMello. 2004. Microscale reactors: nanoscale products.. https://doi.org/10.1039/b403638g
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
This communication describes a spin-coating method to nucleate organic molecular rods of uniform size from an inorganic nanoparticle at a solid surface. The particle-rod hybrid structure spontaneously forms when a film is spin coated from a mixed 2-propanol solution of arachidic acid (AA) and nanoparticles of cadmium selenide capped by mercaptoundecanoic acid (MUA-CdSe) on graphite. AFM images show that MUA-CdSe nanoparticles nucleate single crystalline rods of AA with a cross section of a single unit cell of the C-form. The solution-based process potentially allows the precise tuning of the wetting profile of the solution on the surface-attached nanoparticle, which provides the reservoir for the growth of the single crystalline rods. The results suggest that nanoparticles can be regarded as nanoseeds for the nucleation of guest crystals. It should be possible to further functionalize the AA rods by electrostatic complexation with metal or organic ions.
We provide theoretical modeling of the optical spectrum of recently synthesized triangular CdS nanocrystals by means of atomistic tight-binding theory. Both zinc blende and wurtzite structures are considered. Optical properties predicted for triangular prisms are very different from the ones obtained for tetrahedral quantum dots when z-polarized light is employed. In particular, the ground transition is dim for triangular prisms, whereas it is bright and highly intense for tetrahedra. The high sensitivity of the fine optical properties on the quantum dot shape allows us to discriminate between truncated tetrahedra and triangular prisms and also to estimate the thickness of the nanocrystals.
Herein, we describe a study aimed at synthesizing mixed-monolayer-protected CdS nanoparticles and investigating the reactivity of surface-bound functional groups in order to facilitate the immobilization of nanoparticles on a solid substrate as well as the construction of a three-dimensional nanocomposite. CdS nanoparticles initially prepared by the reverse micelle method were used to modify nanoparticle surfaces with 1-decanethiol molecules by ligand exchange. Subsequently, 11-mercapto-1-undecanol was partially incorporated by a place exchange reaction, thereby providing stable, mixed-monolayer-protected CdS nanoparticles. The nanoparticles obtained at each step were characterized by FT-IR and UV-vis spectroscopy, transmission electron microscopy, and elemental analysis. The reactivity of surface hydroxyl groups was verified by a reaction with isocyanate-bearing molecules that provide carbamate bonds in high yields at ambient temperature. The obtained mixed-monolayer-protected nanoparticles were also successfully immobilized on a glass substrate through a carbamate-bond-forming reaction that could be further utilized for multilayer construction in a layer-by-layer fashion.