- Zhang, H; Liu, Y; Zhang, J; Wang, C; Li, M; Yang, B
- In this study, we demonstrated a general but ignored principle for the preparation of highly luminescent semiconductor nanocrystals (NCs) in aqueous media; namely, interparticle electrostatic repulsion greatly affected the growth rate of NCs, especially in the initial stage. Because both aqueous NCs and their monomers possessed charges, dispersion and aggregation of them were mainly determined by the interparticle electrostatic repulsion. The aggregation of NCs and/or their monomers facilitated the agglomeration growth of NCs. Current work demonstrated that the growth rate of aqueous NCs in the initial stage was accelerated through the deliberate decrease of electrostatic repulsion, represented by a pH effect and salt effect. According to the Derjaguin -Landau - Verwey - Overbeek (DLVO) model, moreover, electrostatic repulsion was more dependent on NC size than other interparticle interactions, thus leading to size-dependent aggregation and disaggregation of NCs in the initial stage. © 2008 American Chemical Society.
- February 14, 2008
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