Diffusion-limited aggregation in dry nanocrystal films

SABA, MICHELE;QUOCHI, FRANCESCO;Orrù M;MURA, ANTONIO ANDREA;BONGIOVANNI, GIOVANNI LUIGI CARLO

2011-01-01

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Abstract

We demonstrate that drop cast films of colloidal nanocrystals containing excess surfactants develop aggregation over several weeks after solvent evaporation. Fingered structures, typical of diffusion-limited aggregation, are created because of the residual mobility that nanocrystals retain in the film. We are able to control the aggregation through the concentration of surfactant molecules and the drying temperature of the films.