| Abstract
| - By employing a colloid chemical reaction method we demonstrate the preparation of organicnanoparticles composed of perylene molecules (PeNPs) based on the reduction of perylene perchlorateby Br- anions in the presence of cetyl trimethyl ammonium bromide (CTA+Br-) in acetonitrile. A discretenucleation event, followed by a slower controlled growth on the existing particles, is identified during formationof PeNPs. By changing the growth parameters, such as the monomer concentration and the method ofinjection, quasi-spherical PeNPs with controllable sizes from 25 to 90 nm could be obtained. Thehomogeneous solution phase of this method makes it capable of large-scale synthesis of PeNPs with asize distribution (<10%) that is improved by formation of a protective layer of CTA+ around the PeNPs.The three-dimensional, hierarchical self-organization of 25-nm PeNPs building blocks is observed to formnanobelts and square nanorods, possibly templated by the CTA+ lamellar micelle structures in acetonitrile.Spectroscopic results reveal two kinds of trends in the development of the optical properties of peryleneas they evolve from the molecular to the bulk phase in the nanometer range. The so-called size dependenceis evidenced by a switch from Y-type to E-type excimers as the size of the PeNPs increased from 25 to 90nm. As the 25-nm PeNPs organize into nanobelts or square nanorods the oscillator strength of the Y-typeexcimers is relatively enhanced. That is, collective phenomena develop as the proximal particles interactin the glassy solids. Our very recent results indicate that this colloid chemical reaction method can also beapplied to other organic compounds.
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