By employing a colloid chemical reaction method we demonstrate the preparation of organic nanoparticles composed of perylene molecules (PeNPs) based on the reduction of perylene perchlorate by Br- anions in the presence of cetyl trimethyl ammonium bromide (CTA+Br-) in acetonitrile. A discrete nucleation event, followed by a slower controlled growth on the existing particles, is identified during formation of PeNPs. By changing the growth parameters, such as the monomer concentration and the method of injection, quasi-spherical PeNPs with controllable sizes from 25 to 90 nm could be obtained. The homogeneous solution phase of this method makes it capable of large-scale synthesis of PeNPs with a size 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 form nanobelts 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 perylene as they evolve from the molecular to the bulk phase in the nanometer range. The so-called size dependence is evidenced by a switch from Y-type to E-type excimers as the size of the PeNPs increased from 25 to 90 nm. As the 25-nm PeNPs organize into nanobelts or square nanorods the oscillator strength of the Y-type excimers is relatively enhanced. That is, collective phenomena develop as the proximal particles interact in the glassy solids. Our very recent results indicate that this colloid chemical reaction method can also be applied to other organic compounds.

中文翻译：

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制备近单分散苝纳米粒子的胶体化学反应途径：尺寸可调合成和三维自组织

通过采用胶体化学反应方法，我们证明了在乙腈中存在十六烷基三甲基溴化铵 (CTA+Br-) 的情况下，基于溴阴离子对高氯酸苝的还原，制备了由苝分子 (PeNPs) 组成的有机纳米粒子。在 PeNPs 的形成过程中，确定了一个离散的成核事件，然后是在现有粒子上缓慢受控的生长。通过改变生长参数，如单体浓度和注射方法，可以获得尺寸可控的准球形 PeNPs，从 25 到 90 nm。该方法的均相溶液相使其能够大规模合成尺寸分布 (<10%) 的 PeNP，该尺寸分布通过在 PeNP 周围形成 CTA+ 保护层而得到改善。三度空间，观察到 25-nm PeNPs 构建块的分层自组织形成纳米带和方形纳米棒，可能以乙腈中的 CTA+ 层状胶束结构为模板。光谱结果揭示了苝光学性质在纳米范围内从分子相演变为体相的两种发展趋势。随着 PeNP 的尺寸从 25 nm 增加到 90 nm，从 Y 型到 E 型准分子的转换证明了所谓的尺寸依赖性。由于 25 nm PeNPs 组织成纳米带或方形纳米棒，Y 型准分子的振子强度相对增强。也就是说，随着近端粒子在玻璃状固体中相互作用，集体现象发展。