Chair of Chemical Materials Science, Department of Chemistry, University of Konstanz, Universitätsstrasse 10, 78457, Konstanz, Germany.
Angew Chem Int Ed Engl. 2017 May 22;56(22):6147-6151. doi: 10.1002/anie.201701000. Epub 2017 Apr 12.
The shape of nanoparticles is decisive for their self-assembly properties, as well as for the behavior of individual particles in many instances. The introduction and control of anisotropy is well-known for inorganic nanocrystals but a largely unresolved problem for polymer nanoparticles, especially for conjugated polymers. Here, we report a reproducible preparation method using heterophase polymerization for a range of stable dispersions of ellipsoidal conjugated polymer nanoparticles with sizes in the range of 50 to 180 nm and narrow size and shape distributions. The nanoparticles show a bright fluorescence with tunable emission wavelengths and quantum yields as high as ϕ=78 %. Structural investigations reveal the nanoparticles to be composed of a highly ordered β- and α'-phase within a nematic matrix. Preliminary studies on the origin of particle anisotropy suggest a concerted mechanism in which anisotropic shape evolves from intersegmental packing that occurs along with progressing chain formation by polymerization.
纳米粒子的形状对其自组装特性以及在许多情况下单个粒子的行为都具有决定性作用。在无机纳米晶体中，各向异性的引入和控制是众所周知的，但对于聚合物纳米粒子，特别是对于共轭聚合物，这仍然是一个尚未解决的问题。在这里，我们报告了一种使用杂相聚合的可重现制备方法，可制备一系列尺寸在 50 至 180nm 范围内、尺寸和形状分布较窄的稳定的各向异性共轭聚合物纳米粒子分散体。这些纳米粒子具有明亮的荧光，可调节发射波长，量子产率高达 78%。结构研究表明，纳米粒子由各向异性β相和向列基质中的α'-相组成。对粒子各向异性起源的初步研究表明，一种协同机制导致了各向异性形状的演变，该机制涉及聚合过程中链形成的同时发生的链段间堆积。
