O'Brien Matthew N, Girard Martin, Lin Hai-Xin, Millan Jaime A, Olvera de la Cruz Monica, Lee Byeongdu, Mirkin Chad A
Department of Chemistry, Northwestern University, Evanston, IL 60208; International Institute for Nanotechnology, Northwestern University, Evanston, IL 60208;
Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208;
Proc Natl Acad Sci U S A. 2016 Sep 20;113(38):10485-90. doi: 10.1073/pnas.1611808113. Epub 2016 Sep 6.
In this work, we present a joint experimental and molecular dynamics simulations effort to understand and map the crystallization behavior of polyhedral nanoparticles assembled via the interaction of DNA surface ligands. In these systems, we systematically investigated the interplay between the effects of particle core (via the particle symmetry and particle size) and ligands (via the ligand length) on crystallization behavior. This investigation revealed rich phase diagrams, previously unobserved phase transitions in polyhedral crystallization behavior, and an unexpected symmetry breaking in the ligand distribution on a particle surface. To understand these results, we introduce the concept of a zone of anisotropy, or the portion of the phase space where the anisotropy of the particle is preserved in the crystallization behavior. Through comparison of the zone of anisotropy for each particle we develop a foundational roadmap to guide future investigations.
在这项工作中，我们开展了一项结合实验与分子动力学模拟的研究，以了解并描绘通过DNA表面配体相互作用组装而成的多面体纳米颗粒的结晶行为。在这些体系中，我们系统地研究了颗粒核心（通过颗粒对称性和颗粒大小）和配体（通过配体长度）对结晶行为的影响之间的相互作用。这项研究揭示了丰富的相图、多面体结晶行为中以前未观察到的相变，以及颗粒表面配体分布中意外的对称性破缺。为了理解这些结果，我们引入了各向异性区域的概念，即相空间中颗粒各向异性在结晶行为中得以保留的部分。通过比较每个颗粒的各向异性区域，我们制定了一个基础路线图，以指导未来的研究。
