Model-driven optimization of multicomponent self-assembly processes
Model-driven optimization of multicomponent self-assembly processes
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DOI：
10.1073/pnas.1310092110
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发表时间：
2013-10-22
影响因子：
11.1
通讯作者：
Meijer, E. W.
中科院分区：
文献类型：
--
作者：
Korevaar, Peter A.;Grenier, Christophe;Meijer, E. W.
在这里，我们报告了一个工程方法，多组分自组装过程中开发的方法来规避虚假的，亚稳态组件。亚稳态聚集体的形成通常阻碍分子构建块自组装成所需的纳米结构。探索策略以通过优化沿着正确途径的组装速率来掌握途径复杂性并避免途径外聚集体。作为一个模型系统，我们研究了两个单体的共组装，R-和S-手性对映异构体的π共轭低聚（对亚苯基亚乙烯基）衍生物。共组装动力学分析通过开发一个动力学模型，它揭示了缓冲游离单体的亚稳态结构的初始组装，从而减缓了化学稳定的组件的形成。当两种单体的比例接近1：1时，亚稳态组装体对分子自组装的影响更大，这与实验结果一致。此外，亚稳态组件的竞争是高度依赖于温度和阻碍组装的平衡纳米结构最有效地在中间温度。我们证明，组装过程的速率可以通过调整冷却速率来优化。最后，它是通过模拟显示，逐步增加组装的驱动力，通过改变溶剂组合物可能会绕过亚稳态途径，从而迫使组装过程直接进入正确的路径。
Here, we report an engineering approach toward multicomponent self-assembly processes by developing a methodology to circumvent spurious, metastable assemblies. The formation of metastable aggregates often hampers self-assembly of molecular building blocks into the desired nanostructures. Strategies are explored to master the pathway complexity and avoid off-pathway aggregates by optimizing the rate of assembly along the correct pathway. We study as a model system the coassembly of two monomers, the R- and S-chiral enantiomers of a pi-conjugated oligo(p-phenylene vinylene) derivative. Coassembly kinetics are analyzed by developing a kinetic model, which reveals the initial assembly of metastable structures buffering free monomers and thereby slows the formation of thermodynamically stable assemblies. These metastable assemblies exert greater influence on the thermodynamically favored self-assembly pathway if the ratio between both monomers approaches 1:1, in agreement with experimental results. Moreover, competition by metastable assemblies is highly temperature dependent and hampers the assembly of equilibrium nanostructures most effectively at intermediate temperatures. We demonstrate that the rate of the assembly process may be optimized by tuning the cooling rate. Finally, it is shown by simulation that increasing the driving force for assembly stepwise by changing the solvent composition may circumvent metastable pathways and thereby force the assembly process directly into the correct pathway.