Kinetics-Controlled Amphiphile Self-Assembly Processes

Abstract
Amphiphile self-assembly is an essential bottom-up approach of fabricating advanced functional materials. Self-assembled materials with desired structures are often obtained through thermodynamic control. Here, we demonstrate that the selection of kinetic pathways can lead to drastically different self-assembled structures, underlining the significance of kinetic control in self-assembly. By constructing kinetic network models from large-scale molecular dynamics simulations, we show that two largely similar amphiphiles, 1-[11-oxo-11-(pyren-1-ylmethoxy)-undecyl]pyridinium bromide (PYR) and 1-(11-((5a1,8a-dihydropyren-1-yl)methylamino)-11-oxoundecyl)pyridinium bromide (PYN), prefer distinct kinetic assembly pathways. While PYR prefers an incremental growth mechanism and forms a nanotube, PYN favors a hopping growth pathway leading to a vesicle. Such preference was found to originate from the subtle difference in the distributions of hydrophobic and hydrophilic groups in their chemical structures, which leads to different rates of the adhesion process among the aggregating micelles. Our results are in good agreement with experimental results, and accentuate the role of kinetics in the rational design of amphiphile self-assembly.

Citation
Zheng, X., Zhu, L., Zeng, X., Meng, L., Zhang, L., Wang, D., & Huang, X. (2017). Kinetics-Controlled Amphiphile Self-Assembly Processes. The Journal of Physical Chemistry Letters, 8(8), 1798–1803. doi:10.1021/acs.jpclett.7b00160

Acknowledgements
We thank the National Basic Research Program of China (973 program, 2013CB834703), Innovative Research Groups of the National Natural Science Foundation of China (21421064), Hong Kong Research Grants Council (16304215, ECS 60981, F-HKUST605/15), and the Innovation and Technology Commission (ITC-CNERC14SC01) for funding. We also acknowledge Peter Pak-Hang Cheung for critical reading of the manuscript. This research made use of the resources of the Supercomputing Laboratory at King Abdullah University of Science and Technology.

Publisher
American Chemical Society (ACS)

Journal
JOURNAL OF PHYSICAL CHEMISTRY LETTERS

DOI
10.1021/acs.jpclett.7b00160

Additional Links
https://pubs.acs.org/doi/10.1021/acs.jpclett.7b00160

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