Kinetics-Controlled Amphiphile Self-Assembly Processes

Abstract

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