Supramolecular Nanotubes Functioning as Morphology Regulators for Fluid-State Molecular Assemblies
Supramolecular Nanotubes Functioning as Morphology Regulators for Fluid-State Molecular Assemblies
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DOI：
10.1021/acs.chemmater.2c01722
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发表时间：
2022-10
影响因子：
8.6
通讯作者：
N. Kameta;Wuxiao Ding;H. Uzawa
中科院分区：
文献类型：
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作者：
N. Kameta;Wuxiao Ding;H. Uzawa
Seven supramolecular nanotubes (inner diameters, 35 nm) with different ester groups on their inner surfaces were prepared from synthetic amphiphiles and used as morphology regulators for three fluid-state molecular assemblies: a phospholipid liposome and two surfactant micelles. At temperatures above the gel-to-liquid crystalline phase transition temperature (Tg–l) of the liposome (diameter, 360 nm), encapsulation in the nanotubes led to morphological transformation of the liposome into either a much smaller vesicle (diameter, 8 nm) or a long, tubular nanofiber (inner diameter, 5 nm), depending on the carbon number of the ester group on the nanotube inner surface. Before encapsulation, the liposome had a typical lamellar molecular packing with a stacking periodicity (d) = 5.45 nm andTg–l= 42.0 °C, whereas the resulting vesicle had an interdigitated molecular packing withd= 3.13 nm andTg–l= 31.8 °C, although this unusual molecular packing was rearranged back to the original lamellar molecular packing after release from the nanotubes. The morphology of the tubular nanofiber (d= 5.06 nm andTg–l= 48.7 °C) was not changed before and after release from the nanotubes. The nanotubes also induced rearrangement of an encapsulated surfactant micelle harboring an environmentally responsive probe, pyrene, either to a spherical morphology with a typical molecular packing of micelles, in which pyrene existed in a monomeric state, or to a twisted, fibrous morphology with a lamellar molecular packing, in which pyrene formed aJ-type aggregate emitting excimer fluorescence. The micelle with the twisted, fibrous morphology exhibited a helicity induced by the confinement in the nanotubes with supramolecular chirality, even though the surfactant itself was achiral.
