Observing the Kinetic Pathway of Nanotube Formation from Bolaamphiphiles by Time-Resolved Small-Angle X-ray Scattering

Abstract

We investigated the formation kinetics of a single monolayer nanotube from bolaamphiphiles (consisting of a sugar residue, an alkyl chain, and an amino group) in solution. In this bolaamphiphile, a transition from a monomerically dispersed state to the nanotube takes place by changing the solvent condition. This transition was induced by fast mixing with a stopped-flow apparatus. From just after the mixing, this transition process was monitored in situ by time-resolved small-angle X-ray scattering. In this manner, we were able to derive the direct structural information as a function of time during the nanotube formation. The results revealed that disklike aggregates initially formed, which then grew and closed to produce a tubular structure.

Time-controllable roll-up onset of polythiophene sheets into nanotubes that exhibit circularly polarized luminescence

“…Disk-like nanostructures grow into fragments of the membrane walls of nanotubes. 44,45 Securement of lifetimes of such precursors has a potential to be useful for time-controllable onset of the transformation into nanotubes. However, the precursors have a wide range of lifetimes.…”

Flower Necklaces of Controllable Length Formed From N-(2-Hydroxypropyl) Methacrylamide-Based Amphiphilic Statistical Copolymers

“…The SAXS profiles were analyzed in terms of the z -average form factor [ P z ( q )], being related to I ( q ) as follows Here, K e is the constant concerning the contrast of the polymers against the solvent (see ref and the Supporting Information), c is the mass concentration of the polymer, and N agg is the weight-average aggregation number. For the copolymers bearing pyrene, the intermolecular interference effect, or the structure factor, was ignored because the polymer is not very hydrophilic, and the concentration is low ( c = 5 mg/mL).…”

Synchrotron Scattering Methods for Nanomaterials and Soft Matter Research

“…Combined SAXS and WAXS revealed the hierarchical morphology of molten and semicrystalline vitrimers [38]. A spectacular case is the hierarchical organization of certain amphiphilic molecules to form well-defined nanotubes [39,40] and microtubes [41], which can be unraveled by SAXS. For example, the nanotubes formed by some amphiphilic peptides such as amyloid β-peptide, which display multiple structural levels from the molecular scale up to the long range ordering of nanotubes [3].…”

“…Figure 6 depicts the structural features of a suspension of nanotubes formed by an heterocyclic ligand DB921 [39]. In this class of systems, the competing hydrophobic and electrostatic interactions lead to a variety of self-assembly pathways to form helical ribbons [39,42] and their closed conformation such as nanotubes [39,40].…”