Sammanfattning
Tubules formed by self-assembly of organic molecules have a vast potential in nanotechnology
applications and the introduction of sensitivity to stimuli into self-assembly tubules represents a
particularly attractive feature. Here we report on the preparation and characterization of a
molecule obtained by chemical modification of a natural bile acid, a biological surfactant, that
self-assembles in pH sensitive tubules in aqueous solutions.
The tubules, that are rigid, single-walled and with a diameter of 60 nm, form at pH 8-9 and open
up when the pH is increased. The transition is reversible, it occurs in the pH range of 9-10 with
an opening mechanism that is remarkably different from those so far proposed in the literature. It
involves a release of wall layers similar to leaves, and is determined by a drastic pH-triggered
change in the molecular arrangement, which in turn induces a radical modification of the wall
curvature. The description of the morphological transformation is performed by means of
cryogenic transmission electron microscopy and represent, to our knowledge, the first detailed
visualization of pH stimulated tubule opening. UV and circular dichroism spectroscopies are
used to investigate the evolution at the molecular level.
applications and the introduction of sensitivity to stimuli into self-assembly tubules represents a
particularly attractive feature. Here we report on the preparation and characterization of a
molecule obtained by chemical modification of a natural bile acid, a biological surfactant, that
self-assembles in pH sensitive tubules in aqueous solutions.
The tubules, that are rigid, single-walled and with a diameter of 60 nm, form at pH 8-9 and open
up when the pH is increased. The transition is reversible, it occurs in the pH range of 9-10 with
an opening mechanism that is remarkably different from those so far proposed in the literature. It
involves a release of wall layers similar to leaves, and is determined by a drastic pH-triggered
change in the molecular arrangement, which in turn induces a radical modification of the wall
curvature. The description of the morphological transformation is performed by means of
cryogenic transmission electron microscopy and represent, to our knowledge, the first detailed
visualization of pH stimulated tubule opening. UV and circular dichroism spectroscopies are
used to investigate the evolution at the molecular level.
| Originalspråk | engelska |
|---|---|
| Sidor (från-till) | 7560-7566 |
| Tidskrift | Physical Chemistry Chemical Physics |
| Volym | 15 |
| Nummer | 20 |
| DOI | |
| Status | Published - 2013 |
Ämnesklassifikation (UKÄ)
- Fysikalisk kemi (Här ingår: Yt- och kolloidkemi)