Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Exact Stoichiometry Far-Off Neutrality Catanionic Nanotubes : Unconventional Self-Assembly of Oppositely Charged Surfactants

La Gambina, Valerio ; Rocchi, Lorenzo A. ; Sennato, Simona ; Radiom, Milad ; Schillén, Karin LU orcid ; Hetherington, Crispin LU orcid ; Francolini, Iolanda ; Vetica, Fabrizio ; Leonelli, Francesca and Del Giudice, Alessandra LU orcid , et al. (2026) In Journal of the American Chemical Society 148(18). p.18733-18745
Abstract

Electrostatic energy plays a pivotal role in the minimization of the free energy of self-assembling oppositely charged ions. This is a fundamental principle that guides the formation of aggregates and the separation of phases characterized by a stoichiometric balance between the opposite charges. However, this study unveils the self-assembly of catanionic nanotubes from a mixture of oppositely charged surfactants in aqueous buffer, comprising an anionic bile salt derivative and the cationic cetyltrimethylammonium bromide (CTAB) at an exact strongly unbalanced charge ratio of 9 anions to 1 cation. This anomalous aggregation leads to the formation of highly stable and ordered supramolecular nanotubes with a uniform cross-section of about... (More)

Electrostatic energy plays a pivotal role in the minimization of the free energy of self-assembling oppositely charged ions. This is a fundamental principle that guides the formation of aggregates and the separation of phases characterized by a stoichiometric balance between the opposite charges. However, this study unveils the self-assembly of catanionic nanotubes from a mixture of oppositely charged surfactants in aqueous buffer, comprising an anionic bile salt derivative and the cationic cetyltrimethylammonium bromide (CTAB) at an exact strongly unbalanced charge ratio of 9 anions to 1 cation. This anomalous aggregation leads to the formation of highly stable and ordered supramolecular nanotubes with a uniform cross-section of about 20 nm. The key to this behavior lies in the unique, rigid, and facial amphiphilic structure of the bile salt derivative, allocating hydrogen bond donors/acceptors and an aromatic residue, which promotes geometrically constrained derivative–derivative interactions. This facilitates the assembly of the anionic derivative into parallel, helically wrapped, negatively charged ribbons with interspersed CTAB cations, acting to promote their adhesion. Supramolecular nanotubes are highly valued in nanotechnology for applications such as catalysis and tissue engineering due to their rigidity, intrinsic directionality, and capability for dual compartmentalization (inner cavity and outer surface). The catanionic structures reported here are ordered architectures that allow for a high charge and a minimal interference from free monomers, which are essential for optimizing functions such as material loading. A loading ability was demonstrated here by the nanotube interaction with positively charged carbon dots and gold nanorods.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; ; ; ; and , et al. (More)
; ; ; ; ; ; ; ; ; ; ; and (Less)
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of the American Chemical Society
volume
148
issue
18
pages
13 pages
publisher
The American Chemical Society (ACS)
external identifiers
  • pmid:42059128
  • scopus:105038683719
  • pmid:42059128
ISSN
1520-5126
DOI
10.1021/jacs.5c21811
language
English
LU publication?
yes
id
8d889a75-106d-42bf-a36b-4cebbc28cde6
date added to LUP
2026-05-02 01:37:51
date last changed
2026-06-01 08:39:50
@article{8d889a75-106d-42bf-a36b-4cebbc28cde6,
  abstract     = {{<p>Electrostatic energy plays a pivotal role in the minimization of the free energy of self-assembling oppositely charged ions. This is a fundamental principle that guides the formation of aggregates and the separation of phases characterized by a stoichiometric balance between the opposite charges. However, this study unveils the self-assembly of catanionic nanotubes from a mixture of oppositely charged surfactants in aqueous buffer, comprising an anionic bile salt derivative and the cationic cetyltrimethylammonium bromide (CTAB) at an exact strongly unbalanced charge ratio of 9 anions to 1 cation. This anomalous aggregation leads to the formation of highly stable and ordered supramolecular nanotubes with a uniform cross-section of about 20 nm. The key to this behavior lies in the unique, rigid, and facial amphiphilic structure of the bile salt derivative, allocating hydrogen bond donors/acceptors and an aromatic residue, which promotes geometrically constrained derivative–derivative interactions. This facilitates the assembly of the anionic derivative into parallel, helically wrapped, negatively charged ribbons with interspersed CTAB cations, acting to promote their adhesion. Supramolecular nanotubes are highly valued in nanotechnology for applications such as catalysis and tissue engineering due to their rigidity, intrinsic directionality, and capability for dual compartmentalization (inner cavity and outer surface). The catanionic structures reported here are ordered architectures that allow for a high charge and a minimal interference from free monomers, which are essential for optimizing functions such as material loading. A loading ability was demonstrated here by the nanotube interaction with positively charged carbon dots and gold nanorods.</p>}},
  author       = {{La Gambina, Valerio and Rocchi, Lorenzo A. and Sennato, Simona and Radiom, Milad and Schillén, Karin and Hetherington, Crispin and Francolini, Iolanda and Vetica, Fabrizio and Leonelli, Francesca and Del Giudice, Alessandra and di Gregorio, Maria Chiara and Mezzenga, Raffaele and Galantini, Luciano}},
  issn         = {{1520-5126}},
  language     = {{eng}},
  month        = {{05}},
  number       = {{18}},
  pages        = {{18733--18745}},
  publisher    = {{The American Chemical Society (ACS)}},
  series       = {{Journal of the American Chemical Society}},
  title        = {{Exact Stoichiometry Far-Off Neutrality Catanionic Nanotubes : Unconventional Self-Assembly of Oppositely Charged Surfactants}},
  url          = {{http://dx.doi.org/10.1021/jacs.5c21811}},
  doi          = {{10.1021/jacs.5c21811}},
  volume       = {{148}},
  year         = {{2026}},
}