Two-Dimensional Binary Superlattice of BNNT-Surfactant Vesicle Complex Induced by Electrostatic Interaction

Area of Science:

• Materials Science
• Nanotechnology
• Supramolecular Chemistry

Background:

• Achieving highly ordered self-assembled structures of boron nitride nanotubes (BNNTs) is crucial for their practical applications.
• Controlling the arrangement of one-dimensional (1D) nanomaterials like BNNTs is a significant challenge in materials science.

Purpose of the Study:

• To report the fabrication of two-dimensional (2D) binary superlattices of individually exfoliated BNNTs.
• To investigate the self-assembly of negatively charged BNNTs with cationic surfactant vesicles through electrostatic interactions.
• To explore the influence of vesicle surface charge density and component ratios on superstructure formation.

Main Methods:

• Utilized electrostatic interactions between negatively charged BNNTs (p-BNNT25) and cationic surfactant vesicles (CTAT/SDBS).
• Mixed p-BNNT25 with CTAT/SDBS vesicles at varying mass ratios and controlled vesicle surface charge density.
• Characterized the resulting self-assembled structures using advanced imaging and structural analysis techniques.

Main Results:

• Successfully formed highly ordered 2D binary superlattices of CTAT/SDBS-BNNT complexes.
• Observed two distinct superstructures: an intercalated lamellar phase (ICLP) and an AB3 structure.
• Demonstrated that the specific structures formed depend on the CTAT/SDBS vesicle surface charge density and the vesicle-to-BNNT mass ratio.

Conclusions:

• This study presents the first known method for fabricating highly ordered superstructures of individually exfoliated, negatively charged BNNTs using positively charged surfactant vesicles via electrostatic interactions.
• The developed electrostatic self-assembly approach offers precise control over the formation of 2D binary superlattices.
• This technique is expected to significantly benefit various applications of one-dimensional (1D) nanoparticles.